Merge tag 'staging-pull-request' of https://gitlab.com/peterx/qemu into stagingHEADmaster

Migration/Memory Pull for 10.2

- PeterX's fix on tls warning for preempt channel when migratino completes
- Arun's series to enhance error reporting for vTPM and migration framework
- PeterX's patch to cleanup multifd send TLS BYE messages
- Juraj's fix on postcopy start state transition when switchover failed
- Yanfei's fix to migrate APIC before VFIO-PCI to avoid irq fallbacks
- Dan's cleanup to simplify error reporting in qemu_fill_buffer()
- PeterM's fix on address space leak when cpu hot plug / unplug
- Steve's cpr-exec wholeset

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#
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# ZGhhdC5jb20ACgkQO1/MzfOr1wZ+mAEA1l2RS9sZS1W3vXQMCNb+Nu8Uo2p+e5Qj
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# -----END PGP SIGNATURE-----
# gpg: Signature made Fri 03 Oct 2025 08:39:14 AM PDT
# gpg:                using EDDSA key B9184DC20CC457DACF7DD1A93B5FCCCDF3ABD706
# gpg:                issuer "peterx@redhat.com"
# gpg: Good signature from "Peter Xu <xzpeter@gmail.com>" [unknown]
# gpg:                 aka "Peter Xu <peterx@redhat.com>" [unknown]
# gpg: WARNING: The key's User ID is not certified with a trusted signature!
# gpg:          There is no indication that the signature belongs to the owner.
# Primary key fingerprint: B918 4DC2 0CC4 57DA CF7D  D1A9 3B5F CCCD F3AB D706

* tag 'staging-pull-request' of https://gitlab.com/peterx/qemu: (45 commits)
  migration-test: test cpr-exec
  vfio: cpr-exec mode
  migration: cpr-exec docs
  migration: cpr-exec mode
  migration: cpr-exec save and load
  migration: cpr-exec-command parameter
  oslib: qemu_clear_cloexec
  migration: add cpr_walk_fd
  migration: multi-mode notifier
  migration: simplify error reporting after channel read
  physmem: Destroy all CPU AddressSpaces on unrealize
  memory: New AS helper to serialize destroy+free
  include/system/memory.h: Clarify address_space_destroy() behaviour
  migration: ensure APIC is loaded prior to VFIO PCI devices
  migration: Fix state transition in postcopy_start() error handling
  migration/multifd/tls: Cleanup BYE message processing on sender side
  migration: HMP: Adjust the order of output fields
  migration: Make migration_has_failed() work even for CANCELLING
  io/crypto: Move tls premature termination handling into QIO layer
  backends/tpm: Propagate vTPM error on migration failure
  ...

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

58 files changed, 1351 insertions, 409 deletions

diff --git a/backends/tpm/tpm_emulator.c b/backends/tpm/tpm_emulator.c
index 4a234ab..dacfca5 100644
--- a/backends/tpm/tpm_emulator.c
+++ b/backends/tpm/tpm_emulator.c
@@ -819,7 +819,8 @@ static int tpm_emulator_get_state_blobs(TPMEmulator *tpm_emu)
 static int tpm_emulator_set_state_blob(TPMEmulator *tpm_emu,
                                        uint32_t type,
                                        TPMSizedBuffer *tsb,
-                                       uint32_t flags)
+                                       uint32_t flags,
+                                       Error **errp)
 {
     ssize_t n;
     ptm_setstate pss;
@@ -838,17 +839,18 @@ static int tpm_emulator_set_state_blob(TPMEmulator *tpm_emu,
     /* write the header only */
     if (tpm_emulator_ctrlcmd(tpm_emu, CMD_SET_STATEBLOB, &pss,
                              offsetof(ptm_setstate, u.req.data), 0, 0) < 0) {
-        error_report("tpm-emulator: could not set state blob type %d : %s",
-                     type, strerror(errno));
+        error_setg_errno(errp, errno,
+                         "tpm-emulator: could not set state blob type %d",
+                         type);
         return -1;
     }
 
     /* now the body */
     n = qemu_chr_fe_write_all(&tpm_emu->ctrl_chr, tsb->buffer, tsb->size);
     if (n != tsb->size) {
-        error_report("tpm-emulator: Writing the stateblob (type %d) "
-                     "failed; could not write %u bytes, but only %zd",
-                     type, tsb->size, n);
+        error_setg(errp, "tpm-emulator: Writing the stateblob (type %d) "
+                   "failed; could not write %u bytes, but only %zd",
+                   type, tsb->size, n);
         return -1;
     }
 
@@ -856,17 +858,17 @@ static int tpm_emulator_set_state_blob(TPMEmulator *tpm_emu,
     n = qemu_chr_fe_read_all(&tpm_emu->ctrl_chr,
                              (uint8_t *)&pss, sizeof(pss.u.resp));
     if (n != sizeof(pss.u.resp)) {
-        error_report("tpm-emulator: Reading response from writing stateblob "
-                     "(type %d) failed; expected %zu bytes, got %zd", type,
-                     sizeof(pss.u.resp), n);
+        error_setg(errp, "tpm-emulator: Reading response from writing "
+                   "stateblob (type %d) failed; expected %zu bytes, "
+                   "got %zd", type, sizeof(pss.u.resp), n);
         return -1;
     }
 
     tpm_result = be32_to_cpu(pss.u.resp.tpm_result);
     if (tpm_result != 0) {
-        error_report("tpm-emulator: Setting the stateblob (type %d) failed "
-                     "with a TPM error 0x%x %s", type, tpm_result,
-                     tpm_emulator_strerror(tpm_result));
+        error_setg(errp, "tpm-emulator: Setting the stateblob (type %d) "
+                   "failed with a TPM error 0x%x %s", type, tpm_result,
+                   tpm_emulator_strerror(tpm_result));
         return -1;
     }
 
@@ -880,7 +882,7 @@ static int tpm_emulator_set_state_blob(TPMEmulator *tpm_emu,
  *
  * Returns a negative errno code in case of error.
  */
-static int tpm_emulator_set_state_blobs(TPMBackend *tb)
+static int tpm_emulator_set_state_blobs(TPMBackend *tb, Error **errp)
 {
     TPMEmulator *tpm_emu = TPM_EMULATOR(tb);
     TPMBlobBuffers *state_blobs = &tpm_emu->state_blobs;
@@ -894,13 +896,13 @@ static int tpm_emulator_set_state_blobs(TPMBackend *tb)
 
     if (tpm_emulator_set_state_blob(tpm_emu, PTM_BLOB_TYPE_PERMANENT,
                                     &state_blobs->permanent,
-                                    state_blobs->permanent_flags) < 0 ||
+                                    state_blobs->permanent_flags, errp) < 0 ||
         tpm_emulator_set_state_blob(tpm_emu, PTM_BLOB_TYPE_VOLATILE,
                                     &state_blobs->volatil,
-                                    state_blobs->volatil_flags) < 0 ||
+                                    state_blobs->volatil_flags, errp) < 0 ||
         tpm_emulator_set_state_blob(tpm_emu, PTM_BLOB_TYPE_SAVESTATE,
                                     &state_blobs->savestate,
-                                    state_blobs->savestate_flags) < 0) {
+                                    state_blobs->savestate_flags, errp) < 0) {
         return -EIO;
     }
 
@@ -948,12 +950,12 @@ static void tpm_emulator_vm_state_change(void *opaque, bool running,
  *
  * Returns negative errno codes in case of error.
  */
-static int tpm_emulator_post_load(void *opaque, int version_id)
+static int tpm_emulator_post_load(void *opaque, int version_id, Error **errp)
 {
     TPMBackend *tb = opaque;
     int ret;
 
-    ret = tpm_emulator_set_state_blobs(tb);
+    ret = tpm_emulator_set_state_blobs(tb, errp);
     if (ret < 0) {
         return ret;
     }
@@ -969,7 +971,7 @@ static const VMStateDescription vmstate_tpm_emulator = {
     .name = "tpm-emulator",
     .version_id = 0,
     .pre_save = tpm_emulator_pre_save,
-    .post_load = tpm_emulator_post_load,
+    .post_load_errp = tpm_emulator_post_load,
     .fields = (const VMStateField[]) {
         VMSTATE_UINT32(state_blobs.permanent_flags, TPMEmulator),
         VMSTATE_UINT32(state_blobs.permanent.size, TPMEmulator),
diff --git a/crypto/tlssession.c b/crypto/tlssession.c
index 86d407a..ac38c21 100644
--- a/crypto/tlssession.c
+++ b/crypto/tlssession.c
@@ -552,7 +552,6 @@ ssize_t
 qcrypto_tls_session_read(QCryptoTLSSession *session,
                          char *buf,
                          size_t len,
-                         bool gracefulTermination,
                          Error **errp)
 {
     ssize_t ret;
@@ -570,9 +569,8 @@ qcrypto_tls_session_read(QCryptoTLSSession *session,
     if (ret < 0) {
         if (ret == GNUTLS_E_AGAIN) {
             return QCRYPTO_TLS_SESSION_ERR_BLOCK;
-        } else if ((ret == GNUTLS_E_PREMATURE_TERMINATION) &&
-                   gracefulTermination){
-            return 0;
+        } else if (ret == GNUTLS_E_PREMATURE_TERMINATION) {
+            return QCRYPTO_TLS_SESSION_PREMATURE_TERMINATION;
         } else {
             if (session->rerr) {
                 error_propagate(errp, session->rerr);
@@ -789,7 +787,6 @@ ssize_t
 qcrypto_tls_session_read(QCryptoTLSSession *sess,
                          char *buf,
                          size_t len,
-                         bool gracefulTermination,
                          Error **errp)
 {
     error_setg(errp, "TLS requires GNUTLS support");
diff --git a/docs/devel/migration/CPR.rst b/docs/devel/migration/CPR.rst
index 0a0fd4f..b617856 100644
--- a/docs/devel/migration/CPR.rst
+++ b/docs/devel/migration/CPR.rst
@@ -5,7 +5,7 @@ CPR is the umbrella name for a set of migration modes in which the
 VM is migrated to a new QEMU instance on the same host.  It is
 intended for use when the goal is to update host software components
 that run the VM, such as QEMU or even the host kernel.  At this time,
-the cpr-reboot and cpr-transfer modes are available.
+the cpr-reboot, cpr-transfer, and cpr-exec modes are available.
 
 Because QEMU is restarted on the same host, with access to the same
 local devices, CPR is allowed in certain cases where normal migration
@@ -324,3 +324,113 @@ descriptors from old to new QEMU.  In the future, descriptors for
 vhost, and char devices could be transferred,
 preserving those devices and their kernel state without interruption,
 even if they do not explicitly support live migration.
+
+cpr-exec mode
+-------------
+
+In this mode, QEMU stops the VM, writes VM state to the migration
+URI, and directly exec's a new version of QEMU on the same host,
+replacing the original process while retaining its PID.  Guest RAM is
+preserved in place, albeit with new virtual addresses.  The user
+completes the migration by specifying the ``-incoming`` option, and
+by issuing the ``migrate-incoming`` command if necessary; see details
+below.
+
+This mode supports VFIO/IOMMUFD devices by preserving device
+descriptors and hence kernel state across the exec, even for devices
+that do not support live migration.
+
+Because the old and new QEMU instances are not active concurrently,
+the URI cannot be a type that streams data from one instance to the
+other.
+
+This mode does not require a channel of type ``cpr``.  The information
+that is passed over that channel for cpr-transfer mode is instead
+serialized to a memfd, the number of the fd is saved in the
+QEMU_CPR_EXEC_STATE environment variable during the exec of new QEMU.
+and new QEMU mmaps the memfd.
+
+Usage
+^^^^^
+
+Arguments for the new QEMU process are taken from the
+@cpr-exec-command parameter.  The first argument should be the
+path of a new QEMU binary, or a prefix command that exec's the
+new QEMU binary, and the arguments should include the ''-incoming''
+option.
+
+Memory backend objects must have the ``share=on`` attribute.
+The VM must be started with the ``-machine aux-ram-share=on`` option.
+
+Outgoing:
+  * Set the migration mode parameter to ``cpr-exec``.
+  * Set the ``cpr-exec-command`` parameter.
+  * Issue the ``migrate`` command.  It is recommended that the URI be
+    a ``file`` type, but one can use other types such as ``exec``,
+    provided the command captures all the data from the outgoing side,
+    and provides all the data to the incoming side.
+
+Incoming:
+  * You do not need to explicitly start new QEMU.  It is started as
+    a side effect of the migrate command above.
+  * If the VM was running when the outgoing ``migrate`` command was
+    issued, then QEMU automatically resumes VM execution.
+
+Example 1: incoming URI
+^^^^^^^^^^^^^^^^^^^^^^^
+
+In these examples, we simply restart the same version of QEMU, but in
+a real scenario one would set a new QEMU binary path in
+cpr-exec-command.
+
+::
+
+  # qemu-kvm -monitor stdio
+  -object memory-backend-memfd,id=ram0,size=4G
+  -machine memory-backend=ram0
+  -machine aux-ram-share=on
+  ...
+
+  QEMU 10.2.50 monitor - type 'help' for more information
+  (qemu) info status
+  VM status: running
+  (qemu) migrate_set_parameter mode cpr-exec
+  (qemu) migrate_set_parameter cpr-exec-command qemu-kvm ... -incoming file:vm.state
+  (qemu) migrate -d file:vm.state
+  (qemu) QEMU 10.2.50 monitor - type 'help' for more information
+  (qemu) info status
+  VM status: running
+
+Example 2: incoming defer
+^^^^^^^^^^^^^^^^^^^^^^^^^
+::
+
+  # qemu-kvm -monitor stdio
+  -object memory-backend-memfd,id=ram0,size=4G
+  -machine memory-backend=ram0
+  -machine aux-ram-share=on
+  ...
+
+  QEMU 10.2.50 monitor - type 'help' for more information
+  (qemu) info status
+  VM status: running
+  (qemu) migrate_set_parameter mode cpr-exec
+  (qemu) migrate_set_parameter cpr-exec-command qemu-kvm ... -incoming defer
+  (qemu) migrate -d file:vm.state
+  (qemu) QEMU 10.2.50 monitor - type 'help' for more information
+  (qemu) info status
+  status: paused (inmigrate)
+  (qemu) migrate_incoming file:vm.state
+  (qemu) info status
+  VM status: running
+
+Caveats
+^^^^^^^
+
+cpr-exec mode may not be used with postcopy, background-snapshot,
+or COLO.
+
+cpr-exec mode requires permission to use the exec system call, which
+is denied by certain sandbox options, such as spawn.
+
+The guest pause time increases for large guest RAM backed by small pages.
diff --git a/docs/devel/migration/main.rst b/docs/devel/migration/main.rst
index 6493c1d..1afe7b9 100644
--- a/docs/devel/migration/main.rst
+++ b/docs/devel/migration/main.rst
@@ -444,6 +444,25 @@ The functions to do that are inside a vmstate definition, and are called:
   This function is called after we save the state of one device
   (even upon failure, unless the call to pre_save returned an error).
 
+Following are the errp variants of these functions.
+
+- ``int (*pre_load_errp)(void *opaque, Error **errp);``
+
+  This function is called before we load the state of one device.
+
+- ``int (*post_load_errp)(void *opaque, int version_id, Error **errp);``
+
+  This function is called after we load the state of one device.
+
+- ``int (*pre_save_errp)(void *opaque, Error **errp);``
+
+  This function is called before we save the state of one device.
+
+New impls should preferentally use 'errp' variants of these
+methods and existing impls incrementally converted.
+The variants without 'errp' are intended to be removed
+once all usage is converted.
+
 Example: You can look at hpet.c, that uses the first three functions
 to massage the state that is transferred.
 
diff --git a/hmp-commands.hx b/hmp-commands.hx
index d0e4f35..3cace8f 100644
--- a/hmp-commands.hx
+++ b/hmp-commands.hx
@@ -1009,7 +1009,7 @@ ERST
 
     {
         .name       = "migrate_set_parameter",
-        .args_type  = "parameter:s,value:s",
+        .args_type  = "parameter:s,value:S",
         .params     = "parameter value",
         .help       = "Set the parameter for migration",
         .cmd        = hmp_migrate_set_parameter,
diff --git a/hw/core/cpu-common.c b/hw/core/cpu-common.c
index 41a3399..8c306c8 100644
--- a/hw/core/cpu-common.c
+++ b/hw/core/cpu-common.c
@@ -294,6 +294,7 @@ void cpu_exec_unrealizefn(CPUState *cpu)
      * accel_cpu_common_unrealize, which may free fields using call_rcu.
      */
     accel_cpu_common_unrealize(cpu);
+    cpu_destroy_address_spaces(cpu);
 }
 
 static void cpu_common_initfn(Object *obj)
diff --git a/hw/display/virtio-gpu.c b/hw/display/virtio-gpu.c
index de35902..3a55512 100644
--- a/hw/display/virtio-gpu.c
+++ b/hw/display/virtio-gpu.c
@@ -1248,7 +1248,8 @@ static int virtio_gpu_save(QEMUFile *f, void *opaque, size_t size,
     }
     qemu_put_be32(f, 0); /* end of list */
 
-    return vmstate_save_state(f, &vmstate_virtio_gpu_scanouts, g, NULL);
+    return vmstate_save_state(f, &vmstate_virtio_gpu_scanouts, g, NULL,
+                              &error_fatal);
 }
 
 static bool virtio_gpu_load_restore_mapping(VirtIOGPU *g,
@@ -1347,7 +1348,7 @@ static int virtio_gpu_load(QEMUFile *f, void *opaque, size_t size,
     }
 
     /* load & apply scanout state */
-    vmstate_load_state(f, &vmstate_virtio_gpu_scanouts, g, 1);
+    vmstate_load_state(f, &vmstate_virtio_gpu_scanouts, g, 1, &error_fatal);
 
     return 0;
 }
diff --git a/hw/intc/apic_common.c b/hw/intc/apic_common.c
index 37a7a70..394fe02 100644
--- a/hw/intc/apic_common.c
+++ b/hw/intc/apic_common.c
@@ -379,6 +379,7 @@ static const VMStateDescription vmstate_apic_common = {
     .pre_load = apic_pre_load,
     .pre_save = apic_dispatch_pre_save,
     .post_load = apic_dispatch_post_load,
+    .priority = MIG_PRI_APIC,
     .fields = (const VMStateField[]) {
         VMSTATE_UINT32(apicbase, APICCommonState),
         VMSTATE_UINT8(id, APICCommonState),
diff --git a/hw/pci/pci.c b/hw/pci/pci.c
index c3df9d6..5e2c3c6 100644
--- a/hw/pci/pci.c
+++ b/hw/pci/pci.c
@@ -926,7 +926,7 @@ void pci_device_save(PCIDevice *s, QEMUFile *f)
      * This makes us compatible with old devices
      * which never set or clear this bit. */
     s->config[PCI_STATUS] &= ~PCI_STATUS_INTERRUPT;
-    vmstate_save_state(f, &vmstate_pci_device, s, NULL);
+    vmstate_save_state(f, &vmstate_pci_device, s, NULL, &error_fatal);
     /* Restore the interrupt status bit. */
     pci_update_irq_status(s);
 }
@@ -934,7 +934,8 @@ void pci_device_save(PCIDevice *s, QEMUFile *f)
 int pci_device_load(PCIDevice *s, QEMUFile *f)
 {
     int ret;
-    ret = vmstate_load_state(f, &vmstate_pci_device, s, s->version_id);
+    ret = vmstate_load_state(f, &vmstate_pci_device, s, s->version_id,
+                             &error_fatal);
     /* Restore the interrupt status bit. */
     pci_update_irq_status(s);
     return ret;
diff --git a/hw/s390x/virtio-ccw.c b/hw/s390x/virtio-ccw.c
index d2f85b3..4cb1ced 100644
--- a/hw/s390x/virtio-ccw.c
+++ b/hw/s390x/virtio-ccw.c
@@ -1130,13 +1130,13 @@ static int virtio_ccw_load_queue(DeviceState *d, int n, QEMUFile *f)
 static void virtio_ccw_save_config(DeviceState *d, QEMUFile *f)
 {
     VirtioCcwDevice *dev = VIRTIO_CCW_DEVICE(d);
-    vmstate_save_state(f, &vmstate_virtio_ccw_dev, dev, NULL);
+    vmstate_save_state(f, &vmstate_virtio_ccw_dev, dev, NULL, &error_fatal);
 }
 
 static int virtio_ccw_load_config(DeviceState *d, QEMUFile *f)
 {
     VirtioCcwDevice *dev = VIRTIO_CCW_DEVICE(d);
-    return vmstate_load_state(f, &vmstate_virtio_ccw_dev, dev, 1);
+    return vmstate_load_state(f, &vmstate_virtio_ccw_dev, dev, 1, &error_fatal);
 }
 
 static void virtio_ccw_pre_plugged(DeviceState *d, Error **errp)
diff --git a/hw/scsi/spapr_vscsi.c b/hw/scsi/spapr_vscsi.c
index 20f70fb..f0a7dd2 100644
--- a/hw/scsi/spapr_vscsi.c
+++ b/hw/scsi/spapr_vscsi.c
@@ -630,7 +630,7 @@ static void vscsi_save_request(QEMUFile *f, SCSIRequest *sreq)
     vscsi_req *req = sreq->hba_private;
     assert(req->active);
 
-    vmstate_save_state(f, &vmstate_spapr_vscsi_req, req, NULL);
+    vmstate_save_state(f, &vmstate_spapr_vscsi_req, req, NULL, &error_fatal);
 
     trace_spapr_vscsi_save_request(req->qtag, req->cur_desc_num,
                                    req->cur_desc_offset);
@@ -642,15 +642,17 @@ static void *vscsi_load_request(QEMUFile *f, SCSIRequest *sreq)
     VSCSIState *s = VIO_SPAPR_VSCSI_DEVICE(bus->qbus.parent);
     vscsi_req *req;
     int rc;
+    Error *local_err = NULL;
 
     assert(sreq->tag < VSCSI_REQ_LIMIT);
     req = &s->reqs[sreq->tag];
     assert(!req->active);
 
     memset(req, 0, sizeof(*req));
-    rc = vmstate_load_state(f, &vmstate_spapr_vscsi_req, req, 1);
+    rc = vmstate_load_state(f, &vmstate_spapr_vscsi_req, req, 1, &local_err);
     if (rc) {
         fprintf(stderr, "VSCSI: failed loading request tag#%u\n", sreq->tag);
+        error_report_err(local_err);
         return NULL;
     }
     assert(req->active);
diff --git a/hw/vfio/container-legacy.c b/hw/vfio/container-legacy.c
index 34352dd..629ff23 100644
--- a/hw/vfio/container-legacy.c
+++ b/hw/vfio/container-legacy.c
@@ -972,7 +972,8 @@ static bool vfio_legacy_attach_device(const char *name, VFIODevice *vbasedev,
         error_setg(&vbasedev->cpr.mdev_blocker,
                    "CPR does not support vfio mdev %s", vbasedev->name);
         if (migrate_add_blocker_modes(&vbasedev->cpr.mdev_blocker, errp,
-                                      MIG_MODE_CPR_TRANSFER, -1) < 0) {
+                                      MIG_MODE_CPR_TRANSFER, MIG_MODE_CPR_EXEC,
+                                      -1) < 0) {
             goto hiod_unref_exit;
         }
     }
diff --git a/hw/vfio/cpr-iommufd.c b/hw/vfio/cpr-iommufd.c
index 1d70c87..8a4d65d 100644
--- a/hw/vfio/cpr-iommufd.c
+++ b/hw/vfio/cpr-iommufd.c
@@ -159,7 +159,8 @@ bool vfio_iommufd_cpr_register_iommufd(IOMMUFDBackend *be, Error **errp)
 
     if (!vfio_cpr_supported(be, cpr_blocker)) {
         return migrate_add_blocker_modes(cpr_blocker, errp,
-                                         MIG_MODE_CPR_TRANSFER, -1) == 0;
+                                         MIG_MODE_CPR_TRANSFER,
+                                         MIG_MODE_CPR_EXEC, -1) == 0;
     }
 
     vmstate_register(NULL, -1, &iommufd_cpr_vmstate, be);
diff --git a/hw/vfio/cpr-legacy.c b/hw/vfio/cpr-legacy.c
index 3a1d126..80af746 100644
--- a/hw/vfio/cpr-legacy.c
+++ b/hw/vfio/cpr-legacy.c
@@ -179,16 +179,17 @@ bool vfio_legacy_cpr_register_container(VFIOLegacyContainer *container,
 
     if (!vfio_cpr_supported(container, cpr_blocker)) {
         return migrate_add_blocker_modes(cpr_blocker, errp,
-                                         MIG_MODE_CPR_TRANSFER, -1) == 0;
+                                         MIG_MODE_CPR_TRANSFER,
+                                         MIG_MODE_CPR_EXEC, -1) == 0;
     }
 
     vfio_cpr_add_kvm_notifier();
 
     vmstate_register(NULL, -1, &vfio_container_vmstate, container);
 
-    migration_add_notifier_mode(&container->cpr.transfer_notifier,
-                                vfio_cpr_fail_notifier,
-                                MIG_MODE_CPR_TRANSFER);
+    migration_add_notifier_modes(&container->cpr.transfer_notifier,
+                                 vfio_cpr_fail_notifier,
+                                 MIG_MODE_CPR_TRANSFER, MIG_MODE_CPR_EXEC, -1);
     return true;
 }
 
diff --git a/hw/vfio/cpr.c b/hw/vfio/cpr.c
index 2c71fc1..db462aa 100644
--- a/hw/vfio/cpr.c
+++ b/hw/vfio/cpr.c
@@ -195,9 +195,10 @@ static int vfio_cpr_kvm_close_notifier(NotifierWithReturn *notifier,
 void vfio_cpr_add_kvm_notifier(void)
 {
     if (!kvm_close_notifier.notify) {
-        migration_add_notifier_mode(&kvm_close_notifier,
-                                    vfio_cpr_kvm_close_notifier,
-                                    MIG_MODE_CPR_TRANSFER);
+        migration_add_notifier_modes(&kvm_close_notifier,
+                                     vfio_cpr_kvm_close_notifier,
+                                     MIG_MODE_CPR_TRANSFER, MIG_MODE_CPR_EXEC,
+                                     -1);
     }
 }
 
@@ -282,9 +283,9 @@ static int vfio_cpr_pci_notifier(NotifierWithReturn *notifier,
 
 void vfio_cpr_pci_register_device(VFIOPCIDevice *vdev)
 {
-    migration_add_notifier_mode(&vdev->cpr.transfer_notifier,
-                                vfio_cpr_pci_notifier,
-                                MIG_MODE_CPR_TRANSFER);
+    migration_add_notifier_modes(&vdev->cpr.transfer_notifier,
+                                 vfio_cpr_pci_notifier,
+                                 MIG_MODE_CPR_TRANSFER, MIG_MODE_CPR_EXEC, -1);
 }
 
 void vfio_cpr_pci_unregister_device(VFIOPCIDevice *vdev)
diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
index 5b022da..06b06af 100644
--- a/hw/vfio/pci.c
+++ b/hw/vfio/pci.c
@@ -2821,8 +2821,8 @@ static int vfio_pci_save_config(VFIODevice *vbasedev, QEMUFile *f, Error **errp)
 {
     VFIOPCIDevice *vdev = container_of(vbasedev, VFIOPCIDevice, vbasedev);
 
-    return vmstate_save_state_with_err(f, &vmstate_vfio_pci_config, vdev, NULL,
-                                       errp);
+    return vmstate_save_state(f, &vmstate_vfio_pci_config, vdev, NULL,
+                              errp);
 }
 
 static int vfio_pci_load_config(VFIODevice *vbasedev, QEMUFile *f)
@@ -2831,13 +2831,16 @@ static int vfio_pci_load_config(VFIODevice *vbasedev, QEMUFile *f)
     PCIDevice *pdev = PCI_DEVICE(vdev);
     pcibus_t old_addr[PCI_NUM_REGIONS - 1];
     int bar, ret;
+    Error *local_err = NULL;
 
     for (bar = 0; bar < PCI_ROM_SLOT; bar++) {
         old_addr[bar] = pdev->io_regions[bar].addr;
     }
 
-    ret = vmstate_load_state(f, &vmstate_vfio_pci_config, vdev, 1);
+    ret = vmstate_load_state(f, &vmstate_vfio_pci_config, vdev, 1,
+                             &local_err);
     if (ret) {
+        error_report_err(local_err);
         return ret;
     }
 
diff --git a/hw/virtio/virtio-mmio.c b/hw/virtio/virtio-mmio.c
index 532c671..fb58c36 100644
--- a/hw/virtio/virtio-mmio.c
+++ b/hw/virtio/virtio-mmio.c
@@ -34,6 +34,7 @@
 #include "qemu/error-report.h"
 #include "qemu/log.h"
 #include "trace.h"
+#include "qapi/error.h"
 
 static bool virtio_mmio_ioeventfd_enabled(DeviceState *d)
 {
@@ -612,14 +613,14 @@ static void virtio_mmio_save_extra_state(DeviceState *opaque, QEMUFile *f)
 {
     VirtIOMMIOProxy *proxy = VIRTIO_MMIO(opaque);
 
-    vmstate_save_state(f, &vmstate_virtio_mmio, proxy, NULL);
+    vmstate_save_state(f, &vmstate_virtio_mmio, proxy, NULL, &error_fatal);
 }
 
 static int virtio_mmio_load_extra_state(DeviceState *opaque, QEMUFile *f)
 {
     VirtIOMMIOProxy *proxy = VIRTIO_MMIO(opaque);
 
-    return vmstate_load_state(f, &vmstate_virtio_mmio, proxy, 1);
+    return vmstate_load_state(f, &vmstate_virtio_mmio, proxy, 1, &error_fatal);
 }
 
 static bool virtio_mmio_has_extra_state(DeviceState *opaque)
diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
index 767216d..d2595fb 100644
--- a/hw/virtio/virtio-pci.c
+++ b/hw/virtio/virtio-pci.c
@@ -154,14 +154,14 @@ static void virtio_pci_save_extra_state(DeviceState *d, QEMUFile *f)
 {
     VirtIOPCIProxy *proxy = to_virtio_pci_proxy(d);
 
-    vmstate_save_state(f, &vmstate_virtio_pci, proxy, NULL);
+    vmstate_save_state(f, &vmstate_virtio_pci, proxy, NULL, &error_fatal);
 }
 
 static int virtio_pci_load_extra_state(DeviceState *d, QEMUFile *f)
 {
     VirtIOPCIProxy *proxy = to_virtio_pci_proxy(d);
 
-    return vmstate_load_state(f, &vmstate_virtio_pci, proxy, 1);
+    return vmstate_load_state(f, &vmstate_virtio_pci, proxy, 1, &error_fatal);
 }
 
 static void virtio_pci_save_queue(DeviceState *d, int n, QEMUFile *f)
diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index 9a81ad9..0a68f1b 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -2992,6 +2992,7 @@ int virtio_save(VirtIODevice *vdev, QEMUFile *f)
     VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev);
     uint32_t guest_features_lo = (vdev->guest_features & 0xffffffff);
     int i;
+    Error *local_err = NULL;
 
     if (k->save_config) {
         k->save_config(qbus->parent, f);
@@ -3035,14 +3036,15 @@ int virtio_save(VirtIODevice *vdev, QEMUFile *f)
     }
 
     if (vdc->vmsd) {
-        int ret = vmstate_save_state(f, vdc->vmsd, vdev, NULL);
+        int ret = vmstate_save_state(f, vdc->vmsd, vdev, NULL, &local_err);
         if (ret) {
+            error_report_err(local_err);
             return ret;
         }
     }
 
     /* Subsections */
-    return vmstate_save_state(f, &vmstate_virtio, vdev, NULL);
+    return vmstate_save_state(f, &vmstate_virtio, vdev, NULL, &error_fatal);
 }
 
 /* A wrapper for use as a VMState .put function */
@@ -3235,6 +3237,7 @@ virtio_load(VirtIODevice *vdev, QEMUFile *f, int version_id)
     BusState *qbus = qdev_get_parent_bus(DEVICE(vdev));
     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
     VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev);
+    Error *local_err = NULL;
 
     /*
      * We poison the endianness to ensure it does not get used before
@@ -3327,15 +3330,17 @@ virtio_load(VirtIODevice *vdev, QEMUFile *f, int version_id)
     }
 
     if (vdc->vmsd) {
-        ret = vmstate_load_state(f, vdc->vmsd, vdev, version_id);
+        ret = vmstate_load_state(f, vdc->vmsd, vdev, version_id, &local_err);
         if (ret) {
+            error_report_err(local_err);
             return ret;
         }
     }
 
     /* Subsections */
-    ret = vmstate_load_state(f, &vmstate_virtio, vdev, 1);
+    ret = vmstate_load_state(f, &vmstate_virtio, vdev, 1, &local_err);
     if (ret) {
+        error_report_err(local_err);
         return ret;
     }
 
diff --git a/include/crypto/tlssession.h b/include/crypto/tlssession.h
index 2f62ce2..2e9fe11 100644
--- a/include/crypto/tlssession.h
+++ b/include/crypto/tlssession.h
@@ -110,6 +110,7 @@
 typedef struct QCryptoTLSSession QCryptoTLSSession;
 
 #define QCRYPTO_TLS_SESSION_ERR_BLOCK -2
+#define QCRYPTO_TLS_SESSION_PREMATURE_TERMINATION -3
 
 /**
  * qcrypto_tls_session_new:
@@ -259,7 +260,6 @@ ssize_t qcrypto_tls_session_write(QCryptoTLSSession *sess,
  * @sess: the TLS session object
  * @buf: to fill with plain text received
  * @len: the length of @buf
- * @gracefulTermination: treat premature termination as graceful EOF
  * @errp: pointer to hold returned error object
  *
  * Receive up to @len bytes of data from the remote peer
@@ -267,22 +267,18 @@ ssize_t qcrypto_tls_session_write(QCryptoTLSSession *sess,
  * qcrypto_tls_session_set_callbacks(), decrypt it and
  * store it in @buf.
  *
- * If @gracefulTermination is true, then a premature termination
- * of the TLS session will be treated as indicating EOF, as
- * opposed to an error.
- *
  * It is an error to call this before
  * qcrypto_tls_session_handshake() returns
  * QCRYPTO_TLS_HANDSHAKE_COMPLETE
  *
  * Returns: the number of bytes received,
  * or QCRYPTO_TLS_SESSION_ERR_BLOCK if the receive would block,
- * or -1 on error.
+ * or QCRYPTO_TLS_SESSION_PREMATURE_TERMINATION if a premature termination
+ * is detected, or -1 on error.
  */
 ssize_t qcrypto_tls_session_read(QCryptoTLSSession *sess,
                                  char *buf,
                                  size_t len,
-                                 bool gracefulTermination,
                                  Error **errp);
 
 /**
diff --git a/include/exec/cpu-common.h b/include/exec/cpu-common.h
index f373781..b96ac49 100644
--- a/include/exec/cpu-common.h
+++ b/include/exec/cpu-common.h
@@ -123,13 +123,13 @@ size_t qemu_ram_pagesize_largest(void);
 void cpu_address_space_init(CPUState *cpu, int asidx,
                             const char *prefix, MemoryRegion *mr);
 /**
- * cpu_address_space_destroy:
- * @cpu: CPU for which address space needs to be destroyed
- * @asidx: integer index of this address space
+ * cpu_destroy_address_spaces:
+ * @cpu: CPU for which address spaces need to be destroyed
  *
- * Note that with KVM only one address space is supported.
+ * Destroy all address spaces associated with this CPU; this
+ * is called as part of unrealizing the CPU.
  */
-void cpu_address_space_destroy(CPUState *cpu, int asidx);
+void cpu_destroy_address_spaces(CPUState *cpu);
 
 void cpu_physical_memory_rw(hwaddr addr, void *buf,
                             hwaddr len, bool is_write);
diff --git a/include/hw/core/cpu.h b/include/hw/core/cpu.h
index c9f40c2..0fcbc92 100644
--- a/include/hw/core/cpu.h
+++ b/include/hw/core/cpu.h
@@ -515,7 +515,6 @@ struct CPUState {
     QSIMPLEQ_HEAD(, qemu_work_item) work_list;
 
     struct CPUAddressSpace *cpu_ases;
-    int cpu_ases_count;
     int num_ases;
     AddressSpace *as;
     MemoryRegion *memory;
diff --git a/include/migration/colo.h b/include/migration/colo.h
index 43222ef..d4fe422 100644
--- a/include/migration/colo.h
+++ b/include/migration/colo.h
@@ -25,7 +25,7 @@ void migrate_start_colo_process(MigrationState *s);
 bool migration_in_colo_state(void);
 
 /* loadvm */
-int migration_incoming_enable_colo(void);
+int migration_incoming_enable_colo(Error **errp);
 void migration_incoming_disable_colo(void);
 bool migration_incoming_colo_enabled(void);
 bool migration_incoming_in_colo_state(void);
diff --git a/include/migration/cpr.h b/include/migration/cpr.h
index 3fc19a7..a412d66 100644
--- a/include/migration/cpr.h
+++ b/include/migration/cpr.h
@@ -34,6 +34,9 @@ void cpr_resave_fd(const char *name, int id, int fd);
 int cpr_open_fd(const char *path, int flags, const char *name, int id,
                 Error **errp);
 
+typedef bool (*cpr_walk_fd_cb)(int fd);
+bool cpr_walk_fd(cpr_walk_fd_cb cb);
+
 MigMode cpr_get_incoming_mode(void);
 void cpr_set_incoming_mode(MigMode mode);
 bool cpr_is_incoming(void);
@@ -50,4 +53,11 @@ int cpr_get_fd_param(const char *name, const char *fdname, int index,
 QEMUFile *cpr_transfer_output(MigrationChannel *channel, Error **errp);
 QEMUFile *cpr_transfer_input(MigrationChannel *channel, Error **errp);
 
+void cpr_exec_init(void);
+QEMUFile *cpr_exec_output(Error **errp);
+QEMUFile *cpr_exec_input(Error **errp);
+void cpr_exec_persist_state(QEMUFile *f);
+bool cpr_exec_has_state(void);
+void cpr_exec_unpersist_state(void);
+void cpr_exec_unpreserve_fds(void);
 #endif
diff --git a/include/migration/misc.h b/include/migration/misc.h
index a261f99..592b930 100644
--- a/include/migration/misc.h
+++ b/include/migration/misc.h
@@ -95,7 +95,19 @@ void migration_add_notifier(NotifierWithReturn *notify,
 void migration_add_notifier_mode(NotifierWithReturn *notify,
                                  MigrationNotifyFunc func, MigMode mode);
 
+/*
+ * Same as migration_add_notifier, but applies to all @mode in the argument
+ * list.  The list is terminated by -1 or MIG_MODE_ALL.  For the latter,
+ * the notifier is added for all modes.
+ */
+void migration_add_notifier_modes(NotifierWithReturn *notify,
+                                  MigrationNotifyFunc func, MigMode mode, ...);
+
+/*
+ * Remove a notifier from all modes.
+ */
 void migration_remove_notifier(NotifierWithReturn *notify);
+
 void migration_file_set_error(int ret, Error *err);
 
 /* True if incoming migration entered POSTCOPY_INCOMING_DISCARD */
diff --git a/include/migration/vmstate.h b/include/migration/vmstate.h
index 1cfddf3..63ccaee 100644
--- a/include/migration/vmstate.h
+++ b/include/migration/vmstate.h
@@ -163,6 +163,7 @@ typedef enum {
     MIG_PRI_IOMMU,              /* Must happen before PCI devices */
     MIG_PRI_PCI_BUS,            /* Must happen before IOMMU */
     MIG_PRI_VIRTIO_MEM,         /* Must happen before IOMMU */
+    MIG_PRI_APIC,               /* Must happen before PCI devices */
     MIG_PRI_GICV3_ITS,          /* Must happen before PCI devices */
     MIG_PRI_GICV3,              /* Must happen before the ITS */
     MIG_PRI_MAX,
@@ -200,14 +201,28 @@ struct VMStateDescription {
      * exclusive. For this reason, also early_setup VMSDs are migrated in a
      * QEMU_VM_SECTION_FULL section, while save_setup() data is migrated in
      * a QEMU_VM_SECTION_START section.
+     *
+     * There are duplicate impls of the post/pre save/load hooks.
+     * New impls should preferentally use 'errp' variants of these
+     * methods and existing impls incrementally converted.
+     * The variants without 'errp' are intended to be removed
+     * once all usage is converted.
+     *
+     * For the errp variants,
+     * Returns: 0 on success,
+     *          <0 on error where -value is an error number from errno.h
      */
+
     bool early_setup;
     int version_id;
     int minimum_version_id;
     MigrationPriority priority;
     int (*pre_load)(void *opaque);
+    int (*pre_load_errp)(void *opaque, Error **errp);
     int (*post_load)(void *opaque, int version_id);
+    int (*post_load_errp)(void *opaque, int version_id, Error **errp);
     int (*pre_save)(void *opaque);
+    int (*pre_save_errp)(void *opaque, Error **errp);
     int (*post_save)(void *opaque);
     bool (*needed)(void *opaque);
     bool (*dev_unplug_pending)(void *opaque);
@@ -1206,10 +1221,8 @@ extern const VMStateInfo vmstate_info_qlist;
     }
 
 int vmstate_load_state(QEMUFile *f, const VMStateDescription *vmsd,
-                       void *opaque, int version_id);
+                       void *opaque, int version_id, Error **errp);
 int vmstate_save_state(QEMUFile *f, const VMStateDescription *vmsd,
-                       void *opaque, JSONWriter *vmdesc);
-int vmstate_save_state_with_err(QEMUFile *f, const VMStateDescription *vmsd,
                        void *opaque, JSONWriter *vmdesc, Error **errp);
 int vmstate_save_state_v(QEMUFile *f, const VMStateDescription *vmsd,
                          void *opaque, JSONWriter *vmdesc,
diff --git a/include/qemu/osdep.h b/include/qemu/osdep.h
index 6de6c0c..cf8d7cf 100644
--- a/include/qemu/osdep.h
+++ b/include/qemu/osdep.h
@@ -689,6 +689,15 @@ ssize_t qemu_write_full(int fd, const void *buf, size_t count)
 void qemu_set_cloexec(int fd);
 bool qemu_set_blocking(int fd, bool block, Error **errp);
 
+/*
+ * Clear FD_CLOEXEC for a descriptor.
+ *
+ * The caller must guarantee that no other fork+exec's occur before the
+ * exec that is intended to inherit this descriptor, eg by suspending CPUs
+ * and blocking monitor commands.
+ */
+void qemu_clear_cloexec(int fd);
+
 /* Return a dynamically allocated directory path that is appropriate for storing
  * local state.
  *
diff --git a/include/system/memory.h b/include/system/memory.h
index aa85fc2..08daf0f 100644
--- a/include/system/memory.h
+++ b/include/system/memory.h
@@ -2727,15 +2727,33 @@ void address_space_init(AddressSpace *as, MemoryRegion *root, const char *name);
 /**
  * address_space_destroy: destroy an address space
  *
- * Releases all resources associated with an address space.  After an address space
- * is destroyed, its root memory region (given by address_space_init()) may be destroyed
- * as well.
+ * Releases all resources associated with an address space.  After an
+ * address space is destroyed, the reference the AddressSpace had to
+ * its root memory region is dropped, which may result in the
+ * destruction of that memory region as well.
+ *
+ * Note that destruction of the AddressSpace is done via RCU;
+ * it is therefore not valid to free the memory the AddressSpace
+ * struct is in until after that RCU callback has completed.
+ * If you want to g_free() the AddressSpace after destruction you
+ * can do that with address_space_destroy_free().
  *
  * @as: address space to be destroyed
  */
 void address_space_destroy(AddressSpace *as);
 
 /**
+ * address_space_destroy_free: destroy an address space and free it
+ *
+ * This does the same thing as address_space_destroy(), and then also
+ * frees (via g_free()) the AddressSpace itself once the destruction
+ * is complete.
+ *
+ * @as: address space to be destroyed
+ */
+void address_space_destroy_free(AddressSpace *as);
+
+/**
  * address_space_remove_listeners: unregister all listeners of an address space
  *
  * Removes all callbacks previously registered with memory_listener_register()
diff --git a/io/channel-tls.c b/io/channel-tls.c
index 7135896..1fbed4b 100644
--- a/io/channel-tls.c
+++ b/io/channel-tls.c
@@ -346,6 +346,19 @@ static void qio_channel_tls_finalize(Object *obj)
     qcrypto_tls_session_free(ioc->session);
 }
 
+static bool
+qio_channel_tls_allow_premature_termination(QIOChannelTLS *tioc, int flags)
+{
+    if (flags & QIO_CHANNEL_READ_FLAG_RELAXED_EOF) {
+        return true;
+    }
+
+    if (qatomic_read(&tioc->shutdown) & QIO_CHANNEL_SHUTDOWN_READ) {
+        return true;
+    }
+
+    return false;
+}
 
 static ssize_t qio_channel_tls_readv(QIOChannel *ioc,
                                      const struct iovec *iov,
@@ -364,8 +377,6 @@ static ssize_t qio_channel_tls_readv(QIOChannel *ioc,
             tioc->session,
             iov[i].iov_base,
             iov[i].iov_len,
-            flags & QIO_CHANNEL_READ_FLAG_RELAXED_EOF ||
-            qatomic_load_acquire(&tioc->shutdown) & QIO_CHANNEL_SHUTDOWN_READ,
             errp);
         if (ret == QCRYPTO_TLS_SESSION_ERR_BLOCK) {
             if (got) {
@@ -373,6 +384,12 @@ static ssize_t qio_channel_tls_readv(QIOChannel *ioc,
             } else {
                 return QIO_CHANNEL_ERR_BLOCK;
             }
+        } else if (ret == QCRYPTO_TLS_SESSION_PREMATURE_TERMINATION) {
+            if (qio_channel_tls_allow_premature_termination(tioc, flags)) {
+                ret = 0;
+            } else {
+                return -1;
+            }
         } else if (ret < 0) {
             return -1;
         }
diff --git a/migration/colo.c b/migration/colo.c
index cf4d71d..db783f6 100644
--- a/migration/colo.c
+++ b/migration/colo.c
@@ -686,11 +686,10 @@ static void colo_incoming_process_checkpoint(MigrationIncomingState *mis,
 
     bql_lock();
     cpu_synchronize_all_states();
-    ret = qemu_loadvm_state_main(mis->from_src_file, mis);
+    ret = qemu_loadvm_state_main(mis->from_src_file, mis, errp);
     bql_unlock();
 
     if (ret < 0) {
-        error_setg(errp, "Load VM's live state (ram) error");
         return;
     }
 
@@ -729,9 +728,8 @@ static void colo_incoming_process_checkpoint(MigrationIncomingState *mis,
     bql_lock();
     vmstate_loading = true;
     colo_flush_ram_cache();
-    ret = qemu_load_device_state(fb);
+    ret = qemu_load_device_state(fb, errp);
     if (ret < 0) {
-        error_setg(errp, "COLO: load device state failed");
         vmstate_loading = false;
         bql_unlock();
         return;
@@ -849,10 +847,6 @@ static void *colo_process_incoming_thread(void *opaque)
     failover_init_state();
 
     mis->to_src_file = qemu_file_get_return_path(mis->from_src_file);
-    if (!mis->to_src_file) {
-        error_report("COLO incoming thread: Open QEMUFile to_src_file failed");
-        goto out;
-    }
     /*
      * Note: the communication between Primary side and Secondary side
      * should be sequential, we set the fd to unblocked in migration incoming
diff --git a/migration/cpr-exec.c b/migration/cpr-exec.c
new file mode 100644
index 0000000..d57714b
--- /dev/null
+++ b/migration/cpr-exec.c
@@ -0,0 +1,194 @@
+/*
+ * Copyright (c) 2021-2025 Oracle and/or its affiliates.
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/cutils.h"
+#include "qemu/error-report.h"
+#include "qemu/memfd.h"
+#include "qapi/error.h"
+#include "qapi/type-helpers.h"
+#include "io/channel-file.h"
+#include "io/channel-socket.h"
+#include "block/block-global-state.h"
+#include "qemu/main-loop.h"
+#include "migration/cpr.h"
+#include "migration/qemu-file.h"
+#include "migration/migration.h"
+#include "migration/misc.h"
+#include "migration/vmstate.h"
+#include "system/runstate.h"
+#include "trace.h"
+
+#define CPR_EXEC_STATE_NAME "QEMU_CPR_EXEC_STATE"
+
+static QEMUFile *qemu_file_new_fd_input(int fd, const char *name)
+{
+    g_autoptr(QIOChannelFile) fioc = qio_channel_file_new_fd(fd);
+    QIOChannel *ioc = QIO_CHANNEL(fioc);
+    qio_channel_set_name(ioc, name);
+    return qemu_file_new_input(ioc);
+}
+
+static QEMUFile *qemu_file_new_fd_output(int fd, const char *name)
+{
+    g_autoptr(QIOChannelFile) fioc = qio_channel_file_new_fd(fd);
+    QIOChannel *ioc = QIO_CHANNEL(fioc);
+    qio_channel_set_name(ioc, name);
+    return qemu_file_new_output(ioc);
+}
+
+void cpr_exec_persist_state(QEMUFile *f)
+{
+    QIOChannelFile *fioc = QIO_CHANNEL_FILE(qemu_file_get_ioc(f));
+    int mfd = dup(fioc->fd);
+    char val[16];
+
+    /* Remember mfd in environment for post-exec load */
+    qemu_clear_cloexec(mfd);
+    snprintf(val, sizeof(val), "%d", mfd);
+    g_setenv(CPR_EXEC_STATE_NAME, val, 1);
+}
+
+static int cpr_exec_find_state(void)
+{
+    const char *val = g_getenv(CPR_EXEC_STATE_NAME);
+    int mfd;
+
+    assert(val);
+    g_unsetenv(CPR_EXEC_STATE_NAME);
+    assert(!qemu_strtoi(val, NULL, 10, &mfd));
+    return mfd;
+}
+
+bool cpr_exec_has_state(void)
+{
+    return g_getenv(CPR_EXEC_STATE_NAME) != NULL;
+}
+
+void cpr_exec_unpersist_state(void)
+{
+    int mfd;
+    const char *val = g_getenv(CPR_EXEC_STATE_NAME);
+
+    g_unsetenv(CPR_EXEC_STATE_NAME);
+    assert(val);
+    assert(!qemu_strtoi(val, NULL, 10, &mfd));
+    close(mfd);
+}
+
+QEMUFile *cpr_exec_output(Error **errp)
+{
+    int mfd;
+
+#ifdef CONFIG_LINUX
+    mfd = qemu_memfd_create(CPR_EXEC_STATE_NAME, 0, false, 0, 0, errp);
+#else
+    mfd = -1;
+#endif
+
+    if (mfd < 0) {
+        return NULL;
+    }
+
+    return qemu_file_new_fd_output(mfd, CPR_EXEC_STATE_NAME);
+}
+
+QEMUFile *cpr_exec_input(Error **errp)
+{
+    int mfd = cpr_exec_find_state();
+
+    lseek(mfd, 0, SEEK_SET);
+    return qemu_file_new_fd_input(mfd, CPR_EXEC_STATE_NAME);
+}
+
+static bool preserve_fd(int fd)
+{
+    qemu_clear_cloexec(fd);
+    return true;
+}
+
+static bool unpreserve_fd(int fd)
+{
+    qemu_set_cloexec(fd);
+    return true;
+}
+
+static void cpr_exec_preserve_fds(void)
+{
+    cpr_walk_fd(preserve_fd);
+}
+
+void cpr_exec_unpreserve_fds(void)
+{
+    cpr_walk_fd(unpreserve_fd);
+}
+
+static void cpr_exec_cb(void *opaque)
+{
+    MigrationState *s = migrate_get_current();
+    char **argv = strv_from_str_list(s->parameters.cpr_exec_command);
+    Error *err = NULL;
+
+    /*
+     * Clear the close-on-exec flag for all preserved fd's.  We cannot do so
+     * earlier because they should not persist across miscellaneous fork and
+     * exec calls that are performed during normal operation.
+     */
+    cpr_exec_preserve_fds();
+
+    trace_cpr_exec();
+    execvp(argv[0], argv);
+
+    /*
+     * exec should only fail if argv[0] is bogus, or has a permissions problem,
+     * or the system is very short on resources.
+     */
+    g_strfreev(argv);
+    cpr_exec_unpreserve_fds();
+
+    error_setg_errno(&err, errno, "execvp %s failed", argv[0]);
+    error_report_err(error_copy(err));
+    migrate_set_state(&s->state, s->state, MIGRATION_STATUS_FAILED);
+    migrate_set_error(s, err);
+
+    /* Note, we can go from state COMPLETED to FAILED */
+    migration_call_notifiers(s, MIG_EVENT_PRECOPY_FAILED, NULL);
+
+    err = NULL;
+    if (!migration_block_activate(&err)) {
+        /* error was already reported */
+        error_free(err);
+        return;
+    }
+
+    if (runstate_is_live(s->vm_old_state)) {
+        vm_start();
+    }
+}
+
+static int cpr_exec_notifier(NotifierWithReturn *notifier, MigrationEvent *e,
+                             Error **errp)
+{
+    MigrationState *s = migrate_get_current();
+
+    if (e->type == MIG_EVENT_PRECOPY_DONE) {
+        QEMUBH *cpr_exec_bh = qemu_bh_new(cpr_exec_cb, NULL);
+        assert(s->state == MIGRATION_STATUS_COMPLETED);
+        qemu_bh_schedule(cpr_exec_bh);
+        qemu_notify_event();
+    } else if (e->type == MIG_EVENT_PRECOPY_FAILED) {
+        cpr_exec_unpersist_state();
+    }
+    return 0;
+}
+
+void cpr_exec_init(void)
+{
+    static NotifierWithReturn exec_notifier;
+
+    migration_add_notifier_mode(&exec_notifier, cpr_exec_notifier,
+                                MIG_MODE_CPR_EXEC);
+}
diff --git a/migration/cpr.c b/migration/cpr.c
index 9848a21..22dbac7 100644
--- a/migration/cpr.c
+++ b/migration/cpr.c
@@ -6,6 +6,7 @@
  */
 
 #include "qemu/osdep.h"
+#include "qemu/error-report.h"
 #include "qapi/error.h"
 #include "qemu/error-report.h"
 #include "hw/vfio/vfio-device.h"
@@ -122,6 +123,19 @@ int cpr_open_fd(const char *path, int flags, const char *name, int id,
     return fd;
 }
 
+bool cpr_walk_fd(cpr_walk_fd_cb cb)
+{
+    CprFd *elem;
+
+    QLIST_FOREACH(elem, &cpr_state.fds, next) {
+        g_assert(elem->fd >= 0);
+        if (!cb(elem->fd)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 /*************************************************************************/
 static const VMStateDescription vmstate_cpr_state = {
     .name = CPR_STATE,
@@ -173,6 +187,8 @@ int cpr_state_save(MigrationChannel *channel, Error **errp)
     if (mode == MIG_MODE_CPR_TRANSFER) {
         g_assert(channel);
         f = cpr_transfer_output(channel, errp);
+    } else if (mode == MIG_MODE_CPR_EXEC) {
+        f = cpr_exec_output(errp);
     } else {
         return 0;
     }
@@ -183,13 +199,16 @@ int cpr_state_save(MigrationChannel *channel, Error **errp)
     qemu_put_be32(f, QEMU_CPR_FILE_MAGIC);
     qemu_put_be32(f, QEMU_CPR_FILE_VERSION);
 
-    ret = vmstate_save_state(f, &vmstate_cpr_state, &cpr_state, 0);
+    ret = vmstate_save_state(f, &vmstate_cpr_state, &cpr_state, 0, errp);
     if (ret) {
-        error_setg(errp, "vmstate_save_state error %d", ret);
         qemu_fclose(f);
         return ret;
     }
 
+    if (migrate_mode() == MIG_MODE_CPR_EXEC) {
+        cpr_exec_persist_state(f);
+    }
+
     /*
      * Close the socket only partially so we can later detect when the other
      * end closes by getting a HUP event.
@@ -208,7 +227,13 @@ int cpr_state_load(MigrationChannel *channel, Error **errp)
     QEMUFile *f;
     MigMode mode = 0;
 
-    if (channel) {
+    if (cpr_exec_has_state()) {
+        mode = MIG_MODE_CPR_EXEC;
+        f = cpr_exec_input(errp);
+        if (channel) {
+            warn_report("ignoring cpr channel for migration mode cpr-exec");
+        }
+    } else if (channel) {
         mode = MIG_MODE_CPR_TRANSFER;
         cpr_set_incoming_mode(mode);
         f = cpr_transfer_input(channel, errp);
@@ -220,6 +245,7 @@ int cpr_state_load(MigrationChannel *channel, Error **errp)
     }
 
     trace_cpr_state_load(MigMode_str(mode));
+    cpr_set_incoming_mode(mode);
 
     v = qemu_get_be32(f);
     if (v != QEMU_CPR_FILE_MAGIC) {
@@ -234,13 +260,17 @@ int cpr_state_load(MigrationChannel *channel, Error **errp)
         return -ENOTSUP;
     }
 
-    ret = vmstate_load_state(f, &vmstate_cpr_state, &cpr_state, 1);
+    ret = vmstate_load_state(f, &vmstate_cpr_state, &cpr_state, 1, errp);
     if (ret) {
-        error_setg(errp, "vmstate_load_state error %d", ret);
         qemu_fclose(f);
         return ret;
     }
 
+    if (migrate_mode() == MIG_MODE_CPR_EXEC) {
+        /* Set cloexec to prevent fd leaks from fork until the next cpr-exec */
+        cpr_exec_unpreserve_fds();
+    }
+
     /*
      * Let the caller decide when to close the socket (and generate a HUP event
      * for the sending side).
@@ -261,7 +291,7 @@ void cpr_state_close(void)
 bool cpr_incoming_needed(void *opaque)
 {
     MigMode mode = migrate_mode();
-    return mode == MIG_MODE_CPR_TRANSFER;
+    return mode == MIG_MODE_CPR_TRANSFER || mode == MIG_MODE_CPR_EXEC;
 }
 
 /*
diff --git a/migration/meson.build b/migration/meson.build
index 0f71544..16909d5 100644
--- a/migration/meson.build
+++ b/migration/meson.build
@@ -16,6 +16,7 @@ system_ss.add(files(
   'channel-block.c',
   'cpr.c',
   'cpr-transfer.c',
+  'cpr-exec.c',
   'cpu-throttle.c',
   'dirtyrate.c',
   'exec.c',
diff --git a/migration/migration-hmp-cmds.c b/migration/migration-hmp-cmds.c
index 0fc21f0..847d18f 100644
--- a/migration/migration-hmp-cmds.c
+++ b/migration/migration-hmp-cmds.c
@@ -306,6 +306,18 @@ void hmp_info_migrate_capabilities(Monitor *mon, const QDict *qdict)
     qapi_free_MigrationCapabilityStatusList(caps);
 }
 
+static void monitor_print_cpr_exec_command(Monitor *mon, strList *args)
+{
+    monitor_printf(mon, "%s:",
+        MigrationParameter_str(MIGRATION_PARAMETER_CPR_EXEC_COMMAND));
+
+    while (args) {
+        monitor_printf(mon, " %s", args->value);
+        args = args->next;
+    }
+    monitor_printf(mon, "\n");
+}
+
 void hmp_info_migrate_parameters(Monitor *mon, const QDict *qdict)
 {
     MigrationParameters *params;
@@ -353,6 +365,10 @@ void hmp_info_migrate_parameters(Monitor *mon, const QDict *qdict)
         monitor_printf(mon, "%s: '%s'\n",
             MigrationParameter_str(MIGRATION_PARAMETER_TLS_HOSTNAME),
             params->tls_hostname);
+        assert(params->tls_authz);
+        monitor_printf(mon, "%s: '%s'\n",
+            MigrationParameter_str(MIGRATION_PARAMETER_TLS_AUTHZ),
+            params->tls_authz);
         assert(params->has_max_bandwidth);
         monitor_printf(mon, "%s: %" PRIu64 " bytes/second\n",
             MigrationParameter_str(MIGRATION_PARAMETER_MAX_BANDWIDTH),
@@ -361,6 +377,10 @@ void hmp_info_migrate_parameters(Monitor *mon, const QDict *qdict)
         monitor_printf(mon, "%s: %" PRIu64 " bytes/second\n",
             MigrationParameter_str(MIGRATION_PARAMETER_AVAIL_SWITCHOVER_BANDWIDTH),
             params->avail_switchover_bandwidth);
+        assert(params->has_max_postcopy_bandwidth);
+        monitor_printf(mon, "%s: %" PRIu64 " bytes/second\n",
+            MigrationParameter_str(MIGRATION_PARAMETER_MAX_POSTCOPY_BANDWIDTH),
+            params->max_postcopy_bandwidth);
         assert(params->has_downtime_limit);
         monitor_printf(mon, "%s: %" PRIu64 " ms\n",
             MigrationParameter_str(MIGRATION_PARAMETER_DOWNTIME_LIMIT),
@@ -383,12 +403,6 @@ void hmp_info_migrate_parameters(Monitor *mon, const QDict *qdict)
         monitor_printf(mon, "%s: %" PRIu64 " bytes\n",
             MigrationParameter_str(MIGRATION_PARAMETER_XBZRLE_CACHE_SIZE),
             params->xbzrle_cache_size);
-        monitor_printf(mon, "%s: %" PRIu64 "\n",
-            MigrationParameter_str(MIGRATION_PARAMETER_MAX_POSTCOPY_BANDWIDTH),
-            params->max_postcopy_bandwidth);
-        monitor_printf(mon, "%s: '%s'\n",
-            MigrationParameter_str(MIGRATION_PARAMETER_TLS_AUTHZ),
-            params->tls_authz);
 
         if (params->has_block_bitmap_mapping) {
             const BitmapMigrationNodeAliasList *bmnal;
@@ -435,6 +449,9 @@ void hmp_info_migrate_parameters(Monitor *mon, const QDict *qdict)
                                MIGRATION_PARAMETER_DIRECT_IO),
                            params->direct_io ? "on" : "off");
         }
+
+        assert(params->has_cpr_exec_command);
+        monitor_print_cpr_exec_command(mon, params->cpr_exec_command);
     }
 
     qapi_free_MigrationParameters(params);
@@ -716,6 +733,21 @@ void hmp_migrate_set_parameter(Monitor *mon, const QDict *qdict)
         p->has_direct_io = true;
         visit_type_bool(v, param, &p->direct_io, &err);
         break;
+    case MIGRATION_PARAMETER_CPR_EXEC_COMMAND: {
+        g_autofree char **strv = NULL;
+        g_autoptr(GError) gerr = NULL;
+        strList **tail = &p->cpr_exec_command;
+
+        if (!g_shell_parse_argv(valuestr, NULL, &strv, &gerr)) {
+            error_setg(&err, "%s", gerr->message);
+            break;
+        }
+        for (int i = 0; strv[i]; i++) {
+            QAPI_LIST_APPEND(tail, strv[i]);
+        }
+        p->has_cpr_exec_command = true;
+        break;
+    }
     default:
         g_assert_not_reached();
     }
diff --git a/migration/migration.c b/migration/migration.c
index e1ac4d7..a63b46b 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -74,11 +74,7 @@
 
 #define INMIGRATE_DEFAULT_EXIT_ON_ERROR true
 
-static NotifierWithReturnList migration_state_notifiers[] = {
-    NOTIFIER_ELEM_INIT(migration_state_notifiers, MIG_MODE_NORMAL),
-    NOTIFIER_ELEM_INIT(migration_state_notifiers, MIG_MODE_CPR_REBOOT),
-    NOTIFIER_ELEM_INIT(migration_state_notifiers, MIG_MODE_CPR_TRANSFER),
-};
+static GSList *migration_state_notifiers[MIG_MODE__MAX];
 
 /* Messages sent on the return path from destination to source */
 enum mig_rp_message_type {
@@ -337,6 +333,7 @@ void migration_object_init(void)
 
     ram_mig_init();
     dirty_bitmap_mig_init();
+    cpr_exec_init();
 
     /* Initialize cpu throttle timers */
     cpu_throttle_init();
@@ -623,22 +620,22 @@ void migration_incoming_disable_colo(void)
     migration_colo_enabled = false;
 }
 
-int migration_incoming_enable_colo(void)
+int migration_incoming_enable_colo(Error **errp)
 {
 #ifndef CONFIG_REPLICATION
-    error_report("ENABLE_COLO command come in migration stream, but the "
-                 "replication module is not built in");
+    error_setg(errp, "ENABLE_COLO command come in migration stream, but the "
+               "replication module is not built in");
     return -ENOTSUP;
 #endif
 
     if (!migrate_colo()) {
-        error_report("ENABLE_COLO command come in migration stream, but x-colo "
-                     "capability is not set");
+        error_setg(errp, "ENABLE_COLO command come in migration stream"
+                   ", but x-colo capability is not set");
         return -EINVAL;
     }
 
     if (ram_block_discard_disable(true)) {
-        error_report("COLO: cannot disable RAM discard");
+        error_setg(errp, "COLO: cannot disable RAM discard");
         return -EBUSY;
     }
     migration_colo_enabled = true;
@@ -881,7 +878,7 @@ process_incoming_migration_co(void *opaque)
                       MIGRATION_STATUS_ACTIVE);
 
     mis->loadvm_co = qemu_coroutine_self();
-    ret = qemu_loadvm_state(mis->from_src_file);
+    ret = qemu_loadvm_state(mis->from_src_file, &local_err);
     mis->loadvm_co = NULL;
 
     trace_vmstate_downtime_checkpoint("dst-precopy-loadvm-completed");
@@ -908,7 +905,8 @@ process_incoming_migration_co(void *opaque)
     }
 
     if (ret < 0) {
-        error_setg(&local_err, "load of migration failed: %s", strerror(-ret));
+        error_prepend(&local_err, "load of migration failed: %s: ",
+                      strerror(-ret));
         goto fail;
     }
 
@@ -935,6 +933,15 @@ fail:
         }
 
         exit(EXIT_FAILURE);
+    } else {
+        /*
+         * Report the error here in case that QEMU abruptly exits
+         * when postcopy is enabled.
+         */
+        WITH_QEMU_LOCK_GUARD(&s->error_mutex) {
+            error_report_err(s->error);
+            s->error = NULL;
+        }
     }
 out:
     /* Pairs with the refcount taken in qmp_migrate_incoming() */
@@ -1665,23 +1672,51 @@ void migration_cancel(void)
     }
 }
 
+static int get_modes(MigMode mode, va_list ap);
+
+static void add_notifiers(NotifierWithReturn *notify, int modes)
+{
+    for (MigMode mode = 0; mode < MIG_MODE__MAX; mode++) {
+        if (modes & BIT(mode)) {
+            migration_state_notifiers[mode] =
+                g_slist_prepend(migration_state_notifiers[mode], notify);
+        }
+    }
+}
+
+void migration_add_notifier_modes(NotifierWithReturn *notify,
+                                  MigrationNotifyFunc func, MigMode mode, ...)
+{
+    int modes;
+    va_list ap;
+
+    va_start(ap, mode);
+    modes = get_modes(mode, ap);
+    va_end(ap);
+
+    notify->notify = (NotifierWithReturnFunc)func;
+    add_notifiers(notify, modes);
+}
+
 void migration_add_notifier_mode(NotifierWithReturn *notify,
                                  MigrationNotifyFunc func, MigMode mode)
 {
-    notify->notify = (NotifierWithReturnFunc)func;
-    notifier_with_return_list_add(&migration_state_notifiers[mode], notify);
+    migration_add_notifier_modes(notify, func, mode, -1);
 }
 
 void migration_add_notifier(NotifierWithReturn *notify,
                             MigrationNotifyFunc func)
 {
-    migration_add_notifier_mode(notify, func, MIG_MODE_NORMAL);
+    migration_add_notifier_modes(notify, func, MIG_MODE_NORMAL, -1);
 }
 
 void migration_remove_notifier(NotifierWithReturn *notify)
 {
     if (notify->notify) {
-        notifier_with_return_remove(notify);
+        for (MigMode mode = 0; mode < MIG_MODE__MAX; mode++) {
+            migration_blockers[mode] =
+                g_slist_remove(migration_state_notifiers[mode], notify);
+        }
         notify->notify = NULL;
     }
 }
@@ -1691,18 +1726,29 @@ int migration_call_notifiers(MigrationState *s, MigrationEventType type,
 {
     MigMode mode = s->parameters.mode;
     MigrationEvent e;
+    NotifierWithReturn *notifier;
+    GSList *elem, *next;
     int ret;
 
     e.type = type;
-    ret = notifier_with_return_list_notify(&migration_state_notifiers[mode],
-                                           &e, errp);
-    assert(!ret || type == MIG_EVENT_PRECOPY_SETUP);
-    return ret;
+
+    for (elem = migration_state_notifiers[mode]; elem; elem = next) {
+        next = elem->next;
+        notifier = (NotifierWithReturn *)elem->data;
+        ret = notifier->notify(notifier, &e, errp);
+        if (ret) {
+            assert(type == MIG_EVENT_PRECOPY_SETUP);
+            return ret;
+        }
+    }
+
+    return 0;
 }
 
 bool migration_has_failed(MigrationState *s)
 {
-    return (s->state == MIGRATION_STATUS_CANCELLED ||
+    return (s->state == MIGRATION_STATUS_CANCELLING ||
+            s->state == MIGRATION_STATUS_CANCELLED ||
             s->state == MIGRATION_STATUS_FAILED);
 }
 
@@ -1762,7 +1808,8 @@ bool migrate_mode_is_cpr(MigrationState *s)
 {
     MigMode mode = s->parameters.mode;
     return mode == MIG_MODE_CPR_REBOOT ||
-           mode == MIG_MODE_CPR_TRANSFER;
+           mode == MIG_MODE_CPR_TRANSFER ||
+           mode == MIG_MODE_CPR_EXEC;
 }
 
 int migrate_init(MigrationState *s, Error **errp)
@@ -2111,6 +2158,12 @@ static bool migrate_prepare(MigrationState *s, bool resume, Error **errp)
         return false;
     }
 
+    if (migrate_mode() == MIG_MODE_CPR_EXEC &&
+        !s->parameters.has_cpr_exec_command) {
+        error_setg(errp, "cpr-exec mode requires setting cpr-exec-command");
+        return false;
+    }
+
     if (migration_is_blocked(errp)) {
         return false;
     }
@@ -2646,12 +2699,9 @@ out:
     return NULL;
 }
 
-static int open_return_path_on_source(MigrationState *ms)
+static void open_return_path_on_source(MigrationState *ms)
 {
     ms->rp_state.from_dst_file = qemu_file_get_return_path(ms->to_dst_file);
-    if (!ms->rp_state.from_dst_file) {
-        return -1;
-    }
 
     trace_open_return_path_on_source();
 
@@ -2660,8 +2710,6 @@ static int open_return_path_on_source(MigrationState *ms)
     ms->rp_state.rp_thread_created = true;
 
     trace_open_return_path_on_source_continue();
-
-    return 0;
 }
 
 /* Return true if error detected, or false otherwise */
@@ -2872,8 +2920,9 @@ static int postcopy_start(MigrationState *ms, Error **errp)
 fail_closefb:
     qemu_fclose(fb);
 fail:
-    migrate_set_state(&ms->state, MIGRATION_STATUS_POSTCOPY_ACTIVE,
-                          MIGRATION_STATUS_FAILED);
+    if (ms->state != MIGRATION_STATUS_CANCELLING) {
+        migrate_set_state(&ms->state, ms->state, MIGRATION_STATUS_FAILED);
+    }
     migration_block_activate(NULL);
     migration_call_notifiers(ms, MIG_EVENT_PRECOPY_FAILED, NULL);
     bql_unlock();
@@ -4012,10 +4061,7 @@ void migration_connect(MigrationState *s, Error *error_in)
      * QEMU uses the return path.
      */
     if (migrate_postcopy_ram() || migrate_return_path()) {
-        if (open_return_path_on_source(s)) {
-            error_setg(&local_err, "Unable to open return-path for postcopy");
-            goto fail;
-        }
+        open_return_path_on_source(s);
     }
 
     /*
diff --git a/migration/multifd.c b/migration/multifd.c
index b255778..98873ce 100644
--- a/migration/multifd.c
+++ b/migration/multifd.c
@@ -439,6 +439,39 @@ static void multifd_send_set_error(Error *err)
     }
 }
 
+/*
+ * Gracefully shutdown IOChannels. Only needed for successful migrations on
+ * top of TLS channels.  Otherwise it is same to qio_channel_shutdown().
+ *
+ * A successful migration also guarantees multifd sender threads are
+ * properly flushed and halted.  It is only safe to send BYE in the
+ * migration thread here when we know there's no other thread writting to
+ * the channel, because GnuTLS doesn't support concurrent writers.
+ */
+static void migration_ioc_shutdown_gracefully(QIOChannel *ioc)
+{
+    g_autoptr(Error) local_err = NULL;
+
+    if (!migration_has_failed(migrate_get_current()) &&
+        object_dynamic_cast((Object *)ioc, TYPE_QIO_CHANNEL_TLS)) {
+
+        /*
+         * The destination expects the TLS session to always be properly
+         * terminated. This helps to detect a premature termination in the
+         * middle of the stream.  Note that older QEMUs always break the
+         * connection on the source and the destination always sees
+         * GNUTLS_E_PREMATURE_TERMINATION.
+         */
+        migration_tls_channel_end(ioc, &local_err);
+        if (local_err) {
+            warn_report("Failed to gracefully terminate TLS connection: %s",
+                        error_get_pretty(local_err));
+        }
+    }
+
+    qio_channel_shutdown(ioc, QIO_CHANNEL_SHUTDOWN_BOTH, NULL);
+}
+
 static void multifd_send_terminate_threads(void)
 {
     int i;
@@ -460,7 +493,7 @@ static void multifd_send_terminate_threads(void)
 
         qemu_sem_post(&p->sem);
         if (p->c) {
-            qio_channel_shutdown(p->c, QIO_CHANNEL_SHUTDOWN_BOTH, NULL);
+            migration_ioc_shutdown_gracefully(p->c);
         }
     }
 
@@ -547,36 +580,6 @@ void multifd_send_shutdown(void)
         return;
     }
 
-    for (i = 0; i < migrate_multifd_channels(); i++) {
-        MultiFDSendParams *p = &multifd_send_state->params[i];
-
-        /* thread_created implies the TLS handshake has succeeded */
-        if (p->tls_thread_created && p->thread_created) {
-            Error *local_err = NULL;
-            /*
-             * The destination expects the TLS session to always be
-             * properly terminated. This helps to detect a premature
-             * termination in the middle of the stream.  Note that
-             * older QEMUs always break the connection on the source
-             * and the destination always sees
-             * GNUTLS_E_PREMATURE_TERMINATION.
-             */
-            migration_tls_channel_end(p->c, &local_err);
-
-            /*
-             * The above can return an error in case the migration has
-             * already failed. If the migration succeeded, errors are
-             * not expected but there's no need to kill the source.
-             */
-            if (local_err && !migration_has_failed(migrate_get_current())) {
-                warn_report(
-                    "multifd_send_%d: Failed to terminate TLS connection: %s",
-                    p->id, error_get_pretty(local_err));
-                break;
-            }
-        }
-    }
-
     multifd_send_terminate_threads();
 
     for (i = 0; i < migrate_multifd_channels(); i++) {
diff --git a/migration/options.c b/migration/options.c
index 4e923a2..5183112 100644
--- a/migration/options.c
+++ b/migration/options.c
@@ -959,6 +959,9 @@ MigrationParameters *qmp_query_migrate_parameters(Error **errp)
     params->zero_page_detection = s->parameters.zero_page_detection;
     params->has_direct_io = true;
     params->direct_io = s->parameters.direct_io;
+    params->has_cpr_exec_command = true;
+    params->cpr_exec_command = QAPI_CLONE(strList,
+                                          s->parameters.cpr_exec_command);
 
     return params;
 }
@@ -993,6 +996,7 @@ void migrate_params_init(MigrationParameters *params)
     params->has_mode = true;
     params->has_zero_page_detection = true;
     params->has_direct_io = true;
+    params->has_cpr_exec_command = true;
 }
 
 /*
@@ -1297,6 +1301,10 @@ static void migrate_params_test_apply(MigrateSetParameters *params,
     if (params->has_direct_io) {
         dest->direct_io = params->direct_io;
     }
+
+    if (params->has_cpr_exec_command) {
+        dest->cpr_exec_command = params->cpr_exec_command;
+    }
 }
 
 static void migrate_params_apply(MigrateSetParameters *params, Error **errp)
@@ -1429,6 +1437,12 @@ static void migrate_params_apply(MigrateSetParameters *params, Error **errp)
     if (params->has_direct_io) {
         s->parameters.direct_io = params->direct_io;
     }
+
+    if (params->has_cpr_exec_command) {
+        qapi_free_strList(s->parameters.cpr_exec_command);
+        s->parameters.cpr_exec_command =
+            QAPI_CLONE(strList, params->cpr_exec_command);
+    }
 }
 
 void qmp_migrate_set_parameters(MigrateSetParameters *params, Error **errp)
diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c
index 0172172..5471efb 100644
--- a/migration/postcopy-ram.c
+++ b/migration/postcopy-ram.c
@@ -681,6 +681,7 @@ out:
  */
 static int init_range(RAMBlock *rb, void *opaque)
 {
+    Error **errp = opaque;
     const char *block_name = qemu_ram_get_idstr(rb);
     void *host_addr = qemu_ram_get_host_addr(rb);
     ram_addr_t offset = qemu_ram_get_offset(rb);
@@ -701,6 +702,8 @@ static int init_range(RAMBlock *rb, void *opaque)
      * (Precopy will just overwrite this data, so doesn't need the discard)
      */
     if (ram_discard_range(block_name, 0, length)) {
+        error_setg(errp, "failed to discard RAM block %s len=%zu",
+                   block_name, length);
         return -1;
     }
 
@@ -749,9 +752,9 @@ static int cleanup_range(RAMBlock *rb, void *opaque)
  * postcopy later; must be called prior to any precopy.
  * called from arch_init's similarly named ram_postcopy_incoming_init
  */
-int postcopy_ram_incoming_init(MigrationIncomingState *mis)
+int postcopy_ram_incoming_init(MigrationIncomingState *mis, Error **errp)
 {
-    if (foreach_not_ignored_block(init_range, NULL)) {
+    if (foreach_not_ignored_block(init_range, errp)) {
         return -1;
     }
 
@@ -1703,7 +1706,7 @@ bool postcopy_ram_supported_by_host(MigrationIncomingState *mis, Error **errp)
     return false;
 }
 
-int postcopy_ram_incoming_init(MigrationIncomingState *mis)
+int postcopy_ram_incoming_init(MigrationIncomingState *mis, Error **errp)
 {
     error_report("postcopy_ram_incoming_init: No OS support");
     return -1;
diff --git a/migration/postcopy-ram.h b/migration/postcopy-ram.h
index 3852141..ca19433 100644
--- a/migration/postcopy-ram.h
+++ b/migration/postcopy-ram.h
@@ -30,7 +30,7 @@ int postcopy_ram_incoming_setup(MigrationIncomingState *mis);
  * postcopy later; must be called prior to any precopy.
  * called from ram.c's similarly named ram_postcopy_incoming_init
  */
-int postcopy_ram_incoming_init(MigrationIncomingState *mis);
+int postcopy_ram_incoming_init(MigrationIncomingState *mis, Error **errp);
 
 /*
  * At the end of a migration where postcopy_ram_incoming_init was called.
diff --git a/migration/qemu-file.c b/migration/qemu-file.c
index 0f4280d..2d4ce17 100644
--- a/migration/qemu-file.c
+++ b/migration/qemu-file.c
@@ -125,7 +125,6 @@ static QEMUFile *qemu_file_new_impl(QIOChannel *ioc, bool is_writable)
 
 /*
  * Result: QEMUFile* for a 'return path' for comms in the opposite direction
- *         NULL if not available
  */
 QEMUFile *qemu_file_get_return_path(QEMUFile *f)
 {
@@ -349,17 +348,13 @@ static ssize_t coroutine_mixed_fn qemu_fill_buffer(QEMUFile *f)
             } else {
                 qio_channel_wait(f->ioc, G_IO_IN);
             }
-        } else if (len < 0) {
-            len = -EIO;
         }
     } while (len == QIO_CHANNEL_ERR_BLOCK);
 
     if (len > 0) {
         f->buf_size += len;
-    } else if (len == 0) {
-        qemu_file_set_error_obj(f, -EIO, local_error);
     } else {
-        qemu_file_set_error_obj(f, len, local_error);
+        qemu_file_set_error_obj(f, -EIO, local_error);
     }
 
     for (int i = 0; i < nfd; i++) {
diff --git a/migration/ram.c b/migration/ram.c
index 7208bc1..9aac896 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -228,6 +228,7 @@ bool migrate_ram_is_ignored(RAMBlock *block)
     MigMode mode = migrate_mode();
     return !qemu_ram_is_migratable(block) ||
            mode == MIG_MODE_CPR_TRANSFER ||
+           mode == MIG_MODE_CPR_EXEC ||
            (migrate_ignore_shared() && qemu_ram_is_shared(block)
                                     && qemu_ram_is_named_file(block));
 }
@@ -3575,8 +3576,10 @@ static void colo_init_ram_state(void)
  * colo cache: this is for secondary VM, we cache the whole
  * memory of the secondary VM, it is need to hold the global lock
  * to call this helper.
+ *
+ * Returns zero to indicate success or -1 on error.
  */
-int colo_init_ram_cache(void)
+int colo_init_ram_cache(Error **errp)
 {
     RAMBlock *block;
 
@@ -3585,16 +3588,16 @@ int colo_init_ram_cache(void)
             block->colo_cache = qemu_anon_ram_alloc(block->used_length,
                                                     NULL, false, false);
             if (!block->colo_cache) {
-                error_report("%s: Can't alloc memory for COLO cache of block %s,"
-                             "size 0x" RAM_ADDR_FMT, __func__, block->idstr,
-                             block->used_length);
+                error_setg(errp, "Can't alloc memory for COLO cache of "
+                           "block %s, size 0x" RAM_ADDR_FMT,
+                           block->idstr, block->used_length);
                 RAMBLOCK_FOREACH_NOT_IGNORED(block) {
                     if (block->colo_cache) {
                         qemu_anon_ram_free(block->colo_cache, block->used_length);
                         block->colo_cache = NULL;
                     }
                 }
-                return -errno;
+                return -1;
             }
             if (!machine_dump_guest_core(current_machine)) {
                 qemu_madvise(block->colo_cache, block->used_length,
@@ -3716,9 +3719,9 @@ static int ram_load_cleanup(void *opaque)
  * postcopy-ram. postcopy-ram's similarly names
  * postcopy_ram_incoming_init does the work.
  */
-int ram_postcopy_incoming_init(MigrationIncomingState *mis)
+int ram_postcopy_incoming_init(MigrationIncomingState *mis, Error **errp)
 {
-    return postcopy_ram_incoming_init(mis);
+    return postcopy_ram_incoming_init(mis, errp);
 }
 
 /**
diff --git a/migration/ram.h b/migration/ram.h
index 921c39a..24cd0bf 100644
--- a/migration/ram.h
+++ b/migration/ram.h
@@ -86,7 +86,7 @@ void ram_postcopy_migrated_memory_release(MigrationState *ms);
 void ram_postcopy_send_discard_bitmap(MigrationState *ms);
 /* For incoming postcopy discard */
 int ram_discard_range(const char *block_name, uint64_t start, size_t length);
-int ram_postcopy_incoming_init(MigrationIncomingState *mis);
+int ram_postcopy_incoming_init(MigrationIncomingState *mis, Error **errp);
 int ram_load_postcopy(QEMUFile *f, int channel);
 
 void ram_handle_zero(void *host, uint64_t size);
@@ -109,7 +109,7 @@ void ramblock_set_file_bmap_atomic(RAMBlock *block, ram_addr_t offset,
                                    bool set);
 
 /* ram cache */
-int colo_init_ram_cache(void);
+int colo_init_ram_cache(Error **errp);
 void colo_flush_ram_cache(void);
 void colo_release_ram_cache(void);
 void colo_incoming_start_dirty_log(void);
diff --git a/migration/savevm.c b/migration/savevm.c
index abe0547..7b35ec4 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -963,13 +963,20 @@ void vmstate_unregister(VMStateIf *obj, const VMStateDescription *vmsd,
     }
 }
 
-static int vmstate_load(QEMUFile *f, SaveStateEntry *se)
+static int vmstate_load(QEMUFile *f, SaveStateEntry *se, Error **errp)
 {
+    int ret;
     trace_vmstate_load(se->idstr, se->vmsd ? se->vmsd->name : "(old)");
     if (!se->vmsd) {         /* Old style */
-        return se->ops->load_state(f, se->opaque, se->load_version_id);
+        ret = se->ops->load_state(f, se->opaque, se->load_version_id);
+        if (ret < 0) {
+            error_setg(errp, "Failed to load vmstate version_id: %d, ret: %d",
+                       se->load_version_id, ret);
+        }
+        return ret;
     }
-    return vmstate_load_state(f, se->vmsd, se->opaque, se->load_version_id);
+    return vmstate_load_state(f, se->vmsd, se->opaque, se->load_version_id,
+                              errp);
 }
 
 static void vmstate_save_old_style(QEMUFile *f, SaveStateEntry *se,
@@ -1049,8 +1056,8 @@ static int vmstate_save(QEMUFile *f, SaveStateEntry *se, JSONWriter *vmdesc,
     if (!se->vmsd) {
         vmstate_save_old_style(f, se, vmdesc);
     } else {
-        ret = vmstate_save_state_with_err(f, se->vmsd, se->opaque, vmdesc,
-                                          errp);
+        ret = vmstate_save_state(f, se->vmsd, se->opaque, vmdesc,
+                                 errp);
         if (ret) {
             return ret;
         }
@@ -1278,6 +1285,7 @@ void qemu_savevm_state_header(QEMUFile *f)
 {
     MigrationState *s = migrate_get_current();
     JSONWriter *vmdesc = s->vmdesc;
+    Error *local_err = NULL;
 
     trace_savevm_state_header();
     qemu_put_be32(f, QEMU_VM_FILE_MAGIC);
@@ -1296,7 +1304,11 @@ void qemu_savevm_state_header(QEMUFile *f)
             json_writer_start_object(vmdesc, "configuration");
         }
 
-        vmstate_save_state(f, &vmstate_configuration, &savevm_state, vmdesc);
+        vmstate_save_state(f, &vmstate_configuration, &savevm_state,
+                           vmdesc, &local_err);
+        if (local_err) {
+            error_report_err(local_err);
+        }
 
         if (vmdesc) {
             json_writer_end_object(vmdesc);
@@ -1905,39 +1917,39 @@ enum LoadVMExitCodes {
  * quickly.
  */
 static int loadvm_postcopy_handle_advise(MigrationIncomingState *mis,
-                                         uint16_t len)
+                                         uint16_t len, Error **errp)
 {
     PostcopyState ps = postcopy_state_set(POSTCOPY_INCOMING_ADVISE);
     uint64_t remote_pagesize_summary, local_pagesize_summary, remote_tps;
     size_t page_size = qemu_target_page_size();
-    Error *local_err = NULL;
 
     trace_loadvm_postcopy_handle_advise();
     if (ps != POSTCOPY_INCOMING_NONE) {
-        error_report("CMD_POSTCOPY_ADVISE in wrong postcopy state (%d)", ps);
+        error_setg(errp, "CMD_POSTCOPY_ADVISE in wrong postcopy state (%d)",
+                   ps);
         return -1;
     }
 
     switch (len) {
     case 0:
         if (migrate_postcopy_ram()) {
-            error_report("RAM postcopy is enabled but have 0 byte advise");
+            error_setg(errp, "RAM postcopy is enabled but have 0 byte advise");
             return -EINVAL;
         }
         return 0;
     case 8 + 8:
         if (!migrate_postcopy_ram()) {
-            error_report("RAM postcopy is disabled but have 16 byte advise");
+            error_setg(errp,
+                       "RAM postcopy is disabled but have 16 byte advise");
             return -EINVAL;
         }
         break;
     default:
-        error_report("CMD_POSTCOPY_ADVISE invalid length (%d)", len);
+        error_setg(errp, "CMD_POSTCOPY_ADVISE invalid length (%d)", len);
         return -EINVAL;
     }
 
-    if (!postcopy_ram_supported_by_host(mis, &local_err)) {
-        error_report_err(local_err);
+    if (!postcopy_ram_supported_by_host(mis, errp)) {
         postcopy_state_set(POSTCOPY_INCOMING_NONE);
         return -1;
     }
@@ -1960,9 +1972,10 @@ static int loadvm_postcopy_handle_advise(MigrationIncomingState *mis,
          *      also fails when passed to an older qemu that doesn't
          *      do huge pages.
          */
-        error_report("Postcopy needs matching RAM page sizes (s=%" PRIx64
-                                                             " d=%" PRIx64 ")",
-                     remote_pagesize_summary, local_pagesize_summary);
+        error_setg(errp,
+                   "Postcopy needs matching RAM page sizes "
+                   "(s=%" PRIx64 " d=%" PRIx64 ")",
+                   remote_pagesize_summary, local_pagesize_summary);
         return -1;
     }
 
@@ -1972,17 +1985,18 @@ static int loadvm_postcopy_handle_advise(MigrationIncomingState *mis,
          * Again, some differences could be dealt with, but for now keep it
          * simple.
          */
-        error_report("Postcopy needs matching target page sizes (s=%d d=%zd)",
-                     (int)remote_tps, page_size);
+        error_setg(errp,
+                   "Postcopy needs matching target page sizes (s=%d d=%zd)",
+                   (int)remote_tps, page_size);
         return -1;
     }
 
-    if (postcopy_notify(POSTCOPY_NOTIFY_INBOUND_ADVISE, &local_err)) {
-        error_report_err(local_err);
+    if (postcopy_notify(POSTCOPY_NOTIFY_INBOUND_ADVISE, errp)) {
         return -1;
     }
 
-    if (ram_postcopy_incoming_init(mis)) {
+    if (ram_postcopy_incoming_init(mis, errp) < 0) {
+        error_prepend(errp, "Postcopy RAM incoming init failed: ");
         return -1;
     }
 
@@ -1995,7 +2009,7 @@ static int loadvm_postcopy_handle_advise(MigrationIncomingState *mis,
  * There can be 0..many of these messages, each encoding multiple pages.
  */
 static int loadvm_postcopy_ram_handle_discard(MigrationIncomingState *mis,
-                                              uint16_t len)
+                                              uint16_t len, Error **errp)
 {
     int tmp;
     char ramid[256];
@@ -2008,6 +2022,7 @@ static int loadvm_postcopy_ram_handle_discard(MigrationIncomingState *mis,
         /* 1st discard */
         tmp = postcopy_ram_prepare_discard(mis);
         if (tmp) {
+            error_setg(errp, "Failed to prepare for RAM discard: %d", tmp);
             return tmp;
         }
         break;
@@ -2017,8 +2032,9 @@ static int loadvm_postcopy_ram_handle_discard(MigrationIncomingState *mis,
         break;
 
     default:
-        error_report("CMD_POSTCOPY_RAM_DISCARD in wrong postcopy state (%d)",
-                     ps);
+        error_setg(errp,
+                   "CMD_POSTCOPY_RAM_DISCARD in wrong postcopy state (%d)",
+                   ps);
         return -1;
     }
     /* We're expecting a
@@ -2027,29 +2043,30 @@ static int loadvm_postcopy_ram_handle_discard(MigrationIncomingState *mis,
      *    then at least 1 16 byte chunk
     */
     if (len < (1 + 1 + 1 + 1 + 2 * 8)) {
-        error_report("CMD_POSTCOPY_RAM_DISCARD invalid length (%d)", len);
+        error_setg(errp, "CMD_POSTCOPY_RAM_DISCARD invalid length (%d)", len);
         return -1;
     }
 
     tmp = qemu_get_byte(mis->from_src_file);
     if (tmp != postcopy_ram_discard_version) {
-        error_report("CMD_POSTCOPY_RAM_DISCARD invalid version (%d)", tmp);
+        error_setg(errp, "CMD_POSTCOPY_RAM_DISCARD invalid version (%d)", tmp);
         return -1;
     }
 
     if (!qemu_get_counted_string(mis->from_src_file, ramid)) {
-        error_report("CMD_POSTCOPY_RAM_DISCARD Failed to read RAMBlock ID");
+        error_setg(errp,
+                   "CMD_POSTCOPY_RAM_DISCARD Failed to read RAMBlock ID");
         return -1;
     }
     tmp = qemu_get_byte(mis->from_src_file);
     if (tmp != 0) {
-        error_report("CMD_POSTCOPY_RAM_DISCARD missing nil (%d)", tmp);
+        error_setg(errp, "CMD_POSTCOPY_RAM_DISCARD missing nil (%d)", tmp);
         return -1;
     }
 
     len -= 3 + strlen(ramid);
     if (len % 16) {
-        error_report("CMD_POSTCOPY_RAM_DISCARD invalid length (%d)", len);
+        error_setg(errp, "CMD_POSTCOPY_RAM_DISCARD invalid length (%d)", len);
         return -1;
     }
     trace_loadvm_postcopy_ram_handle_discard_header(ramid, len);
@@ -2061,6 +2078,7 @@ static int loadvm_postcopy_ram_handle_discard(MigrationIncomingState *mis,
         len -= 16;
         int ret = ram_discard_range(ramid, start_addr, block_length);
         if (ret) {
+            error_setg(errp, "Failed to discard RAM range %s: %d", ramid, ret);
             return ret;
         }
     }
@@ -2082,6 +2100,7 @@ static void *postcopy_ram_listen_thread(void *opaque)
     QEMUFile *f = mis->from_src_file;
     int load_res;
     MigrationState *migr = migrate_get_current();
+    Error *local_err = NULL;
 
     object_ref(OBJECT(migr));
 
@@ -2098,7 +2117,7 @@ static void *postcopy_ram_listen_thread(void *opaque)
     qemu_file_set_blocking(f, true, &error_fatal);
 
     /* TODO: sanity check that only postcopiable data will be loaded here */
-    load_res = qemu_loadvm_state_main(f, mis);
+    load_res = qemu_loadvm_state_main(f, mis, &local_err);
 
     /*
      * This is tricky, but, mis->from_src_file can change after it
@@ -2124,7 +2143,10 @@ static void *postcopy_ram_listen_thread(void *opaque)
                          __func__, load_res);
             load_res = 0; /* prevent further exit() */
         } else {
-            error_report("%s: loadvm failed: %d", __func__, load_res);
+            error_prepend(&local_err,
+                          "loadvm failed during postcopy: %d: ", load_res);
+            migrate_set_error(migr, local_err);
+            error_report_err(local_err);
             migrate_set_state(&mis->state, MIGRATION_STATUS_POSTCOPY_ACTIVE,
                                            MIGRATION_STATUS_FAILED);
         }
@@ -2172,15 +2194,16 @@ static void *postcopy_ram_listen_thread(void *opaque)
 }
 
 /* After this message we must be able to immediately receive postcopy data */
-static int loadvm_postcopy_handle_listen(MigrationIncomingState *mis)
+static int loadvm_postcopy_handle_listen(MigrationIncomingState *mis,
+                                         Error **errp)
 {
     PostcopyState ps = postcopy_state_set(POSTCOPY_INCOMING_LISTENING);
-    Error *local_err = NULL;
 
     trace_loadvm_postcopy_handle_listen("enter");
 
     if (ps != POSTCOPY_INCOMING_ADVISE && ps != POSTCOPY_INCOMING_DISCARD) {
-        error_report("CMD_POSTCOPY_LISTEN in wrong postcopy state (%d)", ps);
+        error_setg(errp,
+                   "CMD_POSTCOPY_LISTEN in wrong postcopy state (%d)", ps);
         return -1;
     }
     if (ps == POSTCOPY_INCOMING_ADVISE) {
@@ -2203,14 +2226,14 @@ static int loadvm_postcopy_handle_listen(MigrationIncomingState *mis)
     if (migrate_postcopy_ram()) {
         if (postcopy_ram_incoming_setup(mis)) {
             postcopy_ram_incoming_cleanup(mis);
+            error_setg(errp, "Failed to setup incoming postcopy RAM blocks");
             return -1;
         }
     }
 
     trace_loadvm_postcopy_handle_listen("after uffd");
 
-    if (postcopy_notify(POSTCOPY_NOTIFY_INBOUND_LISTEN, &local_err)) {
-        error_report_err(local_err);
+    if (postcopy_notify(POSTCOPY_NOTIFY_INBOUND_LISTEN, errp)) {
         return -1;
     }
 
@@ -2263,13 +2286,13 @@ static void loadvm_postcopy_handle_run_bh(void *opaque)
 }
 
 /* After all discards we can start running and asking for pages */
-static int loadvm_postcopy_handle_run(MigrationIncomingState *mis)
+static int loadvm_postcopy_handle_run(MigrationIncomingState *mis, Error **errp)
 {
     PostcopyState ps = postcopy_state_get();
 
     trace_loadvm_postcopy_handle_run();
     if (ps != POSTCOPY_INCOMING_LISTENING) {
-        error_report("CMD_POSTCOPY_RUN in wrong postcopy state (%d)", ps);
+        error_setg(errp, "CMD_POSTCOPY_RUN in wrong postcopy state (%d)", ps);
         return -1;
     }
 
@@ -2327,12 +2350,12 @@ static void migrate_send_rp_req_pages_pending(MigrationIncomingState *mis)
     }
 }
 
-static int loadvm_postcopy_handle_resume(MigrationIncomingState *mis)
+static void loadvm_postcopy_handle_resume(MigrationIncomingState *mis)
 {
     if (mis->state != MIGRATION_STATUS_POSTCOPY_RECOVER) {
-        error_report("%s: illegal resume received", __func__);
+        warn_report("%s: illegal resume received", __func__);
         /* Don't fail the load, only for this. */
-        return 0;
+        return;
     }
 
     /*
@@ -2384,8 +2407,6 @@ static int loadvm_postcopy_handle_resume(MigrationIncomingState *mis)
         /* Kick the fast ram load thread too */
         qemu_sem_post(&mis->postcopy_pause_sem_fast_load);
     }
-
-    return 0;
 }
 
 /**
@@ -2398,7 +2419,7 @@ static int loadvm_postcopy_handle_resume(MigrationIncomingState *mis)
  * Returns: Negative values on error
  *
  */
-static int loadvm_handle_cmd_packaged(MigrationIncomingState *mis)
+static int loadvm_handle_cmd_packaged(MigrationIncomingState *mis, Error **errp)
 {
     int ret;
     size_t length;
@@ -2408,7 +2429,7 @@ static int loadvm_handle_cmd_packaged(MigrationIncomingState *mis)
     trace_loadvm_handle_cmd_packaged(length);
 
     if (length > MAX_VM_CMD_PACKAGED_SIZE) {
-        error_report("Unreasonably large packaged state: %zu", length);
+        error_setg(errp, "Unreasonably large packaged state: %zu", length);
         return -1;
     }
 
@@ -2419,8 +2440,8 @@ static int loadvm_handle_cmd_packaged(MigrationIncomingState *mis)
                           length);
     if (ret != length) {
         object_unref(OBJECT(bioc));
-        error_report("CMD_PACKAGED: Buffer receive fail ret=%d length=%zu",
-                     ret, length);
+        error_setg(errp, "CMD_PACKAGED: Buffer receive fail ret=%d length=%zu",
+                   ret, length);
         return (ret < 0) ? ret : -EAGAIN;
     }
     bioc->usage += length;
@@ -2449,7 +2470,7 @@ static int loadvm_handle_cmd_packaged(MigrationIncomingState *mis)
         qemu_coroutine_yield();
     } while (1);
 
-    ret = qemu_loadvm_state_main(packf, mis);
+    ret = qemu_loadvm_state_main(packf, mis, errp);
     trace_loadvm_handle_cmd_packaged_main(ret);
     qemu_fclose(packf);
     object_unref(OBJECT(bioc));
@@ -2464,32 +2485,35 @@ static int loadvm_handle_cmd_packaged(MigrationIncomingState *mis)
  * len (1 byte) + ramblock_name (<255 bytes)
  */
 static int loadvm_handle_recv_bitmap(MigrationIncomingState *mis,
-                                     uint16_t len)
+                                     uint16_t len, Error **errp)
 {
     QEMUFile *file = mis->from_src_file;
     RAMBlock *rb;
     char block_name[256];
     size_t cnt;
+    int ret;
 
     cnt = qemu_get_counted_string(file, block_name);
     if (!cnt) {
-        error_report("%s: failed to read block name", __func__);
+        error_setg(errp, "failed to read block name");
         return -EINVAL;
     }
 
     /* Validate before using the data */
-    if (qemu_file_get_error(file)) {
-        return qemu_file_get_error(file);
+    ret = qemu_file_get_error(file);
+    if (ret < 0) {
+        error_setg(errp, "loadvm failed: stream error: %d", ret);
+        return ret;
     }
 
     if (len != cnt + 1) {
-        error_report("%s: invalid payload length (%d)", __func__, len);
+        error_setg(errp, "invalid payload length (%d)", len);
         return -EINVAL;
     }
 
     rb = qemu_ram_block_by_name(block_name);
     if (!rb) {
-        error_report("%s: block '%s' not found", __func__, block_name);
+        error_setg(errp, "block '%s' not found", block_name);
         return -EINVAL;
     }
 
@@ -2500,20 +2524,26 @@ static int loadvm_handle_recv_bitmap(MigrationIncomingState *mis,
     return 0;
 }
 
-static int loadvm_process_enable_colo(MigrationIncomingState *mis)
+static int loadvm_process_enable_colo(MigrationIncomingState *mis,
+                                      Error **errp)
 {
-    int ret = migration_incoming_enable_colo();
+    ERRP_GUARD();
+    int ret;
 
-    if (!ret) {
-        ret = colo_init_ram_cache();
-        if (ret) {
-            migration_incoming_disable_colo();
-        }
+    ret = migration_incoming_enable_colo(errp);
+    if (ret < 0) {
+        return ret;
+    }
+
+    ret = colo_init_ram_cache(errp);
+    if (ret) {
+        error_prepend(errp, "failed to init colo RAM cache: %d: ", ret);
+        migration_incoming_disable_colo();
     }
     return ret;
 }
 
-static int loadvm_postcopy_handle_switchover_start(void)
+static int loadvm_postcopy_handle_switchover_start(Error **errp)
 {
     SaveStateEntry *se;
 
@@ -2526,6 +2556,7 @@ static int loadvm_postcopy_handle_switchover_start(void)
 
         ret = se->ops->switchover_start(se->opaque);
         if (ret < 0) {
+            error_setg(errp, "Switchover start failed: %d", ret);
             return ret;
         }
     }
@@ -2539,32 +2570,37 @@ static int loadvm_postcopy_handle_switchover_start(void)
  * LOADVM_QUIT All good, but exit the loop
  * <0          Error
  */
-static int loadvm_process_command(QEMUFile *f)
+static int loadvm_process_command(QEMUFile *f, Error **errp)
 {
     MigrationIncomingState *mis = migration_incoming_get_current();
     uint16_t cmd;
     uint16_t len;
     uint32_t tmp32;
+    int ret;
 
     cmd = qemu_get_be16(f);
     len = qemu_get_be16(f);
 
     /* Check validity before continue processing of cmds */
-    if (qemu_file_get_error(f)) {
-        return qemu_file_get_error(f);
+    ret = qemu_file_get_error(f);
+    if (ret) {
+        error_setg(errp,
+                   "Failed to load VM process command: stream error: %d",
+                   ret);
+        return ret;
     }
 
     if (cmd >= MIG_CMD_MAX || cmd == MIG_CMD_INVALID) {
-        error_report("MIG_CMD 0x%x unknown (len 0x%x)", cmd, len);
+        error_setg(errp, "MIG_CMD 0x%x unknown (len 0x%x)", cmd, len);
         return -EINVAL;
     }
 
     trace_loadvm_process_command(mig_cmd_args[cmd].name, len);
 
     if (mig_cmd_args[cmd].len != -1 && mig_cmd_args[cmd].len != len) {
-        error_report("%s received with bad length - expecting %zu, got %d",
-                     mig_cmd_args[cmd].name,
-                     (size_t)mig_cmd_args[cmd].len, len);
+        error_setg(errp, "%s received with bad length - expecting %zu, got %d",
+                   mig_cmd_args[cmd].name,
+                   (size_t)mig_cmd_args[cmd].len, len);
         return -ERANGE;
     }
 
@@ -2576,10 +2612,6 @@ static int loadvm_process_command(QEMUFile *f)
             return 0;
         }
         mis->to_src_file = qemu_file_get_return_path(f);
-        if (!mis->to_src_file) {
-            error_report("CMD_OPEN_RETURN_PATH failed");
-            return -1;
-        }
 
         /*
          * Switchover ack is enabled but no device uses it, so send an ACK to
@@ -2587,11 +2619,10 @@ static int loadvm_process_command(QEMUFile *f)
          * been created.
          */
         if (migrate_switchover_ack() && !mis->switchover_ack_pending_num) {
-            int ret = migrate_send_rp_switchover_ack(mis);
+            ret = migrate_send_rp_switchover_ack(mis);
             if (ret) {
-                error_report(
-                    "Could not send switchover ack RP MSG, err %d (%s)", ret,
-                    strerror(-ret));
+                error_setg_errno(errp, -ret,
+                                 "Could not send switchover ack RP MSG");
                 return ret;
             }
         }
@@ -2601,39 +2632,40 @@ static int loadvm_process_command(QEMUFile *f)
         tmp32 = qemu_get_be32(f);
         trace_loadvm_process_command_ping(tmp32);
         if (!mis->to_src_file) {
-            error_report("CMD_PING (0x%x) received with no return path",
-                         tmp32);
+            error_setg(errp, "CMD_PING (0x%x) received with no return path",
+                       tmp32);
             return -1;
         }
         migrate_send_rp_pong(mis, tmp32);
         break;
 
     case MIG_CMD_PACKAGED:
-        return loadvm_handle_cmd_packaged(mis);
+        return loadvm_handle_cmd_packaged(mis, errp);
 
     case MIG_CMD_POSTCOPY_ADVISE:
-        return loadvm_postcopy_handle_advise(mis, len);
+        return loadvm_postcopy_handle_advise(mis, len, errp);
 
     case MIG_CMD_POSTCOPY_LISTEN:
-        return loadvm_postcopy_handle_listen(mis);
+        return loadvm_postcopy_handle_listen(mis, errp);
 
     case MIG_CMD_POSTCOPY_RUN:
-        return loadvm_postcopy_handle_run(mis);
+        return loadvm_postcopy_handle_run(mis, errp);
 
     case MIG_CMD_POSTCOPY_RAM_DISCARD:
-        return loadvm_postcopy_ram_handle_discard(mis, len);
+        return loadvm_postcopy_ram_handle_discard(mis, len, errp);
 
     case MIG_CMD_POSTCOPY_RESUME:
-        return loadvm_postcopy_handle_resume(mis);
+        loadvm_postcopy_handle_resume(mis);
+        return 0;
 
     case MIG_CMD_RECV_BITMAP:
-        return loadvm_handle_recv_bitmap(mis, len);
+        return loadvm_handle_recv_bitmap(mis, len, errp);
 
     case MIG_CMD_ENABLE_COLO:
-        return loadvm_process_enable_colo(mis);
+        return loadvm_process_enable_colo(mis, errp);
 
     case MIG_CMD_SWITCHOVER_START:
-        return loadvm_postcopy_handle_switchover_start();
+        return loadvm_postcopy_handle_switchover_start(errp);
     }
 
     return 0;
@@ -2683,8 +2715,9 @@ static bool check_section_footer(QEMUFile *f, SaveStateEntry *se)
 }
 
 static int
-qemu_loadvm_section_start_full(QEMUFile *f, uint8_t type)
+qemu_loadvm_section_start_full(QEMUFile *f, uint8_t type, Error **errp)
 {
+    ERRP_GUARD();
     bool trace_downtime = (type == QEMU_VM_SECTION_FULL);
     uint32_t instance_id, version_id, section_id;
     int64_t start_ts, end_ts;
@@ -2695,8 +2728,8 @@ qemu_loadvm_section_start_full(QEMUFile *f, uint8_t type)
     /* Read section start */
     section_id = qemu_get_be32(f);
     if (!qemu_get_counted_string(f, idstr)) {
-        error_report("Unable to read ID string for section %u",
-                     section_id);
+        error_setg(errp, "Unable to read ID string for section %u",
+                   section_id);
         return -EINVAL;
     }
     instance_id = qemu_get_be32(f);
@@ -2704,8 +2737,7 @@ qemu_loadvm_section_start_full(QEMUFile *f, uint8_t type)
 
     ret = qemu_file_get_error(f);
     if (ret) {
-        error_report("%s: Failed to read instance/version ID: %d",
-                     __func__, ret);
+        error_setg(errp, "Failed to read instance/version ID: %d", ret);
         return ret;
     }
 
@@ -2714,17 +2746,17 @@ qemu_loadvm_section_start_full(QEMUFile *f, uint8_t type)
     /* Find savevm section */
     se = find_se(idstr, instance_id);
     if (se == NULL) {
-        error_report("Unknown savevm section or instance '%s' %"PRIu32". "
-                     "Make sure that your current VM setup matches your "
-                     "saved VM setup, including any hotplugged devices",
-                     idstr, instance_id);
+        error_setg(errp, "Unknown section or instance '%s' %"PRIu32". "
+                   "Make sure that your current VM setup matches your "
+                   "saved VM setup, including any hotplugged devices",
+                   idstr, instance_id);
         return -EINVAL;
     }
 
     /* Validate version */
     if (version_id > se->version_id) {
-        error_report("savevm: unsupported version %d for '%s' v%d",
-                     version_id, idstr, se->version_id);
+        error_setg(errp, "unsupported version %d for '%s' v%d",
+                   version_id, idstr, se->version_id);
         return -EINVAL;
     }
     se->load_version_id = version_id;
@@ -2732,7 +2764,7 @@ qemu_loadvm_section_start_full(QEMUFile *f, uint8_t type)
 
     /* Validate if it is a device's state */
     if (xen_enabled() && se->is_ram) {
-        error_report("loadvm: %s RAM loading not allowed on Xen", idstr);
+        error_setg(errp, "loadvm: %s RAM loading not allowed on Xen", idstr);
         return -EINVAL;
     }
 
@@ -2740,10 +2772,11 @@ qemu_loadvm_section_start_full(QEMUFile *f, uint8_t type)
         start_ts = qemu_clock_get_us(QEMU_CLOCK_REALTIME);
     }
 
-    ret = vmstate_load(f, se);
+    ret = vmstate_load(f, se, errp);
     if (ret < 0) {
-        error_report("error while loading state for instance 0x%"PRIx32" of"
-                     " device '%s'", instance_id, idstr);
+        error_prepend(errp,
+                      "error while loading state for instance 0x%"PRIx32" of"
+                      " device '%s': ", instance_id, idstr);
         return ret;
     }
 
@@ -2754,6 +2787,8 @@ qemu_loadvm_section_start_full(QEMUFile *f, uint8_t type)
     }
 
     if (!check_section_footer(f, se)) {
+        error_setg(errp, "Section footer error, section_id: %d",
+                   section_id);
         return -EINVAL;
     }
 
@@ -2761,7 +2796,7 @@ qemu_loadvm_section_start_full(QEMUFile *f, uint8_t type)
 }
 
 static int
-qemu_loadvm_section_part_end(QEMUFile *f, uint8_t type)
+qemu_loadvm_section_part_end(QEMUFile *f, uint8_t type, Error **errp)
 {
     bool trace_downtime = (type == QEMU_VM_SECTION_END);
     int64_t start_ts, end_ts;
@@ -2773,8 +2808,7 @@ qemu_loadvm_section_part_end(QEMUFile *f, uint8_t type)
 
     ret = qemu_file_get_error(f);
     if (ret) {
-        error_report("%s: Failed to read section ID: %d",
-                     __func__, ret);
+        error_setg(errp, "Failed to read section ID: %d", ret);
         return ret;
     }
 
@@ -2785,7 +2819,7 @@ qemu_loadvm_section_part_end(QEMUFile *f, uint8_t type)
         }
     }
     if (se == NULL) {
-        error_report("Unknown savevm section %d", section_id);
+        error_setg(errp, "Unknown section %d", section_id);
         return -EINVAL;
     }
 
@@ -2793,10 +2827,8 @@ qemu_loadvm_section_part_end(QEMUFile *f, uint8_t type)
         start_ts = qemu_clock_get_us(QEMU_CLOCK_REALTIME);
     }
 
-    ret = vmstate_load(f, se);
+    ret = vmstate_load(f, se, errp);
     if (ret < 0) {
-        error_report("error while loading state section id %d(%s)",
-                     section_id, se->idstr);
         return ret;
     }
 
@@ -2807,40 +2839,50 @@ qemu_loadvm_section_part_end(QEMUFile *f, uint8_t type)
     }
 
     if (!check_section_footer(f, se)) {
+        error_setg(errp, "Section footer error, section_id: %d",
+                   section_id);
         return -EINVAL;
     }
 
     return 0;
 }
 
-static int qemu_loadvm_state_header(QEMUFile *f)
+static int qemu_loadvm_state_header(QEMUFile *f, Error **errp)
 {
     unsigned int v;
     int ret;
 
     v = qemu_get_be32(f);
     if (v != QEMU_VM_FILE_MAGIC) {
-        error_report("Not a migration stream");
+        error_setg(errp, "Not a migration stream, magic: %x != %x",
+                   v, QEMU_VM_FILE_MAGIC);
         return -EINVAL;
     }
 
     v = qemu_get_be32(f);
     if (v == QEMU_VM_FILE_VERSION_COMPAT) {
-        error_report("SaveVM v2 format is obsolete and don't work anymore");
+        error_setg(errp,
+                   "SaveVM v2 format is obsolete and no longer supported");
+
         return -ENOTSUP;
     }
     if (v != QEMU_VM_FILE_VERSION) {
-        error_report("Unsupported migration stream version");
+        error_setg(errp, "Unsupported migration stream version, "
+                   "file version %x != %x",
+                   v, QEMU_VM_FILE_VERSION);
         return -ENOTSUP;
     }
 
     if (migrate_get_current()->send_configuration) {
-        if (qemu_get_byte(f) != QEMU_VM_CONFIGURATION) {
-            error_report("Configuration section missing");
+        v = qemu_get_byte(f);
+        if (v != QEMU_VM_CONFIGURATION) {
+            error_setg(errp, "Configuration section missing, %x != %x",
+                       v, QEMU_VM_CONFIGURATION);
             return -EINVAL;
         }
-        ret = vmstate_load_state(f, &vmstate_configuration, &savevm_state, 0);
 
+        ret = vmstate_load_state(f, &vmstate_configuration, &savevm_state, 0,
+                                 errp);
         if (ret) {
             return ret;
         }
@@ -3028,8 +3070,10 @@ static bool postcopy_pause_incoming(MigrationIncomingState *mis)
     return true;
 }
 
-int qemu_loadvm_state_main(QEMUFile *f, MigrationIncomingState *mis)
+int qemu_loadvm_state_main(QEMUFile *f, MigrationIncomingState *mis,
+                           Error **errp)
 {
+    ERRP_GUARD();
     uint8_t section_type;
     int ret = 0;
 
@@ -3037,8 +3081,11 @@ retry:
     while (true) {
         section_type = qemu_get_byte(f);
 
-        ret = qemu_file_get_error_obj_any(f, mis->postcopy_qemufile_dst, NULL);
+        ret = qemu_file_get_error_obj_any(f, mis->postcopy_qemufile_dst, errp);
         if (ret) {
+            error_prepend(errp,
+                          "Failed to load section ID: stream error: %d: ",
+                          ret);
             break;
         }
 
@@ -3046,20 +3093,20 @@ retry:
         switch (section_type) {
         case QEMU_VM_SECTION_START:
         case QEMU_VM_SECTION_FULL:
-            ret = qemu_loadvm_section_start_full(f, section_type);
+            ret = qemu_loadvm_section_start_full(f, section_type, errp);
             if (ret < 0) {
                 goto out;
             }
             break;
         case QEMU_VM_SECTION_PART:
         case QEMU_VM_SECTION_END:
-            ret = qemu_loadvm_section_part_end(f, section_type);
+            ret = qemu_loadvm_section_part_end(f, section_type, errp);
             if (ret < 0) {
                 goto out;
             }
             break;
         case QEMU_VM_COMMAND:
-            ret = loadvm_process_command(f);
+            ret = loadvm_process_command(f, errp);
             trace_qemu_loadvm_state_section_command(ret);
             if ((ret < 0) || (ret == LOADVM_QUIT)) {
                 goto out;
@@ -3069,7 +3116,7 @@ retry:
             /* This is the end of migration */
             goto out;
         default:
-            error_report("Unknown savevm section type %d", section_type);
+            error_setg(errp, "Unknown section type %d", section_type);
             ret = -EINVAL;
             goto out;
         }
@@ -3097,33 +3144,31 @@ out:
             migrate_postcopy_ram() && postcopy_pause_incoming(mis)) {
             /* Reset f to point to the newly created channel */
             f = mis->from_src_file;
+            error_free_or_abort(errp);
             goto retry;
         }
     }
     return ret;
 }
 
-int qemu_loadvm_state(QEMUFile *f)
+int qemu_loadvm_state(QEMUFile *f, Error **errp)
 {
     MigrationState *s = migrate_get_current();
     MigrationIncomingState *mis = migration_incoming_get_current();
-    Error *local_err = NULL;
     int ret;
 
-    if (qemu_savevm_state_blocked(&local_err)) {
-        error_report_err(local_err);
+    if (qemu_savevm_state_blocked(errp)) {
         return -EINVAL;
     }
 
     qemu_loadvm_thread_pool_create(mis);
 
-    ret = qemu_loadvm_state_header(f);
+    ret = qemu_loadvm_state_header(f, errp);
     if (ret) {
         return ret;
     }
 
-    if (qemu_loadvm_state_setup(f, &local_err) != 0) {
-        error_report_err(local_err);
+    if (qemu_loadvm_state_setup(f, errp) != 0) {
         return -EINVAL;
     }
 
@@ -3133,7 +3178,7 @@ int qemu_loadvm_state(QEMUFile *f)
 
     cpu_synchronize_all_pre_loadvm();
 
-    ret = qemu_loadvm_state_main(f, mis);
+    ret = qemu_loadvm_state_main(f, mis, errp);
     qemu_event_set(&mis->main_thread_load_event);
 
     trace_qemu_loadvm_state_post_main(ret);
@@ -3151,8 +3196,15 @@ int qemu_loadvm_state(QEMUFile *f)
         if (migrate_has_error(migrate_get_current()) ||
             !qemu_loadvm_thread_pool_wait(s, mis)) {
             ret = -EINVAL;
+            error_setg(errp,
+                       "Error while loading vmstate");
         } else {
             ret = qemu_file_get_error(f);
+            if (ret < 0) {
+                error_setg(errp,
+                           "Error while loading vmstate: stream error: %d",
+                           ret);
+            }
         }
     }
     /*
@@ -3201,15 +3253,14 @@ int qemu_loadvm_state(QEMUFile *f)
     return ret;
 }
 
-int qemu_load_device_state(QEMUFile *f)
+int qemu_load_device_state(QEMUFile *f, Error **errp)
 {
     MigrationIncomingState *mis = migration_incoming_get_current();
     int ret;
 
     /* Load QEMU_VM_SECTION_FULL section */
-    ret = qemu_loadvm_state_main(f, mis);
+    ret = qemu_loadvm_state_main(f, mis, errp);
     if (ret < 0) {
-        error_report("Failed to load device state: %d", ret);
         return ret;
     }
 
@@ -3417,6 +3468,7 @@ void qmp_xen_save_devices_state(const char *filename, bool has_live, bool live,
 
 void qmp_xen_load_devices_state(const char *filename, Error **errp)
 {
+    ERRP_GUARD();
     QEMUFile *f;
     QIOChannelFile *ioc;
     int ret;
@@ -3438,10 +3490,10 @@ void qmp_xen_load_devices_state(const char *filename, Error **errp)
     f = qemu_file_new_input(QIO_CHANNEL(ioc));
     object_unref(OBJECT(ioc));
 
-    ret = qemu_loadvm_state(f);
+    ret = qemu_loadvm_state(f, errp);
     qemu_fclose(f);
     if (ret < 0) {
-        error_setg(errp, "loading Xen device state failed");
+        error_prepend(errp, "loading Xen device state failed: ");
     }
     migration_incoming_state_destroy();
 }
@@ -3512,13 +3564,12 @@ bool load_snapshot(const char *name, const char *vmstate,
         ret = -EINVAL;
         goto err_drain;
     }
-    ret = qemu_loadvm_state(f);
+    ret = qemu_loadvm_state(f, errp);
     migration_incoming_state_destroy();
 
     bdrv_drain_all_end();
 
     if (ret < 0) {
-        error_setg(errp, "Error %d while loading VM state", ret);
         return false;
     }
 
diff --git a/migration/savevm.h b/migration/savevm.h
index 2d5e9c7..c337e3e 100644
--- a/migration/savevm.h
+++ b/migration/savevm.h
@@ -64,10 +64,11 @@ void qemu_savevm_send_colo_enable(QEMUFile *f);
 void qemu_savevm_live_state(QEMUFile *f);
 int qemu_save_device_state(QEMUFile *f);
 
-int qemu_loadvm_state(QEMUFile *f);
+int qemu_loadvm_state(QEMUFile *f, Error **errp);
 void qemu_loadvm_state_cleanup(MigrationIncomingState *mis);
-int qemu_loadvm_state_main(QEMUFile *f, MigrationIncomingState *mis);
-int qemu_load_device_state(QEMUFile *f);
+int qemu_loadvm_state_main(QEMUFile *f, MigrationIncomingState *mis,
+                           Error **errp);
+int qemu_load_device_state(QEMUFile *f, Error **errp);
 int qemu_loadvm_approve_switchover(void);
 int qemu_savevm_state_complete_precopy_non_iterable(QEMUFile *f,
         bool in_postcopy);
diff --git a/migration/trace-events b/migration/trace-events
index 706db97..e8edd1f 100644
--- a/migration/trace-events
+++ b/migration/trace-events
@@ -354,6 +354,7 @@ cpr_state_save(const char *mode) "%s mode"
 cpr_state_load(const char *mode) "%s mode"
 cpr_transfer_input(const char *path) "%s"
 cpr_transfer_output(const char *path) "%s"
+cpr_exec(void) ""
 
 # block-dirty-bitmap.c
 send_bitmap_header_enter(void) ""
diff --git a/migration/vmstate-types.c b/migration/vmstate-types.c
index 741a588..4b01dc1 100644
--- a/migration/vmstate-types.c
+++ b/migration/vmstate-types.c
@@ -19,6 +19,7 @@
 #include "qemu/error-report.h"
 #include "qemu/queue.h"
 #include "trace.h"
+#include "qapi/error.h"
 
 /* bool */
 
@@ -321,6 +322,10 @@ static int get_fd(QEMUFile *f, void *pv, size_t size,
                   const VMStateField *field)
 {
     int32_t *v = pv;
+    if (migrate_mode() == MIG_MODE_CPR_EXEC) {
+        qemu_get_sbe32s(f, v);
+        return 0;
+    }
     *v = qemu_file_get_fd(f);
     return 0;
 }
@@ -329,6 +334,10 @@ static int put_fd(QEMUFile *f, void *pv, size_t size,
                   const VMStateField *field, JSONWriter *vmdesc)
 {
     int32_t *v = pv;
+    if (migrate_mode() == MIG_MODE_CPR_EXEC) {
+        qemu_put_sbe32s(f, v);
+        return 0;
+    }
     return qemu_file_put_fd(f, *v);
 }
 
@@ -543,13 +552,17 @@ static int get_tmp(QEMUFile *f, void *pv, size_t size,
                    const VMStateField *field)
 {
     int ret;
+    Error *local_err = NULL;
     const VMStateDescription *vmsd = field->vmsd;
     int version_id = field->version_id;
     void *tmp = g_malloc(size);
 
     /* Writes the parent field which is at the start of the tmp */
     *(void **)tmp = pv;
-    ret = vmstate_load_state(f, vmsd, tmp, version_id);
+    ret = vmstate_load_state(f, vmsd, tmp, version_id, &local_err);
+    if (ret < 0) {
+        error_report_err(local_err);
+    }
     g_free(tmp);
     return ret;
 }
@@ -560,10 +573,14 @@ static int put_tmp(QEMUFile *f, void *pv, size_t size,
     const VMStateDescription *vmsd = field->vmsd;
     void *tmp = g_malloc(size);
     int ret;
+    Error *local_err = NULL;
 
     /* Writes the parent field which is at the start of the tmp */
     *(void **)tmp = pv;
-    ret = vmstate_save_state(f, vmsd, tmp, vmdesc);
+    ret = vmstate_save_state(f, vmsd, tmp, vmdesc, &local_err);
+    if (ret) {
+        error_report_err(local_err);
+    }
     g_free(tmp);
 
     return ret;
@@ -626,6 +643,7 @@ static int get_qtailq(QEMUFile *f, void *pv, size_t unused_size,
                       const VMStateField *field)
 {
     int ret = 0;
+    Error *local_err = NULL;
     const VMStateDescription *vmsd = field->vmsd;
     /* size of a QTAILQ element */
     size_t size = field->size;
@@ -649,8 +667,9 @@ static int get_qtailq(QEMUFile *f, void *pv, size_t unused_size,
 
     while (qemu_get_byte(f)) {
         elm = g_malloc(size);
-        ret = vmstate_load_state(f, vmsd, elm, version_id);
+        ret = vmstate_load_state(f, vmsd, elm, version_id, &local_err);
         if (ret) {
+            error_report_err(local_err);
             return ret;
         }
         QTAILQ_RAW_INSERT_TAIL(pv, elm, entry_offset);
@@ -669,13 +688,15 @@ static int put_qtailq(QEMUFile *f, void *pv, size_t unused_size,
     size_t entry_offset = field->start;
     void *elm;
     int ret;
+    Error *local_err = NULL;
 
     trace_put_qtailq(vmsd->name, vmsd->version_id);
 
     QTAILQ_RAW_FOREACH(elm, pv, entry_offset) {
         qemu_put_byte(f, true);
-        ret = vmstate_save_state(f, vmsd, elm, vmdesc);
+        ret = vmstate_save_state(f, vmsd, elm, vmdesc, &local_err);
         if (ret) {
+            error_report_err(local_err);
             return ret;
         }
     }
@@ -704,6 +725,7 @@ static gboolean put_gtree_elem(gpointer key, gpointer value, gpointer data)
     struct put_gtree_data *capsule = (struct put_gtree_data *)data;
     QEMUFile *f = capsule->f;
     int ret;
+    Error *local_err = NULL;
 
     qemu_put_byte(f, true);
 
@@ -711,16 +733,20 @@ static gboolean put_gtree_elem(gpointer key, gpointer value, gpointer data)
     if (!capsule->key_vmsd) {
         qemu_put_be64(f, (uint64_t)(uintptr_t)(key)); /* direct key */
     } else {
-        ret = vmstate_save_state(f, capsule->key_vmsd, key, capsule->vmdesc);
+        ret = vmstate_save_state(f, capsule->key_vmsd, key, capsule->vmdesc,
+                                 &local_err);
         if (ret) {
+            error_report_err(local_err);
             capsule->ret = ret;
             return true;
         }
     }
 
     /* put the data */
-    ret = vmstate_save_state(f, capsule->val_vmsd, value, capsule->vmdesc);
+    ret = vmstate_save_state(f, capsule->val_vmsd, value, capsule->vmdesc,
+                             &local_err);
     if (ret) {
+        error_report_err(local_err);
         capsule->ret = ret;
         return true;
     }
@@ -772,6 +798,7 @@ static int get_gtree(QEMUFile *f, void *pv, size_t unused_size,
     GTree *tree = *pval;
     void *key, *val;
     int ret = 0;
+    Error *local_err = NULL;
 
     /* in case of direct key, the key vmsd can be {}, ie. check fields */
     if (!direct_key && version_id > key_vmsd->version_id) {
@@ -803,18 +830,16 @@ static int get_gtree(QEMUFile *f, void *pv, size_t unused_size,
             key = (void *)(uintptr_t)qemu_get_be64(f);
         } else {
             key = g_malloc0(key_size);
-            ret = vmstate_load_state(f, key_vmsd, key, version_id);
+            ret = vmstate_load_state(f, key_vmsd, key, version_id, &local_err);
             if (ret) {
-                error_report("%s : failed to load %s (%d)",
-                             field->name, key_vmsd->name, ret);
+                error_report_err(local_err);
                 goto key_error;
             }
         }
         val = g_malloc0(val_size);
-        ret = vmstate_load_state(f, val_vmsd, val, version_id);
+        ret = vmstate_load_state(f, val_vmsd, val, version_id, &local_err);
         if (ret) {
-            error_report("%s : failed to load %s (%d)",
-                         field->name, val_vmsd->name, ret);
+            error_report_err(local_err);
             goto val_error;
         }
         g_tree_insert(tree, key, val);
@@ -851,14 +876,14 @@ static int put_qlist(QEMUFile *f, void *pv, size_t unused_size,
     size_t entry_offset = field->start;
     void *elm;
     int ret;
+    Error *local_err = NULL;
 
     trace_put_qlist(field->name, vmsd->name, vmsd->version_id);
     QLIST_RAW_FOREACH(elm, pv, entry_offset) {
         qemu_put_byte(f, true);
-        ret = vmstate_save_state(f, vmsd, elm, vmdesc);
+        ret = vmstate_save_state(f, vmsd, elm, vmdesc, &local_err);
         if (ret) {
-            error_report("%s: failed to save %s (%d)", field->name,
-                         vmsd->name, ret);
+            error_report_err(local_err);
             return ret;
         }
     }
@@ -872,6 +897,7 @@ static int get_qlist(QEMUFile *f, void *pv, size_t unused_size,
                      const VMStateField *field)
 {
     int ret = 0;
+    Error *local_err = NULL;
     const VMStateDescription *vmsd = field->vmsd;
     /* size of a QLIST element */
     size_t size = field->size;
@@ -892,10 +918,9 @@ static int get_qlist(QEMUFile *f, void *pv, size_t unused_size,
 
     while (qemu_get_byte(f)) {
         elm = g_malloc(size);
-        ret = vmstate_load_state(f, vmsd, elm, version_id);
+        ret = vmstate_load_state(f, vmsd, elm, version_id, &local_err);
         if (ret) {
-            error_report("%s: failed to load %s (%d)", field->name,
-                         vmsd->name, ret);
+            error_report_err(local_err);
             g_free(elm);
             return ret;
         }
diff --git a/migration/vmstate.c b/migration/vmstate.c
index 5feaa32..81eadde 100644
--- a/migration/vmstate.c
+++ b/migration/vmstate.c
@@ -25,7 +25,7 @@ static int vmstate_subsection_save(QEMUFile *f, const VMStateDescription *vmsd,
                                    void *opaque, JSONWriter *vmdesc,
                                    Error **errp);
 static int vmstate_subsection_load(QEMUFile *f, const VMStateDescription *vmsd,
-                                   void *opaque);
+                                   void *opaque, Error **errp);
 
 /* Whether this field should exist for either save or load the VM? */
 static bool
@@ -132,29 +132,43 @@ static void vmstate_handle_alloc(void *ptr, const VMStateField *field,
 }
 
 int vmstate_load_state(QEMUFile *f, const VMStateDescription *vmsd,
-                       void *opaque, int version_id)
+                       void *opaque, int version_id, Error **errp)
 {
+    ERRP_GUARD();
     const VMStateField *field = vmsd->fields;
     int ret = 0;
 
     trace_vmstate_load_state(vmsd->name, version_id);
     if (version_id > vmsd->version_id) {
-        error_report("%s: incoming version_id %d is too new "
-                     "for local version_id %d",
-                     vmsd->name, version_id, vmsd->version_id);
+        error_setg(errp, "%s: incoming version_id %d is too new "
+                   "for local version_id %d",
+                   vmsd->name, version_id, vmsd->version_id);
         trace_vmstate_load_state_end(vmsd->name, "too new", -EINVAL);
         return -EINVAL;
     }
     if  (version_id < vmsd->minimum_version_id) {
-        error_report("%s: incoming version_id %d is too old "
-                     "for local minimum version_id  %d",
-                     vmsd->name, version_id, vmsd->minimum_version_id);
+        error_setg(errp, "%s: incoming version_id %d is too old "
+                   "for local minimum version_id %d",
+                   vmsd->name, version_id, vmsd->minimum_version_id);
         trace_vmstate_load_state_end(vmsd->name, "too old", -EINVAL);
         return -EINVAL;
     }
-    if (vmsd->pre_load) {
+    if (vmsd->pre_load_errp) {
+        ret = vmsd->pre_load_errp(opaque, errp);
+        if (ret < 0) {
+            error_prepend(errp, "pre load hook failed for: '%s', "
+                          "version_id: %d, minimum version_id: %d, "
+                          "ret: %d: ", vmsd->name, vmsd->version_id,
+                          vmsd->minimum_version_id, ret);
+            return ret;
+        }
+    } else if (vmsd->pre_load) {
         ret = vmsd->pre_load(opaque);
         if (ret) {
+            error_setg(errp, "pre load hook failed for: '%s', "
+                       "version_id: %d, minimum version_id: %d, ret: %d",
+                       vmsd->name, vmsd->version_id, vmsd->minimum_version_id,
+                       ret);
             return ret;
         }
     }
@@ -192,13 +206,21 @@ int vmstate_load_state(QEMUFile *f, const VMStateDescription *vmsd,
 
                 if (inner_field->flags & VMS_STRUCT) {
                     ret = vmstate_load_state(f, inner_field->vmsd, curr_elem,
-                                             inner_field->vmsd->version_id);
+                                             inner_field->vmsd->version_id,
+                                             errp);
                 } else if (inner_field->flags & VMS_VSTRUCT) {
                     ret = vmstate_load_state(f, inner_field->vmsd, curr_elem,
-                                             inner_field->struct_version_id);
+                                             inner_field->struct_version_id,
+                                             errp);
                 } else {
                     ret = inner_field->info->get(f, curr_elem, size,
                                                  inner_field);
+                    if (ret < 0) {
+                        error_setg(errp,
+                                   "Failed to load element of type %s for %s: "
+                                   "%d", inner_field->info->name,
+                                   inner_field->name, ret);
+                    }
                 }
 
                 /* If we used a fake temp field.. free it now */
@@ -208,30 +230,47 @@ int vmstate_load_state(QEMUFile *f, const VMStateDescription *vmsd,
 
                 if (ret >= 0) {
                     ret = qemu_file_get_error(f);
+                    if (ret < 0) {
+                        error_setg(errp,
+                                   "Failed to load %s state: stream error: %d",
+                                   vmsd->name, ret);
+                    }
                 }
                 if (ret < 0) {
                     qemu_file_set_error(f, ret);
-                    error_report("Failed to load %s:%s", vmsd->name,
-                                 field->name);
                     trace_vmstate_load_field_error(field->name, ret);
                     return ret;
                 }
             }
         } else if (field->flags & VMS_MUST_EXIST) {
-            error_report("Input validation failed: %s/%s",
-                         vmsd->name, field->name);
+            error_setg(errp, "Input validation failed: %s/%s version_id: %d",
+                       vmsd->name, field->name, vmsd->version_id);
             return -1;
         }
         field++;
     }
     assert(field->flags == VMS_END);
-    ret = vmstate_subsection_load(f, vmsd, opaque);
+    ret = vmstate_subsection_load(f, vmsd, opaque, errp);
     if (ret != 0) {
         qemu_file_set_error(f, ret);
         return ret;
     }
-    if (vmsd->post_load) {
+    if (vmsd->post_load_errp) {
+        ret = vmsd->post_load_errp(opaque, version_id, errp);
+        if (ret < 0) {
+            error_prepend(errp, "post load hook failed for: %s, version_id: "
+                          "%d, minimum_version: %d, ret: %d: ", vmsd->name,
+                          vmsd->version_id, vmsd->minimum_version_id, ret);
+        }
+    } else if (vmsd->post_load) {
         ret = vmsd->post_load(opaque, version_id);
+        if (ret < 0) {
+            error_setg(errp,
+                       "post load hook failed for: %s, version_id: %d, "
+                       "minimum_version: %d, ret: %d",
+                       vmsd->name, vmsd->version_id, vmsd->minimum_version_id,
+                       ret);
+        }
     }
     trace_vmstate_load_state_end(vmsd->name, "end", ret);
     return ret;
@@ -384,12 +423,6 @@ bool vmstate_section_needed(const VMStateDescription *vmsd, void *opaque)
 
 
 int vmstate_save_state(QEMUFile *f, const VMStateDescription *vmsd,
-                       void *opaque, JSONWriter *vmdesc_id)
-{
-    return vmstate_save_state_v(f, vmsd, opaque, vmdesc_id, vmsd->version_id, NULL);
-}
-
-int vmstate_save_state_with_err(QEMUFile *f, const VMStateDescription *vmsd,
                        void *opaque, JSONWriter *vmdesc_id, Error **errp)
 {
     return vmstate_save_state_v(f, vmsd, opaque, vmdesc_id, vmsd->version_id, errp);
@@ -398,12 +431,20 @@ int vmstate_save_state_with_err(QEMUFile *f, const VMStateDescription *vmsd,
 int vmstate_save_state_v(QEMUFile *f, const VMStateDescription *vmsd,
                          void *opaque, JSONWriter *vmdesc, int version_id, Error **errp)
 {
+    ERRP_GUARD();
     int ret = 0;
     const VMStateField *field = vmsd->fields;
 
     trace_vmstate_save_state_top(vmsd->name);
 
-    if (vmsd->pre_save) {
+    if (vmsd->pre_save_errp) {
+        ret = vmsd->pre_save_errp(opaque, errp);
+        trace_vmstate_save_state_pre_save_res(vmsd->name, ret);
+        if (ret < 0) {
+            error_prepend(errp, "pre-save for %s failed, ret: %d: ",
+                          vmsd->name, ret);
+        }
+    } else if (vmsd->pre_save) {
         ret = vmsd->pre_save(opaque);
         trace_vmstate_save_state_pre_save_res(vmsd->name, ret);
         if (ret) {
@@ -490,7 +531,7 @@ int vmstate_save_state_v(QEMUFile *f, const VMStateDescription *vmsd,
 
                 if (inner_field->flags & VMS_STRUCT) {
                     ret = vmstate_save_state(f, inner_field->vmsd,
-                                             curr_elem, vmdesc_loop);
+                                             curr_elem, vmdesc_loop, errp);
                 } else if (inner_field->flags & VMS_VSTRUCT) {
                     ret = vmstate_save_state_v(f, inner_field->vmsd,
                                                curr_elem, vmdesc_loop,
@@ -566,8 +607,9 @@ vmstate_get_subsection(const VMStateDescription * const *sub,
 }
 
 static int vmstate_subsection_load(QEMUFile *f, const VMStateDescription *vmsd,
-                                   void *opaque)
+                                   void *opaque, Error **errp)
 {
+    ERRP_GUARD();
     trace_vmstate_subsection_load(vmsd->name);
 
     while (qemu_peek_byte(f, 0) == QEMU_VM_SUBSECTION) {
@@ -598,6 +640,8 @@ static int vmstate_subsection_load(QEMUFile *f, const VMStateDescription *vmsd,
         sub_vmsd = vmstate_get_subsection(vmsd->subsections, idstr);
         if (sub_vmsd == NULL) {
             trace_vmstate_subsection_load_bad(vmsd->name, idstr, "(lookup)");
+            error_setg(errp, "VM subsection '%s' in '%s' does not exist",
+                       idstr, vmsd->name);
             return -ENOENT;
         }
         qemu_file_skip(f, 1); /* subsection */
@@ -605,9 +649,12 @@ static int vmstate_subsection_load(QEMUFile *f, const VMStateDescription *vmsd,
         qemu_file_skip(f, len); /* idstr */
         version_id = qemu_get_be32(f);
 
-        ret = vmstate_load_state(f, sub_vmsd, opaque, version_id);
+        ret = vmstate_load_state(f, sub_vmsd, opaque, version_id, errp);
         if (ret) {
             trace_vmstate_subsection_load_bad(vmsd->name, idstr, "(child)");
+            error_prepend(errp,
+                          "Loading VM subsection '%s' in '%s' failed: %d: ",
+                          idstr, vmsd->name, ret);
             return ret;
         }
     }
@@ -646,7 +693,7 @@ static int vmstate_subsection_save(QEMUFile *f, const VMStateDescription *vmsd,
             qemu_put_byte(f, len);
             qemu_put_buffer(f, (uint8_t *)vmsdsub->name, len);
             qemu_put_be32(f, vmsdsub->version_id);
-            ret = vmstate_save_state_with_err(f, vmsdsub, opaque, vmdesc, errp);
+            ret = vmstate_save_state(f, vmsdsub, opaque, vmdesc, errp);
             if (ret) {
                 return ret;
             }
diff --git a/qapi/migration.json b/qapi/migration.json
index 2387c21..be0f3fc 100644
--- a/qapi/migration.json
+++ b/qapi/migration.json
@@ -694,9 +694,32 @@
 #     until you issue the `migrate-incoming` command.
 #
 #     (since 10.0)
+#
+# @cpr-exec: The migrate command stops the VM, saves state to the
+#     migration channel, directly exec's a new version of QEMU on the
+#     same host, replacing the original process while retaining its
+#     PID, and loads state from the channel.  Guest RAM is preserved
+#     in place.  Devices and their pinned pages are also preserved for
+#     VFIO and IOMMUFD.
+#
+#     Old QEMU starts new QEMU by exec'ing the command specified by
+#     the @cpr-exec-command parameter.  The command may be a direct
+#     invocation of new QEMU, or may be a wrapper that exec's the new
+#     QEMU binary.
+#
+#     Because old QEMU terminates when new QEMU starts, one cannot
+#     stream data between the two, so the channel must be a type,
+#     such as a file, that accepts all data before old QEMU exits.
+#     Otherwise, old QEMU may quietly block writing to the channel.
+#
+#     Memory-backend objects must have the share=on attribute, but
+#     memory-backend-epc is not supported.  The VM must be started
+#     with the '-machine aux-ram-share=on' option.
+#
+#     (since 10.2)
 ##
 { 'enum': 'MigMode',
-  'data': [ 'normal', 'cpr-reboot', 'cpr-transfer' ] }
+  'data': [ 'normal', 'cpr-reboot', 'cpr-transfer', 'cpr-exec' ] }
 
 ##
 # @ZeroPageDetection:
@@ -924,6 +947,10 @@
 #     only has effect if the @mapped-ram capability is enabled.
 #     (Since 9.1)
 #
+# @cpr-exec-command: Command to start the new QEMU process when @mode
+#     is @cpr-exec.  The first list element is the program's filename,
+#     the remainder its arguments.  (Since 10.2)
+#
 # Features:
 #
 # @unstable: Members @x-checkpoint-delay and
@@ -950,7 +977,8 @@
            'vcpu-dirty-limit',
            'mode',
            'zero-page-detection',
-           'direct-io'] }
+           'direct-io',
+           'cpr-exec-command'] }
 
 ##
 # @MigrateSetParameters:
@@ -1105,6 +1133,10 @@
 #     only has effect if the @mapped-ram capability is enabled.
 #     (Since 9.1)
 #
+# @cpr-exec-command: Command to start the new QEMU process when @mode
+#     is @cpr-exec.  The first list element is the program's filename,
+#     the remainder its arguments.  (Since 10.2)
+#
 # Features:
 #
 # @unstable: Members @x-checkpoint-delay and
@@ -1146,7 +1178,8 @@
             '*vcpu-dirty-limit': 'uint64',
             '*mode': 'MigMode',
             '*zero-page-detection': 'ZeroPageDetection',
-            '*direct-io': 'bool' } }
+            '*direct-io': 'bool',
+            '*cpr-exec-command': [ 'str' ]} }
 
 ##
 # @migrate-set-parameters:
@@ -1315,6 +1348,10 @@
 #     only has effect if the @mapped-ram capability is enabled.
 #     (Since 9.1)
 #
+# @cpr-exec-command: Command to start the new QEMU process when @mode
+#     is @cpr-exec.  The first list element is the program's filename,
+#     the remainder its arguments.  (Since 10.2)
+#
 # Features:
 #
 # @unstable: Members @x-checkpoint-delay and
@@ -1353,7 +1390,8 @@
             '*vcpu-dirty-limit': 'uint64',
             '*mode': 'MigMode',
             '*zero-page-detection': 'ZeroPageDetection',
-            '*direct-io': 'bool' } }
+            '*direct-io': 'bool',
+            '*cpr-exec-command': [ 'str' ]} }
 
 ##
 # @query-migrate-parameters:
diff --git a/stubs/cpu-destroy-address-spaces.c b/stubs/cpu-destroy-address-spaces.c
new file mode 100644
index 0000000..dc6813f
--- /dev/null
+++ b/stubs/cpu-destroy-address-spaces.c
@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#include "qemu/osdep.h"
+#include "exec/cpu-common.h"
+
+/*
+ * user-mode CPUs never create address spaces with
+ * cpu_address_space_init(), so the cleanup function doesn't
+ * need to do anything. We need this stub because cpu-common.c
+ * is built-once so it can't #ifndef CONFIG_USER around the
+ * call; the real function is in physmem.c which is system-only.
+ */
+void cpu_destroy_address_spaces(CPUState *cpu)
+{
+}
diff --git a/stubs/meson.build b/stubs/meson.build
index cef046e..5d57746 100644
--- a/stubs/meson.build
+++ b/stubs/meson.build
@@ -55,6 +55,7 @@ endif
 if have_user
   # Symbols that are used by hw/core.
   stub_ss.add(files('cpu-synchronize-state.c'))
+  stub_ss.add(files('cpu-destroy-address-spaces.c'))
 
   # Stubs for QAPI events.  Those can always be included in the build, but
   # they are not built at all for --disable-system builds.
diff --git a/system/memory.c b/system/memory.c
index cf8cad6..fe8b28a 100644
--- a/system/memory.c
+++ b/system/memory.c
@@ -3278,7 +3278,14 @@ static void do_address_space_destroy(AddressSpace *as)
     memory_region_unref(as->root);
 }
 
-void address_space_destroy(AddressSpace *as)
+static void do_address_space_destroy_free(AddressSpace *as)
+{
+    do_address_space_destroy(as);
+    g_free(as);
+}
+
+/* Detach address space from global view, notify all listeners */
+static void address_space_detach(AddressSpace *as)
 {
     MemoryRegion *root = as->root;
 
@@ -3293,9 +3300,20 @@ void address_space_destroy(AddressSpace *as)
      * values to expire before freeing the data.
      */
     as->root = root;
+}
+
+void address_space_destroy(AddressSpace *as)
+{
+    address_space_detach(as);
     call_rcu(as, do_address_space_destroy, rcu);
 }
 
+void address_space_destroy_free(AddressSpace *as)
+{
+    address_space_detach(as);
+    call_rcu(as, do_address_space_destroy_free, rcu);
+}
+
 static const char *memory_region_type(MemoryRegion *mr)
 {
     if (mr->alias) {
diff --git a/system/physmem.c b/system/physmem.c
index ae8ecd5..dbb2a4e 100644
--- a/system/physmem.c
+++ b/system/physmem.c
@@ -795,7 +795,6 @@ void cpu_address_space_init(CPUState *cpu, int asidx,
 
     if (!cpu->cpu_ases) {
         cpu->cpu_ases = g_new0(CPUAddressSpace, cpu->num_ases);
-        cpu->cpu_ases_count = cpu->num_ases;
     }
 
     newas = &cpu->cpu_ases[asidx];
@@ -809,30 +808,29 @@ void cpu_address_space_init(CPUState *cpu, int asidx,
     }
 }
 
-void cpu_address_space_destroy(CPUState *cpu, int asidx)
+void cpu_destroy_address_spaces(CPUState *cpu)
 {
     CPUAddressSpace *cpuas;
+    int asidx;
 
     assert(cpu->cpu_ases);
-    assert(asidx >= 0 && asidx < cpu->num_ases);
 
-    cpuas = &cpu->cpu_ases[asidx];
-    if (tcg_enabled()) {
-        memory_listener_unregister(&cpuas->tcg_as_listener);
-    }
+    /* convenience alias just points to some cpu_ases[n] */
+    cpu->as = NULL;
 
-    address_space_destroy(cpuas->as);
-    g_free_rcu(cpuas->as, rcu);
-
-    if (asidx == 0) {
-        /* reset the convenience alias for address space 0 */
-        cpu->as = NULL;
+    for (asidx = 0; asidx < cpu->num_ases; asidx++) {
+        cpuas = &cpu->cpu_ases[asidx];
+        if (!cpuas->as) {
+            /* This index was never initialized; no deinit needed */
+            continue;
+        }
+        if (tcg_enabled()) {
+            memory_listener_unregister(&cpuas->tcg_as_listener);
+        }
+        g_clear_pointer(&cpuas->as, address_space_destroy_free);
     }
 
-    if (--cpu->cpu_ases_count == 0) {
-        g_free(cpu->cpu_ases);
-        cpu->cpu_ases = NULL;
-    }
+    g_clear_pointer(&cpu->cpu_ases, g_free);
 }
 
 AddressSpace *cpu_get_address_space(CPUState *cpu, int asidx)
diff --git a/system/vl.c b/system/vl.c
index 00f3694..646239e 100644
--- a/system/vl.c
+++ b/system/vl.c
@@ -3837,6 +3837,8 @@ void qemu_init(int argc, char **argv)
     }
     qemu_init_displays();
     accel_setup_post(current_machine);
-    os_setup_post();
+    if (migrate_mode() != MIG_MODE_CPR_EXEC) {
+        os_setup_post();
+    }
     resume_mux_open();
 }
diff --git a/tests/qtest/migration/cpr-tests.c b/tests/qtest/migration/cpr-tests.c
index c4ce60f..9388ad6 100644
--- a/tests/qtest/migration/cpr-tests.c
+++ b/tests/qtest/migration/cpr-tests.c
@@ -113,6 +113,138 @@ static void test_mode_transfer_defer(void)
     test_mode_transfer_common(true);
 }
 
+static void set_cpr_exec_args(QTestState *who, MigrateCommon *args)
+{
+    g_autofree char *qtest_from_args = NULL;
+    g_autofree char *from_args = NULL;
+    g_autofree char *to_args = NULL;
+    g_autofree char *exec_args = NULL;
+    g_auto(GStrv) argv = NULL;
+    char *from_str, *src, *dst;
+    int ret;
+
+    /*
+     * hide_stderr appends "2>/dev/null" to the command line, but cpr-exec
+     * passes the command-line words to execv, not to the shell, so suppress it
+     * here.  fd 2 was already bound in the source VM, and execv preserves it.
+     */
+    g_assert(args->start.hide_stderr == false);
+
+    ret = migrate_args(&from_args, &to_args, args->listen_uri, &args->start);
+    g_assert(!ret);
+    qtest_from_args = qtest_qemu_args(from_args);
+
+    /*
+     * The generated args may have been formatted using "%s %s" with empty
+     * strings, which can produce consecutive spaces, which g_strsplit would
+     * convert into empty strings.  Ditto for leading and trailing space.
+     * De-dup spaces to avoid that.
+     */
+
+    from_str = src = dst = g_strstrip(qtest_from_args);
+    do {
+        if (*src != ' ' || src[-1] != ' ') {
+            *dst++ = *src;
+        }
+    } while (*src++);
+
+    exec_args = g_strconcat(qtest_qemu_binary(migration_get_env()->qemu_dst),
+                            " -incoming defer ", from_str, NULL);
+    argv = g_strsplit(exec_args, " ", -1);
+    migrate_set_parameter_strv(who, "cpr-exec-command", argv);
+}
+
+static void wait_for_migration_event(QTestState *who, const char *waitfor)
+{
+    QDict *rsp, *data;
+    char *status;
+    bool done = false;
+
+    while (!done) {
+        rsp = qtest_qmp_eventwait_ref(who, "MIGRATION");
+        g_assert(qdict_haskey(rsp, "data"));
+        data = qdict_get_qdict(rsp, "data");
+        g_assert(qdict_haskey(data, "status"));
+        status = g_strdup(qdict_get_str(data, "status"));
+        g_assert(strcmp(status, "failed"));
+        done = !strcmp(status, waitfor);
+        qobject_unref(rsp);
+    }
+}
+
+static void test_cpr_exec(MigrateCommon *args)
+{
+    QTestState *from, *to;
+    void *data_hook = NULL;
+    g_autofree char *connect_uri = g_strdup(args->connect_uri);
+    g_autofree char *filename = g_strdup_printf("%s/%s", tmpfs,
+                                                FILE_TEST_FILENAME);
+
+    if (migrate_start(&from, NULL, args->listen_uri, &args->start)) {
+        return;
+    }
+
+    /* Source and dest never run concurrently */
+    g_assert_false(args->live);
+
+    if (args->start_hook) {
+        data_hook = args->start_hook(from, NULL);
+    }
+
+    wait_for_serial("src_serial");
+    set_cpr_exec_args(from, args);
+    migrate_set_capability(from, "events", true);
+    migrate_qmp(from, NULL, connect_uri, NULL, "{}");
+    wait_for_migration_event(from, "completed");
+
+    to = qtest_init_after_exec(from);
+
+    qtest_qmp_assert_success(to, "{ 'execute': 'migrate-incoming',"
+                             "  'arguments': { "
+                             "      'channels': [ { 'channel-type': 'main',"
+                             "      'addr': { 'transport': 'file',"
+                             "                'filename': %s,"
+                             "                'offset': 0  } } ] } }",
+                             filename);
+    wait_for_migration_complete(to);
+
+    wait_for_resume(to, get_dst());
+    /* Device on target is still named src_serial because args do not change */
+    wait_for_serial("src_serial");
+
+    if (args->end_hook) {
+        args->end_hook(from, to, data_hook);
+    }
+
+    migrate_end(from, to, args->result == MIG_TEST_SUCCEED);
+}
+
+static void *test_mode_exec_start(QTestState *from, QTestState *to)
+{
+    assert(!to);
+    migrate_set_parameter_str(from, "mode", "cpr-exec");
+    return NULL;
+}
+
+static void test_mode_exec(void)
+{
+    g_autofree char *uri = g_strdup_printf("file:%s/%s", tmpfs,
+                                           FILE_TEST_FILENAME);
+    g_autofree char *listen_uri = g_strdup_printf("defer");
+
+    MigrateCommon args = {
+        .start.only_source = true,
+        .start.opts_source = "-machine aux-ram-share=on -nodefaults",
+        .start.memory_backend = "-object memory-backend-memfd,id=pc.ram,size=%s"
+                                " -machine memory-backend=pc.ram",
+        .connect_uri = uri,
+        .listen_uri = listen_uri,
+        .start_hook = test_mode_exec_start,
+    };
+
+    test_cpr_exec(&args);
+}
+
 void migration_test_add_cpr(MigrationTestEnv *env)
 {
     tmpfs = env->tmpfs;
@@ -135,5 +267,6 @@ void migration_test_add_cpr(MigrationTestEnv *env)
         migration_test_add("/migration/mode/transfer", test_mode_transfer);
         migration_test_add("/migration/mode/transfer/defer",
                            test_mode_transfer_defer);
+        migration_test_add("/migration/mode/exec", test_mode_exec);
     }
 }
diff --git a/tests/unit/test-vmstate.c b/tests/unit/test-vmstate.c
index 63f28f2..cadbab3 100644
--- a/tests/unit/test-vmstate.c
+++ b/tests/unit/test-vmstate.c
@@ -30,6 +30,7 @@
 #include "../migration/savevm.h"
 #include "qemu/module.h"
 #include "io/channel-file.h"
+#include "qapi/error.h"
 
 static int temp_fd;
 
@@ -66,9 +67,13 @@ static QEMUFile *open_test_file(bool write)
 static void save_vmstate(const VMStateDescription *desc, void *obj)
 {
     QEMUFile *f = open_test_file(true);
+    Error *local_err = NULL;
 
     /* Save file with vmstate */
-    int ret = vmstate_save_state(f, desc, obj, NULL);
+    int ret = vmstate_save_state(f, desc, obj, NULL, &local_err);
+    if (ret) {
+        error_report_err(local_err);
+    }
     g_assert(!ret);
     qemu_put_byte(f, QEMU_VM_EOF);
     g_assert(!qemu_file_get_error(f));
@@ -108,14 +113,16 @@ static int load_vmstate_one(const VMStateDescription *desc, void *obj,
 {
     QEMUFile *f;
     int ret;
+    Error *local_err = NULL;
 
     f = open_test_file(true);
     qemu_put_buffer(f, wire, size);
     qemu_fclose(f);
 
     f = open_test_file(false);
-    ret = vmstate_load_state(f, desc, obj, version);
+    ret = vmstate_load_state(f, desc, obj, version, &local_err);
     if (ret) {
+        error_report_err(local_err);
         g_assert(qemu_file_get_error(f));
     } else{
         g_assert(!qemu_file_get_error(f));
@@ -355,6 +362,8 @@ static const VMStateDescription vmstate_versioned = {
 
 static void test_load_v1(void)
 {
+    Error *local_err = NULL;
+    int ret;
     uint8_t buf[] = {
         0, 0, 0, 10,             /* a */
         0, 0, 0, 30,             /* c */
@@ -365,7 +374,10 @@ static void test_load_v1(void)
 
     QEMUFile *loading = open_test_file(false);
     TestStruct obj = { .b = 200, .e = 500, .f = 600 };
-    vmstate_load_state(loading, &vmstate_versioned, &obj, 1);
+    ret = vmstate_load_state(loading, &vmstate_versioned, &obj, 1, &local_err);
+    if (ret < 0) {
+        error_report_err(local_err);
+    }
     g_assert(!qemu_file_get_error(loading));
     g_assert_cmpint(obj.a, ==, 10);
     g_assert_cmpint(obj.b, ==, 200);
@@ -378,6 +390,8 @@ static void test_load_v1(void)
 
 static void test_load_v2(void)
 {
+    Error *local_err = NULL;
+    int ret;
     uint8_t buf[] = {
         0, 0, 0, 10,             /* a */
         0, 0, 0, 20,             /* b */
@@ -391,7 +405,10 @@ static void test_load_v2(void)
 
     QEMUFile *loading = open_test_file(false);
     TestStruct obj;
-    vmstate_load_state(loading, &vmstate_versioned, &obj, 2);
+    ret = vmstate_load_state(loading, &vmstate_versioned, &obj, 2, &local_err);
+    if (ret < 0) {
+        error_report_err(local_err);
+    }
     g_assert_cmpint(obj.a, ==, 10);
     g_assert_cmpint(obj.b, ==, 20);
     g_assert_cmpint(obj.c, ==, 30);
@@ -425,10 +442,15 @@ static const VMStateDescription vmstate_skipping = {
 
 static void test_save_noskip(void)
 {
+    Error *local_err = NULL;
     QEMUFile *fsave = open_test_file(true);
     TestStruct obj = { .a = 1, .b = 2, .c = 3, .d = 4, .e = 5, .f = 6,
                        .skip_c_e = false };
-    int ret = vmstate_save_state(fsave, &vmstate_skipping, &obj, NULL);
+    int ret = vmstate_save_state(fsave, &vmstate_skipping, &obj, NULL,
+                                 &local_err);
+    if (ret) {
+        error_report_err(local_err);
+    }
     g_assert(!ret);
     g_assert(!qemu_file_get_error(fsave));
 
@@ -447,10 +469,15 @@ static void test_save_noskip(void)
 
 static void test_save_skip(void)
 {
+    Error *local_err = NULL;
     QEMUFile *fsave = open_test_file(true);
     TestStruct obj = { .a = 1, .b = 2, .c = 3, .d = 4, .e = 5, .f = 6,
                        .skip_c_e = true };
-    int ret = vmstate_save_state(fsave, &vmstate_skipping, &obj, NULL);
+    int ret = vmstate_save_state(fsave, &vmstate_skipping, &obj, NULL,
+                                 &local_err);
+    if (ret) {
+        error_report_err(local_err);
+    }
     g_assert(!ret);
     g_assert(!qemu_file_get_error(fsave));
 
@@ -467,6 +494,8 @@ static void test_save_skip(void)
 
 static void test_load_noskip(void)
 {
+    Error *local_err = NULL;
+    int ret;
     uint8_t buf[] = {
         0, 0, 0, 10,             /* a */
         0, 0, 0, 20,             /* b */
@@ -480,7 +509,10 @@ static void test_load_noskip(void)
 
     QEMUFile *loading = open_test_file(false);
     TestStruct obj = { .skip_c_e = false };
-    vmstate_load_state(loading, &vmstate_skipping, &obj, 2);
+    ret = vmstate_load_state(loading, &vmstate_skipping, &obj, 2, &local_err);
+    if (ret < 0) {
+        error_report_err(local_err);
+    }
     g_assert(!qemu_file_get_error(loading));
     g_assert_cmpint(obj.a, ==, 10);
     g_assert_cmpint(obj.b, ==, 20);
@@ -493,6 +525,8 @@ static void test_load_noskip(void)
 
 static void test_load_skip(void)
 {
+    Error *local_err = NULL;
+    int ret;
     uint8_t buf[] = {
         0, 0, 0, 10,             /* a */
         0, 0, 0, 20,             /* b */
@@ -504,7 +538,10 @@ static void test_load_skip(void)
 
     QEMUFile *loading = open_test_file(false);
     TestStruct obj = { .skip_c_e = true, .c = 300, .e = 500 };
-    vmstate_load_state(loading, &vmstate_skipping, &obj, 2);
+    ret = vmstate_load_state(loading, &vmstate_skipping, &obj, 2, &local_err);
+    if (ret < 0) {
+        error_report_err(local_err);
+    }
     g_assert(!qemu_file_get_error(loading));
     g_assert_cmpint(obj.a, ==, 10);
     g_assert_cmpint(obj.b, ==, 20);
@@ -744,6 +781,8 @@ static void test_save_q(void)
 
 static void test_load_q(void)
 {
+    int ret;
+    Error *local_err = NULL;
     TestQtailq obj_q = {
         .i16 = -512,
         .i32 = 70000,
@@ -773,7 +812,10 @@ static void test_load_q(void)
     TestQtailq tgt;
 
     QTAILQ_INIT(&tgt.q);
-    vmstate_load_state(fload, &vmstate_q, &tgt, 1);
+    ret = vmstate_load_state(fload, &vmstate_q, &tgt, 1, &local_err);
+    if (ret < 0) {
+        error_report_err(local_err);
+    }
     char eof = qemu_get_byte(fload);
     g_assert(!qemu_file_get_error(fload));
     g_assert_cmpint(tgt.i16, ==, obj_q.i16);
@@ -1115,6 +1157,8 @@ static void diff_iommu(TestGTreeIOMMU *iommu1, TestGTreeIOMMU *iommu2)
 
 static void test_gtree_load_domain(void)
 {
+    Error *local_err = NULL;
+    int ret;
     TestGTreeDomain *dest_domain = g_new0(TestGTreeDomain, 1);
     TestGTreeDomain *orig_domain = create_first_domain();
     QEMUFile *fload, *fsave;
@@ -1127,7 +1171,11 @@ static void test_gtree_load_domain(void)
 
     fload = open_test_file(false);
 
-    vmstate_load_state(fload, &vmstate_domain, dest_domain, 1);
+    ret = vmstate_load_state(fload, &vmstate_domain, dest_domain, 1,
+                             &local_err);
+    if (ret < 0) {
+        error_report_err(local_err);
+    }
     eof = qemu_get_byte(fload);
     g_assert(!qemu_file_get_error(fload));
     g_assert_cmpint(orig_domain->id, ==, dest_domain->id);
@@ -1230,6 +1278,8 @@ static void test_gtree_save_iommu(void)
 
 static void test_gtree_load_iommu(void)
 {
+    Error *local_err = NULL;
+    int ret;
     TestGTreeIOMMU *dest_iommu = g_new0(TestGTreeIOMMU, 1);
     TestGTreeIOMMU *orig_iommu = create_iommu();
     QEMUFile *fsave, *fload;
@@ -1241,7 +1291,10 @@ static void test_gtree_load_iommu(void)
     qemu_fclose(fsave);
 
     fload = open_test_file(false);
-    vmstate_load_state(fload, &vmstate_iommu, dest_iommu, 1);
+    ret = vmstate_load_state(fload, &vmstate_iommu, dest_iommu, 1, &local_err);
+    if (ret < 0) {
+        error_report_err(local_err);
+    }
     eof = qemu_get_byte(fload);
     g_assert(!qemu_file_get_error(fload));
     g_assert_cmpint(orig_iommu->id, ==, dest_iommu->id);
@@ -1363,6 +1416,8 @@ static void test_save_qlist(void)
 
 static void test_load_qlist(void)
 {
+    Error *local_err = NULL;
+    int ret;
     QEMUFile *fsave, *fload;
     TestQListContainer *orig_container = alloc_container();
     TestQListContainer *dest_container = g_new0(TestQListContainer, 1);
@@ -1376,7 +1431,11 @@ static void test_load_qlist(void)
     qemu_fclose(fsave);
 
     fload = open_test_file(false);
-    vmstate_load_state(fload, &vmstate_container, dest_container, 1);
+    ret = vmstate_load_state(fload, &vmstate_container, dest_container, 1,
+                             &local_err);
+    if (ret < 0) {
+        error_report_err(local_err);
+    }
     eof = qemu_get_byte(fload);
     g_assert(!qemu_file_get_error(fload));
     g_assert_cmpint(eof, ==, QEMU_VM_EOF);
diff --git a/ui/vdagent.c b/ui/vdagent.c
index c0746fe..ddb91e7 100644
--- a/ui/vdagent.c
+++ b/ui/vdagent.c
@@ -992,7 +992,8 @@ static int put_cbinfo(QEMUFile *f, void *pv, size_t size,
         }
     }
 
-    return vmstate_save_state(f, &vmstate_cbinfo_array, &cbinfo, vmdesc);
+    return vmstate_save_state(f, &vmstate_cbinfo_array, &cbinfo, vmdesc,
+                              &error_fatal);
 }
 
 static int get_cbinfo(QEMUFile *f, void *pv, size_t size,
@@ -1001,6 +1002,7 @@ static int get_cbinfo(QEMUFile *f, void *pv, size_t size,
     VDAgentChardev *vd = QEMU_VDAGENT_CHARDEV(pv);
     struct CBInfoArray cbinfo = {};
     int i, ret;
+    Error *local_err = NULL;
 
     if (!have_clipboard(vd)) {
         return 0;
@@ -1008,8 +1010,10 @@ static int get_cbinfo(QEMUFile *f, void *pv, size_t size,
 
     vdagent_clipboard_peer_register(vd);
 
-    ret = vmstate_load_state(f, &vmstate_cbinfo_array, &cbinfo, 0);
+    ret = vmstate_load_state(f, &vmstate_cbinfo_array, &cbinfo, 0,
+                             &local_err);
     if (ret) {
+        error_report_err(local_err);
         return ret;
     }
 
diff --git a/util/oslib-posix.c b/util/oslib-posix.c
index 14cf94a..3c14b72 100644
--- a/util/oslib-posix.c
+++ b/util/oslib-posix.c
@@ -305,6 +305,15 @@ int qemu_socketpair(int domain, int type, int protocol, int sv[2])
     return ret;
 }
 
+void qemu_clear_cloexec(int fd)
+{
+    int f;
+    f = fcntl(fd, F_GETFD);
+    assert(f != -1);
+    f = fcntl(fd, F_SETFD, f & ~FD_CLOEXEC);
+    assert(f != -1);
+}
+
 char *
 qemu_get_local_state_dir(void)
 {
diff --git a/util/oslib-win32.c b/util/oslib-win32.c
index 84bc65a..839b8a4 100644
--- a/util/oslib-win32.c
+++ b/util/oslib-win32.c
@@ -219,6 +219,10 @@ void qemu_set_cloexec(int fd)
 {
 }
 
+void qemu_clear_cloexec(int fd)
+{
+}
+
 int qemu_get_thread_id(void)
 {
     return GetCurrentThreadId();