Merge tag 'migration-20240311-pull-request' of https://gitlab.com/peterx/qemu into staging

Migration pull request

- Avihai's fix to allow vmstate iterators to not starve for VFIO
- Maksim's fix on additional check on precopy load error
- Fabiano's fix on fdatasync() hang in mapped-ram
- Jonathan's fix on vring cached access over MMIO regions
- Cedric's cleanup patches 1-4 out of his error report series
- Yu's fix for RDMA migration (which used to be broken even for 8.2)
- Anthony's small cleanup/fix on err message
- Steve's patches on privatize migration.h
- Xiang's patchset to enable zero page detections in multifd threads

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* tag 'migration-20240311-pull-request' of https://gitlab.com/peterx/qemu: (34 commits)
  migration/multifd: Add new migration test cases for legacy zero page checking.
  migration/multifd: Enable multifd zero page checking by default.
  migration/multifd: Implement ram_save_target_page_multifd to handle multifd version of MigrationOps::ram_save_target_page.
  migration/multifd: Implement zero page transmission on the multifd thread.
  migration/multifd: Add new migration option zero-page-detection.
  migration/multifd: Allow clearing of the file_bmap from multifd
  migration/multifd: Allow zero pages in file migration
  migration: purge MigrationState from public interface
  migration: delete unused accessors
  migration: privatize colo interfaces
  migration: migration_file_set_error
  migration: migration_is_device
  migration: migration_thread_is_self
  migration: export vcpu_dirty_limit_period
  migration: export migration_is_running
  migration: export migration_is_active
  migration: export migration_is_setup_or_active
  migration: remove migration.h references
  migration: export fewer options
  migration: Fix format in error message
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

3 files changed, 14 insertions, 28 deletions

diff --git a/hw/vfio/common.c b/hw/vfio/common.c
index ff88c3f..011ceaa 100644
--- a/hw/vfio/common.c
+++ b/hw/vfio/common.c
@@ -39,7 +39,6 @@
 #include "sysemu/runstate.h"
 #include "trace.h"
 #include "qapi/error.h"
-#include "migration/migration.h"
 #include "migration/misc.h"
 #include "migration/blocker.h"
 #include "migration/qemu-file.h"
@@ -150,14 +149,8 @@ bool vfio_viommu_preset(VFIODevice *vbasedev)
 
 static void vfio_set_migration_error(int err)
 {
-    MigrationState *ms = migrate_get_current();
-
-    if (migration_is_setup_or_active(ms->state)) {
-        WITH_QEMU_LOCK_GUARD(&ms->qemu_file_lock) {
-            if (ms->to_dst_file) {
-                qemu_file_set_error(ms->to_dst_file, err);
-            }
-        }
+    if (migration_is_setup_or_active()) {
+        migration_file_set_error(err);
     }
 }
 
@@ -180,10 +173,8 @@ bool vfio_device_state_is_precopy(VFIODevice *vbasedev)
 static bool vfio_devices_all_dirty_tracking(VFIOContainerBase *bcontainer)
 {
     VFIODevice *vbasedev;
-    MigrationState *ms = migrate_get_current();
 
-    if (ms->state != MIGRATION_STATUS_ACTIVE &&
-        ms->state != MIGRATION_STATUS_DEVICE) {
+    if (!migration_is_active() && !migration_is_device()) {
         return false;
     }
 
@@ -225,7 +216,7 @@ vfio_devices_all_running_and_mig_active(const VFIOContainerBase *bcontainer)
 {
     VFIODevice *vbasedev;
 
-    if (!migration_is_active(migrate_get_current())) {
+    if (!migration_is_active()) {
         return false;
     }
 
diff --git a/hw/vfio/container.c b/hw/vfio/container.c
index 096d77e..9a775e4 100644
--- a/hw/vfio/container.c
+++ b/hw/vfio/container.c
@@ -32,7 +32,6 @@
 #include "sysemu/reset.h"
 #include "trace.h"
 #include "qapi/error.h"
-#include "migration/migration.h"
 #include "pci.h"
 
 VFIOGroupList vfio_group_list =
diff --git a/hw/vfio/migration.c b/hw/vfio/migration.c
index 2050ac8..1149c6b 100644
--- a/hw/vfio/migration.c
+++ b/hw/vfio/migration.c
@@ -17,14 +17,12 @@
 
 #include "sysemu/runstate.h"
 #include "hw/vfio/vfio-common.h"
-#include "migration/migration.h"
-#include "migration/options.h"
+#include "migration/misc.h"
 #include "migration/savevm.h"
 #include "migration/vmstate.h"
 #include "migration/qemu-file.h"
 #include "migration/register.h"
 #include "migration/blocker.h"
-#include "migration/misc.h"
 #include "qapi/error.h"
 #include "exec/ramlist.h"
 #include "exec/ram_addr.h"
@@ -505,6 +503,12 @@ static bool vfio_is_active_iterate(void *opaque)
     return vfio_device_state_is_precopy(vbasedev);
 }
 
+/*
+ * Note about migration rate limiting: VFIO migration buffer size is currently
+ * limited to 1MB, so there is no need to check if migration rate exceeded (as
+ * in the worst case it will exceed by 1MB). However, if the buffer size is
+ * later changed to a bigger value, migration rate should be enforced here.
+ */
 static int vfio_save_iterate(QEMUFile *f, void *opaque)
 {
     VFIODevice *vbasedev = opaque;
@@ -529,11 +533,7 @@ static int vfio_save_iterate(QEMUFile *f, void *opaque)
     trace_vfio_save_iterate(vbasedev->name, migration->precopy_init_size,
                             migration->precopy_dirty_size);
 
-    /*
-     * A VFIO device's pre-copy dirty_bytes is not guaranteed to reach zero.
-     * Return 1 so following handlers will not be potentially blocked.
-     */
-    return 1;
+    return !migration->precopy_init_size && !migration->precopy_dirty_size;
 }
 
 static int vfio_save_complete_precopy(QEMUFile *f, void *opaque)
@@ -713,9 +713,7 @@ static void vfio_vmstate_change_prepare(void *opaque, bool running,
          * Migration should be aborted in this case, but vm_state_notify()
          * currently does not support reporting failures.
          */
-        if (migrate_get_current()->to_dst_file) {
-            qemu_file_set_error(migrate_get_current()->to_dst_file, ret);
-        }
+        migration_file_set_error(ret);
     }
 
     trace_vfio_vmstate_change_prepare(vbasedev->name, running,
@@ -745,9 +743,7 @@ static void vfio_vmstate_change(void *opaque, bool running, RunState state)
          * Migration should be aborted in this case, but vm_state_notify()
          * currently does not support reporting failures.
          */
-        if (migrate_get_current()->to_dst_file) {
-            qemu_file_set_error(migrate_get_current()->to_dst_file, ret);
-        }
+        migration_file_set_error(ret);
     }
 
     trace_vfio_vmstate_change(vbasedev->name, running, RunState_str(state),