Merge tag 'pull-vfio-20250211' of https://github.com/legoater/qemu into staging

vfio queue:

* Coverity fix
* IGD cleanups using VFIOQuirk
* SIGSEV fix in IOMMUFD host IOMMU device
* Improved error reporting for MMIO region mapping failures

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# gpg: Good signature from "Cédric Le Goater <clg@redhat.com>" [full]
# gpg:                 aka "Cédric Le Goater <clg@kaod.org>" [full]
# Primary key fingerprint: A0F6 6548 F048 95EB FE6B  0B60 51A3 43C7 CFFB ECA1

* tag 'pull-vfio-20250211' of https://github.com/legoater/qemu:
  vfio: Remove superfluous error report in vfio_listener_region_add()
  vfio: Remove reports of DMA mapping errors in backends
  vfio: Improve error reporting when MMIO region mapping fails
  vfio: Introduce vfio_get_vfio_device()
  vfio: Rephrase comment in vfio_listener_region_add() error path
  vfio/pci: Replace "iommu_device" by "vIOMMU"
  util/error: Introduce warn_report_err_once()
  vfio/iommufd: Fix SIGSEV in iommufd_cdev_attach()
  vfio/igd: use VFIOConfigMirrorQuirk for mirrored registers
  vfio/pci: introduce config_offset field in VFIOConfigMirrorQuirk
  vfio/pci: declare generic quirks in a new header file
  vfio/igd: Fix potential overflow in igd_gtt_memory_size()

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

12 files changed, 177 insertions, 165 deletions

diff --git a/backends/iommufd.c b/backends/iommufd.c
index 7b4fc8e..d57da44 100644
--- a/backends/iommufd.c
+++ b/backends/iommufd.c
@@ -167,8 +167,6 @@ int iommufd_backend_map_dma(IOMMUFDBackend *be, uint32_t ioas_id, hwaddr iova,
         /* TODO: Not support mapping hardware PCI BAR region for now. */
         if (errno == EFAULT) {
             warn_report("IOMMU_IOAS_MAP failed: %m, PCI BAR?");
-        } else {
-            error_report("IOMMU_IOAS_MAP failed: %m");
         }
     }
     return ret;
@@ -203,7 +201,6 @@ int iommufd_backend_unmap_dma(IOMMUFDBackend *be, uint32_t ioas_id,
 
     if (ret) {
         ret = -errno;
-        error_report("IOMMU_IOAS_UNMAP failed: %m");
     }
     return ret;
 }
diff --git a/hw/vfio/common.c b/hw/vfio/common.c
index f7499a9..abbdc56 100644
--- a/hw/vfio/common.c
+++ b/hw/vfio/common.c
@@ -555,6 +555,18 @@ static bool vfio_get_section_iova_range(VFIOContainerBase *bcontainer,
     return true;
 }
 
+static void vfio_device_error_append(VFIODevice *vbasedev, Error **errp)
+{
+    /*
+     * MMIO region mapping failures are not fatal but in this case PCI
+     * peer-to-peer transactions are broken.
+     */
+    if (vbasedev && vbasedev->type == VFIO_DEVICE_TYPE_PCI) {
+        error_append_hint(errp, "%s: PCI peer-to-peer transactions "
+                          "on BARs are not supported.\n", vbasedev->name);
+    }
+}
+
 static void vfio_listener_region_add(MemoryListener *listener,
                                      MemoryRegionSection *section)
 {
@@ -582,8 +594,9 @@ static void vfio_listener_region_add(MemoryListener *listener,
         return;
     }
 
+    /* PPC64/pseries machine only */
     if (!vfio_container_add_section_window(bcontainer, section, &err)) {
-        goto fail;
+        goto mmio_dma_error;
     }
 
     memory_region_ref(section->mr);
@@ -668,9 +681,13 @@ static void vfio_listener_region_add(MemoryListener *listener,
                    "0x%"HWADDR_PRIx", %p) = %d (%s)",
                    bcontainer, iova, int128_get64(llsize), vaddr, ret,
                    strerror(-ret));
+    mmio_dma_error:
         if (memory_region_is_ram_device(section->mr)) {
             /* Allow unexpected mappings not to be fatal for RAM devices */
-            error_report_err(err);
+            VFIODevice *vbasedev =
+                vfio_get_vfio_device(memory_region_owner(section->mr));
+            vfio_device_error_append(vbasedev, &err);
+            warn_report_err_once(err);
             return;
         }
         goto fail;
@@ -679,16 +696,12 @@ static void vfio_listener_region_add(MemoryListener *listener,
     return;
 
 fail:
-    if (memory_region_is_ram_device(section->mr)) {
-        error_reportf_err(err, "PCI p2p may not work: ");
-        return;
-    }
-    /*
-     * On the initfn path, store the first error in the container so we
-     * can gracefully fail.  Runtime, there's not much we can do other
-     * than throw a hardware error.
-     */
     if (!bcontainer->initialized) {
+        /*
+         * At machine init time or when the device is attached to the
+         * VM, store the first error in the container so we can
+         * gracefully fail the device realize routine.
+         */
         if (!bcontainer->error) {
             error_propagate_prepend(&bcontainer->error, err,
                                     "Region %s: ",
@@ -697,6 +710,10 @@ fail:
             error_free(err);
         }
     } else {
+        /*
+         * At runtime, there's not much we can do other than throw a
+         * hardware error.
+         */
         error_report_err(err);
         hw_error("vfio: DMA mapping failed, unable to continue");
     }
@@ -786,6 +803,7 @@ static void vfio_listener_region_del(MemoryListener *listener,
 
     memory_region_unref(section->mr);
 
+    /* PPC64/pseries machine only */
     vfio_container_del_section_window(bcontainer, section);
 }
 
diff --git a/hw/vfio/container.c b/hw/vfio/container.c
index 4ebb526..7c57bdd2 100644
--- a/hw/vfio/container.c
+++ b/hw/vfio/container.c
@@ -159,7 +159,6 @@ static int vfio_legacy_dma_unmap(const VFIOContainerBase *bcontainer,
             unmap.size -= 1ULL << ctz64(bcontainer->pgsizes);
             continue;
         }
-        error_report("VFIO_UNMAP_DMA failed: %s", strerror(errno));
         return -errno;
     }
 
@@ -204,7 +203,6 @@ static int vfio_legacy_dma_map(const VFIOContainerBase *bcontainer, hwaddr iova,
         return 0;
     }
 
-    error_report("VFIO_MAP_DMA failed: %s", strerror(errno));
     return -errno;
 }
 
diff --git a/hw/vfio/helpers.c b/hw/vfio/helpers.c
index 913796f..4b255d4 100644
--- a/hw/vfio/helpers.c
+++ b/hw/vfio/helpers.c
@@ -23,6 +23,7 @@
 #include <sys/ioctl.h>
 
 #include "hw/vfio/vfio-common.h"
+#include "hw/vfio/pci.h"
 #include "hw/hw.h"
 #include "trace.h"
 #include "qapi/error.h"
@@ -728,3 +729,12 @@ bool vfio_device_hiod_realize(VFIODevice *vbasedev, Error **errp)
 
     return HOST_IOMMU_DEVICE_GET_CLASS(hiod)->realize(hiod, vbasedev, errp);
 }
+
+VFIODevice *vfio_get_vfio_device(Object *obj)
+{
+    if (object_dynamic_cast(obj, TYPE_VFIO_PCI)) {
+        return &VFIO_PCI(obj)->vbasedev;
+    } else {
+        return NULL;
+    }
+}
diff --git a/hw/vfio/igd.c b/hw/vfio/igd.c
index 0740a5d..b1a237e 100644
--- a/hw/vfio/igd.c
+++ b/hw/vfio/igd.c
@@ -18,6 +18,7 @@
 #include "hw/hw.h"
 #include "hw/nvram/fw_cfg.h"
 #include "pci.h"
+#include "pci-quirks.h"
 #include "trace.h"
 
 /*
@@ -133,7 +134,7 @@ static uint64_t igd_gtt_memory_size(int gen, uint16_t gmch)
     } else {
         ggms = (gmch >> IGD_GMCH_GEN8_GGMS_SHIFT) & IGD_GMCH_GEN8_GGMS_MASK;
         if (ggms != 0) {
-            ggms = 1 << ggms;
+            ggms = 1ULL << ggms;
         }
     }
 
@@ -422,83 +423,13 @@ static const MemoryRegionOps vfio_igd_index_quirk = {
     .endianness = DEVICE_LITTLE_ENDIAN,
 };
 
-static uint64_t vfio_igd_pci_config_read(VFIOPCIDevice *vdev, uint64_t offset,
-                                         unsigned size)
-{
-    switch (size) {
-    case 1:
-        return pci_get_byte(vdev->pdev.config + offset);
-    case 2:
-        return pci_get_word(vdev->pdev.config + offset);
-    case 4:
-        return pci_get_long(vdev->pdev.config + offset);
-    case 8:
-        return pci_get_quad(vdev->pdev.config + offset);
-    default:
-        hw_error("igd: unsupported pci config read at %"PRIx64", size %u",
-                 offset, size);
-        break;
-    }
-
-    return 0;
-}
-
-static void vfio_igd_pci_config_write(VFIOPCIDevice *vdev, uint64_t offset,
-                                      uint64_t data, unsigned size)
-{
-    switch (size) {
-    case 1:
-        pci_set_byte(vdev->pdev.config + offset, data);
-        break;
-    case 2:
-        pci_set_word(vdev->pdev.config + offset, data);
-        break;
-    case 4:
-        pci_set_long(vdev->pdev.config + offset, data);
-        break;
-    case 8:
-        pci_set_quad(vdev->pdev.config + offset, data);
-        break;
-    default:
-        hw_error("igd: unsupported pci config write at %"PRIx64", size %u",
-                 offset, size);
-        break;
-    }
-}
-
-#define VFIO_IGD_QUIRK_MIRROR_REG(reg, name)                            \
-static uint64_t vfio_igd_quirk_read_##name(void *opaque,                \
-                                           hwaddr addr, unsigned size)  \
-{                                                                       \
-    VFIOPCIDevice *vdev = opaque;                                       \
-                                                                        \
-    return vfio_igd_pci_config_read(vdev, reg + addr, size);            \
-}                                                                       \
-                                                                        \
-static void vfio_igd_quirk_write_##name(void *opaque, hwaddr addr,      \
-                                        uint64_t data, unsigned size)   \
-{                                                                       \
-    VFIOPCIDevice *vdev = opaque;                                       \
-                                                                        \
-    vfio_igd_pci_config_write(vdev, reg + addr, data, size);            \
-}                                                                       \
-                                                                        \
-static const MemoryRegionOps vfio_igd_quirk_mirror_##name = {           \
-    .read = vfio_igd_quirk_read_##name,                                 \
-    .write = vfio_igd_quirk_write_##name,                               \
-    .endianness = DEVICE_LITTLE_ENDIAN,                                 \
-};
-
-VFIO_IGD_QUIRK_MIRROR_REG(IGD_GMCH, ggc)
-VFIO_IGD_QUIRK_MIRROR_REG(IGD_BDSM, bdsm)
-VFIO_IGD_QUIRK_MIRROR_REG(IGD_BDSM_GEN11, bdsm64)
-
 #define IGD_GGC_MMIO_OFFSET     0x108040
 #define IGD_BDSM_MMIO_OFFSET    0x1080C0
 
 void vfio_probe_igd_bar0_quirk(VFIOPCIDevice *vdev, int nr)
 {
-    VFIOQuirk *quirk;
+    VFIOQuirk *ggc_quirk, *bdsm_quirk;
+    VFIOConfigMirrorQuirk *ggc_mirror, *bdsm_mirror;
     int gen;
 
     /*
@@ -522,33 +453,39 @@ void vfio_probe_igd_bar0_quirk(VFIOPCIDevice *vdev, int nr)
         return;
     }
 
-    quirk = vfio_quirk_alloc(2);
-    quirk->data = vdev;
+    ggc_quirk = vfio_quirk_alloc(1);
+    ggc_mirror = ggc_quirk->data = g_malloc0(sizeof(*ggc_mirror));
+    ggc_mirror->mem = ggc_quirk->mem;
+    ggc_mirror->vdev = vdev;
+    ggc_mirror->bar = nr;
+    ggc_mirror->offset = IGD_GGC_MMIO_OFFSET;
+    ggc_mirror->config_offset = IGD_GMCH;
 
-    memory_region_init_io(&quirk->mem[0], OBJECT(vdev),
-                          &vfio_igd_quirk_mirror_ggc, vdev,
+    memory_region_init_io(ggc_mirror->mem, OBJECT(vdev),
+                          &vfio_generic_mirror_quirk, ggc_mirror,
                           "vfio-igd-ggc-quirk", 2);
-    memory_region_add_subregion_overlap(vdev->bars[0].region.mem,
-                                        IGD_GGC_MMIO_OFFSET, &quirk->mem[0],
+    memory_region_add_subregion_overlap(vdev->bars[nr].region.mem,
+                                        ggc_mirror->offset, ggc_mirror->mem,
                                         1);
 
-    if (gen < 11) {
-        memory_region_init_io(&quirk->mem[1], OBJECT(vdev),
-                              &vfio_igd_quirk_mirror_bdsm, vdev,
-                              "vfio-igd-bdsm-quirk", 4);
-        memory_region_add_subregion_overlap(vdev->bars[0].region.mem,
-                                            IGD_BDSM_MMIO_OFFSET,
-                                            &quirk->mem[1], 1);
-    } else {
-        memory_region_init_io(&quirk->mem[1], OBJECT(vdev),
-                              &vfio_igd_quirk_mirror_bdsm64, vdev,
-                              "vfio-igd-bdsm-quirk", 8);
-        memory_region_add_subregion_overlap(vdev->bars[0].region.mem,
-                                            IGD_BDSM_MMIO_OFFSET,
-                                            &quirk->mem[1], 1);
-    }
+    QLIST_INSERT_HEAD(&vdev->bars[nr].quirks, ggc_quirk, next);
 
-    QLIST_INSERT_HEAD(&vdev->bars[nr].quirks, quirk, next);
+    bdsm_quirk = vfio_quirk_alloc(1);
+    bdsm_mirror = bdsm_quirk->data = g_malloc0(sizeof(*bdsm_mirror));
+    bdsm_mirror->mem = bdsm_quirk->mem;
+    bdsm_mirror->vdev = vdev;
+    bdsm_mirror->bar = nr;
+    bdsm_mirror->offset = IGD_BDSM_MMIO_OFFSET;
+    bdsm_mirror->config_offset = (gen < 11) ? IGD_BDSM : IGD_BDSM_GEN11;
+
+    memory_region_init_io(bdsm_mirror->mem, OBJECT(vdev),
+                          &vfio_generic_mirror_quirk, bdsm_mirror,
+                          "vfio-igd-bdsm-quirk", (gen < 11) ? 4 : 8);
+    memory_region_add_subregion_overlap(vdev->bars[nr].region.mem,
+                                        bdsm_mirror->offset, bdsm_mirror->mem,
+                                        1);
+
+    QLIST_INSERT_HEAD(&vdev->bars[nr].quirks, bdsm_quirk, next);
 }
 
 void vfio_probe_igd_bar4_quirk(VFIOPCIDevice *vdev, int nr)
diff --git a/hw/vfio/iommufd.c b/hw/vfio/iommufd.c
index 3490a8f..df61edf 100644
--- a/hw/vfio/iommufd.c
+++ b/hw/vfio/iommufd.c
@@ -515,8 +515,8 @@ static bool iommufd_cdev_attach(const char *name, VFIODevice *vbasedev,
         } else {
             ret = iommufd_cdev_ram_block_discard_disable(true);
             if (ret) {
-                error_setg(errp,
-                              "Cannot set discarding of RAM broken (%d)", ret);
+                error_setg_errno(errp, -ret,
+                                 "Cannot set discarding of RAM broken");
                 goto err_discard_disable;
             }
             goto found_container;
@@ -544,6 +544,7 @@ static bool iommufd_cdev_attach(const char *name, VFIODevice *vbasedev,
 
     ret = iommufd_cdev_ram_block_discard_disable(true);
     if (ret) {
+        error_setg_errno(errp, -ret, "Cannot set discarding of RAM broken");
         goto err_discard_disable;
     }
 
diff --git a/hw/vfio/pci-quirks.c b/hw/vfio/pci-quirks.c
index c8e6047..fbe43b0 100644
--- a/hw/vfio/pci-quirks.c
+++ b/hw/vfio/pci-quirks.c
@@ -25,6 +25,7 @@
 #include "hw/nvram/fw_cfg.h"
 #include "hw/qdev-properties.h"
 #include "pci.h"
+#include "pci-quirks.h"
 #include "trace.h"
 
 /*
@@ -66,40 +67,6 @@ bool vfio_opt_rom_in_denylist(VFIOPCIDevice *vdev)
  * Device specific region quirks (mostly backdoors to PCI config space)
  */
 
-/*
- * The generic window quirks operate on an address and data register,
- * vfio_generic_window_address_quirk handles the address register and
- * vfio_generic_window_data_quirk handles the data register.  These ops
- * pass reads and writes through to hardware until a value matching the
- * stored address match/mask is written.  When this occurs, the data
- * register access emulated PCI config space for the device rather than
- * passing through accesses.  This enables devices where PCI config space
- * is accessible behind a window register to maintain the virtualization
- * provided through vfio.
- */
-typedef struct VFIOConfigWindowMatch {
-    uint32_t match;
-    uint32_t mask;
-} VFIOConfigWindowMatch;
-
-typedef struct VFIOConfigWindowQuirk {
-    struct VFIOPCIDevice *vdev;
-
-    uint32_t address_val;
-
-    uint32_t address_offset;
-    uint32_t data_offset;
-
-    bool window_enabled;
-    uint8_t bar;
-
-    MemoryRegion *addr_mem;
-    MemoryRegion *data_mem;
-
-    uint32_t nr_matches;
-    VFIOConfigWindowMatch matches[];
-} VFIOConfigWindowQuirk;
-
 static uint64_t vfio_generic_window_quirk_address_read(void *opaque,
                                                        hwaddr addr,
                                                        unsigned size)
@@ -135,7 +102,7 @@ static void vfio_generic_window_quirk_address_write(void *opaque, hwaddr addr,
     }
 }
 
-static const MemoryRegionOps vfio_generic_window_address_quirk = {
+const MemoryRegionOps vfio_generic_window_address_quirk = {
     .read = vfio_generic_window_quirk_address_read,
     .write = vfio_generic_window_quirk_address_write,
     .endianness = DEVICE_LITTLE_ENDIAN,
@@ -178,26 +145,12 @@ static void vfio_generic_window_quirk_data_write(void *opaque, hwaddr addr,
                       addr + window->data_offset, data, size);
 }
 
-static const MemoryRegionOps vfio_generic_window_data_quirk = {
+const MemoryRegionOps vfio_generic_window_data_quirk = {
     .read = vfio_generic_window_quirk_data_read,
     .write = vfio_generic_window_quirk_data_write,
     .endianness = DEVICE_LITTLE_ENDIAN,
 };
 
-/*
- * The generic mirror quirk handles devices which expose PCI config space
- * through a region within a BAR.  When enabled, reads and writes are
- * redirected through to emulated PCI config space.  XXX if PCI config space
- * used memory regions, this could just be an alias.
- */
-typedef struct VFIOConfigMirrorQuirk {
-    struct VFIOPCIDevice *vdev;
-    uint32_t offset;
-    uint8_t bar;
-    MemoryRegion *mem;
-    uint8_t data[];
-} VFIOConfigMirrorQuirk;
-
 static uint64_t vfio_generic_quirk_mirror_read(void *opaque,
                                                hwaddr addr, unsigned size)
 {
@@ -209,6 +162,7 @@ static uint64_t vfio_generic_quirk_mirror_read(void *opaque,
     (void)vfio_region_read(&vdev->bars[mirror->bar].region,
                            addr + mirror->offset, size);
 
+    addr += mirror->config_offset;
     data = vfio_pci_read_config(&vdev->pdev, addr, size);
     trace_vfio_quirk_generic_mirror_read(vdev->vbasedev.name,
                                          memory_region_name(mirror->mem),
@@ -222,13 +176,14 @@ static void vfio_generic_quirk_mirror_write(void *opaque, hwaddr addr,
     VFIOConfigMirrorQuirk *mirror = opaque;
     VFIOPCIDevice *vdev = mirror->vdev;
 
+    addr += mirror->config_offset;
     vfio_pci_write_config(&vdev->pdev, addr, data, size);
     trace_vfio_quirk_generic_mirror_write(vdev->vbasedev.name,
                                           memory_region_name(mirror->mem),
                                           addr, data);
 }
 
-static const MemoryRegionOps vfio_generic_mirror_quirk = {
+const MemoryRegionOps vfio_generic_mirror_quirk = {
     .read = vfio_generic_quirk_mirror_read,
     .write = vfio_generic_quirk_mirror_write,
     .endianness = DEVICE_LITTLE_ENDIAN,
diff --git a/hw/vfio/pci-quirks.h b/hw/vfio/pci-quirks.h
new file mode 100644
index 0000000..d1532e3
--- /dev/null
+++ b/hw/vfio/pci-quirks.h
@@ -0,0 +1,72 @@
+/*
+ * vfio generic region quirks (mostly backdoors to PCI config space)
+ *
+ * Copyright Red Hat, Inc. 2012-2015
+ *
+ * Authors:
+ *  Alex Williamson <alex.williamson@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.  See
+ * the COPYING file in the top-level directory.
+ */
+#ifndef HW_VFIO_VFIO_PCI_QUIRKS_H
+#define HW_VFIO_VFIO_PCI_QUIRKS_H
+
+#include "qemu/osdep.h"
+#include "exec/memop.h"
+
+/*
+ * The generic window quirks operate on an address and data register,
+ * vfio_generic_window_address_quirk handles the address register and
+ * vfio_generic_window_data_quirk handles the data register.  These ops
+ * pass reads and writes through to hardware until a value matching the
+ * stored address match/mask is written.  When this occurs, the data
+ * register access emulated PCI config space for the device rather than
+ * passing through accesses.  This enables devices where PCI config space
+ * is accessible behind a window register to maintain the virtualization
+ * provided through vfio.
+ */
+typedef struct VFIOConfigWindowMatch {
+    uint32_t match;
+    uint32_t mask;
+} VFIOConfigWindowMatch;
+
+typedef struct VFIOConfigWindowQuirk {
+    struct VFIOPCIDevice *vdev;
+
+    uint32_t address_val;
+
+    uint32_t address_offset;
+    uint32_t data_offset;
+
+    bool window_enabled;
+    uint8_t bar;
+
+    MemoryRegion *addr_mem;
+    MemoryRegion *data_mem;
+
+    uint32_t nr_matches;
+    VFIOConfigWindowMatch matches[];
+} VFIOConfigWindowQuirk;
+
+extern const MemoryRegionOps vfio_generic_window_address_quirk;
+extern const MemoryRegionOps vfio_generic_window_data_quirk;
+
+/*
+ * The generic mirror quirk handles devices which expose PCI config space
+ * through a region within a BAR.  When enabled, reads and writes are
+ * redirected through to emulated PCI config space.  XXX if PCI config space
+ * used memory regions, this could just be an alias.
+ */
+typedef struct VFIOConfigMirrorQuirk {
+    struct VFIOPCIDevice *vdev;
+    uint32_t offset; /* Offset in BAR */
+    uint32_t config_offset; /* Offset in PCI config space */
+    uint8_t bar;
+    MemoryRegion *mem;
+    uint8_t data[];
+} VFIOConfigMirrorQuirk;
+
+extern const MemoryRegionOps vfio_generic_mirror_quirk;
+
+#endif /* HW_VFIO_VFIO_PCI_QUIRKS_H */
diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
index 9a55e7b..89d900e 100644
--- a/hw/vfio/pci.c
+++ b/hw/vfio/pci.c
@@ -3116,7 +3116,7 @@ static void vfio_realize(PCIDevice *pdev, Error **errp)
 
     if (!vbasedev->mdev &&
         !pci_device_set_iommu_device(pdev, vbasedev->hiod, errp)) {
-        error_prepend(errp, "Failed to set iommu_device: ");
+        error_prepend(errp, "Failed to set vIOMMU: ");
         goto out_teardown;
     }
 
diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
index 0c60be5..ac35136 100644
--- a/include/hw/vfio/vfio-common.h
+++ b/include/hw/vfio/vfio-common.h
@@ -252,6 +252,7 @@ bool vfio_device_hiod_realize(VFIODevice *vbasedev, Error **errp);
 bool vfio_attach_device(char *name, VFIODevice *vbasedev,
                         AddressSpace *as, Error **errp);
 void vfio_detach_device(VFIODevice *vbasedev);
+VFIODevice *vfio_get_vfio_device(Object *obj);
 
 int vfio_kvm_device_add_fd(int fd, Error **errp);
 int vfio_kvm_device_del_fd(int fd, Error **errp);
diff --git a/include/qapi/error.h b/include/qapi/error.h
index 71f8fb2..f5fe216 100644
--- a/include/qapi/error.h
+++ b/include/qapi/error.h
@@ -467,6 +467,18 @@ void error_reportf_err(Error *err, const char *fmt, ...)
     G_GNUC_PRINTF(2, 3);
 
 /*
+ * Similar to warn_report_err(), except it prints the message just once.
+ * Return true when it prints, false otherwise.
+ */
+bool warn_report_err_once_cond(bool *printed, Error *err);
+
+#define warn_report_err_once(err)                           \
+    ({                                                      \
+        static bool print_once_;                            \
+        warn_report_err_once_cond(&print_once_, err);       \
+    })
+
+/*
  * Just like error_setg(), except you get to specify the error class.
  * Note: use of error classes other than ERROR_CLASS_GENERIC_ERROR is
  * strongly discouraged.
diff --git a/util/error.c b/util/error.c
index e5e2472..673011b 100644
--- a/util/error.c
+++ b/util/error.c
@@ -247,6 +247,17 @@ void warn_report_err(Error *err)
     error_free(err);
 }
 
+bool warn_report_err_once_cond(bool *printed, Error *err)
+{
+    if (*printed) {
+        error_free(err);
+        return false;
+    }
+    *printed = true;
+    warn_report_err(err);
+    return true;
+}
+
 void error_reportf_err(Error *err, const char *fmt, ...)
 {
     va_list ap;