[PATCH v4 23/25] vfio: Add Error** argument to .get_dirty_bitmap() handler

Cédric Le Goater posted 25 patches 8 months, 3 weeks ago
Maintainers: Stefano Stabellini <sstabellini@kernel.org>, Anthony Perard <anthony.perard@citrix.com>, Paul Durrant <paul@xen.org>, Paolo Bonzini <pbonzini@redhat.com>, Richard Henderson <richard.henderson@linaro.org>, Eduardo Habkost <eduardo@habkost.net>, "Michael S. Tsirkin" <mst@redhat.com>, Marcel Apfelbaum <marcel.apfelbaum@gmail.com>, Nicholas Piggin <npiggin@gmail.com>, Daniel Henrique Barboza <danielhb413@gmail.com>, "Cédric Le Goater" <clg@kaod.org>, David Gibson <david@gibson.dropbear.id.au>, Harsh Prateek Bora <harshpb@linux.ibm.com>, Halil Pasic <pasic@linux.ibm.com>, Christian Borntraeger <borntraeger@linux.ibm.com>, Thomas Huth <thuth@redhat.com>, Eric Farman <farman@linux.ibm.com>, David Hildenbrand <david@redhat.com>, Ilya Leoshkevich <iii@linux.ibm.com>, Alex Williamson <alex.williamson@redhat.com>, Peter Xu <peterx@redhat.com>, "Philippe Mathieu-Daudé" <philmd@linaro.org>, Fabiano Rosas <farosas@suse.de>, Stefan Hajnoczi <stefanha@redhat.com>, Fam Zheng <fam@euphon.net>, Eric Blake <eblake@redhat.com>, Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>, John Snow <jsnow@redhat.com>, Hyman Huang <yong.huang@smartx.com>
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[PATCH v4 23/25] vfio: Add Error** argument to .get_dirty_bitmap() handler
Posted by Cédric Le Goater 8 months, 3 weeks ago
Let the callers do the error reporting. Add documentation while at it.

Signed-off-by: Cédric Le Goater <clg@redhat.com>
---
 include/hw/vfio/vfio-common.h         |  4 +-
 include/hw/vfio/vfio-container-base.h | 17 +++++++-
 hw/vfio/common.c                      | 59 ++++++++++++++++++---------
 hw/vfio/container-base.c              |  5 ++-
 hw/vfio/container.c                   | 13 +++---
 5 files changed, 67 insertions(+), 31 deletions(-)

diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
index 46f88493634b5634a9c14a5caa33a463fbf2c50d..68911d36676667352e94a97895828aff4b194b57 100644
--- a/include/hw/vfio/vfio-common.h
+++ b/include/hw/vfio/vfio-common.h
@@ -274,9 +274,9 @@ bool
 vfio_devices_all_device_dirty_tracking(const VFIOContainerBase *bcontainer);
 int vfio_devices_query_dirty_bitmap(const VFIOContainerBase *bcontainer,
                                     VFIOBitmap *vbmap, hwaddr iova,
-                                    hwaddr size);
+                                    hwaddr size, Error **errp);
 int vfio_get_dirty_bitmap(const VFIOContainerBase *bcontainer, uint64_t iova,
-                          uint64_t size, ram_addr_t ram_addr);
+                          uint64_t size, ram_addr_t ram_addr, Error **errp);
 
 /* Returns 0 on success, or a negative errno. */
 int vfio_device_get_name(VFIODevice *vbasedev, Error **errp);
diff --git a/include/hw/vfio/vfio-container-base.h b/include/hw/vfio/vfio-container-base.h
index c76984654a596e3016a8cf833e10143eb872e102..ebc49ebfbe7de862450941b1129faad5d62b3769 100644
--- a/include/hw/vfio/vfio-container-base.h
+++ b/include/hw/vfio/vfio-container-base.h
@@ -85,7 +85,7 @@ int vfio_container_set_dirty_page_tracking(VFIOContainerBase *bcontainer,
                                            bool start, Error **errp);
 int vfio_container_query_dirty_bitmap(const VFIOContainerBase *bcontainer,
                                       VFIOBitmap *vbmap,
-                                      hwaddr iova, hwaddr size);
+                                      hwaddr iova, hwaddr size, Error **errp);
 
 void vfio_container_init(VFIOContainerBase *bcontainer,
                          VFIOAddressSpace *space,
@@ -138,9 +138,22 @@ struct VFIOIOMMUClass {
      */
     int (*set_dirty_page_tracking)(const VFIOContainerBase *bcontainer,
                                    bool start, Error **errp);
+    /**
+     * @query_dirty_bitmap
+     *
+     * Get list of dirty pages from container
+     *
+     * @bcontainer: #VFIOContainerBase from which to get dirty pages
+     * @vbmap: #VFIOBitmap internal bitmap structure
+     * @iova: iova base address
+     * @size: size of iova range
+     * @errp: pointer to Error*, to store an error if it happens.
+     *
+     * Returns zero to indicate success and negative for error
+     */
     int (*query_dirty_bitmap)(const VFIOContainerBase *bcontainer,
                               VFIOBitmap *vbmap,
-                              hwaddr iova, hwaddr size);
+                              hwaddr iova, hwaddr size, Error **errp);
     /* PCI specific */
     int (*pci_hot_reset)(VFIODevice *vbasedev, bool single);
 
diff --git a/hw/vfio/common.c b/hw/vfio/common.c
index 496e5adaf8f18e9ae7e86dd69be0b9e71e86404f..65a11dc088524647541db97b7b8d6f07e5044728 100644
--- a/hw/vfio/common.c
+++ b/hw/vfio/common.c
@@ -1158,7 +1158,7 @@ static int vfio_device_dma_logging_report(VFIODevice *vbasedev, hwaddr iova,
 
 int vfio_devices_query_dirty_bitmap(const VFIOContainerBase *bcontainer,
                                     VFIOBitmap *vbmap, hwaddr iova,
-                                    hwaddr size)
+                                    hwaddr size, Error **errp)
 {
     VFIODevice *vbasedev;
     int ret;
@@ -1167,10 +1167,10 @@ int vfio_devices_query_dirty_bitmap(const VFIOContainerBase *bcontainer,
         ret = vfio_device_dma_logging_report(vbasedev, iova, size,
                                              vbmap->bitmap);
         if (ret) {
-            error_report("%s: Failed to get DMA logging report, iova: "
-                         "0x%" HWADDR_PRIx ", size: 0x%" HWADDR_PRIx
-                         ", err: %d (%s)",
-                         vbasedev->name, iova, size, ret, strerror(-ret));
+            error_setg(errp, "%s: Failed to get DMA logging report, iova: "
+                       "0x%" HWADDR_PRIx ", size: 0x%" HWADDR_PRIx
+                       ", err: %d (%s)",
+                       vbasedev->name, iova, size, ret, strerror(-ret));
 
             return ret;
         }
@@ -1180,7 +1180,7 @@ int vfio_devices_query_dirty_bitmap(const VFIOContainerBase *bcontainer,
 }
 
 int vfio_get_dirty_bitmap(const VFIOContainerBase *bcontainer, uint64_t iova,
-                          uint64_t size, ram_addr_t ram_addr)
+                          uint64_t size, ram_addr_t ram_addr, Error **errp)
 {
     bool all_device_dirty_tracking =
         vfio_devices_all_device_dirty_tracking(bcontainer);
@@ -1197,13 +1197,17 @@ int vfio_get_dirty_bitmap(const VFIOContainerBase *bcontainer, uint64_t iova,
 
     ret = vfio_bitmap_alloc(&vbmap, size);
     if (ret) {
+        error_setg_errno(errp, -ret,
+                         "Failed to allocate dirty tracking bitmap");
         return ret;
     }
 
     if (all_device_dirty_tracking) {
-        ret = vfio_devices_query_dirty_bitmap(bcontainer, &vbmap, iova, size);
+        ret = vfio_devices_query_dirty_bitmap(bcontainer, &vbmap, iova, size,
+                                              errp);
     } else {
-        ret = vfio_container_query_dirty_bitmap(bcontainer, &vbmap, iova, size);
+        ret = vfio_container_query_dirty_bitmap(bcontainer, &vbmap, iova, size,
+                                                errp);
     }
 
     if (ret) {
@@ -1251,12 +1255,13 @@ static void vfio_iommu_map_dirty_notify(IOMMUNotifier *n, IOMMUTLBEntry *iotlb)
     }
 
     ret = vfio_get_dirty_bitmap(bcontainer, iova, iotlb->addr_mask + 1,
-                                translated_addr);
+                                translated_addr, &local_err);
     if (ret) {
-        error_report("vfio_iommu_map_dirty_notify(%p, 0x%"HWADDR_PRIx", "
-                     "0x%"HWADDR_PRIx") = %d (%s)",
-                     bcontainer, iova, iotlb->addr_mask + 1, ret,
-                     strerror(-ret));
+        error_prepend(&local_err,
+                      "vfio_iommu_map_dirty_notify(%p, 0x%"HWADDR_PRIx", "
+                      "0x%"HWADDR_PRIx") failed :", bcontainer, iova,
+                      iotlb->addr_mask + 1);
+        error_report_err(local_err);
     }
 
 out_lock:
@@ -1276,12 +1281,19 @@ static int vfio_ram_discard_get_dirty_bitmap(MemoryRegionSection *section,
     const ram_addr_t ram_addr = memory_region_get_ram_addr(section->mr) +
                                 section->offset_within_region;
     VFIORamDiscardListener *vrdl = opaque;
+    Error *local_err = NULL;
+    int ret;
 
     /*
      * Sync the whole mapped region (spanning multiple individual mappings)
      * in one go.
      */
-    return vfio_get_dirty_bitmap(vrdl->bcontainer, iova, size, ram_addr);
+    ret = vfio_get_dirty_bitmap(vrdl->bcontainer, iova, size, ram_addr,
+                                &local_err);
+    if (ret) {
+        error_report_err(local_err);
+    }
+    return ret;
 }
 
 static int
@@ -1313,7 +1325,7 @@ vfio_sync_ram_discard_listener_dirty_bitmap(VFIOContainerBase *bcontainer,
 }
 
 static int vfio_sync_dirty_bitmap(VFIOContainerBase *bcontainer,
-                                  MemoryRegionSection *section)
+                                  MemoryRegionSection *section, Error **errp)
 {
     ram_addr_t ram_addr;
 
@@ -1344,7 +1356,14 @@ static int vfio_sync_dirty_bitmap(VFIOContainerBase *bcontainer,
         }
         return 0;
     } else if (memory_region_has_ram_discard_manager(section->mr)) {
-        return vfio_sync_ram_discard_listener_dirty_bitmap(bcontainer, section);
+        int ret;
+
+        ret = vfio_sync_ram_discard_listener_dirty_bitmap(bcontainer, section);
+        if (ret) {
+            error_setg(errp,
+                       "Failed to sync dirty bitmap with RAM discard listener");
+            return ret;
+        }
     }
 
     ram_addr = memory_region_get_ram_addr(section->mr) +
@@ -1352,7 +1371,7 @@ static int vfio_sync_dirty_bitmap(VFIOContainerBase *bcontainer,
 
     return vfio_get_dirty_bitmap(bcontainer,
                    REAL_HOST_PAGE_ALIGN(section->offset_within_address_space),
-                   int128_get64(section->size), ram_addr);
+                                 int128_get64(section->size), ram_addr, errp);
 }
 
 static void vfio_listener_log_sync(MemoryListener *listener,
@@ -1361,16 +1380,16 @@ static void vfio_listener_log_sync(MemoryListener *listener,
     VFIOContainerBase *bcontainer = container_of(listener, VFIOContainerBase,
                                                  listener);
     int ret;
+    Error *local_err = NULL;
 
     if (vfio_listener_skipped_section(section)) {
         return;
     }
 
     if (vfio_devices_all_dirty_tracking(bcontainer)) {
-        ret = vfio_sync_dirty_bitmap(bcontainer, section);
+        ret = vfio_sync_dirty_bitmap(bcontainer, section, &local_err);
         if (ret) {
-            error_report("vfio: Failed to sync dirty bitmap, err: %d (%s)", ret,
-                         strerror(-ret));
+            error_report_err(local_err);
             vfio_set_migration_error(ret);
         }
     }
diff --git a/hw/vfio/container-base.c b/hw/vfio/container-base.c
index 7c0764121d24b02b6c4e66e368d7dff78a6d65aa..8db59881873c3b1edee81104b966af737e5fa6f6 100644
--- a/hw/vfio/container-base.c
+++ b/hw/vfio/container-base.c
@@ -65,10 +65,11 @@ int vfio_container_set_dirty_page_tracking(VFIOContainerBase *bcontainer,
 
 int vfio_container_query_dirty_bitmap(const VFIOContainerBase *bcontainer,
                                       VFIOBitmap *vbmap,
-                                      hwaddr iova, hwaddr size)
+                                      hwaddr iova, hwaddr size, Error **errp)
 {
     g_assert(bcontainer->ops->query_dirty_bitmap);
-    return bcontainer->ops->query_dirty_bitmap(bcontainer, vbmap, iova, size);
+    return bcontainer->ops->query_dirty_bitmap(bcontainer, vbmap, iova, size,
+                                               errp);
 }
 
 void vfio_container_init(VFIOContainerBase *bcontainer, VFIOAddressSpace *space,
diff --git a/hw/vfio/container.c b/hw/vfio/container.c
index 6524575aeddcea8470b5fd10caf57475088d1813..475d96eaaa927998c6aa8cc9aa9f2115f5a1efda 100644
--- a/hw/vfio/container.c
+++ b/hw/vfio/container.c
@@ -131,6 +131,7 @@ static int vfio_legacy_dma_unmap(const VFIOContainerBase *bcontainer,
     };
     bool need_dirty_sync = false;
     int ret;
+    Error *local_err = NULL;
 
     if (iotlb && vfio_devices_all_running_and_mig_active(bcontainer)) {
         if (!vfio_devices_all_device_dirty_tracking(bcontainer) &&
@@ -166,8 +167,9 @@ static int vfio_legacy_dma_unmap(const VFIOContainerBase *bcontainer,
 
     if (need_dirty_sync) {
         ret = vfio_get_dirty_bitmap(bcontainer, iova, size,
-                                    iotlb->translated_addr);
+                                    iotlb->translated_addr, &local_err);
         if (ret) {
+            error_report_err(local_err);
             return ret;
         }
     }
@@ -237,7 +239,8 @@ vfio_legacy_set_dirty_page_tracking(const VFIOContainerBase *bcontainer,
 
 static int vfio_legacy_query_dirty_bitmap(const VFIOContainerBase *bcontainer,
                                           VFIOBitmap *vbmap,
-                                          hwaddr iova, hwaddr size)
+                                          hwaddr iova, hwaddr size,
+                                          Error **errp)
 {
     const VFIOContainer *container = container_of(bcontainer, VFIOContainer,
                                                   bcontainer);
@@ -265,9 +268,9 @@ static int vfio_legacy_query_dirty_bitmap(const VFIOContainerBase *bcontainer,
     ret = ioctl(container->fd, VFIO_IOMMU_DIRTY_PAGES, dbitmap);
     if (ret) {
         ret = -errno;
-        error_report("Failed to get dirty bitmap for iova: 0x%"PRIx64
-                " size: 0x%"PRIx64" err: %d", (uint64_t)range->iova,
-                (uint64_t)range->size, errno);
+        error_setg(errp, "Failed to get dirty bitmap for iova: 0x%"PRIx64
+                   " size: 0x%"PRIx64" err: %d", (uint64_t)range->iova,
+                   (uint64_t)range->size, errno);
     }
 
     g_free(dbitmap);
-- 
2.44.0


Re: [PATCH v4 23/25] vfio: Add Error** argument to .get_dirty_bitmap() handler
Posted by Eric Auger 8 months, 3 weeks ago

On 3/6/24 14:34, Cédric Le Goater wrote:
> Let the callers do the error reporting. Add documentation while at it.
> 
> Signed-off-by: Cédric Le Goater <clg@redhat.com>
> ---
>  include/hw/vfio/vfio-common.h         |  4 +-
>  include/hw/vfio/vfio-container-base.h | 17 +++++++-
>  hw/vfio/common.c                      | 59 ++++++++++++++++++---------
>  hw/vfio/container-base.c              |  5 ++-
>  hw/vfio/container.c                   | 13 +++---
>  5 files changed, 67 insertions(+), 31 deletions(-)
> 
> diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
> index 46f88493634b5634a9c14a5caa33a463fbf2c50d..68911d36676667352e94a97895828aff4b194b57 100644
> --- a/include/hw/vfio/vfio-common.h
> +++ b/include/hw/vfio/vfio-common.h
> @@ -274,9 +274,9 @@ bool
>  vfio_devices_all_device_dirty_tracking(const VFIOContainerBase *bcontainer);
>  int vfio_devices_query_dirty_bitmap(const VFIOContainerBase *bcontainer,
>                                      VFIOBitmap *vbmap, hwaddr iova,
> -                                    hwaddr size);
> +                                    hwaddr size, Error **errp);
>  int vfio_get_dirty_bitmap(const VFIOContainerBase *bcontainer, uint64_t iova,
> -                          uint64_t size, ram_addr_t ram_addr);
> +                          uint64_t size, ram_addr_t ram_addr, Error **errp);
>  
>  /* Returns 0 on success, or a negative errno. */
>  int vfio_device_get_name(VFIODevice *vbasedev, Error **errp);
> diff --git a/include/hw/vfio/vfio-container-base.h b/include/hw/vfio/vfio-container-base.h
> index c76984654a596e3016a8cf833e10143eb872e102..ebc49ebfbe7de862450941b1129faad5d62b3769 100644
> --- a/include/hw/vfio/vfio-container-base.h
> +++ b/include/hw/vfio/vfio-container-base.h
> @@ -85,7 +85,7 @@ int vfio_container_set_dirty_page_tracking(VFIOContainerBase *bcontainer,
>                                             bool start, Error **errp);
>  int vfio_container_query_dirty_bitmap(const VFIOContainerBase *bcontainer,
>                                        VFIOBitmap *vbmap,
> -                                      hwaddr iova, hwaddr size);
> +                                      hwaddr iova, hwaddr size, Error **errp);
>  
>  void vfio_container_init(VFIOContainerBase *bcontainer,
>                           VFIOAddressSpace *space,
> @@ -138,9 +138,22 @@ struct VFIOIOMMUClass {
>       */
>      int (*set_dirty_page_tracking)(const VFIOContainerBase *bcontainer,
>                                     bool start, Error **errp);
> +    /**
> +     * @query_dirty_bitmap
> +     *
> +     * Get list of dirty pages from container
> +     *
> +     * @bcontainer: #VFIOContainerBase from which to get dirty pages
> +     * @vbmap: #VFIOBitmap internal bitmap structure
> +     * @iova: iova base address
> +     * @size: size of iova range
> +     * @errp: pointer to Error*, to store an error if it happens.
> +     *
> +     * Returns zero to indicate success and negative for error
> +     */
>      int (*query_dirty_bitmap)(const VFIOContainerBase *bcontainer,
>                                VFIOBitmap *vbmap,
> -                              hwaddr iova, hwaddr size);
> +                              hwaddr iova, hwaddr size, Error **errp);
>      /* PCI specific */
>      int (*pci_hot_reset)(VFIODevice *vbasedev, bool single);
>  
> diff --git a/hw/vfio/common.c b/hw/vfio/common.c
> index 496e5adaf8f18e9ae7e86dd69be0b9e71e86404f..65a11dc088524647541db97b7b8d6f07e5044728 100644
> --- a/hw/vfio/common.c
> +++ b/hw/vfio/common.c
> @@ -1158,7 +1158,7 @@ static int vfio_device_dma_logging_report(VFIODevice *vbasedev, hwaddr iova,
>  
>  int vfio_devices_query_dirty_bitmap(const VFIOContainerBase *bcontainer,
>                                      VFIOBitmap *vbmap, hwaddr iova,
> -                                    hwaddr size)
> +                                    hwaddr size, Error **errp)
>  {
>      VFIODevice *vbasedev;
>      int ret;
> @@ -1167,10 +1167,10 @@ int vfio_devices_query_dirty_bitmap(const VFIOContainerBase *bcontainer,
>          ret = vfio_device_dma_logging_report(vbasedev, iova, size,
>                                               vbmap->bitmap);
>          if (ret) {
> -            error_report("%s: Failed to get DMA logging report, iova: "
> -                         "0x%" HWADDR_PRIx ", size: 0x%" HWADDR_PRIx
> -                         ", err: %d (%s)",
> -                         vbasedev->name, iova, size, ret, strerror(-ret));
> +            error_setg(errp, "%s: Failed to get DMA logging report, iova: "
> +                       "0x%" HWADDR_PRIx ", size: 0x%" HWADDR_PRIx
> +                       ", err: %d (%s)",
> +                       vbasedev->name, iova, size, ret, strerror(-ret));
use error_setg_errno as below?
>  
>              return ret;
>          }
> @@ -1180,7 +1180,7 @@ int vfio_devices_query_dirty_bitmap(const VFIOContainerBase *bcontainer,
>  }
>  
>  int vfio_get_dirty_bitmap(const VFIOContainerBase *bcontainer, uint64_t iova,
> -                          uint64_t size, ram_addr_t ram_addr)
> +                          uint64_t size, ram_addr_t ram_addr, Error **errp)
>  {
>      bool all_device_dirty_tracking =
>          vfio_devices_all_device_dirty_tracking(bcontainer);
> @@ -1197,13 +1197,17 @@ int vfio_get_dirty_bitmap(const VFIOContainerBase *bcontainer, uint64_t iova,
>  
>      ret = vfio_bitmap_alloc(&vbmap, size);
>      if (ret) {
> +        error_setg_errno(errp, -ret,
> +                         "Failed to allocate dirty tracking bitmap");
>          return ret;
>      }
>  
>      if (all_device_dirty_tracking) {
> -        ret = vfio_devices_query_dirty_bitmap(bcontainer, &vbmap, iova, size);
> +        ret = vfio_devices_query_dirty_bitmap(bcontainer, &vbmap, iova, size,
> +                                              errp);
>      } else {
> -        ret = vfio_container_query_dirty_bitmap(bcontainer, &vbmap, iova, size);
> +        ret = vfio_container_query_dirty_bitmap(bcontainer, &vbmap, iova, size,
> +                                                errp);
>      }
>  
>      if (ret) {
> @@ -1251,12 +1255,13 @@ static void vfio_iommu_map_dirty_notify(IOMMUNotifier *n, IOMMUTLBEntry *iotlb)
>      }
>  
>      ret = vfio_get_dirty_bitmap(bcontainer, iova, iotlb->addr_mask + 1,
> -                                translated_addr);
> +                                translated_addr, &local_err);
>      if (ret) {
> -        error_report("vfio_iommu_map_dirty_notify(%p, 0x%"HWADDR_PRIx", "
> -                     "0x%"HWADDR_PRIx") = %d (%s)",
> -                     bcontainer, iova, iotlb->addr_mask + 1, ret,
> -                     strerror(-ret));
> +        error_prepend(&local_err,
> +                      "vfio_iommu_map_dirty_notify(%p, 0x%"HWADDR_PRIx", "
> +                      "0x%"HWADDR_PRIx") failed :", bcontainer, iova,
nit in previous prepends you used "-" instead of ":" at the end. Maybe
align.
> +                      iotlb->addr_mask + 1);
> +        error_report_err(local_err);
>      }
>  
>  out_lock:
> @@ -1276,12 +1281,19 @@ static int vfio_ram_discard_get_dirty_bitmap(MemoryRegionSection *section,
>      const ram_addr_t ram_addr = memory_region_get_ram_addr(section->mr) +
>                                  section->offset_within_region;
>      VFIORamDiscardListener *vrdl = opaque;
> +    Error *local_err = NULL;
> +    int ret;
>  
>      /*
>       * Sync the whole mapped region (spanning multiple individual mappings)
>       * in one go.
>       */
> -    return vfio_get_dirty_bitmap(vrdl->bcontainer, iova, size, ram_addr);
> +    ret = vfio_get_dirty_bitmap(vrdl->bcontainer, iova, size, ram_addr,
> +                                &local_err);
> +    if (ret) {
> +        error_report_err(local_err);
> +    }
> +    return ret;
>  }
>  
>  static int
> @@ -1313,7 +1325,7 @@ vfio_sync_ram_discard_listener_dirty_bitmap(VFIOContainerBase *bcontainer,
>  }
>  
>  static int vfio_sync_dirty_bitmap(VFIOContainerBase *bcontainer,
> -                                  MemoryRegionSection *section)
> +                                  MemoryRegionSection *section, Error **errp)
>  {
>      ram_addr_t ram_addr;
>  
> @@ -1344,7 +1356,14 @@ static int vfio_sync_dirty_bitmap(VFIOContainerBase *bcontainer,
>          }
>          return 0;
>      } else if (memory_region_has_ram_discard_manager(section->mr)) {
> -        return vfio_sync_ram_discard_listener_dirty_bitmap(bcontainer, section);
> +        int ret;
> +
> +        ret = vfio_sync_ram_discard_listener_dirty_bitmap(bcontainer, section);
> +        if (ret) {
> +            error_setg(errp,
> +                       "Failed to sync dirty bitmap with RAM discard listener");
> +            return ret;
> +        }
>      }
>  
>      ram_addr = memory_region_get_ram_addr(section->mr) +
> @@ -1352,7 +1371,7 @@ static int vfio_sync_dirty_bitmap(VFIOContainerBase *bcontainer,
>  
>      return vfio_get_dirty_bitmap(bcontainer,
>                     REAL_HOST_PAGE_ALIGN(section->offset_within_address_space),
> -                   int128_get64(section->size), ram_addr);
> +                                 int128_get64(section->size), ram_addr, errp);
>  }
>  
>  static void vfio_listener_log_sync(MemoryListener *listener,
> @@ -1361,16 +1380,16 @@ static void vfio_listener_log_sync(MemoryListener *listener,
>      VFIOContainerBase *bcontainer = container_of(listener, VFIOContainerBase,
>                                                   listener);
>      int ret;
> +    Error *local_err = NULL;
>  
>      if (vfio_listener_skipped_section(section)) {
>          return;
>      }
>  
>      if (vfio_devices_all_dirty_tracking(bcontainer)) {
> -        ret = vfio_sync_dirty_bitmap(bcontainer, section);
> +        ret = vfio_sync_dirty_bitmap(bcontainer, section, &local_err);
>          if (ret) {
> -            error_report("vfio: Failed to sync dirty bitmap, err: %d (%s)", ret,
> -                         strerror(-ret));
> +            error_report_err(local_err);
>              vfio_set_migration_error(ret);
>          }
>      }
> diff --git a/hw/vfio/container-base.c b/hw/vfio/container-base.c
> index 7c0764121d24b02b6c4e66e368d7dff78a6d65aa..8db59881873c3b1edee81104b966af737e5fa6f6 100644
> --- a/hw/vfio/container-base.c
> +++ b/hw/vfio/container-base.c
> @@ -65,10 +65,11 @@ int vfio_container_set_dirty_page_tracking(VFIOContainerBase *bcontainer,
>  
>  int vfio_container_query_dirty_bitmap(const VFIOContainerBase *bcontainer,
>                                        VFIOBitmap *vbmap,
> -                                      hwaddr iova, hwaddr size)
> +                                      hwaddr iova, hwaddr size, Error **errp)
>  {
>      g_assert(bcontainer->ops->query_dirty_bitmap);
> -    return bcontainer->ops->query_dirty_bitmap(bcontainer, vbmap, iova, size);
> +    return bcontainer->ops->query_dirty_bitmap(bcontainer, vbmap, iova, size,
> +                                               errp);
>  }
>  
>  void vfio_container_init(VFIOContainerBase *bcontainer, VFIOAddressSpace *space,
> diff --git a/hw/vfio/container.c b/hw/vfio/container.c
> index 6524575aeddcea8470b5fd10caf57475088d1813..475d96eaaa927998c6aa8cc9aa9f2115f5a1efda 100644
> --- a/hw/vfio/container.c
> +++ b/hw/vfio/container.c
> @@ -131,6 +131,7 @@ static int vfio_legacy_dma_unmap(const VFIOContainerBase *bcontainer,
>      };
>      bool need_dirty_sync = false;
>      int ret;
> +    Error *local_err = NULL;
>  
>      if (iotlb && vfio_devices_all_running_and_mig_active(bcontainer)) {
>          if (!vfio_devices_all_device_dirty_tracking(bcontainer) &&
> @@ -166,8 +167,9 @@ static int vfio_legacy_dma_unmap(const VFIOContainerBase *bcontainer,
>  
>      if (need_dirty_sync) {
>          ret = vfio_get_dirty_bitmap(bcontainer, iova, size,
> -                                    iotlb->translated_addr);
> +                                    iotlb->translated_addr, &local_err);
>          if (ret) {
> +            error_report_err(local_err);
>              return ret;
>          }
>      }
> @@ -237,7 +239,8 @@ vfio_legacy_set_dirty_page_tracking(const VFIOContainerBase *bcontainer,
>  
>  static int vfio_legacy_query_dirty_bitmap(const VFIOContainerBase *bcontainer,
>                                            VFIOBitmap *vbmap,
> -                                          hwaddr iova, hwaddr size)
> +                                          hwaddr iova, hwaddr size,
> +                                          Error **errp)
>  {
>      const VFIOContainer *container = container_of(bcontainer, VFIOContainer,
>                                                    bcontainer);
> @@ -265,9 +268,9 @@ static int vfio_legacy_query_dirty_bitmap(const VFIOContainerBase *bcontainer,
>      ret = ioctl(container->fd, VFIO_IOMMU_DIRTY_PAGES, dbitmap);
>      if (ret) {
>          ret = -errno;
> -        error_report("Failed to get dirty bitmap for iova: 0x%"PRIx64
> -                " size: 0x%"PRIx64" err: %d", (uint64_t)range->iova,
> -                (uint64_t)range->size, errno);
> +        error_setg(errp, "Failed to get dirty bitmap for iova: 0x%"PRIx64
> +                   " size: 0x%"PRIx64" err: %d", (uint64_t)range->iova,
> +                   (uint64_t)range->size, errno);
use errno flavour?

Eric
>      }
>  
>      g_free(dbitmap);