Re: [PATCH V3 11/42] vfio/container: mdev cpr blocker

[Cédric Le Goater]

On 5/12/25 17:32, Steve Sistare wrote:

During CPR, after VFIO_DMA_UNMAP_FLAG_VADDR, the vaddr is temporarily
invalid, so mediated devices cannot be supported.  Add a blocker for them.
This restriction will not apply to iommufd containers when CPR is added
for them in a future patch.

Signed-off-by: Steve Sistare <steven.sist...@oracle.com>

Reviewed-by: Cédric Le Goater <c...@redhat.com>

Thanks,

C.

---
  hw/vfio/container.c        | 8 ++++++++
  include/hw/vfio/vfio-cpr.h | 1 +
  2 files changed, 9 insertions(+)

diff --git a/hw/vfio/container.c b/hw/vfio/container.c
index 0e02726..562e3bd 100644
--- a/hw/vfio/container.c
+++ b/hw/vfio/container.c
@@ -995,6 +995,13 @@ static bool vfio_legacy_attach_device(const char *name, 
VFIODevice *vbasedev,
          goto device_put_exit;
      }

+ if (vbasedev->mdev) {

+        error_setg(&vbasedev->cpr.mdev_blocker,
+                   "CPR does not support vfio mdev %s", vbasedev->name);
+        migrate_add_blocker_modes(&vbasedev->cpr.mdev_blocker, &error_fatal,
+                                  MIG_MODE_CPR_TRANSFER, -1);
+    }
+
      return true;

device_put_exit:

@@ -1012,6 +1019,7 @@ static void vfio_legacy_detach_device(VFIODevice 
*vbasedev)

vfio_device_unprepare(vbasedev); + migrate_del_blocker(&vbasedev->cpr.mdev_blocker);

      object_unref(vbasedev->hiod);
      vfio_device_put(vbasedev);
      vfio_group_put(group);
diff --git a/include/hw/vfio/vfio-cpr.h b/include/hw/vfio/vfio-cpr.h
index 1c4f070..0fc7ab2 100644
--- a/include/hw/vfio/vfio-cpr.h
+++ b/include/hw/vfio/vfio-cpr.h
@@ -18,6 +18,7 @@ typedef struct VFIOContainerCPR {

typedef struct VFIODeviceCPR {

      bool reused;
+    Error *mdev_blocker;
  } VFIODeviceCPR;

struct VFIOContainer;