[PULL 16/27] vfio/container: mdev cpr blocker

["Cédric Le Goater" <clg@redhat.com>]

From: Steve Sistare <steven.sistare@oracle.com>

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.sistare@oracle.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Link: https://lore.kernel.org/qemu-devel/1749569991-25171-8-git-send-email-steven.sistare@oracle.com
[ clg: Fixed context change in VFIODevice ]
Signed-off-by: Cédric Le Goater <clg@redhat.com>
---
 include/hw/vfio/vfio-cpr.h    | 3 +++
 include/hw/vfio/vfio-device.h | 2 ++
 hw/vfio/container.c           | 8 ++++++++
 3 files changed, 13 insertions(+)

diff --git a/include/hw/vfio/vfio-cpr.h b/include/hw/vfio/vfio-cpr.h
index 04624475f87361954a09ba3c9a47cf1d8e7cc5b3..b83dd4275183595aa31071d99099ad746931c66a 100644
--- a/include/hw/vfio/vfio-cpr.h
+++ b/include/hw/vfio/vfio-cpr.h
@@ -22,6 +22,9 @@ typedef struct VFIOContainerCPR {
                          void *vaddr, bool readonly, MemoryRegion *mr);
 } VFIOContainerCPR;
 
+typedef struct VFIODeviceCPR {
+    Error *mdev_blocker;
+} VFIODeviceCPR;
 
 bool vfio_legacy_cpr_register_container(struct VFIOContainer *container,
                                         Error **errp);
diff --git a/include/hw/vfio/vfio-device.h b/include/hw/vfio/vfio-device.h
index 9793b2dba0ced9e87b1641ae783867ce1b41e71a..f39259406bdd7b4577c4c54cfb3ac0dbbcedccb2 100644
--- a/include/hw/vfio/vfio-device.h
+++ b/include/hw/vfio/vfio-device.h
@@ -28,6 +28,7 @@
 #endif
 #include "system/system.h"
 #include "hw/vfio/vfio-container-base.h"
+#include "hw/vfio/vfio-cpr.h"
 #include "system/host_iommu_device.h"
 #include "system/iommufd.h"
 
@@ -86,6 +87,7 @@ typedef struct VFIODevice {
     QLIST_ENTRY(VFIODevice) hwpt_next;
     struct vfio_region_info **reginfo;
     int *region_fds;
+    VFIODeviceCPR cpr;
 } VFIODevice;
 
 struct VFIODeviceOps {
diff --git a/hw/vfio/container.c b/hw/vfio/container.c
index 936ce37f190686b0875ed934ee277d9e4ff8cb2f..3e8d645ebbd7b13c55625f38f4250670a63df124 100644
--- a/hw/vfio/container.c
+++ b/hw/vfio/container.c
@@ -987,6 +987,13 @@ 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:
@@ -1004,6 +1011,7 @@ 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);
-- 
2.49.0