Re: [PATCH 4/5] vfio/iommufd: Restore vbasedev's reference to hwpt after CPR transfer

[Steven Sistare]

On 9/25/2025 10:23 PM, Zhenzhong Duan wrote:

After CPR transfer, if there are more than one VFIO devices, the second

device's reference to hwpt isn't restored on destination.

More specifically, the device is not added to hwpt->device_list.

We still need
to call iommufd_cdev_attach_container() to restore it after a matching
container is found, or else SIGSEV triggers.

Fixes: 4296ee07455e ("vfio/iommufd: reconstruct device")
Signed-off-by: Zhenzhong Duan <zhenzhong.d...@intel.com>

Thanks again.

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

---
  hw/vfio/iommufd.c | 5 ++---
  1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/hw/vfio/iommufd.c b/hw/vfio/iommufd.c
index 103ff43426..6df99d3aa6 100644
--- a/hw/vfio/iommufd.c
+++ b/hw/vfio/iommufd.c
@@ -565,10 +565,9 @@ static bool iommufd_cdev_attach(const char *name, 
VFIODevice *vbasedev,
              continue;
          }

- if (!cpr_is_incoming()) {

+        if (!cpr_is_incoming() ||
+            (vbasedev->cpr.ioas_id == container->ioas_id)) {
              res = iommufd_cdev_attach_container(vbasedev, container, &err);
-        } else if (vbasedev->cpr.ioas_id == container->ioas_id) {
-            res = true;
          } else {
              continue;
          }