From: Joao Martins <joao.m.martins@oracle.com>

mdevs aren't "physical" devices and when asking for backing IOMMU info, it
fails the entire provisioning of the guest. Fix that by skipping
HostIOMMUDevice initialization in the presence of mdevs, and skip setting
an iommu device when it is known to be an mdev.

Cc: Zhenzhong Duan <zhenzhong.duan@intel.com>
Fixes: 930589520128 ("vfio/iommufd: Implement HostIOMMUDeviceClass::realize() handler")
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
---
 hw/vfio/common.c |  4 ++++
 hw/vfio/pci.c    | 11 ++++++++---
 2 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/hw/vfio/common.c b/hw/vfio/common.c
index 6d15b36e0bbbdaeb9437725167e61fdf5502555a..d7f02be595b5e71558d7e2d75d21d28f05968252 100644
--- a/hw/vfio/common.c
+++ b/hw/vfio/common.c
@@ -1548,6 +1548,10 @@ bool vfio_attach_device(char *name, VFIODevice *vbasedev,
         return false;
     }
 
+    if (vbasedev->mdev) {
+        return true;
+    }
+
     hiod = HOST_IOMMU_DEVICE(object_new(ops->hiod_typename));
     if (!HOST_IOMMU_DEVICE_GET_CLASS(hiod)->realize(hiod, vbasedev, errp)) {
         object_unref(hiod);
diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
index b34e91468a533ab4d550bf2392e940b867f7b34c..265d3cb82ffc2a6ada02547c0d8e306318442ef7 100644
--- a/hw/vfio/pci.c
+++ b/hw/vfio/pci.c
@@ -3115,7 +3115,8 @@ static void vfio_realize(PCIDevice *pdev, Error **errp)
 
     vfio_bars_register(vdev);
 
-    if (!pci_device_set_iommu_device(pdev, vbasedev->hiod, errp)) {
+    if (!vbasedev->mdev &&
+        !pci_device_set_iommu_device(pdev, vbasedev->hiod, errp)) {
         error_prepend(errp, "Failed to set iommu_device: ");
         goto out_teardown;
     }
@@ -3238,7 +3239,9 @@ out_deregister:
         timer_free(vdev->intx.mmap_timer);
     }
 out_unset_idev:
-    pci_device_unset_iommu_device(pdev);
+    if (!vbasedev->mdev) {
+        pci_device_unset_iommu_device(pdev);
+    }
 out_teardown:
     vfio_teardown_msi(vdev);
     vfio_bars_exit(vdev);
@@ -3283,7 +3286,9 @@ static void vfio_exitfn(PCIDevice *pdev)
     vfio_pci_disable_rp_atomics(vdev);
     vfio_bars_exit(vdev);
     vfio_migration_exit(vbasedev);
-    pci_device_unset_iommu_device(pdev);
+    if (!vbasedev->mdev) {
+        pci_device_unset_iommu_device(pdev);
+    }
 }
 
 static void vfio_pci_reset(DeviceState *dev)
-- 
2.45.2