diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c
index cfaf8f8dd5..f9726636b4 100644
--- a/src/qemu/qemu_domain.c
+++ b/src/qemu/qemu_domain.c
@@ -6350,11 +6350,12 @@ qemuDomainRequiresMemLock(virDomainDefPtr def)
         return true;
 
     for (i = 0; i < def->nhostdevs; i++) {
-        virDomainHostdevDefPtr dev = def->hostdevs[i];
+        virDomainHostdevSubsysPtr subsys = &def->hostdevs[i]->source.subsys;
 
-        if (dev->mode == VIR_DOMAIN_HOSTDEV_MODE_SUBSYS &&
-            dev->source.subsys.type == VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_PCI &&
-            dev->source.subsys.u.pci.backend == VIR_DOMAIN_HOSTDEV_PCI_BACKEND_VFIO)
+        if (def->hostdevs[i]->mode == VIR_DOMAIN_HOSTDEV_MODE_SUBSYS &&
+            (subsys->type == VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_MDEV ||
+             (subsys->type == VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_PCI &&
+              subsys->u.pci.backend == VIR_DOMAIN_HOSTDEV_PCI_BACKEND_VFIO)))
             return true;
     }