From f753d55edab43dae78f9ef5dc13ca53f626e09fe Mon Sep 17 00:00:00 2001 Message-ID: From: Pavel Hrdina Date: Thu, 26 Mar 2026 14:32:36 +0100 Subject: [PATCH] hypervisor: Call virWaitForDevices() after detaching host devices MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Pavel Hrdina On systems with selinux enabled starting a VM with managed host device using IOMMUFD backend can run into race-condition where both libvirt and udev are setting selinux label on /dev/vfio/devices/vfioX device. If udev is the last one to set selinux label starting VM fails with: error: internal error: QEMU unexpectedly closed the monitor (vm='test'): 2026-03-26T15:47:36.620422Z qemu-kvm: -device {"driver":"vfio-pci","id":"hostdev0","iommufd":"iommufd0","fd":"20","bus":"pci.7","addr":"0x0"}: vfio hostdev0: Failed to add fd 20 to KVM VFIO device: Invalid argument We need to wait for udev to finish processing all events. Signed-off-by: Pavel Hrdina Reviewed-by: Ján Tomko (cherry picked from commit b96ea4db3aabac4790d6e1d53e2f309f5e73efae) Resolves: https://redhat.atlassian.net/browse/VOYAGER-309 Signed-off-by: Pavel Hrdina --- src/hypervisor/virhostdev.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/src/hypervisor/virhostdev.c b/src/hypervisor/virhostdev.c index 43155ceb6c..981ca4cd20 100644 --- a/src/hypervisor/virhostdev.c +++ b/src/hypervisor/virhostdev.c @@ -782,6 +782,9 @@ virHostdevPreparePCIDevicesImpl(virHostdevManager *mgr, } } + /* Step 2.5: Wait for udev to handle all events for devices. */ + virWaitForDevices(); + /* At this point, all devices are attached to the stub driver and have * been marked as inactive */ -- 2.53.0