For any backing file we set 'read-only' to true, but didn't do this when modifying the recorded backing store when creating external snapshots. This meant that qemu would attempt to open the backing-file read-write. This would fail for example when selinux is used as qemu doesn't have write permission for the backing file. https://bugzilla.redhat.com/show_bug.cgi?id=1781079 Signed-off-by: Peter Krempa <pkrempa(a)redhat.com&gt; --- src/qemu/qemu_driver.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index 738e8832cc..96e811a893 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -14659,6 +14659,7 @@ qemuDomainSnapshotCreateInactiveExternal(virQEMUDriverPtr driver, goto cleanup; if (virStorageSourceHasBacking(defdisk->src)) { + defdisk->src->readonly = true; newsrc->backingStore = g_steal_pointer(&defdisk->src); } else { virObjectUnref(defdisk->src); @@ -15510,6 +15511,7 @@ qemuDomainSnapshotDiskUpdateSource(virQEMUDriverPtr driver, qemuDomainSnapshotDiskUpdateSourceRenumber(dd->disk->src); if (dd->persistdisk) { + dd->persistdisk->src->readonly = true; dd->persistsrc->backingStore = g_steal_pointer(&dd->persistdisk->src); dd->persistdisk->src = g_steal_pointer(&dd->persistsrc); } -- 2.23.0