Commit v6.4.0-61-g201bd5db63 started to fill the default value for //cpu/@migratable attribute according to QEMU support. However, active domains either have the migratable attribute already set or the capabilities we use for checking the QEMU support were created by older libvirt which didn't probe for this specific capability. https://bugzilla.redhat.com/show_bug.cgi?id=1857967 Reported-by: Mark Mielke <mark.mielke(a)gmail.com&gt; Signed-off-by: Jiri Denemark <jdenemar(a)redhat.com&gt; --- src/qemu/qemu_domain.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c index 4a2daffc0a..2c944ce051 100644 --- a/src/qemu/qemu_domain.c +++ b/src/qemu/qemu_domain.c @@ -3986,9 +3986,13 @@ qemuDomainDefCPUPostParse(virDomainDefPtr def, } } - if (qemuCaps && + /* Running domains were either started before QEMU_CAPS_CPU_MIGRATABLE was + * introduced and thus we can't rely on it or they already have the + * migratable default set. */ + if (def->id == -1 && + qemuCaps && def->cpu->mode == VIR_CPU_MODE_HOST_PASSTHROUGH && - !def->cpu->migratable) { + def->cpu->migratable == VIR_TRISTATE_SWITCH_ABSENT) { if (virQEMUCapsGet(qemuCaps, QEMU_CAPS_CPU_MIGRATABLE)) def->cpu->migratable = VIR_TRISTATE_SWITCH_ON; else if (ARCH_IS_X86(def->os.arch)) -- 2.27.0