[libvirt PATCH 2/3] qemu: Do not set default value //cpu/@migratable for running domains

[Jiri Denemark]

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 at gmail.com>
Signed-off-by: Jiri Denemark <jdenemar at redhat.com>
---
 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