On Wed, Jul 20, 2022 at 4:48 PM Jiri Denemark <jdenemar@redhat.com> wrote:
On Wed, Jul 20, 2022 at 16:29:45 +0200, Eugenio Perez Martin wrote:
On Wed, Jul 20, 2022 at 4:01 PM Jiri Denemark <jdenemar@redhat.com> wrote:
On Wed, Jul 20, 2022 at 14:15:57 +0200, Eugenio Pérez wrote:
since qemu 6.0, if migration is blocked for some reason, 'query-migrate' will return an array of error strings describing the migration blockers. This can be used to check whether there are any devices blocking migration, etc.
Enable qemuMigrationSrcIsAllowed to query it.
Signed-off-by: Eugenio Pérez <eperezma@redhat.com> --- v3: * Report message with a colon. * Report all blockers instead of only the first. --- src/qemu/qemu_migration.c | 34 ++++++++++++++++++++++++++++++++++ 1 file changed, 34 insertions(+)
diff --git a/src/qemu/qemu_migration.c b/src/qemu/qemu_migration.c index b12cb518ee..6ac4ef150b 100644 --- a/src/qemu/qemu_migration.c +++ b/src/qemu/qemu_migration.c @@ -1414,6 +1414,20 @@ qemuMigrationSrcIsAllowedHostdev(const virDomainDef *def) return true; }
+static int +qemuDomainGetMigrationBlockers(virQEMUDriver *driver, + virDomainObj *vm, + char ***blockers) +{ + qemuDomainObjPrivate *priv = vm->privateData; + int rc; + + qemuDomainObjEnterMonitor(driver, vm); + rc = qemuMonitorGetMigrationBlockers(priv->mon, blockers); + qemuDomainObjExitMonitor(vm); + + return rc; +}
/** * qemuMigrationSrcIsAllowed: @@ -1439,6 +1453,26 @@ qemuMigrationSrcIsAllowed(virQEMUDriver *driver, int nsnapshots; int pauseReason; size_t i; + int r; + + /* Ask qemu if it have a migration blocker */ + if (virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_MIGRATION_BLOCKED_REASONS)) { + g_auto(GStrv) blockers = NULL; + r = qemuDomainGetMigrationBlockers(driver, vm, &blockers); + if (r != 0) { + virReportError(VIR_ERR_OPERATION_INVALID, + _("cannot migrate domain: %s"), + _("error getting blockers")); + return false; + }
As mentioned in v2 review the virReportError call should be dropped as it overwrites the error reported by qemuDomainGetMigrationBlockers. That is, you can just
if (qemuDomainGetMigrationBlockers(driver, vm, &blockers) < 0) return false;
But there are a few conditions that don't report an error, like a bad JSON answer. For example, if "blockers" is not an array parsing the response JSON, libvirt would not print any error, isn't it?
Well in qemuDomainGetMigrationBlockers you now have
if (!(jblockers = virJSONValueObjectGetArray(data, "blocked-reasons"))) return 0;
so you would not get pass r != 0 in such case anyway. If you wanted to distinguish missing blocked-reasons (that is no blockers) and blocked-reasons which is not an array (invalid response), you would need to do something else:
if (!(jblockers = virJSONValueObjectGet(data, "blocked-reasons"))) return 0;
if (!virJSONValueIsArray(jblockers)) { virReportError(VIR_ERR_INTERNAL_ERROR, "%s", _("blocker-reasons is not an array")); return -1; }
All this inside qemuDomainGetMigrationBlockers() to make sure the function reports an error when returning -1. The caller would not report any error anyway.
That's right. Deleting error report then. Thanks!