qemu: Don't update count of vCPUs if hot-unplug has failed

After live change of cpu counts, the number of processor threads is
verified. This patch makes use of this approach to check if qemu ignored
the request for cpu hot-unplug and report an appropriate message.

diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 39175f4b36a928f1da96a2773c738a71ce90e4ee..c4be13053c5c4f45448d7ed33bae8c1f31c43d04 100644 (file)
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -3697,6 +3697,15 @@ static int qemuDomainHotplugVcpus(virQEMUDriverPtr driver,
         goto cleanup;
     }
 
+    /* check if hotplug has failed */
+    if (vcpus < oldvcpus && ncpupids == oldvcpus) {
+        virReportError(VIR_ERR_OPERATION_UNSUPPORTED, "%s",
+                       _("qemu didn't unplug the vCPUs properly"));
+        vcpus = oldvcpus;
+        ret = -1;
+        goto cleanup;
+    }
+
     if (ncpupids != vcpus) {
         virReportError(VIR_ERR_INTERNAL_ERROR,
                        _("got wrong number of vCPU pids from QEMU monitor. "