From 6f34957b6242c1537e91684af2864eeed434d5b1 Mon Sep 17 00:00:00 2001
Message-Id: <6f34957b6242c1537e91684af2864eeed434d5b1@dist-git>
From: Pavel Hrdina <phrdina@redhat.com>
Date: Thu, 15 Jan 2015 15:03:51 +0100
Subject: [PATCH] qemu_driver: fix setting vcpus for offline domain

https://bugzilla.redhat.com/show_bug.cgi?id=1161540

Commit e3435caf fixed hot-plugging of vcpus with strict memory pinning
on NUMA hosts, but unfortunately it also broke updating number of vcpus
for offline guests using our API.

The issue is that we try to create a cpu cgroup for non-running guest
which fails as there are no cgroups for that domain. We should create
cgroups and update cpuset.mems only if we are hot-plugging.

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
(cherry picked from commit e105dc981438bc33fa771bd67cece6234dbf6c8d)
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
---
 src/qemu/qemu_driver.c | 26 ++++++++++++++------------
 1 file changed, 14 insertions(+), 12 deletions(-)

diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index afcf326..619f2d6 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -4672,21 +4672,23 @@ qemuDomainSetVcpusFlags(virDomainPtr dom, unsigned int nvcpus,
 
     priv = vm->privateData;
 
-    if (virCgroupNewEmulator(priv->cgroup, false, &cgroup_temp) < 0)
-        goto cleanup;
-
-    if (!(all_nodes = virNumaGetHostNodeset()))
-        goto cleanup;
-
-    if (!(all_nodes_str = virBitmapFormat(all_nodes)))
-        goto cleanup;
-
     if (qemuDomainObjBeginJob(driver, vm, QEMU_JOB_MODIFY) < 0)
         goto cleanup;
 
-    if (virCgroupGetCpusetMems(cgroup_temp, &mem_mask) < 0 ||
-        virCgroupSetCpusetMems(cgroup_temp, all_nodes_str) < 0)
-        goto endjob;
+    if (flags & VIR_DOMAIN_AFFECT_LIVE && !(flags & VIR_DOMAIN_VCPU_GUEST)) {
+        if (virCgroupNewEmulator(priv->cgroup, false, &cgroup_temp) < 0)
+            goto cleanup;
+
+        if (!(all_nodes = virNumaGetHostNodeset()))
+            goto cleanup;
+
+        if (!(all_nodes_str = virBitmapFormat(all_nodes)))
+            goto cleanup;
+
+        if (virCgroupGetCpusetMems(cgroup_temp, &mem_mask) < 0 ||
+            virCgroupSetCpusetMems(cgroup_temp, all_nodes_str) < 0)
+            goto endjob;
+    }
 
     maximum = (flags & VIR_DOMAIN_VCPU_MAXIMUM) != 0;
     flags &= ~VIR_DOMAIN_VCPU_MAXIMUM;
-- 
2.2.1