[libvirt] [PATCH] Fix guest boot failure when vcpu placement="auto" on memoryless numa node

[Nitesh Konkar]

When the vcpu placement is auto and we have memoryless numa nodes on the host,
numad returns a list numa nodes with and without memory. When we try to write it
to /sys/fs/cgroup/*/cpuset.mems it errors out as invlaid argument.

Signed-off-by: Nitesh Konkar <nitkon12 at linux.vnet.ibm.com>
---
numactl --hardware
available: 4 nodes (0-1,16-17)
node 0 cpus: 0 8 16 24 32
node 0 size: 32500 MB
node 0 free: 25584 MB
node 1 cpus: 40 48 56 64 72
node 1 size: 0 MB----------------------------------------------#
node 1 free: 0 MB
node 16 cpus: 80 88 96 104 112
node 16 size: 32613 MB
node 16 free: 30991 MB
node 17 cpus: 120 128 136 144 152
node 17 size: 0 MB--------------------------------------------#
node 17 free: 0 MB
node distances:
node   0   1  16  17 
  0:  10  20  40  40 
  1:  20  10  40  40 
 16:  40  40  10  20 
 17:  40  40  20  10 

virsh start virt-tests-vm1
error: Failed to start domain virt-tests-vm1
error: Invalid value '0-1,16-17' for 'cpuset.mems': Invalid argument--------------NOK

 src/qemu/qemu_cgroup.c  | 4 +++-
 src/qemu/qemu_process.c | 5 ++++-
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/src/qemu/qemu_cgroup.c b/src/qemu/qemu_cgroup.c
index 36762d4..fd8deb1 100644
--- a/src/qemu/qemu_cgroup.c
+++ b/src/qemu/qemu_cgroup.c
@@ -723,10 +723,12 @@ qemuSetupCpusetMems(virDomainObjPtr vm)
 {
     virCgroupPtr cgroup_temp = NULL;
     qemuDomainObjPrivatePtr priv = vm->privateData;
+    virBitmapPtr nodeSet = NULL;
     virDomainNumatuneMemMode mode;
     char *mem_mask = NULL;
     int ret = -1;
 
+    nodeSet = virNumaGetHostMemoryNodeset(); 
     if (!virCgroupHasController(priv->cgroup, VIR_CGROUP_CONTROLLER_CPUSET))
         return 0;
 
@@ -735,7 +737,7 @@ qemuSetupCpusetMems(virDomainObjPtr vm)
         return 0;
 
     if (virDomainNumatuneMaybeFormatNodeset(vm->def->numa,
-                                            priv->autoNodeset,
+                                            nodeSet,
                                             &mem_mask, -1) < 0)
         goto cleanup;
 
diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c
index fa9990e..074a0cd 100644
--- a/src/qemu/qemu_process.c
+++ b/src/qemu/qemu_process.c
@@ -2374,6 +2374,7 @@ qemuProcessSetupPid(virDomainObjPtr vm,
     virDomainNumatuneMemMode mem_mode;
     virCgroupPtr cgroup = NULL;
     virBitmapPtr use_cpumask;
+    virBitmapPtr nodeSet = NULL;
     char *mem_mask = NULL;
     int ret = -1;
 
@@ -2397,13 +2398,15 @@ qemuProcessSetupPid(virDomainObjPtr vm,
      * neither period nor quota settings.  And if CPUSET controller is
      * not initialized either, then there's nothing to do anyway.
      */
+    nodeSet = virNumaGetHostMemoryNodeset(); 
+
     if (virCgroupHasController(priv->cgroup, VIR_CGROUP_CONTROLLER_CPU) ||
         virCgroupHasController(priv->cgroup, VIR_CGROUP_CONTROLLER_CPUSET)) {
 
         if (virDomainNumatuneGetMode(vm->def->numa, -1, &mem_mode) == 0 &&
             mem_mode == VIR_DOMAIN_NUMATUNE_MEM_STRICT &&
             virDomainNumatuneMaybeFormatNodeset(vm->def->numa,
-                                                priv->autoNodeset,
+                                                nodeSet,
                                                 &mem_mask, -1) < 0)
             goto cleanup;
 
-- 
1.8.3.1