qemu: Migrate memory on numatune change

We've never set the cpuset.memory_migrate value to anything, keeping it
on default.  However, we allow changing cpuset.mems on live domain.
That setting, however, don't have any consequence on a domain unless
it's going to allocate new memory.

I managed to make 'virsh numatune' move all the memory to any node I
wanted even without disabling libnuma's numa_set_membind(), so this
should be safe to use with it as well.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1198497Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

src/qemu/qemu_cgroup.c

 /*
  * qemu_cgroup.c: QEMU cgroup management
  *
- * Copyright (C) 2006-2014 Red Hat, Inc.
+ * Copyright (C) 2006-2015 Red Hat, Inc.
  * Copyright (C) 2006 Daniel P. Berrange
  *
  * This library is free software; you can redistribute it and/or
@@ -652,6 +652,9 @@ qemuSetupCpusetCgroup(virDomainObjPtr vm,
     if (!virCgroupHasController(priv->cgroup, VIR_CGROUP_CONTROLLER_CPUSET))
         return 0;
 
+    if (virCgroupSetCpusetMemoryMigrate(priv->cgroup, true) < 0)
+        return -1;
+
     if (vm->def->cpumask ||
         (vm->def->placement_mode == VIR_DOMAIN_CPU_PLACEMENT_MODE_AUTO)) {
 
@@ -792,9 +795,12 @@ static void
 qemuRestoreCgroupState(virDomainObjPtr vm)
 {
     char *mem_mask = NULL;
+    char *nodeset = NULL;
     int empty = -1;
     qemuDomainObjPrivatePtr priv = vm->privateData;
+    size_t i = 0;
     virBitmapPtr all_nodes;
+    virCgroupPtr cgroup_temp = NULL;
 
     if (!(all_nodes = virNumaGetHostNodeset()))
         goto error;
@@ -809,9 +815,37 @@ qemuRestoreCgroupState(virDomainObjPtr vm)
     if (virCgroupSetCpusetMems(priv->cgroup, mem_mask) < 0)
         goto error;
 
+    for (i = 0; i < priv->nvcpupids; i++) {
+        if (virCgroupNewVcpu(priv->cgroup, i, false, &cgroup_temp) < 0 ||
+            virCgroupSetCpusetMemoryMigrate(cgroup_temp, true) < 0 ||
+            virCgroupGetCpusetMems(cgroup_temp, &nodeset) < 0 ||
+            virCgroupSetCpusetMems(cgroup_temp, nodeset) < 0)
+            goto cleanup;
+
+        virCgroupFree(&cgroup_temp);
+    }
+
+    for (i = 0; i < priv->niothreadpids; i++) {
+        if (virCgroupNewIOThread(priv->cgroup, i + 1, false, &cgroup_temp) < 0 ||
+            virCgroupSetCpusetMemoryMigrate(cgroup_temp, true) < 0 ||
+            virCgroupGetCpusetMems(cgroup_temp, &nodeset) < 0 ||
+            virCgroupSetCpusetMems(cgroup_temp, nodeset) < 0)
+            goto cleanup;
+
+        virCgroupFree(&cgroup_temp);
+    }
+
+    if (virCgroupNewEmulator(priv->cgroup, false, &cgroup_temp) < 0 ||
+        virCgroupSetCpusetMemoryMigrate(cgroup_temp, true) < 0 ||
+        virCgroupGetCpusetMems(cgroup_temp, &nodeset) < 0 ||
+        virCgroupSetCpusetMems(cgroup_temp, nodeset) < 0)
+        goto cleanup;
+
  cleanup:
     VIR_FREE(mem_mask);
+    VIR_FREE(nodeset);
     virBitmapFree(all_nodes);
+    virCgroupFree(&cgroup_temp);
     return;
 
  error: