[libvirt] [PATCH 1/1] reset vcpu pin info from config for zero mask

[Konstantin Neumoin]

The option for removing vcpu pinning information from config was added
in:
'7ea9778 vcpupin: add vcpupin resetting feature to qemu driver'
and removed in:
'a02a161 qemu: libxl: vcpupin: Don't reset pinning when pinning to all pcpus'
by some reasons.

So, for now there is no way to remove vcpu pinning from config.
This patch returns options for remove vcpu/emulator pinning settings
from both configs if zero mask(mask filled by zeros) was specified.

Signed-off-by: Konstantin Neumoin <kneumoin at virtuozzo.com>
---
 src/qemu/qemu_driver.c | 74 +++++++++++++++++++++++++++++++++++---------------
 1 file changed, 52 insertions(+), 22 deletions(-)

diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index bec7a38..7aa64a4 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -4969,7 +4969,8 @@ qemuDomainPinVcpuLive(virDomainObjPtr vm,
                       virQEMUDriverConfigPtr cfg,
                       virBitmapPtr cpumap)
 {
-    virBitmapPtr tmpmap = NULL;
+    virBitmapPtr effective_cpumap = NULL;
+    virBitmapPtr allcpu_map = NULL;
     virDomainVcpuInfoPtr vcpuinfo;
     qemuDomainObjPrivatePtr priv = vm->privateData;
     virCgroupPtr cgroup_vcpu = NULL;
@@ -4980,6 +4981,7 @@ qemuDomainPinVcpuLive(virDomainObjPtr vm,
     int eventNparams = 0;
     int eventMaxparams = 0;
     int ret = -1;
+    int hostcpus = 0;
 
     if (!qemuDomainHasVcpuPids(vm)) {
         virReportError(VIR_ERR_OPERATION_INVALID,
@@ -4994,29 +4996,38 @@ qemuDomainPinVcpuLive(virDomainObjPtr vm,
         goto cleanup;
     }
 
-    if (!(tmpmap = virBitmapNewCopy(cpumap)))
-        goto cleanup;
+    if (vcpuinfo->online) {
+        if (cpumap) {
+            effective_cpumap = cpumap;
+        } else if (def->cpumask) {
+            effective_cpumap = def->cpumask;
+        } else {
+            if ((hostcpus = nodeGetCPUCount(NULL)) < 0)
+                goto cleanup;
 
-    if (!(str = virBitmapFormat(cpumap)))
-        goto cleanup;
+            if (!(allcpu_map = virBitmapNew(hostcpus)))
+                goto cleanup;
+            virBitmapSetAll(allcpu_map);
+            effective_cpumap = allcpu_map;
+        }
 
-    if (vcpuinfo->online) {
         /* Configure the corresponding cpuset cgroup before set affinity. */
         if (virCgroupHasController(priv->cgroup, VIR_CGROUP_CONTROLLER_CPUSET)) {
             if (virCgroupNewThread(priv->cgroup, VIR_CGROUP_THREAD_VCPU, vcpu,
                                    false, &cgroup_vcpu) < 0)
                 goto cleanup;
-            if (qemuSetupCgroupCpusetCpus(cgroup_vcpu, cpumap) < 0)
+            if (qemuSetupCgroupCpusetCpus(cgroup_vcpu, effective_cpumap) < 0)
                 goto cleanup;
         }
 
-        if (virProcessSetAffinity(qemuDomainGetVcpuPid(vm, vcpu), cpumap) < 0)
+        if (virProcessSetAffinity(qemuDomainGetVcpuPid(vm, vcpu), effective_cpumap) < 0)
             goto cleanup;
     }
 
     virBitmapFree(vcpuinfo->cpumask);
-    vcpuinfo->cpumask = tmpmap;
-    tmpmap = NULL;
+    vcpuinfo->cpumask = NULL;
+    if (cpumap && !(vcpuinfo->cpumask = virBitmapNewCopy(cpumap)))
+        goto cleanup;
 
     if (virDomainSaveStatus(driver->xmlopt, cfg->stateDir, vm, driver->caps) < 0)
         goto cleanup;
@@ -5026,6 +5037,9 @@ qemuDomainPinVcpuLive(virDomainObjPtr vm,
         goto cleanup;
     }
 
+    if (!(str = virBitmapFormat(effective_cpumap)))
+        goto cleanup;
+
     if (virTypedParamsAddString(&eventParams, &eventNparams,
                                 &eventMaxparams, paramField, str) < 0)
         goto cleanup;
@@ -5035,7 +5049,7 @@ qemuDomainPinVcpuLive(virDomainObjPtr vm,
     ret = 0;
 
  cleanup:
-    virBitmapFree(tmpmap);
+    virBitmapFree(allcpu_map);
     virCgroupFree(&cgroup_vcpu);
     VIR_FREE(str);
     qemuDomainEventQueue(driver, event);
@@ -5089,9 +5103,8 @@ qemuDomainPinVcpuFlags(virDomainPtr dom,
         goto endjob;
 
     if (virBitmapIsAllClear(pcpumap)) {
-        virReportError(VIR_ERR_INVALID_ARG, "%s",
-                       _("Empty cpu list for pinning"));
-        goto endjob;
+        virBitmapFree(pcpumap);
+        pcpumap = NULL;
     }
 
     if (def &&
@@ -5177,12 +5190,15 @@ qemuDomainPinEmulator(virDomainPtr dom,
     int ret = -1;
     qemuDomainObjPrivatePtr priv;
     virBitmapPtr pcpumap = NULL;
+    virBitmapPtr allcpu_map = NULL;
+    virBitmapPtr effective_pcpumap = NULL;
     virQEMUDriverConfigPtr cfg = NULL;
     virObjectEventPtr event = NULL;
     char *str = NULL;
     virTypedParameterPtr eventParams = NULL;
     int eventNparams = 0;
     int eventMaxparams = 0;
+    int hostcpus = 0;
 
     virCheckFlags(VIR_DOMAIN_AFFECT_LIVE |
                   VIR_DOMAIN_AFFECT_CONFIG, -1);
@@ -5207,18 +5223,31 @@ qemuDomainPinEmulator(virDomainPtr dom,
         goto endjob;
 
     if (virBitmapIsAllClear(pcpumap)) {
-        virReportError(VIR_ERR_INVALID_ARG, "%s",
-                       _("Empty cpu list for pinning"));
-        goto endjob;
+        virBitmapFree(pcpumap);
+        pcpumap = NULL;
     }
 
     if (def) {
+        if (pcpumap) {
+            effective_pcpumap = pcpumap;
+        } else if (def->cpumask) {
+            effective_pcpumap = def->cpumask;
+        } else {
+            if ((hostcpus = nodeGetCPUCount(NULL)) < 0)
+                goto cleanup;
+
+            if (!(allcpu_map = virBitmapNew(hostcpus)))
+                goto cleanup;
+            virBitmapSetAll(allcpu_map);
+            effective_pcpumap = allcpu_map;
+        }
+
         if (virCgroupHasController(priv->cgroup, VIR_CGROUP_CONTROLLER_CPUSET)) {
             if (virCgroupNewThread(priv->cgroup, VIR_CGROUP_THREAD_EMULATOR,
                                    0, false, &cgroup_emulator) < 0)
                 goto endjob;
 
-            if (qemuSetupCgroupCpusetCpus(cgroup_emulator, pcpumap) < 0) {
+            if (qemuSetupCgroupCpusetCpus(cgroup_emulator, effective_pcpumap) < 0) {
                 virReportError(VIR_ERR_OPERATION_INVALID, "%s",
                                _("failed to set cpuset.cpus in cgroup"
                                  " for emulator threads"));
@@ -5226,19 +5255,19 @@ qemuDomainPinEmulator(virDomainPtr dom,
             }
         }
 
-        if (virProcessSetAffinity(vm->pid, pcpumap) < 0)
+        if (virProcessSetAffinity(vm->pid, effective_pcpumap) < 0)
             goto endjob;
 
         virBitmapFree(def->cputune.emulatorpin);
         def->cputune.emulatorpin = NULL;
 
-        if (!(def->cputune.emulatorpin = virBitmapNewCopy(pcpumap)))
+        if (pcpumap && !(def->cputune.emulatorpin = virBitmapNewCopy(pcpumap)))
             goto endjob;
 
         if (virDomainSaveStatus(driver->xmlopt, cfg->stateDir, vm, driver->caps) < 0)
             goto endjob;
 
-        str = virBitmapFormat(pcpumap);
+        str = virBitmapFormat(effective_pcpumap);
         if (virTypedParamsAddString(&eventParams, &eventNparams,
                                     &eventMaxparams,
                                     VIR_DOMAIN_TUNABLE_CPU_EMULATORPIN,
@@ -5252,7 +5281,7 @@ qemuDomainPinEmulator(virDomainPtr dom,
         virBitmapFree(persistentDef->cputune.emulatorpin);
         persistentDef->cputune.emulatorpin = NULL;
 
-        if (!(persistentDef->cputune.emulatorpin = virBitmapNewCopy(pcpumap)))
+        if (pcpumap && !(persistentDef->cputune.emulatorpin = virBitmapNewCopy(pcpumap)))
             goto endjob;
 
         ret = virDomainSaveConfig(cfg->configDir, driver->caps, persistentDef);
@@ -5270,6 +5299,7 @@ qemuDomainPinEmulator(virDomainPtr dom,
     qemuDomainEventQueue(driver, event);
     VIR_FREE(str);
     virBitmapFree(pcpumap);
+    virBitmapFree(allcpu_map);
     virDomainObjEndAPI(&vm);
     virObjectUnref(cfg);
     return ret;
-- 
2.5.5