[libvirt] [PATCH v3] qemu: Implement CPUs check against machine type's cpu-max

Michal Novotny minovotn at redhat.com
Wed Apr 17 14:15:25 UTC 2013


Implement check whether (maximum) vCPUs doesn't exceed machine
type's cpu-max settings.

On older versions of QEMU the check is disabled.

Signed-off-by: Michal Novotny <minovotn at redhat.com>
---
 src/qemu/qemu_capabilities.c | 38 +++++++++++++++++++++++++++++++++++++-
 src/qemu/qemu_capabilities.h |  3 ++-
 src/qemu/qemu_monitor.h      |  1 +
 src/qemu/qemu_monitor_json.c |  7 +++++++
 src/qemu/qemu_process.c      | 27 +++++++++++++++++++++++++++
 5 files changed, 74 insertions(+), 2 deletions(-)

diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c
index d10c8aa..bbfe85f 100644
--- a/src/qemu/qemu_capabilities.c
+++ b/src/qemu/qemu_capabilities.c
@@ -243,6 +243,7 @@ struct _virQEMUCaps {
     size_t nmachineTypes;
     char **machineTypes;
     char **machineAliases;
+    int *machineMaxCpus;
 };
 
 struct _virQEMUCapsCache {
@@ -322,6 +323,7 @@ virQEMUCapsSetDefaultMachine(virQEMUCapsPtr qemuCaps,
 {
     char *name = qemuCaps->machineTypes[defIdx];
     char *alias = qemuCaps->machineAliases[defIdx];
+    int cpu_max = qemuCaps->machineMaxCpus[defIdx];
 
     memmove(qemuCaps->machineTypes + 1,
             qemuCaps->machineTypes,
@@ -329,8 +331,12 @@ virQEMUCapsSetDefaultMachine(virQEMUCapsPtr qemuCaps,
     memmove(qemuCaps->machineAliases + 1,
             qemuCaps->machineAliases,
             sizeof(qemuCaps->machineAliases[0]) * defIdx);
+    memmove(qemuCaps->machineMaxCpus + 1,
+            qemuCaps->machineMaxCpus,
+            sizeof(qemuCaps->machineMaxCpus[0]) * defIdx);
     qemuCaps->machineTypes[0] = name;
     qemuCaps->machineAliases[0] = alias;
+    qemuCaps->machineMaxCpus[0] = cpu_max;
 }
 
 /* Format is:
@@ -377,7 +383,8 @@ virQEMUCapsParseMachineTypesStr(const char *output,
         }
 
         if (VIR_REALLOC_N(qemuCaps->machineTypes, qemuCaps->nmachineTypes + 1) < 0 ||
-            VIR_REALLOC_N(qemuCaps->machineAliases, qemuCaps->nmachineTypes + 1) < 0) {
+            VIR_REALLOC_N(qemuCaps->machineAliases, qemuCaps->nmachineTypes + 1) < 0 ||
+            VIR_REALLOC_N(qemuCaps->machineMaxCpus, qemuCaps->nmachineTypes + 1) < 0) {
             VIR_FREE(name);
             VIR_FREE(canonical);
             goto no_memory;
@@ -390,6 +397,8 @@ virQEMUCapsParseMachineTypesStr(const char *output,
             qemuCaps->machineTypes[qemuCaps->nmachineTypes-1] = name;
             qemuCaps->machineAliases[qemuCaps->nmachineTypes-1] = NULL;
         }
+        /* Value 0 means "unknown" as it's not exposed by QEMU binary */
+        qemuCaps->machineMaxCpus[qemuCaps->nmachineTypes-1] = 0;
     } while ((p = next));
 
 
@@ -1718,6 +1727,8 @@ virQEMUCapsPtr virQEMUCapsNewCopy(virQEMUCapsPtr qemuCaps)
         goto no_memory;
     if (VIR_ALLOC_N(ret->machineAliases, qemuCaps->nmachineTypes) < 0)
         goto no_memory;
+    if (VIR_ALLOC_N(ret->machineMaxCpus, qemuCaps->nmachineTypes) < 0)
+        goto no_memory;
     ret->nmachineTypes = qemuCaps->nmachineTypes;
     for (i = 0 ; i < qemuCaps->nmachineTypes ; i++) {
         if (!(ret->machineTypes[i] = strdup(qemuCaps->machineTypes[i])))
@@ -1725,6 +1736,7 @@ virQEMUCapsPtr virQEMUCapsNewCopy(virQEMUCapsPtr qemuCaps)
         if (qemuCaps->machineAliases[i] &&
             !(ret->machineAliases[i] = strdup(qemuCaps->machineAliases[i])))
             goto no_memory;
+        ret->machineMaxCpus[i] = qemuCaps->machineMaxCpus[i];
     }
 
     return ret;
@@ -1923,6 +1935,25 @@ const char *virQEMUCapsGetCanonicalMachine(virQEMUCapsPtr qemuCaps,
 }
 
 
+int virQEMUCapsGetMachineMaxCpus(virQEMUCapsPtr qemuCaps,
+                                 const char *name)
+{
+    size_t i;
+
+    if (!name)
+        return 0;
+
+    for (i = 0 ; i < qemuCaps->nmachineTypes ; i++) {
+        if (!qemuCaps->machineMaxCpus[i])
+            continue;
+        if (STREQ(qemuCaps->machineTypes[i], name))
+            return qemuCaps->machineMaxCpus[i];
+    }
+
+    return 0;
+}
+
+
 static int
 virQEMUCapsProbeQMPCommands(virQEMUCapsPtr qemuCaps,
                             qemuMonitorPtr mon)
@@ -2073,6 +2104,10 @@ virQEMUCapsProbeQMPMachineTypes(virQEMUCapsPtr qemuCaps,
         virReportOOMError();
         goto cleanup;
     }
+    if (VIR_ALLOC_N(qemuCaps->machineMaxCpus, nmachines) < 0) {
+        virReportOOMError();
+        goto cleanup;
+    }
 
     for (i = 0 ; i < nmachines ; i++) {
         if (machines[i]->alias) {
@@ -2087,6 +2122,7 @@ virQEMUCapsProbeQMPMachineTypes(virQEMUCapsPtr qemuCaps,
         }
         if (machines[i]->isDefault)
             defIdx = i;
+        qemuCaps->machineMaxCpus[i] = machines[i]->cpu_max;
     }
     qemuCaps->nmachineTypes = nmachines;
 
diff --git a/src/qemu/qemu_capabilities.h b/src/qemu/qemu_capabilities.h
index 4e76799..bd97e8d 100644
--- a/src/qemu/qemu_capabilities.h
+++ b/src/qemu/qemu_capabilities.h
@@ -223,7 +223,8 @@ size_t virQEMUCapsGetMachineTypes(virQEMUCapsPtr qemuCaps,
                                   char ***names);
 const char *virQEMUCapsGetCanonicalMachine(virQEMUCapsPtr qemuCaps,
                                            const char *name);
-
+int virQEMUCapsGetMachineMaxCpus(virQEMUCapsPtr qemuCaps,
+                                 const char *name);
 int virQEMUCapsGetMachineTypesCaps(virQEMUCapsPtr qemuCaps,
                                    size_t *nmachines,
                                    virCapsGuestMachinePtr **machines);
diff --git a/src/qemu/qemu_monitor.h b/src/qemu/qemu_monitor.h
index f39f009..c097953 100644
--- a/src/qemu/qemu_monitor.h
+++ b/src/qemu/qemu_monitor.h
@@ -650,6 +650,7 @@ struct _qemuMonitorMachineInfo {
     char *name;
     bool isDefault;
     char *alias;
+    int cpu_max;
 };
 
 int qemuMonitorGetMachines(qemuMonitorPtr mon,
diff --git a/src/qemu/qemu_monitor_json.c b/src/qemu/qemu_monitor_json.c
index 6fdd650..adbd865 100644
--- a/src/qemu/qemu_monitor_json.c
+++ b/src/qemu/qemu_monitor_json.c
@@ -4024,6 +4024,13 @@ int qemuMonitorJSONGetMachines(qemuMonitorPtr mon,
                 goto cleanup;
             }
         }
+
+        if (virJSONValueObjectHasKey(child, "cpu-max") &&
+            virJSONValueObjectGetNumberInt(child, "cpu-max", &info->cpu_max) < 0) {
+            virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+                           _("query-machines reply has malformed 'cpu-max' data"));
+            goto cleanup;
+        }
     }
 
     ret = n;
diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c
index ce9f501..9eae8f6 100644
--- a/src/qemu/qemu_process.c
+++ b/src/qemu/qemu_process.c
@@ -3266,6 +3266,30 @@ qemuSetUnprivSGIO(virDomainDiskDefPtr disk)
     return ret;
 }
 
+static bool
+qemuValidateCpuMax(virDomainDefPtr def, virQEMUCapsPtr qemuCaps)
+{
+    int cpu_max;
+
+    cpu_max = virQEMUCapsGetMachineMaxCpus(qemuCaps, def->os.machine);
+    if (!cpu_max)
+        return true;
+
+    if (def->vcpus > cpu_max) {
+        virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+                       "%s", _("CPUs greater than specified machine type limit"));
+        return false;
+    }
+
+    if (def->maxvcpus > cpu_max) {
+        virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+                       "%s", _("Maximum CPUs greater than specified machine type limit"));
+        return false;
+    }
+
+    return true;
+}
+
 int qemuProcessStart(virConnectPtr conn,
                      virQEMUDriverPtr driver,
                      virDomainObjPtr vm,
@@ -3481,6 +3505,9 @@ int qemuProcessStart(virConnectPtr conn,
                                                       vm->def->emulator)))
         goto cleanup;
 
+    if (!qemuValidateCpuMax(vm->def, priv->qemuCaps))
+        goto cleanup;
+
     if (qemuAssignDeviceAliases(vm->def, priv->qemuCaps) < 0)
         goto cleanup;
 
-- 
1.7.11.7




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