perf: add new xml element

This patch adds new xml element, and so we can have the option of
also having perf events enabled immediately at startup.

Signed-off-by: Qiaowei Ren <qiaowei.ren@intel.com>
Message-id: 1459171833-26416-6-git-send-email-qiaowei.ren@intel.com

docs/schemas/domaincommon.rng

@@ -55,6 +55,9 @@
         <optional>
           <ref name="pm"/>
         </optional>
+        <optional>
+          <ref name="perf"/>
+        </optional>
         <optional>
           <ref name="idmap"/>
         </optional>
@@ -392,6 +395,30 @@
     </element>
   </define>
 
+  <!--
+      Enable or disable perf events for the domain. For each
+      of the events the following rules apply:
+      on: the event will be forcefully enabled
+      off: the event will be forcefully disabled
+      not specified: the event will be disabled by default
+  -->
+  <define name="perf">
+    <element name="perf">
+      <oneOrMore>
+        <element name="event">
+          <attribute name="name">
+            <choice>
+              <value>cmt</value>
+            </choice>
+          </attribute>
+          <attribute name="enabled">
+            <ref name="virYesNo"/>
+          </attribute>
+        </element>
+      </oneOrMore>
+    </element>
+  </define>
+
   <!--
       The Identifiers can be:
       - an optional id attribute with a number on the domain element

src/conf/domain_conf.c

@@ -2642,6 +2642,8 @@ void virDomainDefFree(virDomainDefPtr def)
 
     VIR_FREE(def->keywrap);
 
+    VIR_FREE(def->perf);
+
     if (def->namespaceData && def->ns.free)
         (def->ns.free)(def->namespaceData);
 
@@ -12567,6 +12569,91 @@ virDomainPMStateParseXML(xmlXPathContextPtr ctxt,
 }
 
 
+static int
+virDomainPerfEventDefParseXML(virDomainPerfDefPtr perf,
+                              xmlNodePtr node,
+                              xmlXPathContextPtr ctxt)
+{
+    char *name = NULL;
+    char *enabled = NULL;
+    int enabled_type;
+    int name_type;
+    int ret = -1;
+
+    xmlNodePtr oldnode = ctxt->node;
+
+    ctxt->node = node;
+    if (!(name = virXPathString("string(./@name)", ctxt))) {
+        virReportError(VIR_ERR_CONF_SYNTAX, "%s",
+                       _("missing name for event"));
+        goto cleanup;
+    }
+
+    if ((name_type = virPerfEventTypeFromString(name)) < 0) {
+        virReportError(VIR_ERR_CONF_SYNTAX,
+                       _("%s is not a supported event name"), name);
+        goto cleanup;
+    }
+
+    if (!(enabled = virXPathString("string(./@enabled)", ctxt))) {
+        virReportError(VIR_ERR_CONF_SYNTAX,
+                       _("missing state for cipher named %s"), name);
+        goto cleanup;
+    }
+
+    if ((enabled_type = virTristateBoolTypeFromString(enabled)) < 0) {
+        virReportError(VIR_ERR_CONF_SYNTAX,
+                       _("%s is not a supported enabled state"), enabled);
+        goto cleanup;
+    }
+
+    if (perf->events[VIR_PERF_EVENT_CMT] != VIR_TRISTATE_BOOL_ABSENT) {
+        virReportError(VIR_ERR_INTERNAL_ERROR,
+                       _("A domain definition can have no more than "
+                         "one event node with name %s"),
+                       virTristateBoolTypeToString(name_type));
+
+        goto cleanup;
+    }
+    perf->events[VIR_PERF_EVENT_CMT] = enabled_type;
+
+    ret = 0;
+ cleanup:
+    VIR_FREE(name);
+    VIR_FREE(enabled);
+    ctxt->node = oldnode;
+    return ret;
+}
+
+static int
+virDomainPerfDefParseXML(virDomainDefPtr def,
+                         xmlXPathContextPtr ctxt)
+{
+    size_t i;
+    int ret = -1;
+    xmlNodePtr *nodes = NULL;
+    int n;
+
+    if ((n = virXPathNodeSet("./perf/event", ctxt, &nodes)) < 0)
+        return n;
+
+    if (VIR_ALLOC(def->perf) < 0)
+        goto cleanup;
+
+    for (i = 0; i < n; i++) {
+        if (virDomainPerfEventDefParseXML(def->perf, nodes[i], ctxt) < 0)
+            goto cleanup;
+    }
+
+    ret = 0;
+
+ cleanup:
+    if (ret < 0)
+        VIR_FREE(def->perf);
+    VIR_FREE(nodes);
+    return ret;
+}
+
 static int
 virDomainMemorySourceDefParseXML(xmlNodePtr node,
                                  xmlXPathContextPtr ctxt,
@@ -15792,6 +15879,9 @@ virDomainDefParseXML(xmlDocPtr xml,
                                  &def->pm.s4) < 0)
         goto error;
 
+    if (virDomainPerfDefParseXML(def, ctxt) < 0)
+        goto error;
+
     if ((tmp = virXPathString("string(./clock/@offset)", ctxt)) &&
         (def->clock.offset = virDomainClockOffsetTypeFromString(tmp)) < 0) {
         virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
@@ -21692,6 +21782,33 @@ virDomainKeyWrapDefFormat(virBufferPtr buf, virDomainKeyWrapDefPtr keywrap)
     virBufferAddLit(buf, "</keywrap>\n");
 }
 
+static void
+virDomainPerfDefFormat(virBufferPtr buf, virDomainPerfDefPtr perf)
+{
+    size_t i;
+    bool wantPerf = false;
+
+    for (i = 0; i < VIR_PERF_EVENT_LAST; i++) {
+        if (perf->events[i])
+            wantPerf = true;
+    }
+    if (!wantPerf)
+        return;
+
+    virBufferAddLit(buf, "<perf>\n");
+    virBufferAdjustIndent(buf, 2);
+
+    for (i = 0; i < VIR_PERF_EVENT_LAST; i++) {
+        if (perf->events[i])
+            virBufferAsprintf(buf, "<event name='%s' enabled='%s'/>\n",
+                              virPerfEventTypeToString(i),
+                              virTristateBoolTypeToString(perf->events[i]));
+    }
+
+    virBufferAdjustIndent(buf, -2);
+    virBufferAddLit(buf, "</perf>\n");
+}
+
 static bool
 virDomainDefHasCapabilitiesFeatures(virDomainDefPtr def)
 {
@@ -22565,6 +22682,9 @@ virDomainDefFormatInternal(virDomainDefPtr def,
         virBufferAddLit(buf, "</pm>\n");
     }
 
+    if (def->perf)
+        virDomainPerfDefFormat(buf, def->perf);
+
     virBufferAddLit(buf, "<devices>\n");
     virBufferAdjustIndent(buf, 2);
 

src/conf/domain_conf.h

@@ -51,6 +51,7 @@
 # include "virseclabel.h"
 # include "virprocess.h"
 # include "virgic.h"
+# include "virperf.h"
 
 /* forward declarations of all device types, required by
  * virDomainDeviceDef
@@ -2187,6 +2188,13 @@ struct _virDomainPowerManagement {
     int s4;
 };
 
+typedef struct _virDomainPerfDef virDomainPerfDef;
+typedef virDomainPerfDef *virDomainPerfDefPtr;
+struct _virDomainPerfDef {
+    /* These options are of type enum virTristateBool */
+    int events[VIR_PERF_EVENT_LAST];
+};
+
 typedef struct _virDomainKeyWrapDef virDomainKeyWrapDef;
 typedef virDomainKeyWrapDef *virDomainKeyWrapDefPtr;
 struct _virDomainKeyWrapDef {
@@ -2237,6 +2245,8 @@ struct _virDomainDef {
 
     virDomainPowerManagement pm;
 
+    virDomainPerfDefPtr perf;
+
     virDomainOSDef os;
     char *emulator;
     /* These three options are of type virTristateSwitch,

src/qemu/qemu_driver.c

@@ -10042,9 +10042,14 @@ qemuDomainSetPerfEvents(virDomainPtr dom,
                         virTypedParameterPtr params,
                         int nparams)
 {
+    virQEMUDriverPtr driver = dom->conn->privateData;
     size_t i;
     virDomainObjPtr vm = NULL;
+    virQEMUDriverConfigPtr cfg = NULL;
     qemuDomainObjPrivatePtr priv;
+    virDomainDefPtr def;
+    virDomainDefPtr persistentDef;
+    unsigned int flags = VIR_DOMAIN_AFFECT_CURRENT;
     int ret = -1;
     virPerfEventType type;
     bool enabled;
@@ -10055,11 +10060,15 @@ qemuDomainSetPerfEvents(virDomainPtr dom,
     if (!(vm = qemuDomObjFromDomain(dom)))
         return -1;
 
+    cfg = virQEMUDriverGetConfig(driver);
     priv = vm->privateData;
 
     if (virDomainSetPerfEventsEnsureACL(dom->conn, vm->def) < 0)
         goto cleanup;
 
+    if (virDomainObjGetDefs(vm, flags, &def, &persistentDef) < 0)
+        goto cleanup;
+
     for (i = 0; i < nparams; i++) {
         virTypedParameterPtr param = &params[i];
         enabled = params->value.b;
@@ -10069,12 +10078,29 @@ qemuDomainSetPerfEvents(virDomainPtr dom,
             goto cleanup;
         if (enabled && virPerfEventEnable(priv->perf, type, vm->pid))
             goto cleanup;
+
+        if (def) {
+            def->perf->events[type] = enabled ?
+                VIR_TRISTATE_BOOL_YES : VIR_TRISTATE_BOOL_NO;
+
+            if (virDomainSaveStatus(driver->xmlopt, cfg->stateDir, vm, driver->caps) < 0)
+                goto cleanup;
+        }
+
+        if (persistentDef) {
+            persistentDef->perf->events[type] = enabled ?
+                VIR_TRISTATE_BOOL_YES : VIR_TRISTATE_BOOL_NO;
+
+            if (virDomainSaveConfig(cfg->configDir, driver->caps, persistentDef) < 0)
+                goto cleanup;
+        }
     }
 
     ret = 0;
 
  cleanup:
     virDomainObjEndAPI(&vm);
+    virObjectUnref(cfg);
     return ret;
 }
 

src/qemu/qemu_process.c

@@ -5127,6 +5127,7 @@ qemuProcessLaunch(virConnectPtr conn,
     virCapsPtr caps = NULL;
     size_t nnicindexes = 0;
     int *nicindexes = NULL;
+    size_t i;
 
     VIR_DEBUG("vm=%p name=%s id=%d asyncJob=%d "
               "incoming.launchURI=%s incoming.deferredURI=%s "
@@ -5254,8 +5255,12 @@ qemuProcessLaunch(virConnectPtr conn,
         goto cleanup;
 
     priv->perf = virPerfNew();
-    if (!priv->perf)
+    if (priv->perf) {
-        goto cleanup;
+        for (i = 0; i < VIR_PERF_EVENT_LAST; i++) {
+            if (vm->def->perf->events[i] == VIR_TRISTATE_BOOL_YES)
+                virPerfEventEnable(priv->perf, i, vm->pid);
+        }
+    }
 
     /* This must be done after cgroup placement to avoid resetting CPU
      * affinity */

tests/domainschemadata/domain-perf-simple.xml

@@ -0,0 +1,20 @@
+<domain type='qemu'>
+  <name>QEMUGuest1</name>
+  <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
+  <currentMemory unit='KiB'>219136</currentMemory>
+  <vcpu placement='static'>1</vcpu>
+  <os>
+    <type arch='x86_64' machine='pc'>hvm</type>
+    <boot dev='hd'/>
+  </os>
+  <perf>
+      <event name='cmt' enabled='yes'/>
+  </perf>
+  <clock offset='utc'/>
+  <on_poweroff>destroy</on_poweroff>
+  <on_reboot>restart</on_reboot>
+  <on_crash>destroy</on_crash>
+  <devices>
+    <emulator>/usr/bin/qemu</emulator>
+  </devices>
+</domain>