[libvirt] [PATCH 6/8] perf: reenable perf events when libvirtd restart

[Qiaowei Ren]

When libvirtd daemon restart, this patch will reenable those perf
events previously enabled.

Signed-off-by: Qiaowei Ren <qiaowei.ren at intel.com>
---
 src/qemu/qemu_driver.c | 36 ++++++++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)

diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 7d95364..09607ca 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -164,6 +164,9 @@ static int qemuDomainGetMaxVcpus(virDomainPtr dom);
 static int qemuDomainManagedSaveLoad(virDomainObjPtr vm,
                                      void *opaque);
 
+static int qemuDomainPerfRestart(virDomainObjPtr vm,
+                                 void *data);
+
 static int qemuOpenFile(virQEMUDriverPtr driver,
                         virDomainObjPtr vm,
                         const char *path, int oflags,
@@ -939,6 +942,10 @@ qemuStateInitialize(bool privileged,
                             qemuDomainManagedSaveLoad,
                             qemu_driver);
 
+    virDomainObjListForEach(qemu_driver->domains,
+                            qemuDomainPerfRestart,
+                            NULL);
+
     qemuProcessReconnectAll(conn, qemu_driver);
 
     qemu_driver->workerPool = virThreadPoolNew(0, 1, 0, qemuProcessEventHandler, qemu_driver);
@@ -3460,6 +3467,35 @@ qemuDomainManagedSaveLoad(virDomainObjPtr vm,
     return ret;
 }
 
+static int
+qemuDomainPerfRestart(virDomainObjPtr vm,
+                      void *data ATTRIBUTE_UNUSED)
+{
+    size_t i;
+    virDomainDefPtr def = vm->def;
+    qemuDomainObjPrivatePtr priv = vm->privateData;
+
+    virPerfFree(priv->perf);
+
+    priv->perf = virPerfNew();
+    if (!priv->perf)
+        return -1;
+
+    for (i = 0; i < VIR_PERF_EVENT_LAST; i++) {
+        if (def->perf->events[i] &&
+            def->perf->events[i] == VIR_TRISTATE_BOOL_YES) {
+            if (virPerfEventEnable(priv->perf, i, vm->pid))
+                goto cleanup;
+        }
+    }
+
+    return 0;
+
+ cleanup:
+    virPerfFree(priv->perf);
+    return -1;
+}
+
 
 static int
 qemuDomainHasManagedSaveImage(virDomainPtr dom, unsigned int flags)
-- 
1.9.1