[libvirt] [PATCH] qemu: lock: unlock vm during qemuBuildCommandLine

zhang bo oscar.zhangbo at huawei.com
Thu Apr 23 03:44:49 UTC 2015

The function qemuBuildCommandLine() may take a long time, for example
if we configure tens of vifs for the guest, each may cost hundrands of
milliseconds to create tap dev, senconds in total. Thus, unlock vm
before calling it.

Signed-off-by: Zhang Bo <oscar.zhangbo at huawei.com>
Signed-off-by: Zhou Yimin <zhouyimin at huawei.com>
 src/qemu/qemu_process.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c
index 753afe8..d1aaaec 100644
--- a/src/qemu/qemu_process.c
+++ b/src/qemu/qemu_process.c
@@ -4628,14 +4628,18 @@ int qemuProcessStart(virConnectPtr conn,

     VIR_DEBUG("Building emulator command line");
+    virObjectUnlock(vm);
     if (!(cmd = qemuBuildCommandLine(conn, driver, vm->def, priv->monConfig,
                                      priv->monJSON, priv->qemuCaps,
                                      migrateFrom, stdin_fd, snapshot, vmop,
                                      &buildCommandLineCallbacks, false,
-                                     &nnicindexes, &nicindexes)))
+                                     &nnicindexes, &nicindexes))) {
+        virObjectLock(vm);
         goto cleanup;
+    }
+    virObjectLock(vm);

     /* now that we know it is about to start call the hook if present */
     if (virHookPresent(VIR_HOOK_DRIVER_QEMU)) {

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