[libvirt] KVM/qemu: problems with autostart of vms with non-bridged nets

[Daniel P. Berrange]

On Tue, Dec 02, 2008 at 11:38:36AM +0000, Daniel P. Berrange wrote:
> On Mon, Dec 01, 2008 at 12:23:12PM +0100, Gerd v. Egidy wrote:
> > Hi Daniel,
> > 
> > > > This patch alone not, but this patch + the one in my first mail
> > > > (see
> > > > https://www.redhat.com/archives/libvir-list/2008-November/msg00457.html)
> > > > together make it work for me. The first patch fixes the autostart order,
> > > > the second one adds the necessary conn structure.
> > >
> > > Oh yes, I totally missed the patch in your first mail. The first patch
> > > is definitely correct and I'll apply that shortly.
> > 
> > I just added some documentation (same as in virInitialize) to make sure this 
> > bug does not get introduced again. New version attached.
> > 
> > > While your second 
> > > patch is also functionally OK, I'm not entirely happy with creating a
> > > connection object deep inside the QEMU driver code.
> > 
> > Yeah, that was exactly my thought too.
> > 
> > > So I'm going to 
> > > think about whether there's a better way todo that bit.
> > 
> > I looked through the rest of the qemu-initialization and it looks like this is 
> > the only point where the conn-object is needed. So a solution would be to 
> > directly access the network driver functions. But on the other hand these 
> > functions seem all to imply that there is a valid conn available. So we would 
> > have to change that, at least for the lookup-by-name case.
> 
> I've committed this patch now. I'll send a suggestion for the second patch
> shortly...

Ok, I think your suggested patch is the best we can manage at this point
in time. Here's an update which also handle it for UML driver, and adds
a check for NULL on connection open.

Daniel

Index: src/qemu_driver.c
===================================================================
RCS file: /data/cvs/libvirt/src/qemu_driver.c,v
retrieving revision 1.162
diff -u -p -r1.162 qemu_driver.c
--- src/qemu_driver.c	28 Nov 2008 12:03:20 -0000	1.162
+++ src/qemu_driver.c	2 Dec 2008 11:52:28 -0000
@@ -138,12 +138,26 @@ static struct qemud_driver *qemu_driver 
 static void
 qemudAutostartConfigs(struct qemud_driver *driver) {
     unsigned int i;
+    /* XXX: Figure out a better way todo this. The domain
+     * startup code needs a connection handle in order
+     * to lookup the bridge associated with a virtual
+     * network
+     */
+    virConnectPtr conn = virConnectOpen(getuid() ?
+                                        "qemu:///session" :
+                                        "qemu:///system");
+
+    if (!conn) {
+        qemudLog(QEMUD_ERR, "%s",
+                 _("Cannot autostart domains, failed to open connection"));
+        return;
+    }
 
     for (i = 0 ; i < driver->domains.count ; i++) {
         virDomainObjPtr vm = driver->domains.objs[i];
         if (vm->autostart &&
             !virDomainIsActive(vm)) {
-            int ret = qemudStartVMDaemon(NULL, driver, vm, NULL);
+            int ret = qemudStartVMDaemon(conn, driver, vm, NULL);
             if (ret < 0) {
                 virErrorPtr err = virGetLastError();
                 qemudLog(QEMUD_ERR, _("Failed to autostart VM '%s': %s\n"),
@@ -155,6 +169,8 @@ qemudAutostartConfigs(struct qemud_drive
             }
         }
     }
+
+    virConnectClose(conn);
 }
 
 /**
Index: src/uml_driver.c
===================================================================
RCS file: /data/cvs/libvirt/src/uml_driver.c,v
retrieving revision 1.6
diff -u -p -r1.6 uml_driver.c
--- src/uml_driver.c	2 Dec 2008 11:23:27 -0000	1.6
+++ src/uml_driver.c	2 Dec 2008 11:52:28 -0000
@@ -117,16 +117,32 @@ static struct uml_driver *uml_driver = N
 static void
 umlAutostartConfigs(struct uml_driver *driver) {
     unsigned int i;
+    /* XXX: Figure out a better way todo this. The domain
+     * startup code needs a connection handle in order
+     * to lookup the bridge associated with a virtual
+     * network
+     */
+    virConnectPtr conn = virConnectOpen(getuid() ?
+                                        "uml:///session" :
+                                        "uml:///system");
+
+    if (!conn) {
+        umlLog(UML_ERR, "%s",
+               _("Cannot autostart domains, failed to open connection"));
+        return;
+    }
 
     for (i = 0 ; i < driver->domains.count ; i++) {
         if (driver->domains.objs[i]->autostart &&
             !virDomainIsActive(driver->domains.objs[i]) &&
-            umlStartVMDaemon(NULL, driver, driver->domains.objs[i]) < 0) {
+            umlStartVMDaemon(conn, driver, driver->domains.objs[i]) < 0) {
             virErrorPtr err = virGetLastError();
             umlLog(UML_ERR, _("Failed to autostart VM '%s': %s\n"),
                      driver->domains.objs[i]->def->name, err->message);
         }
     }
+
+    virConnectClose(conn);
 }
 
 

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