xen: Don't add dom0 twice on driver reload

When the xen driver loads, it probes libxl for some info about dom0 and
adds it to the virDomainObjList. The driver then looks for any domains
in stateDir and if they are still alive adds them to the list as well.
This logic is a bit flawed wrt handling driver reload and causes the
following error

  internal error: unexpected domain Domain-0 already exists

A simple fix is to load all domains from stateDir first and then only
add dom0 if needed.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>

diff --git a/src/libxl/libxl_driver.c b/src/libxl/libxl_driver.c
index 161a6882f3a5166ac577f8352dad078d402d4940..083738871de6697b2814f43ef3edc3ce072acd32 100644 (file)
--- a/src/libxl/libxl_driver.c
+++ b/src/libxl/libxl_driver.c
@@ -604,27 +604,33 @@ libxlAddDom0(libxlDriverPrivatePtr driver)
         goto cleanup;
     }
 
-    if (!(def = virDomainDefNew()))
-        goto cleanup;
+    /*
+     * On a driver reload dom0 will already exist. On host restart it must
+     * created.
+     */
+    if ((vm = virDomainObjListFindByID(driver->domains, 0)) == NULL) {
+        if (!(def = virDomainDefNew()))
+            goto cleanup;
 
-    def->id = 0;
-    def->virtType = VIR_DOMAIN_VIRT_XEN;
-    def->name = g_strdup("Domain-0");
+        def->id = 0;
+        def->virtType = VIR_DOMAIN_VIRT_XEN;
+        def->name = g_strdup("Domain-0");
 
-    def->os.type = VIR_DOMAIN_OSTYPE_XEN;
+        def->os.type = VIR_DOMAIN_OSTYPE_XEN;
 
-    if (virUUIDParse("00000000-0000-0000-0000-000000000000", def->uuid) < 0)
-        goto cleanup;
+        if (virUUIDParse("00000000-0000-0000-0000-000000000000", def->uuid) < 0)
+            goto cleanup;
 
-    if (!(vm = virDomainObjListAdd(driver->domains, def,
-                                   driver->xmlopt,
-                                   0,
-                                   NULL)))
-        goto cleanup;
-    def = NULL;
+        if (!(vm = virDomainObjListAdd(driver->domains, def,
+                                       driver->xmlopt,
+                                       0,
+                                       NULL)))
+            goto cleanup;
+
+        vm->persistent = 1;
+        virDomainObjSetState(vm, VIR_DOMAIN_RUNNING, VIR_DOMAIN_RUNNING_BOOTED);
+    }
 
-    vm->persistent = 1;
-    virDomainObjSetState(vm, VIR_DOMAIN_RUNNING, VIR_DOMAIN_RUNNING_BOOTED);
     if (virDomainDefSetVcpusMax(vm->def, d_info.vcpu_max_id + 1, driver->xmlopt))
         goto cleanup;
 
@@ -783,10 +789,6 @@ libxlStateInitialize(bool privileged,
     if (!(libxl_driver->xmlopt = libxlCreateXMLConf(libxl_driver)))
         goto error;
 
-    /* Add Domain-0 */
-    if (libxlAddDom0(libxl_driver) < 0)
-        goto error;
-
     /* Load running domains first. */
     if (virDomainObjListLoadAllConfigs(libxl_driver->domains,
                                        cfg->stateDir,
@@ -796,6 +798,10 @@ libxlStateInitialize(bool privileged,
                                        NULL, NULL) < 0)
         goto error;
 
+    /* Add Domain-0 */
+    if (libxlAddDom0(libxl_driver) < 0)
+        goto error;
+
     libxlReconnectDomains(libxl_driver);
 
     /* Then inactive persistent configs */