File de49d5ba-xen-avoid-multiple-dom0.patch of Package libvirt

commit de49d5bad33565544f0ba5cf734b60dbb7fe5948
Author: Jim Fehlig <jfehlig@suse.com>
Date:   Fri Sep 11 11:35:47 2020 -0600

    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>

Index: libvirt-6.0.0/src/libxl/libxl_driver.c
===================================================================
--- libvirt-6.0.0.orig/src/libxl/libxl_driver.c
+++ libvirt-6.0.0/src/libxl/libxl_driver.c
@@ -605,27 +605,34 @@ libxlAddDom0(libxlDriverPrivatePtr drive
         goto cleanup;
     }
 
-    if (!(def = virDomainDefNew()))
-        goto cleanup;
-
-    def->id = 0;
-    def->virtType = VIR_DOMAIN_VIRT_XEN;
-    def->name = g_strdup("Domain-0");
-
-    def->os.type = VIR_DOMAIN_OSTYPE_XEN;
-
-    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;
+    /*
+     * 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->os.type = VIR_DOMAIN_OSTYPE_XEN;
+
+        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;
+        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;
 
@@ -776,10 +783,6 @@ 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,
@@ -789,6 +792,10 @@ 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 */