migrate: v2: use VIR_DOMAIN_XML_MIGRATABLE when available

In v2 migration protocol, XML is obtained by calling domainGetXMLDesc.
This includes the default USB controller in XML, which breaks migration
to older libvirt (before 0.9.2).

Commit 409b5f549530e7b3a33f4505f2cad2e26896107c
    qemu: Emit compatible XML when migrating a domain
only fixed this for v3 migration.

This patch uses the new VIR_DOMAIN_XML_MIGRATABLE flag (detected by
VIR_DRV_FEATURE_XML_MIGRATABLE) to obtain XML without the default controller,
enabling backward v2 migration.

diff --git a/src/libvirt.c b/src/libvirt.c
index 6d659652e619e7bda4e674d5ad05a4f2fba2934a..33cf7cbeb6e398c67d30306d80d8e5497b0caa8e 100644 (file)
--- a/src/libvirt.c
+++ b/src/libvirt.c
@@ -4620,6 +4620,7 @@ virDomainMigrateVersion2 (virDomainPtr domain,
     int cookielen = 0, ret;
     virDomainInfo info;
     virErrorPtr orig_err = NULL;
+    unsigned int getxml_flags = 0;
     int cancelled;
     VIR_DOMAIN_DEBUG(domain,
                      "dconn=%p, flags=%lx, dname=%s, uri=%s, bandwidth=%lu",
@@ -4646,9 +4647,15 @@ virDomainMigrateVersion2 (virDomainPtr domain,
         virDispatchError(domain->conn);
         return NULL;
     }
-    dom_xml = domain->conn->driver->domainGetXMLDesc(domain,
-                                                     VIR_DOMAIN_XML_SECURE |
-                                                     VIR_DOMAIN_XML_UPDATE_CPU);
+
+    if (VIR_DRV_SUPPORTS_FEATURE(domain->conn->driver, domain->conn,
+                                 VIR_DRV_FEATURE_XML_MIGRATABLE)) {
+        getxml_flags |= VIR_DOMAIN_XML_MIGRATABLE;
+    } else {
+        getxml_flags |= VIR_DOMAIN_XML_SECURE | VIR_DOMAIN_XML_UPDATE_CPU;
+    }
+
+    dom_xml = domain->conn->driver->domainGetXMLDesc(domain, getxml_flags);
     if (!dom_xml)
         return NULL;
 

diff --git a/src/libvirt_internal.h b/src/libvirt_internal.h
index 23e71535d048c0cd887f264a0b28b65d1b511fe8..71483e4695497c1022d9b20aa9ae5c2bc82e7804 100644 (file)
--- a/src/libvirt_internal.h
+++ b/src/libvirt_internal.h
@@ -95,6 +95,11 @@ enum {
      * messages).
      */
     VIR_DRV_FEATURE_PROGRAM_KEEPALIVE = 10,
+
+    /*
+     * Support for VIR_DOMAIN_XML_MIGRATABLE flag in domainGetXMLDesc
+     */
+    VIR_DRV_FEATURE_XML_MIGRATABLE = 11,
 };
 
 

diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index feda4d9a218bae9df103c63e0992cae0300bbaf6..2f83626127b64ec42471d06864c183faf7cdc894 100644 (file)
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -1130,6 +1130,7 @@ qemudSupportsFeature (virConnectPtr conn ATTRIBUTE_UNUSED, int feature)
     case VIR_DRV_FEATURE_MIGRATE_CHANGE_PROTECTION:
     case VIR_DRV_FEATURE_FD_PASSING:
     case VIR_DRV_FEATURE_TYPED_PARAM_STRING:
+    case VIR_DRV_FEATURE_XML_MIGRATABLE:
         return 1;
     default:
         return 0;