Add MIGRATABLE flag for virDomainGetXMLDesc

Using VIR_DOMAIN_XML_MIGRATABLE flag, one can request domain's XML
configuration that is suitable for migration or save/restore. Such XML
may contain extra run-time stuff internal to libvirt and some default
configuration may be removed for better compatibility of the XML with
older libvirt releases.

This flag may serve as an easy way to get the XML that can be passed
(after desired modifications) to APIs that accept custom XMLs, such as
virDomainMigrate{,ToURI}2 or virDomainSaveFlags.

include/libvirt/libvirt.h.in

@@ -1651,6 +1651,7 @@ typedef enum {
     VIR_DOMAIN_XML_SECURE       = (1 << 0), /* dump security sensitive information too */
     VIR_DOMAIN_XML_INACTIVE     = (1 << 1), /* dump inactive domain information */
     VIR_DOMAIN_XML_UPDATE_CPU   = (1 << 2), /* update guest CPU requirements according to host CPU */
+    VIR_DOMAIN_XML_MIGRATABLE   = (1 << 3), /* dump XML suitable for migration */
 } virDomainXMLFlags;
 
 char *                  virDomainGetXMLDesc     (virDomainPtr domain,

src/conf/domain_conf.c

@@ -13314,7 +13314,8 @@ virDomainHubDefFormat(virBufferPtr buf,
 #define DUMPXML_FLAGS                           \
     (VIR_DOMAIN_XML_SECURE |                    \
      VIR_DOMAIN_XML_INACTIVE |                  \
-     VIR_DOMAIN_XML_UPDATE_CPU)
+     VIR_DOMAIN_XML_UPDATE_CPU |                \
+     VIR_DOMAIN_XML_MIGRATABLE)
 
 verify(((VIR_DOMAIN_XML_INTERNAL_STATUS |
          VIR_DOMAIN_XML_INTERNAL_ACTUAL_NET |

src/qemu/qemu_domain.c

@@ -46,10 +46,6 @@
 
 #define QEMU_NAMESPACE_HREF "http://libvirt.org/schemas/domain/qemu/1.0"
 
-#define QEMU_DOMAIN_FORMAT_LIVE_FLAGS       \
-    (VIR_DOMAIN_XML_SECURE |                \
-     VIR_DOMAIN_XML_UPDATE_CPU)
-
 VIR_ENUM_IMPL(qemuDomainJob, QEMU_JOB_LAST,
               "none",
               "query",
@@ -1220,7 +1216,6 @@ int
 qemuDomainDefFormatBuf(struct qemud_driver *driver,
                        virDomainDefPtr def,
                        unsigned int flags,
-                       bool compatible,
                        virBuffer *buf)
 {
     int ret = -1;
@@ -1245,7 +1240,7 @@ qemuDomainDefFormatBuf(struct qemud_driver *driver,
         def->cpu = cpu;
     }
 
-    if (compatible) {
+    if ((flags & VIR_DOMAIN_XML_MIGRATABLE)) {
         int i;
         virDomainControllerDefPtr usb = NULL;
 
@@ -1297,12 +1292,11 @@ cleanup:
 
 char *qemuDomainDefFormatXML(struct qemud_driver *driver,
                              virDomainDefPtr def,
-                             unsigned int flags,
-                             bool compatible)
+                             unsigned int flags)
 {
     virBuffer buf = VIR_BUFFER_INITIALIZER;
 
-    if (qemuDomainDefFormatBuf(driver, def, flags, compatible, &buf) < 0) {
+    if (qemuDomainDefFormatBuf(driver, def, flags, &buf) < 0) {
         virBufferFreeAndReset(&buf);
         return NULL;
     }
@@ -1318,8 +1312,7 @@ char *qemuDomainDefFormatXML(struct qemud_driver *driver,
 
 char *qemuDomainFormatXML(struct qemud_driver *driver,
                           virDomainObjPtr vm,
-                          unsigned int flags,
-                          bool compatible)
+                          unsigned int flags)
 {
     virDomainDefPtr def;
 
@@ -1328,7 +1321,7 @@ char *qemuDomainFormatXML(struct qemud_driver *driver,
     else
         def = vm->def;
 
-    return qemuDomainDefFormatXML(driver, def, flags, compatible);
+    return qemuDomainDefFormatXML(driver, def, flags);
 }
 
 char *
@@ -1341,8 +1334,10 @@ qemuDomainDefFormatLive(struct qemud_driver *driver,
 
     if (inactive)
         flags |= VIR_DOMAIN_XML_INACTIVE;
+    if (compatible)
+        flags |= VIR_DOMAIN_XML_MIGRATABLE;
 
-    return qemuDomainDefFormatXML(driver, def, flags, compatible);
+    return qemuDomainDefFormatXML(driver, def, flags);
 }
 
 

src/qemu/qemu_domain.h

@@ -39,6 +39,10 @@
      (1 << VIR_DOMAIN_VIRT_KVM) |      \
      (1 << VIR_DOMAIN_VIRT_XEN))
 
+# define QEMU_DOMAIN_FORMAT_LIVE_FLAGS      \
+    (VIR_DOMAIN_XML_SECURE |                \
+     VIR_DOMAIN_XML_UPDATE_CPU)
+
 # if ULONG_MAX == 4294967295
 /* Qemu has a 64-bit limit, but we are limited by our historical choice of
  * representing bandwidth in a long instead of a 64-bit int.  */
@@ -253,18 +257,15 @@ void qemuDomainObjExitRemoteWithDriver(struct qemud_driver *driver,
 int qemuDomainDefFormatBuf(struct qemud_driver *driver,
                            virDomainDefPtr vm,
                            unsigned int flags,
-                           bool compatible,
                            virBuffer *buf);
 
 char *qemuDomainDefFormatXML(struct qemud_driver *driver,
                              virDomainDefPtr vm,
-                             unsigned int flags,
-                             bool compatible);
+                             unsigned int flags);
 
 char *qemuDomainFormatXML(struct qemud_driver *driver,
                           virDomainObjPtr vm,
-                          unsigned int flags,
-                          bool compatible);
+                          unsigned int flags);
 
 char *qemuDomainDefFormatLive(struct qemud_driver *driver,
                               virDomainDefPtr def,

src/qemu/qemu_driver.c

@@ -4966,7 +4966,7 @@ qemuDomainSaveImageGetXMLDesc(virConnectPtr conn, const char *path,
     if (fd < 0)
         goto cleanup;
 
-    ret = qemuDomainDefFormatXML(driver, def, flags, false);
+    ret = qemuDomainDefFormatXML(driver, def, flags);
 
 cleanup:
     virDomainDefFree(def);
@@ -5010,8 +5010,8 @@ qemuDomainSaveImageDefineXML(virConnectPtr conn, const char *path,
 
     xml = qemuDomainDefFormatXML(driver, def,
                                  VIR_DOMAIN_XML_INACTIVE |
-                                 VIR_DOMAIN_XML_SECURE,
-                                 true);
+                                 VIR_DOMAIN_XML_SECURE |
+                                 VIR_DOMAIN_XML_MIGRATABLE);
     if (!xml)
         goto cleanup;
     len = strlen(xml) + 1;
@@ -5161,7 +5161,10 @@ endjob:
         }
     }
 
-    ret = qemuDomainFormatXML(driver, vm, flags, false);
+    if ((flags & VIR_DOMAIN_XML_MIGRATABLE))
+        flags |= QEMU_DOMAIN_FORMAT_LIVE_FLAGS;
+
+    ret = qemuDomainFormatXML(driver, vm, flags);
 
 cleanup:
     if (vm)
@@ -5201,7 +5204,7 @@ static char *qemuDomainXMLFromNative(virConnectPtr conn,
         goto cleanup;
     }
 
-    xml = qemuDomainDefFormatXML(driver, def, VIR_DOMAIN_XML_INACTIVE, false);
+    xml = qemuDomainDefFormatXML(driver, def, VIR_DOMAIN_XML_INACTIVE);
 
 cleanup:
     virDomainDefFree(def);
@@ -11732,8 +11735,7 @@ static int qemuDomainRevertToSnapshot(virDomainSnapshotPtr snapshot,
         if (!(xml = qemuDomainDefFormatXML(driver,
                                            snap->def->dom,
                                            VIR_DOMAIN_XML_INACTIVE |
-                                           VIR_DOMAIN_XML_SECURE,
-                                           false)))
+                                           VIR_DOMAIN_XML_SECURE)))
             goto cleanup;
         config = virDomainDefParseString(driver->caps, xml,
                                          QEMU_EXPECTED_VIRT_TYPES,

src/qemu/qemu_migration.c

@@ -432,8 +432,8 @@ qemuMigrationCookieXMLFormat(struct qemud_driver *driver,
         if (qemuDomainDefFormatBuf(driver,
                                    mig->persistent,
                                    VIR_DOMAIN_XML_INACTIVE |
-                                   VIR_DOMAIN_XML_SECURE,
-                                   true,
+                                   VIR_DOMAIN_XML_SECURE |
+                                   VIR_DOMAIN_XML_MIGRATABLE,
                                    buf) < 0)
             return -1;
         virBufferAdjustIndent(buf, -2);
@@ -1264,7 +1264,7 @@ qemuMigrationPrepareAny(struct qemud_driver *driver,
         int hookret;
 
         if (!(xml = qemuDomainDefFormatXML(driver, def,
-                                           VIR_DOMAIN_XML_SECURE, false)))
+                                           VIR_DOMAIN_XML_SECURE)))
             goto cleanup;
 
         hookret = virHookCall(VIR_HOOK_DRIVER_QEMU, def->name,
@@ -2213,9 +2213,8 @@ static int doPeer2PeerMigrate2(struct qemud_driver *driver,
      * and pass it to Prepare2.
      */
     if (!(dom_xml = qemuDomainFormatXML(driver, vm,
-                                        VIR_DOMAIN_XML_SECURE |
-                                        VIR_DOMAIN_XML_UPDATE_CPU,
-                                        true)))
+                                        QEMU_DOMAIN_FORMAT_LIVE_FLAGS |
+                                        VIR_DOMAIN_XML_MIGRATABLE)))
         return -1;
 
     if (virDomainObjGetState(vm, NULL) == VIR_DOMAIN_PAUSED)

src/qemu/qemu_process.c

@@ -3139,7 +3139,7 @@ qemuProcessReconnect(void *opaque)
 
     /* Run an hook to allow admins to do some magic */
     if (virHookPresent(VIR_HOOK_DRIVER_QEMU)) {
-        char *xml = qemuDomainDefFormatXML(driver, obj->def, 0, false);
+        char *xml = qemuDomainDefFormatXML(driver, obj->def, 0);
         int hookret;
 
         hookret = virHookCall(VIR_HOOK_DRIVER_QEMU, obj->def->name,
@@ -3367,7 +3367,7 @@ int qemuProcessStart(virConnectPtr conn,
 
     /* Run an early hook to set-up missing devices */
     if (virHookPresent(VIR_HOOK_DRIVER_QEMU)) {
-        char *xml = qemuDomainDefFormatXML(driver, vm->def, 0, false);
+        char *xml = qemuDomainDefFormatXML(driver, vm->def, 0);
         int hookret;
 
         hookret = virHookCall(VIR_HOOK_DRIVER_QEMU, vm->def->name,
@@ -3584,7 +3584,7 @@ int qemuProcessStart(virConnectPtr conn,
 
     /* now that we know it is about to start call the hook if present */
     if (virHookPresent(VIR_HOOK_DRIVER_QEMU)) {
-        char *xml = qemuDomainDefFormatXML(driver, vm->def, 0, false);
+        char *xml = qemuDomainDefFormatXML(driver, vm->def, 0);
         int hookret;
 
         hookret = virHookCall(VIR_HOOK_DRIVER_QEMU, vm->def->name,
@@ -3825,7 +3825,7 @@ int qemuProcessStart(virConnectPtr conn,
 
     /* finally we can call the 'started' hook script if any */
     if (virHookPresent(VIR_HOOK_DRIVER_QEMU)) {
-        char *xml = qemuDomainDefFormatXML(driver, vm->def, 0, false);
+        char *xml = qemuDomainDefFormatXML(driver, vm->def, 0);
         int hookret;
 
         hookret = virHookCall(VIR_HOOK_DRIVER_QEMU, vm->def->name,
@@ -4005,7 +4005,7 @@ void qemuProcessStop(struct qemud_driver *driver,
 
     /* now that we know it's stopped call the hook if present */
     if (virHookPresent(VIR_HOOK_DRIVER_QEMU)) {
-        char *xml = qemuDomainDefFormatXML(driver, vm->def, 0, false);
+        char *xml = qemuDomainDefFormatXML(driver, vm->def, 0);
 
         /* we can't stop the operation even if the script raised an error */
         virHookCall(VIR_HOOK_DRIVER_QEMU, vm->def->name,
@@ -4100,7 +4100,7 @@ retry:
 
     /* The "release" hook cleans up additional resources */
     if (virHookPresent(VIR_HOOK_DRIVER_QEMU)) {
-        char *xml = qemuDomainDefFormatXML(driver, vm->def, 0, false);
+        char *xml = qemuDomainDefFormatXML(driver, vm->def, 0);
 
         /* we can't stop the operation even if the script raised an error */
         virHookCall(VIR_HOOK_DRIVER_QEMU, vm->def->name,
@@ -4302,7 +4302,7 @@ int qemuProcessAttach(virConnectPtr conn ATTRIBUTE_UNUSED,
 
     /* Run an hook to allow admins to do some magic */
     if (virHookPresent(VIR_HOOK_DRIVER_QEMU)) {
-        char *xml = qemuDomainDefFormatXML(driver, vm->def, 0, false);
+        char *xml = qemuDomainDefFormatXML(driver, vm->def, 0);
         int hookret;
 
         hookret = virHookCall(VIR_HOOK_DRIVER_QEMU, vm->def->name,

tools/virsh-domain.c

@@ -6399,6 +6399,7 @@ static const vshCmdOptDef opts_dumpxml[] = {
     {"inactive", VSH_OT_BOOL, 0, N_("show inactive defined XML")},
     {"security-info", VSH_OT_BOOL, 0, N_("include security sensitive information in XML dump")},
     {"update-cpu", VSH_OT_BOOL, 0, N_("update guest CPU according to host CPU")},
+    {"migratable", VSH_OT_BOOL, 0, N_("provide XML suitable for migrations")},
     {NULL, 0, 0, NULL}
 };
 
@@ -6412,6 +6413,7 @@ cmdDumpXML(vshControl *ctl, const vshCmd *cmd)
     bool inactive = vshCommandOptBool(cmd, "inactive");
     bool secure = vshCommandOptBool(cmd, "security-info");
     bool update = vshCommandOptBool(cmd, "update-cpu");
+    bool migratable = vshCommandOptBool(cmd, "migratable");
 
     if (inactive)
         flags |= VIR_DOMAIN_XML_INACTIVE;
@@ -6419,6 +6421,8 @@ cmdDumpXML(vshControl *ctl, const vshCmd *cmd)
         flags |= VIR_DOMAIN_XML_SECURE;
     if (update)
         flags |= VIR_DOMAIN_XML_UPDATE_CPU;
+    if (migratable)
+        flags |= VIR_DOMAIN_XML_MIGRATABLE;
 
     if (!(dom = vshCommandOptDomain(ctl, cmd, NULL)))
         return false;

tools/virsh.pod

@@ -948,7 +948,7 @@ NOTE: Some hypervisors may require the user to manually ensure proper
 permissions on file and path specified by argument I<corefilepath>.
 
 =item B<dumpxml> I<domain> [I<--inactive>] [I<--security-info>]
-[I<--update-cpu>]
+[I<--update-cpu>] [I<--migratable>]
 
 Output the domain information as an XML dump to stdout, this format can be used
 by the B<create> command. Additional options affecting the XML dump may be
@@ -956,7 +956,10 @@ used. I<--inactive> tells virsh to dump domain configuration that will be used
 on next start of the domain as opposed to the current domain configuration.
 Using I<--security-info> will also include security sensitive information
 in the XML dump. I<--update-cpu> updates domain CPU requirements according to
-host CPU.
+host CPU. With I<--migratable> one can request an XML that is suitable for
+migrations, i.e., compatible with older libvirt releases and possibly amended
+with internal run-time options. This option may automatically enable other
+options (I<--update-cpu>, I<--security-info>, ...) as necessary.
 
 =item B<edit> I<domain>