qemu: Report the original CPU in migratable xml

The destination host may not be able to start a domain using the live
updated CPU definition because either libvirt or QEMU may not be new
enough. Thus we need to send the original guest CPU definition.

Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Reviewed-by: Pavel Hrdina <phrdina@redhat.com>

src/qemu/qemu_domain.c

@@ -4216,9 +4216,11 @@ qemuDomainDefCopy(virQEMUDriverPtr driver,
     return ret;
 }
 
-int
+
-qemuDomainDefFormatBuf(virQEMUDriverPtr driver,
+static int
+qemuDomainDefFormatBufInternal(virQEMUDriverPtr driver,
                                virDomainDefPtr def,
+                               virCPUDefPtr origCPU,
                                unsigned int flags,
                                virBuffer *buf)
 {
@@ -4341,6 +4343,16 @@ qemuDomainDefFormatBuf(virQEMUDriverPtr driver,
             if (qemuDomainChrDefDropDefaultPath(def->channels[i], driver) < 0)
                 goto cleanup;
         }
+
+        /* Replace the CPU definition updated according to QEMU with the one
+         * used for starting the domain. The updated def will be sent
+         * separately for backward compatibility.
+         */
+        if (origCPU) {
+            virCPUDefFree(def->cpu);
+            if (!(def->cpu = virCPUDefCopy(origCPU)))
+                goto cleanup;
+        }
     }
 
  format:
@@ -4354,13 +4366,26 @@ qemuDomainDefFormatBuf(virQEMUDriverPtr driver,
     return ret;
 }
 
-char *qemuDomainDefFormatXML(virQEMUDriverPtr driver,
+
+int
+qemuDomainDefFormatBuf(virQEMUDriverPtr driver,
                        virDomainDefPtr def,
+                       unsigned int flags,
+                       virBufferPtr buf)
+{
+    return qemuDomainDefFormatBufInternal(driver, def, NULL, flags, buf);
+}
+
+
+static char *
+qemuDomainDefFormatXMLInternal(virQEMUDriverPtr driver,
+                               virDomainDefPtr def,
+                               virCPUDefPtr origCPU,
                                unsigned int flags)
 {
     virBuffer buf = VIR_BUFFER_INITIALIZER;
 
-    if (qemuDomainDefFormatBuf(driver, def, flags, &buf) < 0) {
+    if (qemuDomainDefFormatBufInternal(driver, def, origCPU, flags, &buf) < 0) {
         virBufferFreeAndReset(&buf);
         return NULL;
     }
@@ -4374,26 +4399,40 @@ char *qemuDomainDefFormatXML(virQEMUDriverPtr driver,
     return virBufferContentAndReset(&buf);
 }
 
+
+char *
+qemuDomainDefFormatXML(virQEMUDriverPtr driver,
+                       virDomainDefPtr def,
+                       unsigned int flags)
+{
+    return qemuDomainDefFormatXMLInternal(driver, def, NULL, flags);
+}
+
+
 char *qemuDomainFormatXML(virQEMUDriverPtr driver,
                           virDomainObjPtr vm,
                           unsigned int flags)
 {
     virDomainDefPtr def;
+    qemuDomainObjPrivatePtr priv = vm->privateData;
+    virCPUDefPtr origCPU = NULL;
 
     if ((flags & VIR_DOMAIN_XML_INACTIVE) && vm->newDef) {
         def = vm->newDef;
     } else {
         def = vm->def;
+        origCPU = priv->origCPU;
         if (virDomainObjIsActive(vm))
             flags &= ~VIR_DOMAIN_XML_UPDATE_CPU;
     }
 
-    return qemuDomainDefFormatXML(driver, def, flags);
+    return qemuDomainDefFormatXMLInternal(driver, def, origCPU, flags);
 }
 
 char *
 qemuDomainDefFormatLive(virQEMUDriverPtr driver,
                         virDomainDefPtr def,
+                        virCPUDefPtr origCPU,
                         bool inactive,
                         bool compatible)
 {
@@ -4404,7 +4443,7 @@ qemuDomainDefFormatLive(virQEMUDriverPtr driver,
     if (compatible)
         flags |= VIR_DOMAIN_XML_MIGRATABLE;
 
-    return qemuDomainDefFormatXML(driver, def, flags);
+    return qemuDomainDefFormatXMLInternal(driver, def, origCPU, flags);
 }
 
 

src/qemu/qemu_domain.h

@@ -515,6 +515,7 @@ char *qemuDomainFormatXML(virQEMUDriverPtr driver,
 
 char *qemuDomainDefFormatLive(virQEMUDriverPtr driver,
                               virDomainDefPtr def,
+                              virCPUDefPtr origCPU,
                               bool inactive,
                               bool compatible);
 

src/qemu/qemu_driver.c

@@ -3344,9 +3344,9 @@ qemuDomainSaveInternal(virQEMUDriverPtr driver, virDomainPtr dom,
             virDomainDefFree(def);
             goto endjob;
         }
-        xml = qemuDomainDefFormatLive(driver, def, true, true);
+        xml = qemuDomainDefFormatLive(driver, def, NULL, true, true);
     } else {
-        xml = qemuDomainDefFormatLive(driver, vm->def, true, true);
+        xml = qemuDomainDefFormatLive(driver, vm->def, priv->origCPU, true, true);
     }
     if (!xml) {
         virReportError(VIR_ERR_OPERATION_FAILED,
@@ -14511,7 +14511,8 @@ qemuDomainSnapshotCreateActiveExternal(virConnectPtr conn,
                                                     "snapshot", false)) < 0)
             goto cleanup;
 
-        if (!(xml = qemuDomainDefFormatLive(driver, vm->def, true, true)) ||
+        if (!(xml = qemuDomainDefFormatLive(driver, vm->def, priv->origCPU,
+                                            true, true)) ||
             !(snap->def->cookie = (virObjectPtr) qemuDomainSaveCookieNew(vm)))
             goto cleanup;
 
@@ -14622,6 +14623,7 @@ qemuDomainSnapshotCreateXML(virDomainPtr domain,
     bool align_match = true;
     virQEMUDriverConfigPtr cfg = NULL;
     virCapsPtr caps = NULL;
+    qemuDomainObjPrivatePtr priv;
 
     virCheckFlags(VIR_DOMAIN_SNAPSHOT_CREATE_REDEFINE |
                   VIR_DOMAIN_SNAPSHOT_CREATE_CURRENT |
@@ -14739,6 +14741,8 @@ qemuDomainSnapshotCreateXML(virDomainPtr domain,
 
     qemuDomainObjSetAsyncJobMask(vm, QEMU_JOB_NONE);
 
+    priv = vm->privateData;
+
     if (redefine) {
         if (virDomainSnapshotRedefinePrep(domain, vm, &def, &snap,
                                           driver->xmlopt,
@@ -14747,7 +14751,8 @@ qemuDomainSnapshotCreateXML(virDomainPtr domain,
     } else {
         /* Easiest way to clone inactive portion of vm->def is via
          * conversion in and back out of xml.  */
-        if (!(xml = qemuDomainDefFormatLive(driver, vm->def, true, true)) ||
+        if (!(xml = qemuDomainDefFormatLive(driver, vm->def, priv->origCPU,
+                                            true, true)) ||
             !(def->dom = virDomainDefParseString(xml, caps, driver->xmlopt, NULL,
                                                  VIR_DOMAIN_DEF_PARSE_INACTIVE |
                                                  VIR_DOMAIN_DEF_PARSE_SKIP_VALIDATE)))

src/qemu/qemu_migration.c

@@ -2059,9 +2059,10 @@ qemuMigrationBeginPhase(virQEMUDriverPtr driver,
         if (!qemuDomainDefCheckABIStability(driver, vm->def, def))
             goto cleanup;
 
-        rv = qemuDomainDefFormatLive(driver, def, false, true);
+        rv = qemuDomainDefFormatLive(driver, def, NULL, false, true);
     } else {
-        rv = qemuDomainDefFormatLive(driver, vm->def, false, true);
+        rv = qemuDomainDefFormatLive(driver, vm->def, priv->origCPU,
+                                     false, true);
     }
 
  cleanup: