Add ability to set a default driver name/type when parsing disks

Record a default driver name/type in capabilities struct. Use this
when parsing disks if value is not set in XML config.

* src/conf/capabilities.h: Record default driver name/type for disks
* src/conf/domain_conf.c: Fallback to default driver name/type
  when parsing disks
* src/qemu/qemu_driver.c: Set default driver name/type to raw

src/conf/capabilities.c

@@ -175,6 +175,9 @@ virCapabilitiesFree(virCapsPtr caps) {
     VIR_FREE(caps->host.secModel.doi);
     virCPUDefFree(caps->host.cpu);
 
+    VIR_FREE(caps->defaultDiskDriverName);
+    VIR_FREE(caps->defaultDiskDriverType);
+
     VIR_FREE(caps);
 }
 

src/conf/capabilities.h

@@ -123,6 +123,8 @@ struct _virCaps {
     virCapsGuestPtr *guests;
     unsigned char macPrefix[VIR_MAC_PREFIX_BUFLEN];
     unsigned int emulatorRequired : 1;
+    const char *defaultDiskDriverName;
+    const char *defaultDiskDriverType;
     void *(*privateDataAllocFunc)(void);
     void (*privateDataFreeFunc)(void *);
     int (*privateDataXMLFormat)(virBufferPtr, void *);

src/conf/domain_conf.c

@@ -1639,6 +1639,16 @@ virDomainDiskDefParseXML(virCapsPtr caps,
     def->serial = serial;
     serial = NULL;
 
+    if (!def->driverType &&
+        caps->defaultDiskDriverType &&
+        !(def->driverType = strdup(caps->defaultDiskDriverType)))
+        goto no_memory;
+
+    if (!def->driverName &&
+        caps->defaultDiskDriverName &&
+        !(def->driverName = strdup(caps->defaultDiskDriverName)))
+        goto no_memory;
+
     if (def->info.type == VIR_DOMAIN_DEVICE_ADDRESS_TYPE_NONE
         && virDomainDiskDefAssignAddress(caps, def) < 0)
         goto error;
@@ -1659,6 +1669,9 @@ cleanup:
 
     return def;
 
+no_memory:
+    virReportOOMError();
+
  error:
     virDomainDiskDefFree(def);
     def = NULL;
@@ -4275,7 +4288,8 @@ static virDomainDefPtr virDomainDefParseXML(virCapsPtr caps,
     if (n && VIR_ALLOC_N(def->disks, n) < 0)
         goto no_memory;
     for (i = 0 ; i < n ; i++) {
-        virDomainDiskDefPtr disk = virDomainDiskDefParseXML(caps, nodes[i],
+        virDomainDiskDefPtr disk = virDomainDiskDefParseXML(caps,
+                                                            nodes[i],
                                                             flags);
         if (!disk)
             goto error;

src/qemu/qemu_driver.c

@@ -1361,6 +1361,14 @@ qemuCreateCapabilities(virCapsPtr oldcaps,
         return NULL;
     }
 
+    if (driver->allowDiskFormatProbing) {
+        caps->defaultDiskDriverName = NULL;
+        caps->defaultDiskDriverType = NULL;
+    } else {
+        caps->defaultDiskDriverName = "qemu";
+        caps->defaultDiskDriverType = "raw";
+    }
+
     /* Domain XML parser hooks */
     caps->privateDataAllocFunc = qemuDomainObjPrivateAlloc;
     caps->privateDataFreeFunc = qemuDomainObjPrivateFree;