qemuProcessStartWithMemoryState: add snapshot argument

When called from snapshot code we will need to pass snapshot object in
order to make internal snapshots work correctly.

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>

src/qemu/qemu_process.c

@@ -8099,6 +8099,7 @@ qemuProcessStart(virConnectPtr conn,
  * @vm: domain object
  * @fd: FD pointer of memory state file
  * @path: path to memory state file
+ * @snapshot: internal snapshot to load when starting QEMU process or NULL
  * @data: data from memory state file
  * @asyncJob: type of asynchronous job
  * @start_flags: flags to start QEMU process with
@@ -8108,6 +8109,11 @@ qemuProcessStart(virConnectPtr conn,
  * Start VM with existing memory state. Make sure that the stored memory state
  * is correctly decompressed so it can be loaded by QEMU process.
  *
+ * When reverting to internal snapshot caller needs to pass @snapshot as well
+ * to correctly start QEMU process.
+ *
+ * When restoring VM from saved image @snapshot needs to be NULL.
+ *
  * For audit purposes the expected @reason is one of `restored` or `from-snapshot`.
  *
  * Returns 0 on success, -1 on error.
@@ -8118,6 +8124,7 @@ qemuProcessStartWithMemoryState(virConnectPtr conn,
                                 virDomainObj *vm,
                                 int *fd,
                                 const char *path,
+                                virDomainMomentObj *snapshot,
                                 virQEMUSaveData *data,
                                 virDomainAsyncJob asyncJob,
                                 unsigned int start_flags,
@@ -8149,7 +8156,7 @@ qemuProcessStartWithMemoryState(virConnectPtr conn,
         priv->disableSlirp = true;
 
     if (qemuProcessStart(conn, driver, vm, cookie ? cookie->cpu : NULL,
-                         asyncJob, "stdio", *fd, path, NULL,
+                         asyncJob, "stdio", *fd, path, snapshot,
                          VIR_NETDEV_VPORT_PROFILE_OP_RESTORE,
                          start_flags) == 0)
         *started = true;

src/qemu/qemu_process.h

@@ -96,6 +96,7 @@ int qemuProcessStartWithMemoryState(virConnectPtr conn,
                                     virDomainObj *vm,
                                     int *fd,
                                     const char *path,
+                                    virDomainMomentObj *snapshot,
                                     virQEMUSaveData *data,
                                     virDomainAsyncJob asyncJob,
                                     unsigned int start_flags,

src/qemu/qemu_saveimage.c

@@ -698,7 +698,7 @@ qemuSaveImageStartVM(virConnectPtr conn,
     if (reset_nvram)
         start_flags |= VIR_QEMU_PROCESS_START_RESET_NVRAM;
 
-    if (qemuProcessStartWithMemoryState(conn, driver, vm, fd, path, data,
+    if (qemuProcessStartWithMemoryState(conn, driver, vm, fd, path, NULL, data,
                                         asyncJob, start_flags, "restored",
                                         &started) < 0) {
         goto cleanup;