qemu: snapshot: Forbid empty snapshots

If neither disks nor memory are selected for snapshot we'd record
metadata in case of external snapshot and do a disk snapshot in case of
external disk snapshot. Forbid this as it doesn't make much sense.

diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 936e7bda3d2298c9b3d3971b9e778fa285e66b84..9dbfc0798f7582632e4bb556af8b3df150c2d728 100644 (file)
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -12703,6 +12703,13 @@ qemuDomainSnapshotPrepare(virConnectPtr conn,
         }
     }
 
+    if (!found_internal && !external &&
+        def->memory == VIR_DOMAIN_SNAPSHOT_LOCATION_NONE) {
+        virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                       _("nothing selected for snapshot"));
+        goto cleanup;
+    }
+
     /* internal snapshot requires a disk image to store the memory image to, and
      * also disks can't be excluded from an internal snapshot*/
     if ((def->memory == VIR_DOMAIN_SNAPSHOT_LOCATION_INTERNAL && !found_internal) ||