Create external memory only snapshot

Create a memroy only snapshot on VM.
SC1: Create memory only snapshot by --diskspec snapshot=no option
SC2: Specify snapshot=no in guest xml and create memory only snapshot

Committer: Bolatbek Issakh <[email protected]>

Author: Bolatbek Issakh

libvirt/tests/cfg/snapshot/virsh_memonly_snapshot.cfg

@@ -0,0 +1,10 @@
+- virsh_memonly_snapshot:
+    type = virsh_memonly_snapshot
+    start_vm = yes
+    variants:
+        - cli_diskspec:
+            scenario = cli_diskspec
+        - xml_snapshot_no:
+            scenario = xml_snapshot_no
+            set_snapshot_no_in_xml = yes
+

libvirt/tests/src/snapshot/virsh_memonly_snapshot.py

@@ -0,0 +1,85 @@
+# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+#
+#   virsh_memonly_snapshot.py
+#
+#   SPDX-License-Identifier: GPL-2.0
+#
+# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+import time
+from pathlib import Path
+
+from virttest import virsh, data_dir
+from virttest.libvirt_xml import vm_xml
+from virttest.utils_libvirt import libvirt_vmxml
+
+
+def run(test, params, env):
+    """
+    Create a memory-only snapshot of a running VM.
+
+    SC1: CLI only — pass --diskspec snapshot=no for all disks.
+    SC2: XML path — set snapshot='no' on all <disk> in guest XML, then run CLI without --diskspec.
+    """
+    vm_name = params.get("main_vm")
+    # Use Avocado tmp dir by default; auto-cleaned by Avocado
+    default_mem = Path(data_dir.get_tmp_dir()) / f"{vm_name}-{int(time.time())}.mem"
+    mem_file = Path(params.get("mem_file", str(default_mem)))
+
+    variant = str(params.get("variant") or params.get("case") or params.get("scenario") or "")
+    set_xml = params.get("set_snapshot_no_in_xml", "no").lower() in ("yes", "true", "1") or (
+        "xml_snapshot_no" in variant
+    )
+
+    vm = env.get_vm(vm_name)
+    if vm is None:
+        test.error(f"VM '{vm_name}' not found in env")
+
+    disk_targets = []  # filled in setup_test()
+
+    def _ensure_running():
+        if not vm.is_alive():
+            vm.start()
+
+    def _all_disk_targets():
+        devs = []
+        vmx = vm_xml.VMXML.new_from_dumpxml(vm_name)
+        for disk in (vmx.get_devices("disk") or []):
+            tgt = (disk.target or {}).get("dev")
+            if tgt:
+                devs.append(tgt)
+        return devs
+
+    def _snapshot_create():
+        mem_file.parent.mkdir(parents=True, exist_ok=True)
+        opts = f"--no-metadata --memspec file={mem_file} --live"
+        if not set_xml:
+            for dev in disk_targets:
+                opts += f" --diskspec {dev},snapshot=no"
+        virsh.snapshot_create_as(vm_name, options=opts, ignore_status=False, debug=True)
+
+    backup_xml = None
+
+    def setup_test():
+        nonlocal backup_xml, disk_targets
+        backup_xml = vm_xml.VMXML.new_from_inactive_dumpxml(vm_name)
+        disk_targets = _all_disk_targets()
+        if set_xml:
+            vmx = vm_xml.VMXML.new_from_inactive_dumpxml(vm_name)
+            for dev in disk_targets:
+                disk_dict = {"target": {"dev": dev}, "snapshot": "no"}
+                libvirt_vmxml.modify_vm_device(vmx, "disk", disk_dict)
+        _ensure_running()
+
+    def run_test():
+        _snapshot_create()
+
+    def teardown_test():
+        if backup_xml is not None:
+            backup_xml.sync()
+
+    try:
+        setup_test()
+        run_test()
+    finally:
+        teardown_test()