[PATCH 07/11] qemu: check internal snaphshot memory disk

[Nikolay Shirokovskiy <nikolay.shirokovskiy@xxxxxxxxxx>]

- check it is supported by the QEMU
- check disk itself has internal snapshot
- for modern QEMU select it if it is not specified explicitly

Signed-off-by: Nikolay Shirokovskiy <nikolay.shirokovskiy@xxxxxxxxxx>
---
 src/qemu/qemu_snapshot.c | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/src/qemu/qemu_snapshot.c b/src/qemu/qemu_snapshot.c
index 579d744c60..54eafb5020 100644
--- a/src/qemu/qemu_snapshot.c
+++ b/src/qemu/qemu_snapshot.c
@@ -1852,6 +1852,38 @@ qemuSnapshotCreateAlignDisks(virDomainObj *vm,
     if (virDomainSnapshotAlignDisks(def, NULL, align_location, true) < 0)
         return -1;
 
+    if (def->memory == VIR_DOMAIN_SNAPSHOT_LOCATION_INTERNAL) {
+        bool modern = virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_SNAPSHOT_SAVE);
+
+        if (modern) {
+            size_t i;
+
+            for (i = 0; i < def->ndisks; i++) {
+                if (def->disks[i].snapshot != VIR_DOMAIN_SNAPSHOT_LOCATION_INTERNAL)
+                    continue;
+
+                if (def->memorydisk) {
+                    if (STREQ(def->memorydisk, def->disks[i].name))
+                        break;
+                } else {
+                    def->memorydisk = g_strdup(def->disks[i].name);
+                    break;
+                }
+            }
+
+            if (i == def->ndisks && def->memorydisk) {
+                virReportError(VIR_ERR_OPERATION_UNSUPPORTED,
+                               _("memory disk '%s' should itself have internal snapshot"),
+                               def->memorydisk);
+                return -1;
+            }
+        } else if (def->memorydisk) {
+            virReportError(VIR_ERR_OPERATION_UNSUPPORTED, "%s",
+                           _("specifing memory disk is not supported by this QEMU"));
+            return -1;
+        }
+    }
+
     return 0;
 }
 
-- 
2.35.1