[Qemu-devel] [RFC PATCH 1/4] qapi: Convert savevm

[Pavel Hrdina]

Signed-off-by: Pavel Hrdina <address@hidden>
---
 hmp-commands.hx  |    2 +-
 hmp.c            |   10 ++++++++++
 hmp.h            |    1 +
 qapi-schema.json |   22 ++++++++++++++++++++++
 qerror.c         |   24 ++++++++++++++++++++++++
 qerror.h         |   18 ++++++++++++++++++
 qmp-commands.hx  |   26 ++++++++++++++++++++++++++
 savevm.c         |   29 ++++++++++++++---------------
 sysemu.h         |    1 -
 9 files changed, 116 insertions(+), 17 deletions(-)

diff --git a/hmp-commands.hx b/hmp-commands.hx
index f5d9d91..e8c5325 100644
--- a/hmp-commands.hx
+++ b/hmp-commands.hx
@@ -267,7 +267,7 @@ ETEXI
         .args_type  = "name:s?",
         .params     = "[tag|id]",
         .help       = "save a VM snapshot. If no tag or id are provided, a new 
snapshot is created",
-        .mhandler.cmd = do_savevm,
+        .mhandler.cmd = hmp_savevm,
     },
 
 STEXI
diff --git a/hmp.c b/hmp.c
index 4c6d4ae..491599d 100644
--- a/hmp.c
+++ b/hmp.c
@@ -1002,3 +1002,13 @@ void hmp_netdev_del(Monitor *mon, const QDict *qdict)
     qmp_netdev_del(id, &err);
     hmp_handle_error(mon, &err);
 }
+
+void hmp_savevm(Monitor *mon, const QDict *qdict)
+{
+    const char *name = qdict_get_try_str(qdict, "name");
+    Error *err = NULL;
+
+    qmp_savevm(!!name, name, &err);
+
+    hmp_handle_error(mon, &err);
+}
diff --git a/hmp.h b/hmp.h
index 79d138d..dc6410b 100644
--- a/hmp.h
+++ b/hmp.h
@@ -64,5 +64,6 @@ void hmp_device_del(Monitor *mon, const QDict *qdict);
 void hmp_dump_guest_memory(Monitor *mon, const QDict *qdict);
 void hmp_netdev_add(Monitor *mon, const QDict *qdict);
 void hmp_netdev_del(Monitor *mon, const QDict *qdict);
+void hmp_savevm(Monitor *mon, const QDict *qdict);
 
 #endif
diff --git a/qapi-schema.json b/qapi-schema.json
index 1ab5dbd..4db1447 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -1868,3 +1868,25 @@
 # Since: 0.14.0
 ##
 { 'command': 'netdev_del', 'data': {'id': 'str'} }
+
+##
+# @savevm:
+#
+# Create a snapshot of the whole virtual machine. If 'tag' is provided,
+# it is used as human readable identifier. If there is already a snapshot
+# with the same tag or ID, it is replaced.
+#
+# @name: tag or id of new or existing snapshot
+#
+# Returns: Nothing on success
+#          If there is a writable device not supporting snapshots,
+#            SnapshotNotSupported
+#          If no block device can accept snapshots, SnapshotNotAccepted
+#          If an error occures while creating a snapshot, SnapshotCreateFailed
+#          If open a block device for vm state fail, SnapshotOpenFailed
+#          If an error uccures while writing vm state, SnapshotWriteFailed
+#          If delete snapshot with same 'name' fail, SnapshotDeleteFailed
+#
+# Since: 1.2
+##
+{ 'command': 'savevm', 'data': {'*name': 'str'} }
\ No newline at end of file
diff --git a/qerror.c b/qerror.c
index 92c4eff..4e6efa1 100644
--- a/qerror.c
+++ b/qerror.c
@@ -309,6 +309,30 @@ static const QErrorStringTable qerror_table[] = {
         .desc      = "Could not start VNC server on %(target)",
     },
     {
+        .error_fmt = QERR_SNAPSHOT_CREATE_FAILED,
+        .desc      = "Error '%(errno)' while creating snapshot on '%(device)'",
+    },
+    {
+        .error_fmt = QERR_SNAPSHOT_DELETE_FAILED,
+        .desc      = "Error '%(errno)' while deleting snapshot on '%(device)'",
+    },
+    {
+        .error_fmt = QERR_SNAPSHOT_NOT_ACCEPTED,
+        .desc      = "No block device can accept snapshots",
+    },
+    {
+        .error_fmt = QERR_SNAPSHOT_NOT_SUPPORTED,
+        .desc      = "Device '%(device)' is writable but does not support 
snapshots",
+    },
+    {
+        .error_fmt = QERR_SNAPSHOT_OPEN_FAILED,
+        .desc      = "Error while opening snapshot on '%(device)'",
+    },
+    {
+        .error_fmt = QERR_SNAPSHOT_WRITE_FAILED,
+        .desc      = "Error '%(errno)' while writing snapshot on '%(device)'",
+    },
+    {
         .error_fmt = QERR_SOCKET_CONNECT_IN_PROGRESS,
         .desc      = "Connection can not be completed immediately",
     },
diff --git a/qerror.h b/qerror.h
index b4c8758..bc47f4a 100644
--- a/qerror.h
+++ b/qerror.h
@@ -251,6 +251,24 @@ QError *qobject_to_qerror(const QObject *obj);
 #define QERR_VNC_SERVER_FAILED \
     "{ 'class': 'VNCServerFailed', 'data': { 'target': %s } }"
 
+#define QERR_SNAPSHOT_CREATE_FAILED \
+    "{ 'class': 'SnapshotCreateFailed', 'data': { 'device': %s, 'errno': %d } 
}"
+
+#define QERR_SNAPSHOT_DELETE_FAILED \
+    "{ 'class': 'SnapshotDeleteFailed', 'data': { 'device': %s, 'errno': %d } 
}"
+
+#define QERR_SNAPSHOT_NOT_ACCEPTED \
+    "{ 'class': 'SnapshotNotAccepted', 'data': {} }"
+
+#define QERR_SNAPSHOT_NOT_SUPPORTED \
+    "{ 'class': 'SnapshotNotSupported', 'data': { 'device': %s } }"
+
+#define QERR_SNAPSHOT_OPEN_FAILED \
+    "{ 'class': 'SnapshotOpenFailed', 'data': { 'device': %s } }"
+
+#define QERR_SNAPSHOT_WRITE_FAILED \
+    "{ 'class': 'SnapshotWriteFailed', 'data': { 'device': %s, 'errno': %d } }"
+
 #define QERR_SOCKET_CONNECT_IN_PROGRESS \
     "{ 'class': 'SockConnectInprogress', 'data': {} }"
 
diff --git a/qmp-commands.hx b/qmp-commands.hx
index 2e1a38e..a1c82f7 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -1061,6 +1061,32 @@ Example:
 
 EQMP
     {
+        .name       = "savevm",
+        .args_type  = "name:s?",
+        .params     = "name",
+        .help       = "save a VM snapshot. If no tag or id are provided, a new 
snapshot is created",
+        .mhandler.cmd_new = qmp_marshal_input_savevm
+    },
+
+SQMP
+savevm
+------
+
+Create a snapshot of the whole virtual machine. If 'tag' is provided,
+it is used as human readable identifier. If there is already a snapshot
+with the same tag or ID, it is replaced.
+
+Arguments:
+
+- "name": tag or id of new or existing snapshot
+
+Example:
+
+-> { "execute": "savevm", "arguments": { "name": "my_snapshot" } }
+<- { "return": {} }
+
+EQMP
+    {
         .name       = "qmp_capabilities",
         .args_type  = "",
         .params     = "",
diff --git a/savevm.c b/savevm.c
index a15c163..9fc1b53 100644
--- a/savevm.c
+++ b/savevm.c
@@ -2033,7 +2033,7 @@ static int bdrv_snapshot_find(BlockDriverState *bs, 
QEMUSnapshotInfo *sn_info,
 /*
  * Deletes snapshots of a given name in all opened images.
  */
-static int del_existing_snapshots(Monitor *mon, const char *name)
+static int del_existing_snapshots(Error **errp, const char *name)
 {
     BlockDriverState *bs;
     QEMUSnapshotInfo sn1, *snapshot = &sn1;
@@ -2046,9 +2046,8 @@ static int del_existing_snapshots(Monitor *mon, const 
char *name)
         {
             ret = bdrv_snapshot_delete(bs, name);
             if (ret < 0) {
-                monitor_printf(mon,
-                               "Error while deleting snapshot on '%s'\n",
-                               bdrv_get_device_name(bs));
+                error_set(errp, QERR_SNAPSHOT_DELETE_FAILED,
+                          bdrv_get_device_name(bs), ret);
                 return -1;
             }
         }
@@ -2057,7 +2056,7 @@ static int del_existing_snapshots(Monitor *mon, const 
char *name)
     return 0;
 }
 
-void do_savevm(Monitor *mon, const QDict *qdict)
+void qmp_savevm(bool has_name, const char *name, Error **errp)
 {
     BlockDriverState *bs, *bs1;
     QEMUSnapshotInfo sn1, *sn = &sn1, old_sn1, *old_sn = &old_sn1;
@@ -2072,7 +2071,6 @@ void do_savevm(Monitor *mon, const QDict *qdict)
     struct timeval tv;
     struct tm tm;
 #endif
-    const char *name = qdict_get_try_str(qdict, "name");
 
     /* Verify if there is a device that doesn't support snapshots and is 
writable */
     bs = NULL;
@@ -2083,15 +2081,15 @@ void do_savevm(Monitor *mon, const QDict *qdict)
         }
 
         if (!bdrv_can_snapshot(bs)) {
-            monitor_printf(mon, "Device '%s' is writable but does not support 
snapshots.\n",
-                               bdrv_get_device_name(bs));
+            error_set(errp, QERR_SNAPSHOT_NOT_SUPPORTED,
+                      bdrv_get_device_name(bs));
             return;
         }
     }
 
     bs = bdrv_snapshots();
     if (!bs) {
-        monitor_printf(mon, "No block device can accept snapshots\n");
+        error_set(errp, QERR_SNAPSHOT_NOT_ACCEPTED);
         return;
     }
 
@@ -2112,7 +2110,7 @@ void do_savevm(Monitor *mon, const QDict *qdict)
 #endif
     sn->vm_clock_nsec = qemu_get_clock_ns(vm_clock);
 
-    if (name) {
+    if (has_name) {
         ret = bdrv_snapshot_find(bs, old_sn, name);
         if (ret >= 0) {
             pstrcpy(sn->name, sizeof(sn->name), old_sn->name);
@@ -2133,21 +2131,22 @@ void do_savevm(Monitor *mon, const QDict *qdict)
     }
 
     /* Delete old snapshots of the same name */
-    if (name && del_existing_snapshots(mon, name) < 0) {
+    if (has_name && del_existing_snapshots(errp, name) < 0) {
         goto the_end;
     }
 
     /* save the VM state */
     f = qemu_fopen_bdrv(bs, 1);
     if (!f) {
-        monitor_printf(mon, "Could not open VM state file\n");
+        error_set(errp, QERR_SNAPSHOT_OPEN_FAILED, bdrv_get_device_name(bs));
         goto the_end;
     }
     ret = qemu_savevm_state(f);
     vm_state_size = qemu_ftell(f);
     qemu_fclose(f);
     if (ret < 0) {
-        monitor_printf(mon, "Error %d while writing VM\n", ret);
+        error_set(errp, QERR_SNAPSHOT_WRITE_FAILED,
+                  bdrv_get_device_name(bs), ret);
         goto the_end;
     }
 
@@ -2160,8 +2159,8 @@ void do_savevm(Monitor *mon, const QDict *qdict)
             sn->vm_state_size = (bs == bs1 ? vm_state_size : 0);
             ret = bdrv_snapshot_create(bs1, sn);
             if (ret < 0) {
-                monitor_printf(mon, "Error while creating snapshot on '%s'\n",
-                               bdrv_get_device_name(bs1));
+                error_set(errp, QERR_SNAPSHOT_CREATE_FAILED,
+                          bdrv_get_device_name(bs1), ret);
             }
         }
     }
diff --git a/sysemu.h b/sysemu.h
index 6540c79..95d1207 100644
--- a/sysemu.h
+++ b/sysemu.h
@@ -69,7 +69,6 @@ void qemu_remove_exit_notifier(Notifier *notify);
 
 void qemu_add_machine_init_done_notifier(Notifier *notify);
 
-void do_savevm(Monitor *mon, const QDict *qdict);
 int load_vmstate(const char *name);
 void do_delvm(Monitor *mon, const QDict *qdict);
 void do_info_snapshots(Monitor *mon);
-- 
1.7.10.4