Since QMP transactions are supposed to take (pseudo) QMP commands,
add a standalone drive-mirror command.
The corresponding HMP command does not provide atomic snapshot+mirror,
but it can still be used together with image streaming.
Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
---
blockdev.c | 15 +++++++++++++++
hmp-commands.hx | 22 ++++++++++++++++++++++
hmp.c | 28 ++++++++++++++++++++++++++++
hmp.h | 1 +
qapi-schema.json | 27 +++++++++++++++++++++++++++
qmp-commands.hx | 33 +++++++++++++++++++++++++++++++++
6 files changed, 126 insertions(+), 0 deletions(-)
diff --git a/blockdev.c b/blockdev.c
index 9d3a362..2958419 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -675,6 +675,21 @@ void qmp_blockdev_snapshot_sync(const char *device, const
char *snapshot_file,
errp);
}
+void qmp_drive_mirror(const char *device, const char *target,
+ bool has_format, const char *format,
+ bool has_mode, enum NewImageMode mode, Error **errp)
+{
+ BlockdevMirror mirror = {
+ .device = (char *) device,
+ .target = (char *) target,
+ .has_format = has_format,
+ .format = (char *) format,
+ .has_mode = has_mode,
+ .mode = mode,
+ };
+ blockdev_do_action(BLOCKDEV_ACTION_KIND_DRIVE_MIRROR, &mirror, errp);
+}
+
/* New and old BlockDriverState structs for group snapshots */
typedef struct BlkTransactionStates {
diff --git a/hmp-commands.hx b/hmp-commands.hx
index 6980214..9c49c33 100644
--- a/hmp-commands.hx
+++ b/hmp-commands.hx
@@ -903,6 +903,28 @@ Snapshot device, using snapshot file as target if provided
ETEXI
{
+ .name = "drive_mirror",
+ .args_type = "reuse:-n,no-backing:-s,device:B,target:s,format:s?",
+ .params = "[-n] [-s] device [new-image-file] [format]",
+ .help = "initiates live storage\n\t\t\t"
+ "migration for a device. New writes are mirrored to
the\n\t\t\t"
+ "specified new image file, and the block_stream\n\t\t\t"
+ "command can then be started.\n\t\t\t"
+ "The default format is qcow2. The -n flag requests
QEMU\n\t\t\t"
+ "to reuse the image found in new-image-file, instead
of\n\t\t\t"
+ "recreating it from scratch. The -s flag requests
QEMU\n\t\t\t"
+ "to create a root image, that does not have the
current\n\t\t\t"
+ "image as the backing file.",
+ .mhandler.cmd = hmp_drive_mirror,
+ },
+STEXI
+@item drive_mirror
+@findex drive_mirror
+Start mirroring a block device's writes to a new destination,
+using the specified target.
+ETEXI
+
+ {
.name = "drive_add",
.args_type = "pci_addr:s,opts:s",
.params = "[[<domain>:]<bus>:]<slot>\n"
diff --git a/hmp.c b/hmp.c
index 290c43d..e706db9 100644
--- a/hmp.c
+++ b/hmp.c
@@ -687,6 +687,34 @@ void hmp_block_resize(Monitor *mon, const QDict *qdict)
hmp_handle_error(mon, &errp);
}
+void hmp_drive_mirror(Monitor *mon, const QDict *qdict)
+{
+ const char *device = qdict_get_str(qdict, "device");
+ const char *filename = qdict_get_try_str(qdict, "target");
+ const char *format = qdict_get_try_str(qdict, "format");
+ int reuse = qdict_get_try_bool(qdict, "reuse", 0);
+ int no_backing = qdict_get_try_bool(qdict, "no-backing", 0);
+ enum NewImageMode mode;
+ Error *errp = NULL;
+
+ if (!filename) {
+ error_set(&errp, QERR_MISSING_PARAMETER, "target");
+ hmp_handle_error(mon, &errp);
+ return;
+ }
+
+ if (reuse) {
+ mode = NEW_IMAGE_MODE_EXISTING;
+ } else if (no_backing) {
+ mode = NEW_IMAGE_MODE_NO_BACKING_FILE;
+ } else {
+ mode = NEW_IMAGE_MODE_ABSOLUTE_PATHS;
+ }
+
+ qmp_drive_mirror(device, filename, !!format, format, true, mode, &errp);
+ hmp_handle_error(mon, &errp);
+}
+
void hmp_snapshot_blkdev(Monitor *mon, const QDict *qdict)
{
const char *device = qdict_get_str(qdict, "device");
diff --git a/hmp.h b/hmp.h
index 5409464..5352f00 100644
--- a/hmp.h
+++ b/hmp.h
@@ -48,6 +48,7 @@ void hmp_block_passwd(Monitor *mon, const QDict *qdict);
void hmp_balloon(Monitor *mon, const QDict *qdict);
void hmp_block_resize(Monitor *mon, const QDict *qdict);
void hmp_snapshot_blkdev(Monitor *mon, const QDict *qdict);
+void hmp_drive_mirror(Monitor *mon, const QDict *qdict);
void hmp_migrate_cancel(Monitor *mon, const QDict *qdict);
void hmp_migrate_set_downtime(Monitor *mon, const QDict *qdict);
void hmp_migrate_set_speed(Monitor *mon, const QDict *qdict);
diff --git a/qapi-schema.json b/qapi-schema.json
index 75ac978..4cebf78 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -1263,6 +1263,33 @@
'returns': 'str' }
##
+# @drive-mirror
+#
+# Start mirroring a block device's writes to a new destination.
+#
+# @device: the name of the device whose writes should be mirrored.
+#
+# @target: the target of the new image. If the file exists, or if it
+# is a device, the existing file/device will be used as the new
+# destination. If it does not exist, a new file will be created.
+#
+# @format: #optional the format of the new destination, default is 'qcow2'.
+#
+# @mode: #optional whether and how QEMU should create a new image, default is
+# 'absolute-paths'.
+#
+# Returns: nothing on success
+# If @device is not a valid block device, DeviceNotFound
+# If @target can't be opened, OpenFileFailed
+# If @format is invalid, InvalidBlockFormat
+#
+# Since 1.1
+##
+{ 'command': 'drive-mirror',
+ 'data': { 'device': 'str', 'target': 'str', '*format': 'str',
+ '*mode': 'NewImageMode'} }
+
+##
# @migrate_cancel
#
# Cancel the current executing migration process.
diff --git a/qmp-commands.hx b/qmp-commands.hx
index 0438632..122ebe7 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -785,6 +785,39 @@ Example:
EQMP
{
+ .name = "drive-mirror",
+ .args_type = "device:B,snapshot-file:s,mode:s?,format:s?",
+ .mhandler.cmd_new = qmp_marshal_input_drive_mirror,
+ },
+
+SQMP
+drive-mirror
+------------
+
+Start mirroring a block device's writes to a new destination. target
+specifies the target of the new image. If the file exists, or if it is
+a device, it will be used as the new destination for writes. If does not
+exist, a new file will be created. format specifies the format of the
+mirror image, default is qcow2.
+
+Arguments:
+
+- "device": device name to operate on (json-string)
+- "target": name of new image file (json-string)
+- "format": format of new image (json-string, optional)
+- "mode": how an image file should be created into the target
+ file/device (NewImageMode, optional, default 'absolute-paths')
+
+Example:
+
+-> { "execute": "drive-mirror", "arguments": { "device": "ide-hd0",
+ "target":
"/some/place/my-image",
+ "format": "qcow2" } }
+<- { "return": {} }
+
+EQMP
+
+ {
.name = "balloon",
.args_type = "value:M",
.mhandler.cmd_new = qmp_marshal_input_balloon,
--
1.7.7.6
