Add the block_stream command, which starts copy backing file contents
into the image file. Also add the BLOCK_JOB_COMPLETED QMP event which
is emitted when image streaming completes. Later patches add control
over the background copy speed, cancelation, and querying running
streaming operations.
Signed-off-by: Stefan Hajnoczi <stefa...@linux.vnet.ibm.com>
---
QMP/qmp-events.txt | 29 ++++++++++++++++++++++
blockdev.c | 67 ++++++++++++++++++++++++++++++++++++++++++++++++++++
hmp-commands.hx | 13 ++++++++++
hmp.c | 11 ++++++++
hmp.h | 1 +
monitor.c | 3 ++
monitor.h | 1 +
qapi-schema.json | 32 ++++++++++++++++++++++++
qerror.c | 4 +++
qerror.h | 3 ++
qmp-commands.hx | 6 ++++
trace-events | 4 +++
12 files changed, 174 insertions(+), 0 deletions(-)
diff --git a/QMP/qmp-events.txt b/QMP/qmp-events.txt
index af586ec..0cd2275 100644
--- a/QMP/qmp-events.txt
+++ b/QMP/qmp-events.txt
@@ -264,3 +264,32 @@ Example:
Note: If action is "reset", "shutdown", or "pause" the WATCHDOG event is
followed respectively by the RESET, SHUTDOWN, or STOP events.
+
+
+BLOCK_JOB_COMPLETED
+-------------------
+
+Emitted when a block job has completed.
+
+Data:
+
+- "type": Job type ("stream" for image streaming, json-string)
+- "device": Device name (json-string)
+- "len": Maximum progress value (json-int)
+- "offset": Current progress value (json-int)
+ On success this is equal to len.
+ On failure this is less than len.
+- "speed": Rate limit, bytes per second (json-int)
+- "error": Error message (json-string, optional)
+ Only present on failure. This field contains a human-readable
+ error message. There are no semantics other than that streaming
+ has failed and clients should not try to interpret the error
+ string.
+
+Example:
+
+{ "event": "BLOCK_JOB_COMPLETED",
+ "data": { "type": "stream", "device": "virtio-disk0",
+ "len": 10737418240, "offset": 10737418240,
+ "speed": 0 },
+ "timestamp": { "seconds": 1267061043, "microseconds": 959568 } }
diff --git a/blockdev.c b/blockdev.c
index 6d78b36..ba973b0 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -13,9 +13,11 @@
#include "qerror.h"
#include "qemu-option.h"
#include "qemu-config.h"
+#include "qemu-objects.h"
#include "sysemu.h"
#include "block_int.h"
#include "qmp-commands.h"
+#include "trace.h"
static QTAILQ_HEAD(drivelist, DriveInfo) drives =
QTAILQ_HEAD_INITIALIZER(drives);
@@ -880,3 +882,68 @@ void qmp_block_resize(const char *device, int64_t size,
Error **errp)
return;
}
}
+
+static QObject *qobject_from_block_job(BlockJob *job)
+{
+ return qobject_from_jsonf("{ 'type': %s,"
+ "'device': %s,"
+ "'len': %" PRId64 ","
+ "'offset': %" PRId64 ","
+ "'speed': %" PRId64 " }",
+ job->job_type->job_type,
+ bdrv_get_device_name(job->bs),
+ job->len,
+ job->offset,
+ job->speed);
+}
+
+static void block_stream_cb(void *opaque, int ret)
+{
+ BlockDriverState *bs = opaque;
+ QObject *obj;
+
+ trace_block_stream_cb(bs, bs->job, ret);
+
+ assert(bs->job);
+ obj = qobject_from_block_job(bs->job);
+ if (ret < 0) {
+ QDict *dict = qobject_to_qdict(obj);
+ qdict_put(dict, "error", qstring_from_str(strerror(-ret)));
+ }
+
+ monitor_protocol_event(QEVENT_BLOCK_JOB_COMPLETED, obj);
+ qobject_decref(obj);
+}
+
+void qmp_block_stream(const char *device, bool has_base,
+ const char *base, Error **errp)
+{
+ BlockDriverState *bs;
+ int ret;
+
+ bs = bdrv_find(device);
+ if (!bs) {
+ error_set(errp, QERR_DEVICE_NOT_FOUND, device);
+ return;
+ }
+
+ /* Base device not supported */
+ if (base) {
+ error_set(errp, QERR_NOT_SUPPORTED);
+ return;
+ }
+
+ ret = stream_start(bs, NULL, block_stream_cb, bs);
+ if (ret < 0) {
+ switch (ret) {
+ case -EBUSY:
+ error_set(errp, QERR_DEVICE_IN_USE, device);
+ return;
+ default:
+ error_set(errp, QERR_NOT_SUPPORTED);
+ return;
+ }
+ }
+
+ trace_qmp_block_stream(bs, bs->job);
+}
diff --git a/hmp-commands.hx b/hmp-commands.hx
index a586498..dc6c8c3 100644
--- a/hmp-commands.hx
+++ b/hmp-commands.hx
@@ -69,6 +69,19 @@ but should be used with extreme caution. Note that this
command only
resizes image files, it can not resize block devices like LVM volumes.
ETEXI
+ {
+ .name = "block_stream",
+ .args_type = "device:B,base:s?",
+ .params = "device [base]",
+ .help = "copy data from a backing file into a block device",
+ .mhandler.cmd = hmp_block_stream,
+ },
+
+STEXI
+@item block_stream
+@findex block_stream
+Copy data from a backing file into a block device.
+ETEXI
{
.name = "eject",
diff --git a/hmp.c b/hmp.c
index e7659d5..b6e5913 100644
--- a/hmp.c
+++ b/hmp.c
@@ -679,3 +679,14 @@ void hmp_migrate_set_speed(Monitor *mon, const QDict
*qdict)
int64_t value = qdict_get_int(qdict, "value");
qmp_migrate_set_speed(value, NULL);
}
+
+void hmp_block_stream(Monitor *mon, const QDict *qdict)
+{
+ Error *error = NULL;
+ const char *device = qdict_get_str(qdict, "device");
+ const char *base = qdict_get_try_str(qdict, "base");
+
+ qmp_block_stream(device, base != NULL, base, &error);
+
+ hmp_handle_error(mon, &error);
+}
diff --git a/hmp.h b/hmp.h
index 093242d..b55c295 100644
--- a/hmp.h
+++ b/hmp.h
@@ -49,5 +49,6 @@ void hmp_snapshot_blkdev(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);
+void hmp_block_stream(Monitor *mon, const QDict *qdict);
#endif
diff --git a/monitor.c b/monitor.c
index 7334401..bb42580 100644
--- a/monitor.c
+++ b/monitor.c
@@ -479,6 +479,9 @@ void monitor_protocol_event(MonitorEvent event, QObject
*data)
case QEVENT_SPICE_DISCONNECTED:
event_name = "SPICE_DISCONNECTED";
break;
+ case QEVENT_BLOCK_JOB_COMPLETED:
+ event_name = "BLOCK_JOB_COMPLETED";
+ break;
default:
abort();
break;
diff --git a/monitor.h b/monitor.h
index cfa2f67..7324236 100644
--- a/monitor.h
+++ b/monitor.h
@@ -35,6 +35,7 @@ typedef enum MonitorEvent {
QEVENT_SPICE_CONNECTED,
QEVENT_SPICE_INITIALIZED,
QEVENT_SPICE_DISCONNECTED,
+ QEVENT_BLOCK_JOB_COMPLETED,
QEVENT_MAX,
} MonitorEvent;
diff --git a/qapi-schema.json b/qapi-schema.json
index 44cf764..3821982 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -1275,3 +1275,35 @@
{ 'command': 'qom-set',
'data': { 'path': 'str', 'property': 'str', 'value': 'visitor' },
'gen': 'no' }
+
+##
+# @block_stream:
+#
+# Copy data from a backing file into a block device.
+#
+# The block streaming operation is performed in the background until the entire
+# backing file has been copied. This command returns immediately once
streaming
+# has started. The status of ongoing block streaming operations can be checked
+# with query-block-jobs. The operation can be stopped before it has completed
+# using the block_job_cancel command.
+#
+# If a base file is specified then sectors are not copied from that base file
and
+# its backing chain. When streaming completes the image file will have the
base
+# file as its backing file. This can be used to stream a subset of the backing
+# file chain instead of flattening the entire image.
+#
+# On successful completion the image file is updated to drop the backing file
+# and the BLOCK_JOB_COMPLETED event is emitted.
+#
+# @device: the device name
+#
+# @base: #optional the common backing file name
+#
+# Returns: Nothing on success
+# If streaming is already active on this device, DeviceInUse
+# If @device does not exist, DeviceNotFound
+# If image streaming is not supported by this device, NotSupported
+#
+# Since: 1.1
+##
+{ 'command': 'block_stream', 'data': { 'device': 'str', '*base': 'str' } }
diff --git a/qerror.c b/qerror.c
index 9a75d06..feb3d35 100644
--- a/qerror.c
+++ b/qerror.c
@@ -182,6 +182,10 @@ static const QErrorStringTable qerror_table[] = {
.desc = "No '%(bus)' bus found for device '%(device)'",
},
{
+ .error_fmt = QERR_NOT_SUPPORTED,
+ .desc = "Not supported",
+ },
+ {
.error_fmt = QERR_OPEN_FILE_FAILED,
.desc = "Could not open '%(filename)'",
},
diff --git a/qerror.h b/qerror.h
index efda232..095ba9d 100644
--- a/qerror.h
+++ b/qerror.h
@@ -153,6 +153,9 @@ QError *qobject_to_qerror(const QObject *obj);
#define QERR_NO_BUS_FOR_DEVICE \
"{ 'class': 'NoBusForDevice', 'data': { 'device': %s, 'bus': %s } }"
+#define QERR_NOT_SUPPORTED \
+ "{ 'class': 'NotSupported', 'data': {} }"
+
#define QERR_OPEN_FILE_FAILED \
"{ 'class': 'OpenFileFailed', 'data': { 'filename': %s } }"
diff --git a/qmp-commands.hx b/qmp-commands.hx
index 7e3f4b9..b9ebb76 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -655,6 +655,12 @@ Example:
EQMP
{
+ .name = "block_stream",
+ .args_type = "device:B,base:s?",
+ .mhandler.cmd_new = qmp_marshal_input_block_stream,
+ },
+
+ {
.name = "blockdev-snapshot-sync",
.args_type = "device:B,snapshot-file:s,format:s?",
.mhandler.cmd_new = qmp_marshal_input_blockdev_snapshot_sync,
diff --git a/trace-events b/trace-events
index c5368fa..6ff0d43 100644
--- a/trace-events
+++ b/trace-events
@@ -74,6 +74,10 @@ bdrv_co_copy_on_readv(void *bs, int64_t sector_num, int
nb_sectors, int64_t clus
stream_one_iteration(void *s, int64_t sector_num, int nb_sectors, int
is_allocated) "s %p sector_num %"PRId64" nb_sectors %d is_allocated %d"
stream_start(void *bs, void *base, void *s, void *co, void *opaque) "bs %p
base %p s %p co %p opaque %p"
+# blockdev.c
+block_stream_cb(void *bs, void *job, int ret) "bs %p job %p ret %d"
+qmp_block_stream(void *bs, void *job) "bs %p job %p"
+
# hw/virtio-blk.c
virtio_blk_req_complete(void *req, int status) "req %p status %d"
virtio_blk_rw_complete(void *req, int ret) "req %p ret %d"
--
1.7.7.3
