This command sets a watermark value for a device. The next commit
will add the BLOCK_WATERMARK event, which is emitted when this
value is reached.
Please, note that currently only the 'high' watermark value is
supported.
Signed-off-by: Luiz Capitulino <lcapitul...@redhat.com>
---
block.c | 5 +++++
block.h | 2 ++
block_int.h | 3 +++
monitor.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++
qemu-monitor.hx | 16 ++++++++++++++++
5 files changed, 72 insertions(+), 0 deletions(-)
diff --git a/block.c b/block.c
index 31d1ba4..260502a 100644
--- a/block.c
+++ b/block.c
@@ -1209,6 +1209,11 @@ void bdrv_flush_all(void)
bdrv_flush(bs);
}
+void bdrv_set_high_watermark(BlockDriverState *bs, uint64_t offset)
+{
+ bs->high_watermark = offset;
+}
+
/*
* Returns true iff the specified sector is present in the disk image. Drivers
* not implementing the functionality are assumed to not support backing files,
diff --git a/block.h b/block.h
index edf5704..af32436 100644
--- a/block.h
+++ b/block.h
@@ -130,6 +130,8 @@ BlockDriverAIOCB *bdrv_aio_ioctl(BlockDriverState *bs,
void bdrv_flush(BlockDriverState *bs);
void bdrv_flush_all(void);
+void bdrv_set_high_watermark(BlockDriverState *bs, uint64_t offset);
+
int bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num, int nb_sectors,
int *pnum);
diff --git a/block_int.h b/block_int.h
index 50e1a0b..53e087d 100644
--- a/block_int.h
+++ b/block_int.h
@@ -156,6 +156,9 @@ struct BlockDriverState {
void *sync_aiocb;
+ /* high watermark for monitor event */
+ uint64_t high_watermark;
+
/* I/O stats (display with "info blockstats"). */
uint64_t rd_bytes;
uint64_t wr_bytes;
diff --git a/monitor.c b/monitor.c
index 672ae47..595bd62 100644
--- a/monitor.c
+++ b/monitor.c
@@ -1041,6 +1041,52 @@ static int do_eject(Monitor *mon, const QDict *qdict,
QObject **ret_data)
return eject_device(mon, bs, force);
}
+static int do_block_set_watermark(Monitor *mon, const QDict *qdict,
+ QObject **ret_data)
+{
+ int64_t offset;
+ char format[32];
+ BlockDriverState *bs;
+
+ bs = bdrv_find(qdict_get_str(qdict, "device"));
+ if (!bs) {
+ qemu_error_new(QERR_DEVICE_NOT_FOUND, qdict_get_str(qdict, "device"));
+ return -1;
+ }
+
+ bdrv_get_format(bs, format, sizeof(format));
+
+ if (format[0] == '\0') {
+ qemu_error_new(QERR_DEVICE_NOT_ACTIVE, qdict_get_str(qdict, "device"));
+ return -1;
+ }
+
+ /* we only support qcow2 currently */
+ if (strcmp(format, "qcow2")) {
+ qemu_error_new(QERR_INVALID_BLOCK_FORMAT, format);
+ return -1;
+ }
+
+ if (strcmp(qdict_get_str(qdict, "type"), "high")) {
+ qemu_error_new(QERR_INVALID_PARAMETER, "type");
+ return -1;
+ }
+
+ offset = qdict_get_int(qdict, "offset");
+ if (offset < 0) {
+ qemu_error_new(QERR_INVALID_PARAMETER, "offset");
+ return -1;
+ }
+
+ /*
+ * XXX: 'offset' is int64_t because the monitor code doesn't
+ * work with uint64_t. Does it matter? If it does, the
+ * monitor has to be fixed.
+ */
+ bdrv_set_high_watermark(bs, offset);
+ return 0;
+}
+
static int do_block_set_passwd(Monitor *mon, const QDict *qdict,
QObject **ret_data)
{
diff --git a/qemu-monitor.hx b/qemu-monitor.hx
index 7f9d261..c4b48db 100644
--- a/qemu-monitor.hx
+++ b/qemu-monitor.hx
@@ -1127,6 +1127,22 @@ Set the encrypted device @var{device} password to
@var{password}
ETEXI
{
+ .name = "block_watermark",
+ .args_type = "device:B,type:s,offset:l",
+ .params = "device type offset",
+ .help = "set block device watermark",
+ .user_print = monitor_user_noop,
+ .mhandler.cmd_new = do_block_set_watermark,
+ },
+
+STEXI
+...@item block_watermark @var{device} @var{type} @var{offset}
+...@findex block_watermark
+Set the block device @var{device} watermark @var{type} to @var{offset}
+ETEXI
+
+
+ {
.name = "qmp_capabilities",
.args_type = "",
.params = "",
--
1.7.0.1
