===================================================================
@@ -70,6 +70,21 @@ but should be used with extreme caution.
resizes image files, it can not resize block devices like LVM volumes.
ETEXI
+ {
+ .name = "block_set",
+ .args_type = "device:B,name:s,enable:b",
+ .params = "device name enable",
+ .help = "On/Off block device parameters like hostcache",
+ .user_print = monitor_user_noop,
+ .mhandler.cmd_new = do_block_set,
+ },
+
+STEXI
+@item block_set
+@findex block_set
+Change block device params (eg:"hostcache"=on/off) while guest is running.
+ETEXI
+
{
.name = "eject",
===================================================================
@@ -693,7 +693,35 @@ Example:
EQMP
- {
+ {
+ .name = "block_set",
+ .args_type = "device:B,name:s,enable:b",
+ .params = "device name enable",
+ .help = "Enable/Disable block device params like hostcache",
+ .user_print = monitor_user_noop,
+ .mhandler.cmd_new = do_block_set,
+ },
+
+SQMP
+block_set
+---------
+
+Change various block device parameters like hostcache.
+
+Arguments:
+
+- "device": the device's ID, must be unique (json-string)
+- "name": name of the parameter to be changed" (json-string)
+- "enable": value to be set for the parameter, 'true' or 'false'
(json-bool)
+
+Example:
+
+-> { "execute": "block_set", "arguments": { "device": "ide0-hd0",
"name": "hostcache", "enable": true } }
+<- { "return": {} }
+
+EQMP
+
+ {
.name = "balloon",
.args_type = "value:M",
.params = "target",
===================================================================
@@ -797,3 +797,35 @@ int do_block_resize(Monitor *mon, const
return 0;
}
+
+
+/*
+ * Handle changes to block device settings, like hostcache,
+ * while guest is running.
+*/
+int do_block_set(Monitor *mon, const QDict *qdict, QObject **ret_data)
+{
+ const char *device = qdict_get_str(qdict, "device");
+ const char *name = qdict_get_str(qdict, "name");
+ int enable = qdict_get_bool(qdict, "enable");
+ BlockDriverState *bs;
+
+ bs = bdrv_find(device);
+ if (!bs) {
+ qerror_report(QERR_DEVICE_NOT_FOUND, device);
+ return -1;
+ }
+
+ if (!(strcmp(name, "hostcache"))) {
+ if (bdrv_is_inserted(bs)) {
+ /* cache change applicable only if device inserted */
+ return bdrv_change_hostcache(bs, enable);
+ } else {
+ qerror_report(QERR_DEVICE_NOT_INSERTED, device);
+ return -1;
+ }
+ }
+
+ return 0;
+}
+
===================================================================
@@ -651,6 +651,33 @@ unlink_and_fail:
return ret;
}
+int bdrv_reopen(BlockDriverState *bs, int bdrv_flags)
+{
+ BlockDriver *drv = bs->drv;
+ int ret = 0;
+
+ /* No need to reopen as no change in flags */
+ if (bdrv_flags == bs->open_flags)
+ return 0;
+
+ /* Quiesce IO for the given block device */
+ qemu_aio_flush();
+ bdrv_flush(bs);
+
+ bdrv_close(bs);
+ ret = bdrv_open(bs, bs->filename, bdrv_flags, drv);
+
+ /*
+ * A failed attempt to reopen the image file must lead to 'abort()'
+ */
+ if (ret != 0) {
+ qerror_report(QERR_REOPEN_FILE_FAILED, bs->filename);
+ abort();
+ }
+
+ return ret;
+}
+
void bdrv_close(BlockDriverState *bs)
{
if (bs->drv) {
@@ -691,6 +718,20 @@ void bdrv_close_all(void)
}
}
+int bdrv_change_hostcache(BlockDriverState *bs, bool enable_host_cache)
+{
+ int bdrv_flags = bs->open_flags;
+
+ /* set hostcache flags (without changing WCE/flush bits) */
+ if (enable_host_cache)
+ bdrv_flags &= ~BDRV_O_NOCACHE;
+ else
+ bdrv_flags |= BDRV_O_NOCACHE;
+
+ /* Reopen file with changed set of flags */
+ return bdrv_reopen(bs, bdrv_flags);
+}
+
/* make a BlockDriverState anonymous by removing from bdrv_state list.
Also, NULL terminate the device_name to prevent double remove */
void bdrv_make_anon(BlockDriverState *bs)
===================================================================
@@ -71,6 +71,7 @@ void bdrv_delete(BlockDriverState *bs);
int bdrv_file_open(BlockDriverState **pbs, const char *filename, int
flags);
int bdrv_open(BlockDriverState *bs, const char *filename, int flags,
BlockDriver *drv);
+int bdrv_reopen(BlockDriverState *bs, int bdrv_flags);
void bdrv_close(BlockDriverState *bs);
int bdrv_attach(BlockDriverState *bs, DeviceState *qdev);
void bdrv_detach(BlockDriverState *bs, DeviceState *qdev);
@@ -96,6 +97,7 @@ void bdrv_commit_all(void);
int bdrv_change_backing_file(BlockDriverState *bs,
const char *backing_file, const char *backing_fmt);
void bdrv_register(BlockDriver *bdrv);
+int bdrv_change_hostcache(BlockDriverState *bs, bool enable_host_cache);
typedef struct BdrvCheckResult {
===================================================================
@@ -65,5 +65,6 @@ int do_change_block(Monitor *mon, const
int do_drive_del(Monitor *mon, const QDict *qdict, QObject **ret_data);
int do_snapshot_blkdev(Monitor *mon, const QDict *qdict, QObject
**ret_data);
int do_block_resize(Monitor *mon, const QDict *qdict, QObject **ret_data);
+int do_block_set(Monitor *mon, const QDict *qdict, QObject **ret_data);
Resending block_set command patch to avoid mismatch between "paramname" defined for human monitor and "name" used in do_block_set for reading name of block device parameter. --- New command "block_set" added for dynamically changing any of the block device parameters. For now, dynamic setting of hostcache params using block_set is implemented. Other block device parameter changes can be integrated in similar lines. Signed-off-by: Supriya Kannery <supriyak@in.ibm.com> --- block.c | 41 +++++++++++++++++++++++++++++++++++++++++ block.h | 2 ++ blockdev.c | 32 ++++++++++++++++++++++++++++++++ blockdev.h | 1 + hmp-commands.hx | 15 +++++++++++++++ qmp-commands.hx | 30 +++++++++++++++++++++++++++++- 6 files changed, 120 insertions(+), 1 deletion(-) #endif