On Wednesday 20 June 2012 11:48 PM, Jeff Cody wrote:
On 06/15/2012 04:47 PM, Supriya Kannery wrote:
> New command "block_set_hostcache" added for dynamically changing
> host pagecache setting of a block device.
>
> Usage:
> block_set_hostcache <device> <option>
> <device> = block device
> <option> = on/off
>
> Example:
> (qemu) block_set_hostcache ide0-hd0 off
>
> Signed-off-by: Supriya Kannery <supri...@linux.vnet.ibm.com>
>
> ---
> block.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
> block.h | 2 ++
> blockdev.c | 26 ++++++++++++++++++++++++++
> blockdev.h | 2 ++
> hmp-commands.hx | 14 ++++++++++++++
> qmp-commands.hx | 27 +++++++++++++++++++++++++++
> 6 files changed, 125 insertions(+)
>
> Index: qemu/block.c
> ===================================================================
> --- qemu.orig/block.c
> +++ qemu/block.c
> @@ -858,6 +858,35 @@ unlink_and_fail:
> return ret;
> }
>
> +int bdrv_reopen(BlockDriverState *bs, int bdrv_flags)
> +{
> + BlockDriver *drv = bs->drv;
> + int ret = 0, open_flags;
> +
> + /* Quiesce IO for the given block device */
> + qemu_aio_flush();
> + ret = bdrv_flush(bs);
> + if (ret != 0) {
> + qerror_report(QERR_DATA_SYNC_FAILED, bs->device_name);
> + return ret;
> + }
> + open_flags = bs->open_flags;
> + bdrv_close(bs);
> +
> + ret = bdrv_open(bs, bs->filename, bdrv_flags, drv);
> + if (ret < 0) {
> + /* Reopen failed. Try to open with original flags */
> + qerror_report(QERR_OPEN_FILE_FAILED, bs->filename);
> + ret = bdrv_open(bs, bs->filename, open_flags, drv);
> + if (ret < 0) {
> + /* Reopen failed with orig and modified flags */
> + abort();
> + }
> + }
> +
> + return ret;
> +}
> +
> void bdrv_close(BlockDriverState *bs)
> {
> bdrv_flush(bs);
> @@ -953,6 +982,34 @@ void bdrv_drain_all(void)
> }
> }
>
> +int bdrv_change_hostcache(BlockDriverState *bs, bool enable)
> +{
> + int bdrv_flags = bs->open_flags;
> +
> + /* set hostcache flags (without changing WCE/flush bits) */
> + if (enable) {
> + bdrv_flags &= ~BDRV_O_NOCACHE;
> + } else {
> + bdrv_flags |= BDRV_O_NOCACHE;
> + }
> +
> + /* If no change in flags, no need to reopen */
> + if (bdrv_flags == bs->open_flags) {
> + printf("no need to change\n");
> + return 0;
> + }
> +
> + if (bdrv_is_inserted(bs)) {
> + /* Reopen file with changed set of flags */
> + bdrv_flags &= ~BDRV_O_CACHE_WB;
> + return bdrv_reopen(bs, bdrv_flags);
> + } else {
> + /* Save hostcache change for future use */
> + bs->open_flags = bdrv_flags;
> + return 0;
> + }
> +}
> +
> /* 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)
> Index: qemu/block.h
> ===================================================================
> --- qemu.orig/block.h
> +++ qemu/block.h
> @@ -128,6 +128,7 @@ int bdrv_parse_cache_flags(const char *m
> 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_dev(BlockDriverState *bs, void *dev);
> void bdrv_attach_dev_nofail(BlockDriverState *bs, void *dev);
> @@ -177,6 +178,7 @@ int 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 {
> Index: qemu/blockdev.c
> ===================================================================
> --- qemu.orig/blockdev.c
> +++ qemu/blockdev.c
> @@ -1198,3 +1198,27 @@ BlockJobInfoList *qmp_query_block_jobs(E
> bdrv_iterate(do_qmp_query_block_jobs_one, &prev);
> return dummy.next;
> }
> +
> +
> +/*
> + * Change host page cache setting while guest is running.
> +*/
> +void qmp_block_set_hostcache(const char *device, bool enable,
> + Error **errp)
> +{
> + BlockDriverState *bs = NULL;
> +
> + /* Validate device */
> + bs = bdrv_find(device);
> + if (!bs) {
> + error_set(errp, QERR_DEVICE_NOT_FOUND, device);
> + return;
> + }
> +
> + if (bdrv_change_hostcache(bs, enable)) {
> + error_set(errp, QERR_HOSTCACHE_NOT_CHANGED, device);
> + }
> +
> + return;
> +}
> +
> Index: qemu/hmp-commands.hx
> ===================================================================
> --- qemu.orig/hmp-commands.hx
> +++ qemu/hmp-commands.hx
> @@ -808,7 +808,6 @@ ETEXI
> .mhandler.cmd = hmp_migrate,
> },
>
> -
> STEXI
> @item migrate [-d] [-b] [-i] @var{uri}
> @findex migrate
> @@ -1314,6 +1313,21 @@ client. @var{keep} changes the password
> ETEXI
>
> {
> + .name = "block_set_hostcache",
> + .args_type = "device:B,option:b",
> + .params = "device on|off",
> + .help = "Change setting of host pagecache",
> + .mhandler.cmd = hmp_block_set_hostcache,
> + },
> +
> +STEXI
> +@item block_set_hostcache @var{device} @var{option}
> +@findex block_set_hostcache
> +Change host pagecache setting of a block device while guest is running.
> +ETEXI
> +
> +
> + {
> .name = "expire_password",
> .args_type = "protocol:s,time:s",
> .params = "protocol time",
> Index: qemu/qmp-commands.hx
> ===================================================================
> --- qemu.orig/qmp-commands.hx
> +++ qemu/qmp-commands.hx
> @@ -821,7 +821,31 @@ Example:
>
> EQMP
>
> +
> {
> + .name = "block_set_hostcache",
> + .args_type = "device:B,option:b",
> + .mhandler.cmd_new = qmp_block_set_hostcache,
The QAPI commands need to go through the marshaller - this needs to be:
.mhandler.cmd_new = qmp_marshal_input_block_set_hostcache,
(qmp_marshal_input_block_set_hostcache is automatically generated, and
it will call qmp_block_set_hostcache)
> + },
> +
> +SQMP
> +block_set_hostcache
> +-------------------
> +
> +Change host pagecache setting of a block device
> +
> +Arguments:
> +
> +- "device": the device's ID, must be unique (json-string)
> +- "option": hostcache setting (json-bool)
> +
> +Example:
> +-> { "execute": "block_set_hostcache", "arguments": { "device":
"ide0-hd0", "option": false } }
> +<- { "return": {} }
> +
> +EQMP
> +
> + {
> .name = "balloon",
> .args_type = "value:M",
> .mhandler.cmd_new = qmp_marshal_input_balloon,
> Index: qemu/qapi-schema.json
> ===================================================================
> --- qemu.orig/qapi-schema.json
> +++ qemu/qapi-schema.json
> @@ -1598,6 +1598,22 @@
> { 'command': 'block_set_io_throttle',
> 'data': { 'device': 'str', 'bps': 'int', 'bps_rd': 'int', 'bps_wr':
'int',
> 'iops': 'int', 'iops_rd': 'int', 'iops_wr': 'int' } }
> +##
> +# @block_set_hostcache:
> +#
> +# Change host pagecache setting of a block device
> +#
> +# @device: name of the block device
> +#
> +# @option: hostcache setting (true/false)
> +#
> +# Returns: Nothing on success
> +# If @device is not a valid block device, DeviceNotFound
> +#
> +# Since: 1.2
> +##
> +{ 'command': 'block_set_hostcache',
> + 'data': { 'device': 'str', 'option': 'bool' } }
>
> ##
> # @block-stream:
> Index: qemu/hmp.c
> ===================================================================
> --- qemu.orig/hmp.c
> +++ qemu/hmp.c
> @@ -836,6 +836,15 @@ void hmp_block_set_io_throttle(Monitor *
> hmp_handle_error(mon, &err);
> }
>
> +void hmp_block_set_hostcache(Monitor *mon, const QDict *qdict)
> +{
> + Error *err = NULL;
> +
> + qmp_block_set_hostcache(qdict_get_str(qdict, "device"),
> + qdict_get_bool(qdict, "option"), &err);
> + hmp_handle_error(mon, &err);
> +}
> +
> void hmp_block_stream(Monitor *mon, const QDict *qdict)
> {
> Error *error = NULL;
> Index: qemu/hmp.h
> ===================================================================
> --- qemu.orig/hmp.h
> +++ qemu/hmp.h
> @@ -64,5 +64,6 @@ void hmp_device_del(Monitor *mon, const
> 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_block_set_hostcache(Monitor *mon, const QDict *qdict);
>
> #endif
>
>
Updated patch to auto generate qmp_marshal_input_block_set_hostcache
--------------------------------------------------------------------
New command "block_set_hostcache" added for dynamically changing
host pagecache setting of a block device.
Usage:
block_set_hostcache <device> <option>
<device> = block device
<option> = on/off
Example:
(qemu) block_set_hostcache ide0-hd0 off
Signed-off-by: Supriya Kannery <supri...@linux.vnet.ibm.com>
Signed-off-by: Shrinidhi Joshi <spjosh...@gmail.com>
---
block.c | 54
++++++++++++++++++++++++++++++++++++++++++++++++++++++
block.h | 2 ++
blockdev.c | 26 ++++++++++++++++++++++++++
blockdev.h | 2 ++
hmp-commands.hx | 14 ++++++++++++++
qmp-commands.hx | 27 +++++++++++++++++++++++++++
6 files changed, 125 insertions(+)
Index: qemu/block.c
===================================================================
--- qemu.orig/block.c 2012-06-19 17:24:34.335927717 +0530
+++ qemu/block.c 2012-06-25 09:18:06.940040103 +0530
@@ -859,6 +859,35 @@
return ret;
}
+int bdrv_reopen(BlockDriverState *bs, int bdrv_flags)
+{
+ BlockDriver *drv = bs->drv;
+ int ret = 0, open_flags;
+
+ /* Quiesce IO for the given block device */
+ qemu_aio_flush();
+ ret = bdrv_flush(bs);
+ if (ret != 0) {
+ qerror_report(QERR_DATA_SYNC_FAILED, bs->device_name);
+ return ret;
+ }
+ open_flags = bs->open_flags;
+ bdrv_close(bs);
+
+ ret = bdrv_open(bs, bs->filename, bdrv_flags, drv);
+ if (ret < 0) {
+ /* Reopen failed. Try to open with original flags */
+ qerror_report(QERR_OPEN_FILE_FAILED, bs->filename);
+ ret = bdrv_open(bs, bs->filename, open_flags, drv);
+ if (ret < 0) {
+ /* Reopen failed with orig and modified flags */
+ abort();
+ }
+ }
+
+ return ret;
+}
+
void bdrv_close(BlockDriverState *bs)
{
bdrv_flush(bs);
@@ -954,6 +983,34 @@
}
}
+int bdrv_change_hostcache(BlockDriverState *bs, bool enable)
+{
+ int bdrv_flags = bs->open_flags;
+
+ /* set hostcache flags (without changing WCE/flush bits) */
+ if (enable) {
+ bdrv_flags &= ~BDRV_O_NOCACHE;
+ } else {
+ bdrv_flags |= BDRV_O_NOCACHE;
+ }
+
+ /* If no change in flags, no need to reopen */
+ if (bdrv_flags == bs->open_flags) {
+ printf("no need to change\n");
+ return 0;
+ }
+
+ if (bdrv_is_inserted(bs)) {
+ /* Reopen file with changed set of flags */
+ bdrv_flags &= ~BDRV_O_CACHE_WB;
+ return bdrv_reopen(bs, bdrv_flags);
+ } else {
+ /* Save hostcache change for future use */
+ bs->open_flags = bdrv_flags;
+ return 0;
+ }
+}
+
/* 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)
Index: qemu/block.h
===================================================================
--- qemu.orig/block.h 2012-06-19 15:52:43.516601040 +0530
+++ qemu/block.h 2012-06-25 09:18:06.912039970 +0530
@@ -128,6 +128,7 @@
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_dev(BlockDriverState *bs, void *dev);
void bdrv_attach_dev_nofail(BlockDriverState *bs, void *dev);
@@ -181,6 +182,7 @@
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 {
Index: qemu/blockdev.c
===================================================================
--- qemu.orig/blockdev.c 2012-06-19 15:52:43.532601120 +0530
+++ qemu/blockdev.c 2012-06-19 17:24:54.124025837 +0530
@@ -1195,3 +1195,27 @@
bdrv_iterate(do_qmp_query_block_jobs_one, &prev);
return dummy.next;
}
+
+
+/*
+ * Change host page cache setting while guest is running.
+*/
+void qmp_block_set_hostcache(const char *device, bool enable,
+ Error **errp)
+{
+ BlockDriverState *bs = NULL;
+
+ /* Validate device */
+ bs = bdrv_find(device);
+ if (!bs) {
+ error_set(errp, QERR_DEVICE_NOT_FOUND, device);
+ return;
+ }
+
+ if (bdrv_change_hostcache(bs, enable)) {
+ error_set(errp, QERR_HOSTCACHE_NOT_CHANGED, device);
+ }
+
+ return;
+}
+
Index: qemu/hmp-commands.hx
===================================================================
--- qemu.orig/hmp-commands.hx 2012-06-19 15:52:43.536601135 +0530
+++ qemu/hmp-commands.hx 2012-06-19 17:24:54.124025837 +0530
@@ -808,7 +808,6 @@
.mhandler.cmd = hmp_migrate,
},
-
STEXI
@item migrate [-d] [-b] [-i] @var{uri}
@findex migrate
@@ -1314,6 +1313,21 @@
ETEXI
{
+ .name = "block_set_hostcache",
+ .args_type = "device:B,option:b",
+ .params = "device on|off",
+ .help = "Change setting of host pagecache",
+ .mhandler.cmd = hmp_block_set_hostcache,
+ },
+
+STEXI
+@item block_set_hostcache @var{device} @var{option}
+@findex block_set_hostcache
+Change host pagecache setting of a block device while guest is running.
+ETEXI
+
+
+ {
.name = "expire_password",
.args_type = "protocol:s,time:s",
.params = "protocol time",
Index: qemu/qmp-commands.hx
===================================================================
--- qemu.orig/qmp-commands.hx 2012-06-19 15:52:43.552601213 +0530
+++ qemu/qmp-commands.hx 2012-06-19 18:37:32.557638142 +0530
@@ -821,7 +821,31 @@
EQMP
+
{
+ .name = "block_set_hostcache",
+ .args_type = "device:B,option:b",
+ .mhandler.cmd_new = qmp_marshal_input_block_set_hostcache,
+ },
+
+SQMP
+block_set_hostcache
+-------------------
+
+Change host pagecache setting of a block device
+
+Arguments:
+
+- "device": the device's ID, must be unique (json-string)
+- "option": hostcache setting (json-bool)
+
+Example:
+-> { "execute": "block_set_hostcache", "arguments": { "device":
"ide0-hd0", "option": false } }
+<- { "return": {} }
+
+EQMP
+
+ {
.name = "balloon",
.args_type = "value:M",
.mhandler.cmd_new = qmp_marshal_input_balloon,
Index: qemu/qapi-schema.json
===================================================================
--- qemu.orig/qapi-schema.json 2012-06-19 17:24:34.335927717 +0530
+++ qemu/qapi-schema.json 2012-06-19 17:24:54.128025861 +0530
@@ -1598,6 +1598,22 @@
{ 'command': 'block_set_io_throttle',
'data': { 'device': 'str', 'bps': 'int', 'bps_rd': 'int', 'bps_wr':
'int',
'iops': 'int', 'iops_rd': 'int', 'iops_wr': 'int' } }
+##
+# @block_set_hostcache:
+#
+# Change host pagecache setting of a block device
+#
+# @device: name of the block device
+#
+# @option: hostcache setting (true/false)
+#
+# Returns: Nothing on success
+# If @device is not a valid block device, DeviceNotFound
+#
+# Since: 1.2
+##
+{ 'command': 'block_set_hostcache',
+ 'data': { 'device': 'str', 'option': 'bool' } }
##
# @block-stream:
Index: qemu/hmp.c
===================================================================
--- qemu.orig/hmp.c 2012-06-19 17:24:34.335927717 +0530
+++ qemu/hmp.c 2012-06-19 17:24:54.128025861 +0530
@@ -837,6 +837,15 @@
hmp_handle_error(mon, &err);
}
+void hmp_block_set_hostcache(Monitor *mon, const QDict *qdict)
+{
+ Error *err = NULL;
+
+ qmp_block_set_hostcache(qdict_get_str(qdict, "device"),
+ qdict_get_bool(qdict, "option"), &err);
+ hmp_handle_error(mon, &err);
+}
+
void hmp_block_stream(Monitor *mon, const QDict *qdict)
{
Error *error = NULL;
Index: qemu/hmp.h
===================================================================
--- qemu.orig/hmp.h 2012-06-19 15:52:43.500600959 +0530
+++ qemu/hmp.h 2012-06-19 17:24:54.128025861 +0530
@@ -64,5 +64,6 @@
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_block_set_hostcache(Monitor *mon, const QDict *qdict);
#endif
