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
<supriyak@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 <supriyak@linux.vnet.ibm.com>
Signed-off-by: Shrinidhi Joshi <spjoshi31@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