From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([208.118.235.92]:41464)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <spjoshi31@gmail.com>) id 1SmHr6-00029i-Fl
	for qemu-devel@nongnu.org; Wed, 04 Jul 2012 01:10:27 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <spjoshi31@gmail.com>) id 1SmHr2-0000XY-Gn
	for qemu-devel@nongnu.org; Wed, 04 Jul 2012 01:10:24 -0400
Received: from mail-gg0-f173.google.com ([209.85.161.173]:51321)
	by eggs.gnu.org with esmtp (Exim 4.71)
	(envelope-from <spjoshi31@gmail.com>) id 1SmHr2-0000Vk-4i
	for qemu-devel@nongnu.org; Wed, 04 Jul 2012 01:10:20 -0400
Received: by ggnp1 with SMTP id p1so6530552ggn.4
	for <qemu-devel@nongnu.org>; Tue, 03 Jul 2012 22:10:18 -0700 (PDT)
Message-ID: <4FF3D031.90101@gmail.com>
Date: Wed, 04 Jul 2012 10:40:09 +0530
From: Shrinidhi Joshi <spjoshi31@gmail.com>
MIME-Version: 1.0
References: <20120615204648.9853.1225.sendpatchset@skannery.in.ibm.com>
	<20120615204730.9853.61858.sendpatchset@skannery.in.ibm.com>
	<4FE213FE.7010908@redhat.com>
In-Reply-To: <4FE213FE.7010908@redhat.com>
Content-Type: multipart/alternative;
	boundary="------------020402010900070308040607"
Subject: Re: [Qemu-devel] [v1 Patch 3/10]Qemu: Cmd "block_set_hostcache" for
 dynamic cache change
List-Id: <qemu-devel.nongnu.org>
List-Unsubscribe: <https://lists.nongnu.org/mailman/options/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.nongnu.org/archive/html/qemu-devel>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <https://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: jcody@redhat.com
Cc: Kevin Wolf <kwolf@redhat.com>, Stefan Hajnoczi <stefanha@gmail.com>, Christoph Hellwig <hch@lst.de>, qemu-devel@nongnu.org, Luiz Capitulino <lcapitulino@redhat.com>

This is a multi-part message in MIME format.
--------------020402010900070308040607
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit

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




--------------020402010900070308040607
Content-Type: text/html; charset=ISO-8859-1
Content-Transfer-Encoding: 7bit

<html>
  <head>
    <meta content="text/html; charset=ISO-8859-1"
      http-equiv="Content-Type">
  </head>
  <body text="#000000" bgcolor="#FFFFFF">
    On Wednesday 20 June 2012 11:48 PM, Jeff Cody wrote:<br>
    <span style="white-space: pre;">&gt; On 06/15/2012 04:47 PM, Supriya
      Kannery wrote:<br>
      &gt;&gt; New command "block_set_hostcache" added for dynamically
      changing <br>
      &gt;&gt; host pagecache setting of a block device.<br>
      &gt;&gt;<br>
      &gt;&gt; Usage: <br>
      &gt;&gt; block_set_hostcache &lt;device&gt; &lt;option&gt;<br>
      &gt;&gt; &lt;device&gt; = block device<br>
      &gt;&gt; &lt;option&gt; = on/off<br>
      &gt;&gt;<br>
      &gt;&gt; Example:<br>
      &gt;&gt; (qemu) block_set_hostcache ide0-hd0 off<br>
      &gt;&gt;<br>
      &gt;&gt; Signed-off-by: Supriya Kannery
      <a class="moz-txt-link-rfc2396E" href="mailto:supriyak@linux.vnet.ibm.com">&lt;supriyak@linux.vnet.ibm.com&gt;</a><br>
      &gt;&gt;<br>
      &gt;&gt; ---<br>
      &gt;&gt; block.c | 54
      ++++++++++++++++++++++++++++++++++++++++++++++++++++++<br>
      &gt;&gt; block.h | 2 ++<br>
      &gt;&gt; blockdev.c | 26 ++++++++++++++++++++++++++<br>
      &gt;&gt; blockdev.h | 2 ++<br>
      &gt;&gt; hmp-commands.hx | 14 ++++++++++++++<br>
      &gt;&gt; qmp-commands.hx | 27 +++++++++++++++++++++++++++<br>
      &gt;&gt; 6 files changed, 125 insertions(+)<br>
      &gt;&gt;<br>
      &gt;&gt; Index: qemu/block.c<br>
      &gt;&gt;
      ===================================================================<br>
      &gt;&gt; --- qemu.orig/block.c<br>
      &gt;&gt; +++ qemu/block.c<br>
      &gt;&gt; @@ -858,6 +858,35 @@ unlink_and_fail:<br>
      &gt;&gt; return ret;<br>
      &gt;&gt; }<br>
      &gt;&gt; <br>
      &gt;&gt; +int bdrv_reopen(BlockDriverState *bs, int bdrv_flags)<br>
      &gt;&gt; +{<br>
      &gt;&gt; + BlockDriver *drv = bs-&gt;drv;<br>
      &gt;&gt; + int ret = 0, open_flags;<br>
      &gt;&gt; +<br>
      &gt;&gt; + /* Quiesce IO for the given block device */<br>
      &gt;&gt; + qemu_aio_flush();<br>
      &gt;&gt; + ret = bdrv_flush(bs);<br>
      &gt;&gt; + if (ret != 0) {<br>
      &gt;&gt; + qerror_report(QERR_DATA_SYNC_FAILED,
      bs-&gt;device_name);<br>
      &gt;&gt; + return ret;<br>
      &gt;&gt; + }<br>
      &gt;&gt; + open_flags = bs-&gt;open_flags;<br>
      &gt;&gt; + bdrv_close(bs);<br>
      &gt;&gt; +<br>
      &gt;&gt; + ret = bdrv_open(bs, bs-&gt;filename, bdrv_flags, drv);<br>
      &gt;&gt; + if (ret &lt; 0) {<br>
      &gt;&gt; + /* Reopen failed. Try to open with original flags */<br>
      &gt;&gt; + qerror_report(QERR_OPEN_FILE_FAILED, bs-&gt;filename);<br>
      &gt;&gt; + ret = bdrv_open(bs, bs-&gt;filename, open_flags, drv);<br>
      &gt;&gt; + if (ret &lt; 0) {<br>
      &gt;&gt; + /* Reopen failed with orig and modified flags */<br>
      &gt;&gt; + abort();<br>
      &gt;&gt; + }<br>
      &gt;&gt; + }<br>
      &gt;&gt; +<br>
      &gt;&gt; + return ret;<br>
      &gt;&gt; +}<br>
      &gt;&gt; +<br>
      &gt;&gt; void bdrv_close(BlockDriverState *bs)<br>
      &gt;&gt; {<br>
      &gt;&gt; bdrv_flush(bs);<br>
      &gt;&gt; @@ -953,6 +982,34 @@ void bdrv_drain_all(void)<br>
      &gt;&gt; }<br>
      &gt;&gt; }<br>
      &gt;&gt; <br>
      &gt;&gt; +int bdrv_change_hostcache(BlockDriverState *bs, bool
      enable)<br>
      &gt;&gt; +{<br>
      &gt;&gt; + int bdrv_flags = bs-&gt;open_flags;<br>
      &gt;&gt; +<br>
      &gt;&gt; + /* set hostcache flags (without changing WCE/flush
      bits) */<br>
      &gt;&gt; + if (enable) {<br>
      &gt;&gt; + bdrv_flags &amp;= ~BDRV_O_NOCACHE;<br>
      &gt;&gt; + } else {<br>
      &gt;&gt; + bdrv_flags |= BDRV_O_NOCACHE;<br>
      &gt;&gt; + }<br>
      &gt;&gt; +<br>
      &gt;&gt; + /* If no change in flags, no need to reopen */<br>
      &gt;&gt; + if (bdrv_flags == bs-&gt;open_flags) {<br>
      &gt;&gt; + printf("no need to change\n");<br>
      &gt;&gt; + return 0;<br>
      &gt;&gt; + }<br>
      &gt;&gt; +<br>
      &gt;&gt; + if (bdrv_is_inserted(bs)) {<br>
      &gt;&gt; + /* Reopen file with changed set of flags */<br>
      &gt;&gt; + bdrv_flags &amp;= ~BDRV_O_CACHE_WB;<br>
      &gt;&gt; + return bdrv_reopen(bs, bdrv_flags);<br>
      &gt;&gt; + } else {<br>
      &gt;&gt; + /* Save hostcache change for future use */<br>
      &gt;&gt; + bs-&gt;open_flags = bdrv_flags;<br>
      &gt;&gt; + return 0;<br>
      &gt;&gt; + }<br>
      &gt;&gt; +}<br>
      &gt;&gt; +<br>
      &gt;&gt; /* make a BlockDriverState anonymous by removing from
      bdrv_state list.<br>
      &gt;&gt; Also, NULL terminate the device_name to prevent double
      remove */<br>
      &gt;&gt; void bdrv_make_anon(BlockDriverState *bs)<br>
      &gt;&gt; Index: qemu/block.h<br>
      &gt;&gt;
      ===================================================================<br>
      &gt;&gt; --- qemu.orig/block.h<br>
      &gt;&gt; +++ qemu/block.h<br>
      &gt;&gt; @@ -128,6 +128,7 @@ int bdrv_parse_cache_flags(const char
      *m<br>
      &gt;&gt; int bdrv_file_open(BlockDriverState **pbs, const char
      *filename, int flags);<br>
      &gt;&gt; int bdrv_open(BlockDriverState *bs, const char *filename,
      int flags,<br>
      &gt;&gt; BlockDriver *drv);<br>
      &gt;&gt; +int bdrv_reopen(BlockDriverState *bs, int bdrv_flags);<br>
      &gt;&gt; void bdrv_close(BlockDriverState *bs);<br>
      &gt;&gt; int bdrv_attach_dev(BlockDriverState *bs, void *dev);<br>
      &gt;&gt; void bdrv_attach_dev_nofail(BlockDriverState *bs, void
      *dev);<br>
      &gt;&gt; @@ -177,6 +178,7 @@ int bdrv_commit_all(void);<br>
      &gt;&gt; int bdrv_change_backing_file(BlockDriverState *bs,<br>
      &gt;&gt; const char *backing_file, const char *backing_fmt);<br>
      &gt;&gt; void bdrv_register(BlockDriver *bdrv);<br>
      &gt;&gt; +int bdrv_change_hostcache(BlockDriverState *bs, bool
      enable_host_cache);<br>
      &gt;&gt; <br>
      &gt;&gt; <br>
      &gt;&gt; typedef struct BdrvCheckResult {<br>
      &gt;&gt; Index: qemu/blockdev.c<br>
      &gt;&gt;
      ===================================================================<br>
      &gt;&gt; --- qemu.orig/blockdev.c<br>
      &gt;&gt; +++ qemu/blockdev.c<br>
      &gt;&gt; @@ -1198,3 +1198,27 @@ BlockJobInfoList
      *qmp_query_block_jobs(E<br>
      &gt;&gt; bdrv_iterate(do_qmp_query_block_jobs_one, &amp;prev);<br>
      &gt;&gt; return dummy.next;<br>
      &gt;&gt; }<br>
      &gt;&gt; +<br>
      &gt;&gt; +<br>
      &gt;&gt; +/*<br>
      &gt;&gt; + * Change host page cache setting while guest is
      running.<br>
      &gt;&gt; +*/<br>
      &gt;&gt; +void qmp_block_set_hostcache(const char *device, bool
      enable,<br>
      &gt;&gt; + Error **errp)<br>
      &gt;&gt; +{<br>
      &gt;&gt; + BlockDriverState *bs = NULL;<br>
      &gt;&gt; +<br>
      &gt;&gt; + /* Validate device */<br>
      &gt;&gt; + bs = bdrv_find(device);<br>
      &gt;&gt; + if (!bs) {<br>
      &gt;&gt; + error_set(errp, QERR_DEVICE_NOT_FOUND, device);<br>
      &gt;&gt; + return;<br>
      &gt;&gt; + }<br>
      &gt;&gt; +<br>
      &gt;&gt; + if (bdrv_change_hostcache(bs, enable)) {<br>
      &gt;&gt; + error_set(errp, QERR_HOSTCACHE_NOT_CHANGED, device);<br>
      &gt;&gt; + }<br>
      &gt;&gt; +<br>
      &gt;&gt; + return;<br>
      &gt;&gt; +}<br>
      &gt;&gt; +<br>
      &gt;&gt; Index: qemu/hmp-commands.hx<br>
      &gt;&gt;
      ===================================================================<br>
      &gt;&gt; --- qemu.orig/hmp-commands.hx<br>
      &gt;&gt; +++ qemu/hmp-commands.hx<br>
      &gt;&gt; @@ -808,7 +808,6 @@ ETEXI<br>
      &gt;&gt; .mhandler.cmd = hmp_migrate,<br>
      &gt;&gt; },<br>
      &gt;&gt; <br>
      &gt;&gt; -<br>
      &gt;&gt; STEXI<br>
      &gt;&gt; @item migrate [-d] [-b] [-i] @var{uri}<br>
      &gt;&gt; @findex migrate<br>
      &gt;&gt; @@ -1314,6 +1313,21 @@ client. @var{keep} changes the
      password<br>
      &gt;&gt; ETEXI<br>
      &gt;&gt; <br>
      &gt;&gt; {<br>
      &gt;&gt; + .name = "block_set_hostcache",<br>
      &gt;&gt; + .args_type = "device:B,option:b",<br>
      &gt;&gt; + .params = "device on|off",<br>
      &gt;&gt; + .help = "Change setting of host pagecache",<br>
      &gt;&gt; + .mhandler.cmd = hmp_block_set_hostcache,<br>
      &gt;&gt; + },<br>
      &gt;&gt; +<br>
      &gt;&gt; +STEXI<br>
      &gt;&gt; +@item block_set_hostcache @var{device} @var{option}<br>
      &gt;&gt; +@findex block_set_hostcache<br>
      &gt;&gt; +Change host pagecache setting of a block device while
      guest is running.<br>
      &gt;&gt; +ETEXI<br>
      &gt;&gt; +<br>
      &gt;&gt; +<br>
      &gt;&gt; + {<br>
      &gt;&gt; .name = "expire_password",<br>
      &gt;&gt; .args_type = "protocol:s,time:s",<br>
      &gt;&gt; .params = "protocol time",<br>
      &gt;&gt; Index: qemu/qmp-commands.hx<br>
      &gt;&gt;
      ===================================================================<br>
      &gt;&gt; --- qemu.orig/qmp-commands.hx<br>
      &gt;&gt; +++ qemu/qmp-commands.hx<br>
      &gt;&gt; @@ -821,7 +821,31 @@ Example:<br>
      &gt;&gt; <br>
      &gt;&gt; EQMP<br>
      &gt;&gt; <br>
      &gt;&gt; +<br>
      &gt;&gt; {<br>
      &gt;&gt; + .name = "block_set_hostcache",<br>
      &gt;&gt; + .args_type = "device:B,option:b",<br>
      &gt;&gt; + .mhandler.cmd_new = qmp_block_set_hostcache,<br>
      &gt;<br>
      &gt; The QAPI commands need to go through the marshaller - this
      needs to be:<br>
      &gt; .mhandler.cmd_new = qmp_marshal_input_block_set_hostcache,<br>
      &gt;<br>
      &gt; (qmp_marshal_input_block_set_hostcache is automatically
      generated, and<br>
      &gt; it will call qmp_block_set_hostcache)<br>
      &gt;<br>
      &gt;&gt; + },<br>
      &gt;&gt; +<br>
      &gt;&gt; +SQMP<br>
      &gt;&gt; +block_set_hostcache<br>
      &gt;&gt; +-------------------<br>
      &gt;&gt; +<br>
      &gt;&gt; +Change host pagecache setting of a block device<br>
      &gt;&gt; +<br>
      &gt;&gt; +Arguments:<br>
      &gt;&gt; +<br>
      &gt;&gt; +- "device": the device's ID, must be unique
      (json-string)<br>
      &gt;&gt; +- "option": hostcache setting (json-bool)<br>
      &gt;&gt; +<br>
      &gt;&gt; +Example:<br>
      &gt;&gt; +-&gt; { "execute": "block_set_hostcache", "arguments": {
      "device": "ide0-hd0", "option": false } }<br>
      &gt;&gt; +&lt;- { "return": {} }<br>
      &gt;&gt; +<br>
      &gt;&gt; +EQMP<br>
      &gt;&gt; +<br>
      &gt;&gt; + {<br>
      &gt;&gt; .name = "balloon",<br>
      &gt;&gt; .args_type = "value:M",<br>
      &gt;&gt; .mhandler.cmd_new = qmp_marshal_input_balloon,<br>
      &gt;&gt; Index: qemu/qapi-schema.json<br>
      &gt;&gt;
      ===================================================================<br>
      &gt;&gt; --- qemu.orig/qapi-schema.json<br>
      &gt;&gt; +++ qemu/qapi-schema.json<br>
      &gt;&gt; @@ -1598,6 +1598,22 @@<br>
      &gt;&gt; { 'command': 'block_set_io_throttle',<br>
      &gt;&gt; 'data': { 'device': 'str', 'bps': 'int', 'bps_rd': 'int',
      'bps_wr': 'int',<br>
      &gt;&gt; 'iops': 'int', 'iops_rd': 'int', 'iops_wr': 'int' } }<br>
      &gt;&gt; +##<br>
      &gt;&gt; +# @block_set_hostcache:<br>
      &gt;&gt; +#<br>
      &gt;&gt; +# Change host pagecache setting of a block device<br>
      &gt;&gt; +#<br>
      &gt;&gt; +# @device: name of the block device<br>
      &gt;&gt; +#<br>
      &gt;&gt; +# @option: hostcache setting (true/false)<br>
      &gt;&gt; +#<br>
      &gt;&gt; +# Returns: Nothing on success<br>
      &gt;&gt; +# If @device is not a valid block device, DeviceNotFound<br>
      &gt;&gt; +#<br>
      &gt;&gt; +# Since: 1.2<br>
      &gt;&gt; +##<br>
      &gt;&gt; +{ 'command': 'block_set_hostcache',<br>
      &gt;&gt; + 'data': { 'device': 'str', 'option': 'bool' } }<br>
      &gt;&gt; <br>
      &gt;&gt; ##<br>
      &gt;&gt; # @block-stream:<br>
      &gt;&gt; Index: qemu/hmp.c<br>
      &gt;&gt;
      ===================================================================<br>
      &gt;&gt; --- qemu.orig/hmp.c<br>
      &gt;&gt; +++ qemu/hmp.c<br>
      &gt;&gt; @@ -836,6 +836,15 @@ void
      hmp_block_set_io_throttle(Monitor *<br>
      &gt;&gt; hmp_handle_error(mon, &amp;err);<br>
      &gt;&gt; }<br>
      &gt;&gt; <br>
      &gt;&gt; +void hmp_block_set_hostcache(Monitor *mon, const QDict
      *qdict)<br>
      &gt;&gt; +{<br>
      &gt;&gt; + Error *err = NULL;<br>
      &gt;&gt; +<br>
      &gt;&gt; + qmp_block_set_hostcache(qdict_get_str(qdict, "device"),<br>
      &gt;&gt; + qdict_get_bool(qdict, "option"), &amp;err);<br>
      &gt;&gt; + hmp_handle_error(mon, &amp;err);<br>
      &gt;&gt; +}<br>
      &gt;&gt; +<br>
      &gt;&gt; void hmp_block_stream(Monitor *mon, const QDict *qdict)<br>
      &gt;&gt; {<br>
      &gt;&gt; Error *error = NULL;<br>
      &gt;&gt; Index: qemu/hmp.h<br>
      &gt;&gt;
      ===================================================================<br>
      &gt;&gt; --- qemu.orig/hmp.h<br>
      &gt;&gt; +++ qemu/hmp.h<br>
      &gt;&gt; @@ -64,5 +64,6 @@ void hmp_device_del(Monitor *mon, const
      <br>
      &gt;&gt; void hmp_dump_guest_memory(Monitor *mon, const QDict
      *qdict);<br>
      &gt;&gt; void hmp_netdev_add(Monitor *mon, const QDict *qdict);<br>
      &gt;&gt; void hmp_netdev_del(Monitor *mon, const QDict *qdict);<br>
      &gt;&gt; +void hmp_block_set_hostcache(Monitor *mon, const QDict
      *qdict);<br>
      &gt;&gt; <br>
      &gt;&gt; #endif<br>
      &gt;&gt;<br>
      &gt;&gt;<br>
      &gt;</span><br>
    Updated patch to auto generate qmp_marshal_input_block_set_hostcache<br>
    <br>
    --------------------------------------------------------------------<br>
    New command "block_set_hostcache" added for dynamically changing <br>
    host pagecache setting of a block device.<br>
    <br>
    Usage: <br>
    &nbsp;block_set_hostcache&nbsp; &lt;device&gt; &lt;option&gt;<br>
    &nbsp;&nbsp; &lt;device&gt; = block device<br>
    &nbsp;&nbsp; &lt;option&gt; = on/off<br>
    <br>
    Example:<br>
    &nbsp;(qemu) block_set_hostcache ide0-hd0 off<br>
    <br>
    Signed-off-by: Supriya Kannery <a class="moz-txt-link-rfc2396E" href="mailto:supriyak@linux.vnet.ibm.com">&lt;supriyak@linux.vnet.ibm.com&gt;</a><br>
    <br>
    Signed-off-by: Shrinidhi Joshi <a class="moz-txt-link-rfc2396E" href="mailto:spjoshi31@gmail.com">&lt;spjoshi31@gmail.com&gt;</a><br>
    ---<br>
    &nbsp;block.c&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; |&nbsp;&nbsp; 54
    ++++++++++++++++++++++++++++++++++++++++++++++++++++++<br>
    &nbsp;block.h&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; |&nbsp;&nbsp;&nbsp; 2 ++<br>
    &nbsp;blockdev.c&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; |&nbsp;&nbsp; 26 ++++++++++++++++++++++++++<br>
    &nbsp;blockdev.h&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; |&nbsp;&nbsp;&nbsp; 2 ++<br>
    &nbsp;hmp-commands.hx |&nbsp;&nbsp; 14 ++++++++++++++<br>
    &nbsp;qmp-commands.hx |&nbsp;&nbsp; 27 +++++++++++++++++++++++++++<br>
    &nbsp;6 files changed, 125 insertions(+)<br>
    <br>
    Index: qemu/block.c<br>
    ===================================================================<br>
    --- qemu.orig/block.c&nbsp;&nbsp;&nbsp; 2012-06-19 17:24:34.335927717 +0530<br>
    +++ qemu/block.c&nbsp;&nbsp;&nbsp; 2012-06-25 09:18:06.940040103 +0530<br>
    @@ -859,6 +859,35 @@<br>
    &nbsp;&nbsp;&nbsp;&nbsp; return ret;<br>
    &nbsp;}<br>
    &nbsp;<br>
    +int bdrv_reopen(BlockDriverState *bs, int bdrv_flags)<br>
    +{<br>
    +&nbsp;&nbsp;&nbsp; BlockDriver *drv = bs-&gt;drv;<br>
    +&nbsp;&nbsp;&nbsp; int ret = 0, open_flags;<br>
    +<br>
    +&nbsp;&nbsp;&nbsp; /* Quiesce IO for the given block device */<br>
    +&nbsp;&nbsp;&nbsp; qemu_aio_flush();<br>
    +&nbsp;&nbsp;&nbsp; ret = bdrv_flush(bs);<br>
    +&nbsp;&nbsp;&nbsp; if (ret != 0) {<br>
    +&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; qerror_report(QERR_DATA_SYNC_FAILED, bs-&gt;device_name);<br>
    +&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; return ret;<br>
    +&nbsp;&nbsp;&nbsp; }<br>
    +&nbsp;&nbsp;&nbsp; open_flags = bs-&gt;open_flags;<br>
    +&nbsp;&nbsp;&nbsp; bdrv_close(bs);<br>
    +<br>
    +&nbsp;&nbsp;&nbsp; ret = bdrv_open(bs, bs-&gt;filename, bdrv_flags, drv);<br>
    +&nbsp;&nbsp;&nbsp; if (ret &lt; 0) {<br>
    +&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; /* Reopen failed. Try to open with original flags */<br>
    +&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; qerror_report(QERR_OPEN_FILE_FAILED, bs-&gt;filename);<br>
    +&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; ret = bdrv_open(bs, bs-&gt;filename, open_flags, drv);<br>
    +&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; if (ret &lt; 0) {<br>
    +&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; /* Reopen failed with orig and modified flags */<br>
    +&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; abort();<br>
    +&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; }<br>
    +&nbsp;&nbsp;&nbsp; }<br>
    +<br>
    +&nbsp;&nbsp;&nbsp; return ret;<br>
    +}<br>
    +<br>
    &nbsp;void bdrv_close(BlockDriverState *bs)<br>
    &nbsp;{<br>
    &nbsp;&nbsp;&nbsp;&nbsp; bdrv_flush(bs);<br>
    @@ -954,6 +983,34 @@<br>
    &nbsp;&nbsp;&nbsp;&nbsp; }<br>
    &nbsp;}<br>
    &nbsp;<br>
    +int bdrv_change_hostcache(BlockDriverState *bs, bool enable)<br>
    +{<br>
    +&nbsp;&nbsp;&nbsp; int bdrv_flags = bs-&gt;open_flags;<br>
    +<br>
    +&nbsp;&nbsp;&nbsp; /* set hostcache flags (without changing WCE/flush bits) */<br>
    +&nbsp;&nbsp;&nbsp; if (enable) {<br>
    +&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; bdrv_flags &amp;= ~BDRV_O_NOCACHE;<br>
    +&nbsp;&nbsp;&nbsp; } else {<br>
    +&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; bdrv_flags |= BDRV_O_NOCACHE;<br>
    +&nbsp;&nbsp;&nbsp; }<br>
    +<br>
    +&nbsp;&nbsp;&nbsp; /* If no change in flags, no need to reopen */<br>
    +&nbsp;&nbsp;&nbsp; if (bdrv_flags == bs-&gt;open_flags) {<br>
    +&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; printf("no need to change\n");<br>
    +&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; return 0;<br>
    +&nbsp;&nbsp;&nbsp; }<br>
    +<br>
    +&nbsp;&nbsp;&nbsp; if (bdrv_is_inserted(bs)) {<br>
    +&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; /* Reopen file with changed set of flags */<br>
    +&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; bdrv_flags &amp;= ~BDRV_O_CACHE_WB;<br>
    +&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; return bdrv_reopen(bs, bdrv_flags);<br>
    +&nbsp;&nbsp;&nbsp; } else {<br>
    +&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; /* Save hostcache change for future use */<br>
    +&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; bs-&gt;open_flags = bdrv_flags;<br>
    +&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; return 0;<br>
    +&nbsp;&nbsp;&nbsp; }<br>
    +}<br>
    +<br>
    &nbsp;/* make a BlockDriverState anonymous by removing from bdrv_state
    list.<br>
    &nbsp;&nbsp;&nbsp; Also, NULL terminate the device_name to prevent double remove */<br>
    &nbsp;void bdrv_make_anon(BlockDriverState *bs)<br>
    Index: qemu/block.h<br>
    ===================================================================<br>
    --- qemu.orig/block.h&nbsp;&nbsp;&nbsp; 2012-06-19 15:52:43.516601040 +0530<br>
    +++ qemu/block.h&nbsp;&nbsp;&nbsp; 2012-06-25 09:18:06.912039970 +0530<br>
    @@ -128,6 +128,7 @@<br>
    &nbsp;int bdrv_file_open(BlockDriverState **pbs, const char *filename,
    int flags);<br>
    &nbsp;int bdrv_open(BlockDriverState *bs, const char *filename, int
    flags,<br>
    &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; BlockDriver *drv);<br>
    +int bdrv_reopen(BlockDriverState *bs, int bdrv_flags);<br>
    &nbsp;void bdrv_close(BlockDriverState *bs);<br>
    &nbsp;int bdrv_attach_dev(BlockDriverState *bs, void *dev);<br>
    &nbsp;void bdrv_attach_dev_nofail(BlockDriverState *bs, void *dev);<br>
    @@ -181,6 +182,7 @@<br>
    &nbsp;int bdrv_change_backing_file(BlockDriverState *bs,<br>
    &nbsp;&nbsp;&nbsp;&nbsp; const char *backing_file, const char *backing_fmt);<br>
    &nbsp;void bdrv_register(BlockDriver *bdrv);<br>
    +int bdrv_change_hostcache(BlockDriverState *bs, bool
    enable_host_cache);<br>
    &nbsp;<br>
    &nbsp;<br>
    &nbsp;typedef struct BdrvCheckResult {<br>
    Index: qemu/blockdev.c<br>
    ===================================================================<br>
    --- qemu.orig/blockdev.c&nbsp;&nbsp;&nbsp; 2012-06-19 15:52:43.532601120 +0530<br>
    +++ qemu/blockdev.c&nbsp;&nbsp;&nbsp; 2012-06-19 17:24:54.124025837 +0530<br>
    @@ -1195,3 +1195,27 @@<br>
    &nbsp;&nbsp;&nbsp;&nbsp; bdrv_iterate(do_qmp_query_block_jobs_one, &amp;prev);<br>
    &nbsp;&nbsp;&nbsp;&nbsp; return dummy.next;<br>
    &nbsp;}<br>
    +<br>
    +<br>
    +/*<br>
    + * Change host page cache setting while guest is running.<br>
    +*/<br>
    +void qmp_block_set_hostcache(const char *device, bool enable,<br>
    +&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Error **errp)<br>
    +{<br>
    +&nbsp;&nbsp;&nbsp; BlockDriverState *bs = NULL;<br>
    +<br>
    +&nbsp;&nbsp;&nbsp; /* Validate device */<br>
    +&nbsp;&nbsp;&nbsp; bs = bdrv_find(device);<br>
    +&nbsp;&nbsp;&nbsp; if (!bs) {<br>
    +&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; error_set(errp, QERR_DEVICE_NOT_FOUND, device);<br>
    +&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; return;<br>
    +&nbsp;&nbsp;&nbsp; }<br>
    +<br>
    +&nbsp;&nbsp;&nbsp; if (bdrv_change_hostcache(bs, enable)) {<br>
    +&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; error_set(errp, QERR_HOSTCACHE_NOT_CHANGED, device);<br>
    +&nbsp;&nbsp;&nbsp; }<br>
    +<br>
    +&nbsp;&nbsp;&nbsp; return;<br>
    +}<br>
    +<br>
    Index: qemu/hmp-commands.hx<br>
    ===================================================================<br>
    --- qemu.orig/hmp-commands.hx&nbsp;&nbsp;&nbsp; 2012-06-19 15:52:43.536601135 +0530<br>
    +++ qemu/hmp-commands.hx&nbsp;&nbsp;&nbsp; 2012-06-19 17:24:54.124025837 +0530<br>
    @@ -808,7 +808,6 @@<br>
    &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; .mhandler.cmd = hmp_migrate,<br>
    &nbsp;&nbsp;&nbsp;&nbsp; },<br>
    &nbsp;<br>
    -<br>
    &nbsp;STEXI<br>
    &nbsp;@item migrate [-d] [-b] [-i] @var{uri}<br>
    &nbsp;@findex migrate<br>
    @@ -1314,6 +1313,21 @@<br>
    &nbsp;ETEXI<br>
    &nbsp;<br>
    &nbsp;&nbsp;&nbsp;&nbsp; {<br>
    +&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; .name&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; = "block_set_hostcache",<br>
    +&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; .args_type&nbsp; = "device:B,option:b",<br>
    +&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; .params&nbsp;&nbsp;&nbsp;&nbsp; = "device on|off",<br>
    +&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; .help&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; = "Change setting of host pagecache",<br>
    +&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; .mhandler.cmd = hmp_block_set_hostcache,<br>
    +&nbsp;&nbsp;&nbsp; },<br>
    +<br>
    +STEXI<br>
    +@item block_set_hostcache @var{device} @var{option}<br>
    +@findex block_set_hostcache<br>
    +Change host pagecache setting of a block device while guest is
    running.<br>
    +ETEXI<br>
    +<br>
    +<br>
    +&nbsp;&nbsp;&nbsp; {<br>
    &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; .name&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; = "expire_password",<br>
    &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; .args_type&nbsp; = "protocol:s,time:s",<br>
    &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; .params&nbsp;&nbsp;&nbsp;&nbsp; = "protocol time",<br>
    Index: qemu/qmp-commands.hx<br>
    ===================================================================<br>
    --- qemu.orig/qmp-commands.hx&nbsp;&nbsp;&nbsp; 2012-06-19 15:52:43.552601213 +0530<br>
    +++ qemu/qmp-commands.hx&nbsp;&nbsp;&nbsp; 2012-06-19 18:37:32.557638142 +0530<br>
    @@ -821,7 +821,31 @@<br>
    &nbsp;<br>
    &nbsp;EQMP<br>
    &nbsp;<br>
    +<br>
    &nbsp;&nbsp;&nbsp;&nbsp; {<br>
    +&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; .name&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; = "block_set_hostcache",<br>
    +&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; .args_type&nbsp; = "device:B,option:b",<br>
    +&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; .mhandler.cmd_new = qmp_marshal_input_block_set_hostcache,<br>
    +&nbsp;&nbsp;&nbsp; },<br>
    +<br>
    +SQMP<br>
    +block_set_hostcache<br>
    +-------------------<br>
    +<br>
    +Change host pagecache setting of a block device<br>
    +<br>
    +Arguments:<br>
    +<br>
    +- "device": the device's ID, must be unique (json-string)<br>
    +- "option": hostcache setting (json-bool)<br>
    +<br>
    +Example:<br>
    +-&gt; { "execute": "block_set_hostcache", "arguments": { "device":
    "ide0-hd0", "option": false } }<br>
    +&lt;- { "return": {} }<br>
    +<br>
    +EQMP<br>
    +<br>
    +&nbsp;&nbsp;&nbsp; {<br>
    &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; .name&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; = "balloon",<br>
    &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; .args_type&nbsp; = "value:M",<br>
    &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; .mhandler.cmd_new = qmp_marshal_input_balloon,<br>
    Index: qemu/qapi-schema.json<br>
    ===================================================================<br>
    --- qemu.orig/qapi-schema.json&nbsp;&nbsp;&nbsp; 2012-06-19 17:24:34.335927717
    +0530<br>
    +++ qemu/qapi-schema.json&nbsp;&nbsp;&nbsp; 2012-06-19 17:24:54.128025861 +0530<br>
    @@ -1598,6 +1598,22 @@<br>
    &nbsp;{ 'command': 'block_set_io_throttle',<br>
    &nbsp;&nbsp; 'data': { 'device': 'str', 'bps': 'int', 'bps_rd': 'int',
    'bps_wr': 'int',<br>
    &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 'iops': 'int', 'iops_rd': 'int', 'iops_wr': 'int' } }<br>
    +##<br>
    +# @block_set_hostcache:<br>
    +#<br>
    +# Change host pagecache setting of a block device<br>
    +#<br>
    +# @device: name of the block device<br>
    +#<br>
    +# @option: hostcache setting (true/false)<br>
    +#<br>
    +# Returns: Nothing on success<br>
    +#&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; If @device is not a valid block device, DeviceNotFound<br>
    +#<br>
    +# Since: 1.2<br>
    +##<br>
    +{ 'command': 'block_set_hostcache',<br>
    +&nbsp; 'data': { 'device': 'str', 'option': 'bool' } }<br>
    &nbsp;<br>
    &nbsp;##<br>
    &nbsp;# @block-stream:<br>
    Index: qemu/hmp.c<br>
    ===================================================================<br>
    --- qemu.orig/hmp.c&nbsp;&nbsp;&nbsp; 2012-06-19 17:24:34.335927717 +0530<br>
    +++ qemu/hmp.c&nbsp;&nbsp;&nbsp; 2012-06-19 17:24:54.128025861 +0530<br>
    @@ -837,6 +837,15 @@<br>
    &nbsp;&nbsp;&nbsp;&nbsp; hmp_handle_error(mon, &amp;err);<br>
    &nbsp;}<br>
    &nbsp;<br>
    +void hmp_block_set_hostcache(Monitor *mon, const QDict *qdict)<br>
    +{<br>
    +&nbsp;&nbsp;&nbsp; Error *err = NULL;<br>
    +<br>
    +&nbsp;&nbsp;&nbsp; qmp_block_set_hostcache(qdict_get_str(qdict, "device"),<br>
    +&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; qdict_get_bool(qdict, "option"),
    &amp;err);<br>
    +&nbsp;&nbsp;&nbsp; hmp_handle_error(mon, &amp;err);<br>
    +}<br>
    +<br>
    &nbsp;void hmp_block_stream(Monitor *mon, const QDict *qdict)<br>
    &nbsp;{<br>
    &nbsp;&nbsp;&nbsp;&nbsp; Error *error = NULL;<br>
    Index: qemu/hmp.h<br>
    ===================================================================<br>
    --- qemu.orig/hmp.h&nbsp;&nbsp;&nbsp; 2012-06-19 15:52:43.500600959 +0530<br>
    +++ qemu/hmp.h&nbsp;&nbsp;&nbsp; 2012-06-19 17:24:54.128025861 +0530<br>
    @@ -64,5 +64,6 @@<br>
    &nbsp;void hmp_dump_guest_memory(Monitor *mon, const QDict *qdict);<br>
    &nbsp;void hmp_netdev_add(Monitor *mon, const QDict *qdict);<br>
    &nbsp;void hmp_netdev_del(Monitor *mon, const QDict *qdict);<br>
    +void hmp_block_set_hostcache(Monitor *mon, const QDict *qdict);<br>
    &nbsp;<br>
    &nbsp;#endif<br>
    <br>
    <br>
    <br>
  </body>
</html>

--------------020402010900070308040607--