[Qemu-devel] [PATCH v5 4/4] qmp/hmp: add block_set_io_throttle

[Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>]

The patch introduce one new command block_set_io_throttle; For its usage syntax, if you have better idea, pls let me know.

Signed-off-by: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
---
 blockdev.c      |   69 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 blockdev.h      |    2 +
 hmp-commands.hx |   15 ++++++++++++
 qerror.c        |    4 +++
 qerror.h        |    3 ++
 qmp-commands.hx |   52 ++++++++++++++++++++++++++++++++++++++++-
 6 files changed, 144 insertions(+), 1 deletions(-)

diff --git a/blockdev.c b/blockdev.c
index 9c78548..ddf7af9 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -782,6 +782,75 @@ int do_change_block(Monitor *mon, const char *device,
     return monitor_read_bdrv_key_start(mon, bs, NULL, NULL);
 }
 
+/* throttling disk I/O limits */
+int do_block_set_io_throttle(Monitor *mon,
+                       const QDict *qdict, QObject **ret_data)
+{
+    const char *devname = qdict_get_str(qdict, "device");
+    uint64_t bps        = qdict_get_try_int(qdict, "bps", -1);
+    uint64_t bps_rd     = qdict_get_try_int(qdict, "bps_rd", -1);
+    uint64_t bps_wr     = qdict_get_try_int(qdict, "bps_wr", -1);
+    uint64_t iops       = qdict_get_try_int(qdict, "iops", -1);
+    uint64_t iops_rd    = qdict_get_try_int(qdict, "iops_rd", -1);
+    uint64_t iops_wr    = qdict_get_try_int(qdict, "iops_wr", -1);
+    BlockDriverState *bs;
+
+    bs = bdrv_find(devname);
+    if (!bs) {
+        qerror_report(QERR_DEVICE_NOT_FOUND, devname);
+        return -1;
+    }
+
+    if ((bps == -1) && (bps_rd == -1) && (bps_wr == -1)
+        && (iops == -1) && (iops_rd == -1) && (iops_wr == -1)) {
+        qerror_report(QERR_MISSING_PARAMETER,
+                      "bps/bps_rd/bps_wr/iops/iops_rd/iops_wr");
+        return -1;
+    }
+
+    if (((bps != -1) && ((bps_rd != -1) || (bps_wr != -1)))
+        || ((iops != -1) && ((iops_rd != -1) || (iops_wr != -1)))) {
+        qerror_report(QERR_INVALID_PARAMETER_COMBINATION);
+        return -1;
+    }
+
+    if (bps != -1) {
+        bs->io_limits.bps[BLOCK_IO_LIMIT_TOTAL] = bps;
+        bs->io_limits.bps[BLOCK_IO_LIMIT_READ]  = 0;
+        bs->io_limits.bps[BLOCK_IO_LIMIT_WRITE] = 0;
+    }
+
+    if ((bps_rd != -1) || (bps_wr != -1)) {
+        bs->io_limits.bps[BLOCK_IO_LIMIT_READ]   =
+           (bps_rd == -1) ? bs->io_limits.bps[BLOCK_IO_LIMIT_READ] : bps_rd;
+        bs->io_limits.bps[BLOCK_IO_LIMIT_WRITE]  =
+           (bps_wr == -1) ? bs->io_limits.bps[BLOCK_IO_LIMIT_WRITE] : bps_wr;
+        bs->io_limits.bps[BLOCK_IO_LIMIT_TOTAL]  = 0;
+    }
+
+    if (iops != -1) {
+        bs->io_limits.iops[BLOCK_IO_LIMIT_TOTAL] = iops;
+        bs->io_limits.iops[BLOCK_IO_LIMIT_READ]  = 0;
+        bs->io_limits.iops[BLOCK_IO_LIMIT_WRITE] = 0;
+    }
+
+    if ((iops_rd != -1) || (iops_wr != -1)) {
+        bs->io_limits.iops[BLOCK_IO_LIMIT_READ]  =
+           (iops_rd == -1) ? bs->io_limits.iops[BLOCK_IO_LIMIT_READ] : iops_rd;
+        bs->io_limits.iops[BLOCK_IO_LIMIT_WRITE] =
+           (iops_wr == -1) ? bs->io_limits.iops[BLOCK_IO_LIMIT_WRITE] : iops_wr;
+        bs->io_limits.iops[BLOCK_IO_LIMIT_TOTAL] = 0;
+    }
+
+    if (!bs->io_limits_enabled && bdrv_io_limits_enabled(bs)) {
+        bdrv_io_limits_enable(bs);
+    } else if (bs->io_limits_enabled && !bdrv_io_limits_enabled(bs)) {
+        bdrv_io_limits_disable(bs);
+    }
+
+    return 0;
+}
+
 int do_drive_del(Monitor *mon, const QDict *qdict, QObject **ret_data)
 {
     const char *id = qdict_get_str(qdict, "id");
diff --git a/blockdev.h b/blockdev.h
index 0a5144c..d0d0d77 100644
--- a/blockdev.h
+++ b/blockdev.h
@@ -63,6 +63,8 @@ int do_block_set_passwd(Monitor *mon, const QDict *qdict, QObject **ret_data);
 int do_change_block(Monitor *mon, const char *device,
                     const char *filename, const char *fmt);
 int do_drive_del(Monitor *mon, const QDict *qdict, QObject **ret_data);
+int do_block_set_io_throttle(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);
 
diff --git a/hmp-commands.hx b/hmp-commands.hx
index aceba74..3ca496d 100644
--- a/hmp-commands.hx
+++ b/hmp-commands.hx
@@ -1210,6 +1210,21 @@ ETEXI
     },
 
 STEXI
+@item block_set_io_throttle @var{device} @var{bps} @var{bps_rd} @var{bps_wr} @var{iops} @var{iops_rd} @var{iops_wr}
+@findex block_set_io_throttle
+Change I/O throttle limits for a block drive to @var{bps} @var{bps_rd} @var{bps_wr} @var{iops} @var{iops_rd} @var{iops_wr}
+ETEXI
+
+    {
+        .name       = "block_set_io_throttle",
+        .args_type  = "device:B,bps:i?,bps_rd:i?,bps_wr:i?,iops:i?,iops_rd:i?,iops_wr:i?",
+        .params     = "device [bps] [bps_rd] [bps_wr] [iops] [iops_rd] [iops_wr]",
+        .help       = "change I/O throttle limts for a block drive",
+        .user_print = monitor_user_noop,
+        .mhandler.cmd_new = do_block_set_io_throttle,
+    },
+
+STEXI
 @item block_passwd @var{device} @var{password}
 @findex block_passwd
 Set the encrypted device @var{device} password to @var{password}
diff --git a/qerror.c b/qerror.c
index d7fcd93..3a21560 100644
--- a/qerror.c
+++ b/qerror.c
@@ -213,6 +213,10 @@ static const QErrorStringTable qerror_table[] = {
         .error_fmt = QERR_VNC_SERVER_FAILED,
         .desc      = "Could not start VNC server on %(target)",
     },
+    {
+        .error_fmt = QERR_INVALID_PARAMETER_COMBINATION,
+        .desc      = "Invalid paramter combination",
+    },
     {}
 };
 
diff --git a/qerror.h b/qerror.h
index 16c830d..81cfe79 100644
--- a/qerror.h
+++ b/qerror.h
@@ -181,4 +181,7 @@ QError *qobject_to_qerror(const QObject *obj);
 #define QERR_FEATURE_DISABLED \
     "{ 'class': 'FeatureDisabled', 'data': { 'name': %s } }"
 
+#define QERR_INVALID_PARAMETER_COMBINATION \
+    "{ 'class': 'InvalidParameterCombination', 'data': {} }"
+
 #endif /* QERROR_H */
diff --git a/qmp-commands.hx b/qmp-commands.hx
index 92c5c3a..9b594cd 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -828,6 +828,44 @@ Example:
 EQMP
 
     {
+        .name       = "block_set_io_throttle",
+        .args_type  = "device:B,bps:i?,bps_rd:i?,bps_wr:i?,iops:i?,iops_rd:i?,iops_wr:i?",
+        .params     = "device [bps] [bps_rd] [bps_wr] [iops] [iops_rd] [iops_wr]",
+        .help       = "change I/O throttle limts for a block drive",
+        .user_print = monitor_user_noop,
+        .mhandler.cmd_new = do_block_set_io_throttle,
+    },
+
+SQMP
+block_set_io_throttle
+------------
+
+Change I/O throttle limits for a block drive.
+
+Arguments:
+
+- "device": device name (json-string)
+- "bps":  total throughput limit in bytes per second(json-int, optional)
+- "bps_rd":  read throughput limit in bytes per second(json-int, optional)
+- "bps_wr":  read throughput limit in bytes per second(json-int, optional)
+- "iops":  total I/O operations per second(json-int, optional)
+- "iops_rd":  read I/O operations per second(json-int, optional)
+- "iops_wr":  write I/O operations per second(json-int, optional)
+
+Example:
+
+-> { "execute": "block_set_io_throttle", "arguments": { "device": "virtio0",
+                                               "bps": "1000000",
+                                               "bps_rd": "0",
+                                               "bps_wr": "0",
+                                               "iops": "0",
+                                               "iops_rd": "0",
+                                               "iops_wr": "0" } }
+<- { "return": {} }
+
+EQMP
+
+    {
         .name       = "set_password",
         .args_type  = "protocol:s,password:s,connected:s?",
         .params     = "protocol password action-if-connected",
@@ -1082,6 +1120,12 @@ Each json-object contain the following:
                                 "tftp", "vdi", "vmdk", "vpc", "vvfat"
          - "backing_file": backing file name (json-string, optional)
          - "encrypted": true if encrypted, false otherwise (json-bool)
+         - "bps": limit total bytes per second (json-int)
+         - "bps_rd": limit read bytes per second (json-int)
+         - "bps_wr": limit write bytes per second (json-int)
+         - "iops": limit total I/O operations per second (json-int)
+         - "iops_rd": limit read operations per second (json-int)
+         - "iops_wr": limit write operations per second (json-int)
 
 Example:
 
@@ -1096,7 +1140,13 @@ Example:
                "ro":false,
                "drv":"qcow2",
                "encrypted":false,
-               "file":"disks/test.img"
+               "file":"disks/test.img",
+               "bps":1000000,
+               "bps_rd":0,
+               "bps_wr":0,
+               "iops":1000000,
+               "iops_rd":0,
+               "iops_wr":0,
             },
             "type":"unknown"
          },
-- 
1.7.2.3