[Qemu-devel] [PATCH v9 0/9] discard blockstats

[Qemu-devel] [PATCH v9 0/9] discard blockstats

[Anton Nefedov]

v9:
 - fixed patch 5 so the fields are actually numbered in sectors not blocks
 - fixed patch 7 accordingly
 - patch 8: make stat fields unsigned
 - qapi patches: "since 4.1" -> "since 4.2"

v8: https://lists.gnu.org/archive/html/qemu-devel/2019-05/msg03709.html

----

qmp query-blockstats provides stats info for write/read/flush ops.

Patches 1-7 implement the similar for discard (unmap) command for scsi
and ide disks.
Discard stat "unmap_ops / unmap_bytes" is supposed to account the ops that
have completed without an error.

However, discard operation is advisory. Specifically,
 - common block layer ignores ENOTSUP error code.
   That might be returned if the block driver does not support discard,
   or discard has been configured to be ignored.
 - format drivers such as qcow2 may ignore discard if they were configured
   to ignore that, or if the corresponding area is already marked unused
   (unallocated / zero clusters).

And what is actually useful is the number of bytes actually discarded
down on the host filesystem.
To achieve that, driver-specific statistics has been added to blockstats
(patch 9).
With patch 8, file-posix driver accounts discard operations on its level too.

query-blockstat result:

(note the difference between blockdevice unmap and file discard stats. qcow2
sends fewer ops down to the file as the clusters are actually unallocated
on qcow2 level)

    {
      "device": "drive-scsi0-0-0-0",
      "node-name": "#block159",
      "stats": {
>       "invalid_unmap_operations": 0,
>       "failed_unmap_operations": 0,
        "wr_highest_offset": 13411688448,
        "rd_total_time_ns": 2859566315,
        "rd_bytes": 103182336,
        "rd_merged": 0,
        "flush_operations": 19,
        "invalid_wr_operations": 0,
        "flush_total_time_ns": 23111608,
        "failed_rd_operations": 0,
        "failed_flush_operations": 0,
        "invalid_flush_operations": 0,
        "timed_stats": [
          
        ],
        "wr_merged": 0,
        "wr_bytes": 1702912,
>       "unmap_bytes": 11954954240,
>       "unmap_operations": 865,
        "idle_time_ns": 2669508623,
        "account_invalid": true,
>       "unmap_total_time_ns": 19698002,
        "wr_operations": 143,
        "failed_wr_operations": 0,
        "rd_operations": 4816,
        "account_failed": true,
>       "unmap_merged": 0,
        "wr_total_time_ns": 1262686124,
        "invalid_rd_operations": 0
      },
      "parent": {
>       "driver-specific": {
>         "discard-nb-failed": 0,
>         "discard-bytes-ok": 720896,
>         "driver": "file",
>         "discard-nb-ok": 8
>       },
        "node-name": "#block009",
        "stats": {
        [..]
        }
      }
    },
    {
      "device": "floppy0",

Anton Nefedov (9):
  qapi: group BlockDeviceStats fields
  qapi: add unmap to BlockDeviceStats
  block: add empty account cookie type
  ide: account UNMAP (TRIM) operations
  scsi: store unmap offset and nb_sectors in request struct
  scsi: move unmap error checking to the complete callback
  scsi: account unmap operations
  file-posix: account discard operations
  qapi: query-blockstat: add driver specific file-posix stats

 qapi/block-core.json       | 81 ++++++++++++++++++++++++++++++++------
 include/block/accounting.h |  2 +
 include/block/block.h      |  1 +
 include/block/block_int.h  |  1 +
 block.c                    |  9 +++++
 block/accounting.c         |  6 +++
 block/file-posix.c         | 54 ++++++++++++++++++++++++-
 block/qapi.c               | 11 ++++++
 hw/ide/core.c              | 12 ++++++
 hw/scsi/scsi-disk.c        | 34 ++++++++++------
 tests/qemu-iotests/227.out | 18 +++++++++
 11 files changed, 206 insertions(+), 23 deletions(-)

-- 
2.17.1

[Qemu-devel] [PATCH v9 1/9] qapi: group BlockDeviceStats fields

[Anton Nefedov]

Make the stat fields definition slightly more readable.
Also reorder total_time_ns stats read-write-flush as done elsewhere.
Cosmetic change only.

Signed-off-by: Anton Nefedov <anton.nefedov@virtuozzo.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
 qapi/block-core.json | 26 +++++++++++++++-----------
 1 file changed, 15 insertions(+), 11 deletions(-)

diff --git a/qapi/block-core.json b/qapi/block-core.json
index e6edd641f1..5ab554b54a 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -867,12 +867,12 @@
 # @flush_operations: The number of cache flush operations performed by the
 #                    device (since 0.15.0)
 #
-# @flush_total_time_ns: Total time spend on cache flushes in nano-seconds
-#                       (since 0.15.0).
+# @rd_total_time_ns: Total time spent on reads in nanoseconds (since 0.15.0).
 #
-# @wr_total_time_ns: Total time spend on writes in nano-seconds (since 0.15.0).
+# @wr_total_time_ns: Total time spent on writes in nanoseconds (since 0.15.0).
 #
-# @rd_total_time_ns: Total_time_spend on reads in nano-seconds (since 0.15.0).
+# @flush_total_time_ns: Total time spent on cache flushes in nanoseconds
+#                       (since 0.15.0).
 #
 # @wr_highest_offset: The offset after the greatest byte written to the
 #                     device.  The intended use of this information is for
@@ -925,14 +925,18 @@
 # Since: 0.14.0
 ##
 { 'struct': 'BlockDeviceStats',
-  'data': {'rd_bytes': 'int', 'wr_bytes': 'int', 'rd_operations': 'int',
-           'wr_operations': 'int', 'flush_operations': 'int',
-           'flush_total_time_ns': 'int', 'wr_total_time_ns': 'int',
-           'rd_total_time_ns': 'int', 'wr_highest_offset': 'int',
-           'rd_merged': 'int', 'wr_merged': 'int', '*idle_time_ns': 'int',
+  'data': {'rd_bytes': 'int', 'wr_bytes': 'int',
+           'rd_operations': 'int', 'wr_operations': 'int',
+           'flush_operations': 'int',
+           'rd_total_time_ns': 'int', 'wr_total_time_ns': 'int',
+           'flush_total_time_ns': 'int',
+           'wr_highest_offset': 'int',
+           'rd_merged': 'int', 'wr_merged': 'int',
+           '*idle_time_ns': 'int',
            'failed_rd_operations': 'int', 'failed_wr_operations': 'int',
-           'failed_flush_operations': 'int', 'invalid_rd_operations': 'int',
-           'invalid_wr_operations': 'int', 'invalid_flush_operations': 'int',
+           'failed_flush_operations': 'int',
+           'invalid_rd_operations': 'int', 'invalid_wr_operations': 'int',
+           'invalid_flush_operations': 'int',
            'account_invalid': 'bool', 'account_failed': 'bool',
            'timed_stats': ['BlockDeviceTimedStats'],
            '*rd_latency_histogram': 'BlockLatencyHistogramInfo',
-- 
2.17.1

[Qemu-devel] [PATCH v9 2/9] qapi: add unmap to BlockDeviceStats

[Anton Nefedov]

Signed-off-by: Anton Nefedov <anton.nefedov@virtuozzo.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
---
 qapi/block-core.json       | 29 +++++++++++++++++++++++------
 include/block/accounting.h |  1 +
 block/qapi.c               |  6 ++++++
 tests/qemu-iotests/227.out | 18 ++++++++++++++++++
 4 files changed, 48 insertions(+), 6 deletions(-)

diff --git a/qapi/block-core.json b/qapi/block-core.json
index 5ab554b54a..7d3e05891c 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -860,6 +860,8 @@
 #
 # @wr_bytes:      The number of bytes written by the device.
 #
+# @unmap_bytes: The number of bytes unmapped by the device (Since 4.2)
+#
 # @rd_operations: The number of read operations performed by the device.
 #
 # @wr_operations: The number of write operations performed by the device.
@@ -867,6 +869,9 @@
 # @flush_operations: The number of cache flush operations performed by the
 #                    device (since 0.15.0)
 #
+# @unmap_operations: The number of unmap operations performed by the device
+#                    (Since 4.2)
+#
 # @rd_total_time_ns: Total time spent on reads in nanoseconds (since 0.15.0).
 #
 # @wr_total_time_ns: Total time spent on writes in nanoseconds (since 0.15.0).
@@ -874,6 +879,9 @@
 # @flush_total_time_ns: Total time spent on cache flushes in nanoseconds
 #                       (since 0.15.0).
 #
+# @unmap_total_time_ns: Total time spent on unmap operations in nanoseconds
+#                       (Since 4.2)
+#
 # @wr_highest_offset: The offset after the greatest byte written to the
 #                     device.  The intended use of this information is for
 #                     growable sparse files (like qcow2) that are used on top
@@ -885,6 +893,9 @@
 # @wr_merged: Number of write requests that have been merged into another
 #             request (Since 2.3).
 #
+# @unmap_merged: Number of unmap requests that have been merged into another
+#                request (Since 4.2)
+#
 # @idle_time_ns: Time since the last I/O operation, in
 #                nanoseconds. If the field is absent it means that
 #                there haven't been any operations yet (Since 2.5).
@@ -898,6 +909,9 @@
 # @failed_flush_operations: The number of failed flush operations
 #                           performed by the device (Since 2.5)
 #
+# @failed_unmap_operations: The number of failed unmap operations performed
+#                           by the device (Since 4.2)
+#
 # @invalid_rd_operations: The number of invalid read operations
 #                          performed by the device (Since 2.5)
 #
@@ -907,6 +921,9 @@
 # @invalid_flush_operations: The number of invalid flush operations
 #                            performed by the device (Since 2.5)
 #
+# @invalid_unmap_operations: The number of invalid unmap operations performed
+#                            by the device (Since 4.2)
+#
 # @account_invalid: Whether invalid operations are included in the
 #                   last access statistics (Since 2.5)
 #
@@ -925,18 +942,18 @@
 # Since: 0.14.0
 ##
 { 'struct': 'BlockDeviceStats',
-  'data': {'rd_bytes': 'int', 'wr_bytes': 'int',
+  'data': {'rd_bytes': 'int', 'wr_bytes': 'int', 'unmap_bytes' : 'int',
            'rd_operations': 'int', 'wr_operations': 'int',
-           'flush_operations': 'int',
+           'flush_operations': 'int', 'unmap_operations': 'int',
            'rd_total_time_ns': 'int', 'wr_total_time_ns': 'int',
-           'flush_total_time_ns': 'int',
+           'flush_total_time_ns': 'int', 'unmap_total_time_ns': 'int',
            'wr_highest_offset': 'int',
-           'rd_merged': 'int', 'wr_merged': 'int',
+           'rd_merged': 'int', 'wr_merged': 'int', 'unmap_merged': 'int',
            '*idle_time_ns': 'int',
            'failed_rd_operations': 'int', 'failed_wr_operations': 'int',
-           'failed_flush_operations': 'int',
+           'failed_flush_operations': 'int', 'failed_unmap_operations': 'int',
            'invalid_rd_operations': 'int', 'invalid_wr_operations': 'int',
-           'invalid_flush_operations': 'int',
+           'invalid_flush_operations': 'int', 'invalid_unmap_operations': 'int',
            'account_invalid': 'bool', 'account_failed': 'bool',
            'timed_stats': ['BlockDeviceTimedStats'],
            '*rd_latency_histogram': 'BlockLatencyHistogramInfo',
diff --git a/include/block/accounting.h b/include/block/accounting.h
index d1f67b10dd..ba8b04d572 100644
--- a/include/block/accounting.h
+++ b/include/block/accounting.h
@@ -36,6 +36,7 @@ enum BlockAcctType {
     BLOCK_ACCT_READ,
     BLOCK_ACCT_WRITE,
     BLOCK_ACCT_FLUSH,
+    BLOCK_ACCT_UNMAP,
     BLOCK_MAX_IOTYPE,
 };
 
diff --git a/block/qapi.c b/block/qapi.c
index 15f1030264..3356a1dc59 100644
--- a/block/qapi.c
+++ b/block/qapi.c
@@ -440,24 +440,30 @@ static void bdrv_query_blk_stats(BlockDeviceStats *ds, BlockBackend *blk)
 
     ds->rd_bytes = stats->nr_bytes[BLOCK_ACCT_READ];
     ds->wr_bytes = stats->nr_bytes[BLOCK_ACCT_WRITE];
+    ds->unmap_bytes = stats->nr_bytes[BLOCK_ACCT_UNMAP];
     ds->rd_operations = stats->nr_ops[BLOCK_ACCT_READ];
     ds->wr_operations = stats->nr_ops[BLOCK_ACCT_WRITE];
+    ds->unmap_operations = stats->nr_ops[BLOCK_ACCT_UNMAP];
 
     ds->failed_rd_operations = stats->failed_ops[BLOCK_ACCT_READ];
     ds->failed_wr_operations = stats->failed_ops[BLOCK_ACCT_WRITE];
     ds->failed_flush_operations = stats->failed_ops[BLOCK_ACCT_FLUSH];
+    ds->failed_unmap_operations = stats->failed_ops[BLOCK_ACCT_UNMAP];
 
     ds->invalid_rd_operations = stats->invalid_ops[BLOCK_ACCT_READ];
     ds->invalid_wr_operations = stats->invalid_ops[BLOCK_ACCT_WRITE];
     ds->invalid_flush_operations =
         stats->invalid_ops[BLOCK_ACCT_FLUSH];
+    ds->invalid_unmap_operations = stats->invalid_ops[BLOCK_ACCT_UNMAP];
 
     ds->rd_merged = stats->merged[BLOCK_ACCT_READ];
     ds->wr_merged = stats->merged[BLOCK_ACCT_WRITE];
+    ds->unmap_merged = stats->merged[BLOCK_ACCT_UNMAP];
     ds->flush_operations = stats->nr_ops[BLOCK_ACCT_FLUSH];
     ds->wr_total_time_ns = stats->total_time_ns[BLOCK_ACCT_WRITE];
     ds->rd_total_time_ns = stats->total_time_ns[BLOCK_ACCT_READ];
     ds->flush_total_time_ns = stats->total_time_ns[BLOCK_ACCT_FLUSH];
+    ds->unmap_total_time_ns = stats->total_time_ns[BLOCK_ACCT_UNMAP];
 
     ds->has_idle_time_ns = stats->last_access_time_ns > 0;
     if (ds->has_idle_time_ns) {
diff --git a/tests/qemu-iotests/227.out b/tests/qemu-iotests/227.out
index 3dd3ca5708..9c09ee3917 100644
--- a/tests/qemu-iotests/227.out
+++ b/tests/qemu-iotests/227.out
@@ -15,6 +15,8 @@ Testing: -drive driver=null-co,read-zeroes=on,if=virtio
         {
             "device": "virtio0",
             "stats": {
+                "unmap_operations": 0,
+                "unmap_merged": 0,
                 "flush_total_time_ns": 0,
                 "wr_highest_offset": 0,
                 "wr_total_time_ns": 0,
@@ -24,13 +26,17 @@ Testing: -drive driver=null-co,read-zeroes=on,if=virtio
                 "wr_bytes": 0,
                 "timed_stats": [
                 ],
+                "failed_unmap_operations": 0,
                 "failed_flush_operations": 0,
                 "account_invalid": true,
                 "rd_total_time_ns": 0,
+                "invalid_unmap_operations": 0,
                 "flush_operations": 0,
                 "wr_operations": 0,
+                "unmap_bytes": 0,
                 "rd_merged": 0,
                 "rd_bytes": 0,
+                "unmap_total_time_ns": 0,
                 "invalid_flush_operations": 0,
                 "account_failed": true,
                 "rd_operations": 0,
@@ -74,6 +80,8 @@ Testing: -drive driver=null-co,if=none
         {
             "device": "none0",
             "stats": {
+                "unmap_operations": 0,
+                "unmap_merged": 0,
                 "flush_total_time_ns": 0,
                 "wr_highest_offset": 0,
                 "wr_total_time_ns": 0,
@@ -83,13 +91,17 @@ Testing: -drive driver=null-co,if=none
                 "wr_bytes": 0,
                 "timed_stats": [
                 ],
+                "failed_unmap_operations": 0,
                 "failed_flush_operations": 0,
                 "account_invalid": true,
                 "rd_total_time_ns": 0,
+                "invalid_unmap_operations": 0,
                 "flush_operations": 0,
                 "wr_operations": 0,
+                "unmap_bytes": 0,
                 "rd_merged": 0,
                 "rd_bytes": 0,
+                "unmap_total_time_ns": 0,
                 "invalid_flush_operations": 0,
                 "account_failed": true,
                 "rd_operations": 0,
@@ -163,6 +175,8 @@ Testing: -blockdev driver=null-co,read-zeroes=on,node-name=null -device virtio-b
         {
             "device": "",
             "stats": {
+                "unmap_operations": 0,
+                "unmap_merged": 0,
                 "flush_total_time_ns": 0,
                 "wr_highest_offset": 0,
                 "wr_total_time_ns": 0,
@@ -172,13 +186,17 @@ Testing: -blockdev driver=null-co,read-zeroes=on,node-name=null -device virtio-b
                 "wr_bytes": 0,
                 "timed_stats": [
                 ],
+                "failed_unmap_operations": 0,
                 "failed_flush_operations": 0,
                 "account_invalid": false,
                 "rd_total_time_ns": 0,
+                "invalid_unmap_operations": 0,
                 "flush_operations": 0,
                 "wr_operations": 0,
+                "unmap_bytes": 0,
                 "rd_merged": 0,
                 "rd_bytes": 0,
+                "unmap_total_time_ns": 0,
                 "invalid_flush_operations": 0,
                 "account_failed": false,
                 "rd_operations": 0,
-- 
2.17.1

[Qemu-devel] [PATCH v9 3/9] block: add empty account cookie type

[Anton Nefedov]

This adds some protection from accounting uninitialized cookie.
That is, block_acct_failed/done without previous block_acct_start;
in that case, cookie probably holds values from previous operation.

(Note: it might also be uninitialized holding garbage value and there is
 still "< BLOCK_MAX_IOTYPE" assertion for that.
 So block_acct_failed/done without previous block_acct_start should be used
 with caution.)

Currently this is particularly useful in ide code where it's hard to
keep track whether the request started accounting or not. For example,
trim requests do the accounting separately.

Signed-off-by: Anton Nefedov <anton.nefedov@virtuozzo.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
 include/block/accounting.h | 1 +
 block/accounting.c         | 6 ++++++
 2 files changed, 7 insertions(+)

diff --git a/include/block/accounting.h b/include/block/accounting.h
index ba8b04d572..878b4c3581 100644
--- a/include/block/accounting.h
+++ b/include/block/accounting.h
@@ -33,6 +33,7 @@ typedef struct BlockAcctTimedStats BlockAcctTimedStats;
 typedef struct BlockAcctStats BlockAcctStats;
 
 enum BlockAcctType {
+    BLOCK_ACCT_NONE = 0,
     BLOCK_ACCT_READ,
     BLOCK_ACCT_WRITE,
     BLOCK_ACCT_FLUSH,
diff --git a/block/accounting.c b/block/accounting.c
index 70a3d9a426..8d41c8a83a 100644
--- a/block/accounting.c
+++ b/block/accounting.c
@@ -195,6 +195,10 @@ static void block_account_one_io(BlockAcctStats *stats, BlockAcctCookie *cookie,
 
     assert(cookie->type < BLOCK_MAX_IOTYPE);
 
+    if (cookie->type == BLOCK_ACCT_NONE) {
+        return;
+    }
+
     qemu_mutex_lock(&stats->lock);
 
     if (failed) {
@@ -217,6 +221,8 @@ static void block_account_one_io(BlockAcctStats *stats, BlockAcctCookie *cookie,
     }
 
     qemu_mutex_unlock(&stats->lock);
+
+    cookie->type = BLOCK_ACCT_NONE;
 }
 
 void block_acct_done(BlockAcctStats *stats, BlockAcctCookie *cookie)
-- 
2.17.1

[Qemu-devel] [PATCH v9 4/9] ide: account UNMAP (TRIM) operations

[Anton Nefedov]

Signed-off-by: Anton Nefedov <anton.nefedov@virtuozzo.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
 hw/ide/core.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/hw/ide/core.c b/hw/ide/core.c
index e6e54c6c9a..754ff4dc34 100644
--- a/hw/ide/core.c
+++ b/hw/ide/core.c
@@ -442,6 +442,14 @@ static void ide_issue_trim_cb(void *opaque, int ret)
     TrimAIOCB *iocb = opaque;
     IDEState *s = iocb->s;
 
+    if (iocb->i >= 0) {
+        if (ret >= 0) {
+            block_acct_done(blk_get_stats(s->blk), &s->acct);
+        } else {
+            block_acct_failed(blk_get_stats(s->blk), &s->acct);
+        }
+    }
+
     if (ret >= 0) {
         while (iocb->j < iocb->qiov->niov) {
             int j = iocb->j;
@@ -459,10 +467,14 @@ static void ide_issue_trim_cb(void *opaque, int ret)
                 }
 
                 if (!ide_sect_range_ok(s, sector, count)) {
+                    block_acct_invalid(blk_get_stats(s->blk), BLOCK_ACCT_UNMAP);
                     iocb->ret = -EINVAL;
                     goto done;
                 }
 
+                block_acct_start(blk_get_stats(s->blk), &s->acct,
+                                 count << BDRV_SECTOR_BITS, BLOCK_ACCT_UNMAP);
+
                 /* Got an entry! Submit and exit.  */
                 iocb->aiocb = blk_aio_pdiscard(s->blk,
                                                sector << BDRV_SECTOR_BITS,
-- 
2.17.1

[Qemu-devel] [PATCH v9 5/9] scsi: store unmap offset and nb_sectors in request struct

[Anton Nefedov]

it allows to report it in the error handler

Signed-off-by: Anton Nefedov <anton.nefedov@virtuozzo.com>
---
 hw/scsi/scsi-disk.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/hw/scsi/scsi-disk.c b/hw/scsi/scsi-disk.c
index 915641a0f1..b3dd21800d 100644
--- a/hw/scsi/scsi-disk.c
+++ b/hw/scsi/scsi-disk.c
@@ -1608,8 +1608,6 @@ static void scsi_unmap_complete_noio(UnmapCBData *data, int ret)
 {
     SCSIDiskReq *r = data->r;
     SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, r->req.dev);
-    uint64_t sector_num;
-    uint32_t nb_sectors;
 
     assert(r->req.aiocb == NULL);
     if (scsi_disk_req_check_error(r, ret, false)) {
@@ -1617,16 +1615,18 @@ static void scsi_unmap_complete_noio(UnmapCBData *data, int ret)
     }
 
     if (data->count > 0) {
-        sector_num = ldq_be_p(&data->inbuf[0]);
-        nb_sectors = ldl_be_p(&data->inbuf[8]) & 0xffffffffULL;
-        if (!check_lba_range(s, sector_num, nb_sectors)) {
+        r->sector = ldq_be_p(&data->inbuf[0])
+            * (s->qdev.blocksize / BDRV_SECTOR_SIZE);
+        r->sector_count = (ldl_be_p(&data->inbuf[8]) & 0xffffffffULL)
+            * (s->qdev.blocksize / BDRV_SECTOR_SIZE);
+        if (!check_lba_range(s, r->sector, r->sector_count)) {
             scsi_check_condition(r, SENSE_CODE(LBA_OUT_OF_RANGE));
             goto done;
         }
 
         r->req.aiocb = blk_aio_pdiscard(s->qdev.conf.blk,
-                                        sector_num * s->qdev.blocksize,
-                                        nb_sectors * s->qdev.blocksize,
+                                        r->sector * BDRV_SECTOR_SIZE,
+                                        r->sector_count * BDRV_SECTOR_SIZE,
                                         scsi_unmap_complete, data);
         data->count--;
         data->inbuf += 16;
-- 
2.17.1

[Qemu-devel] [PATCH v9 6/9] scsi: move unmap error checking to the complete callback

[Anton Nefedov]

This will help to account the operation in the following commit.

The difference is that we don't call scsi_disk_req_check_error() before
the 1st discard iteration anymore. That function also checks if
the request is cancelled, however it shouldn't get canceled until it
yields in blk_aio() functions anyway.
Same approach is already used for emulate_write_same.

Signed-off-by: Anton Nefedov <anton.nefedov@virtuozzo.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
---
 hw/scsi/scsi-disk.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/hw/scsi/scsi-disk.c b/hw/scsi/scsi-disk.c
index b3dd21800d..a002fdabe8 100644
--- a/hw/scsi/scsi-disk.c
+++ b/hw/scsi/scsi-disk.c
@@ -1610,9 +1610,6 @@ static void scsi_unmap_complete_noio(UnmapCBData *data, int ret)
     SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, r->req.dev);
 
     assert(r->req.aiocb == NULL);
-    if (scsi_disk_req_check_error(r, ret, false)) {
-        goto done;
-    }
 
     if (data->count > 0) {
         r->sector = ldq_be_p(&data->inbuf[0])
@@ -1650,7 +1647,12 @@ static void scsi_unmap_complete(void *opaque, int ret)
     r->req.aiocb = NULL;
 
     aio_context_acquire(blk_get_aio_context(s->qdev.conf.blk));
-    scsi_unmap_complete_noio(data, ret);
+    if (scsi_disk_req_check_error(r, ret, false)) {
+        scsi_req_unref(&r->req);
+        g_free(data);
+    } else {
+        scsi_unmap_complete_noio(data, ret);
+    }
     aio_context_release(blk_get_aio_context(s->qdev.conf.blk));
 }
 
-- 
2.17.1

[Qemu-devel] [PATCH v9 7/9] scsi: account unmap operations

[Anton Nefedov]

Signed-off-by: Anton Nefedov <anton.nefedov@virtuozzo.com>
---
 hw/scsi/scsi-disk.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/hw/scsi/scsi-disk.c b/hw/scsi/scsi-disk.c
index a002fdabe8..68b1675fd9 100644
--- a/hw/scsi/scsi-disk.c
+++ b/hw/scsi/scsi-disk.c
@@ -1617,10 +1617,16 @@ static void scsi_unmap_complete_noio(UnmapCBData *data, int ret)
         r->sector_count = (ldl_be_p(&data->inbuf[8]) & 0xffffffffULL)
             * (s->qdev.blocksize / BDRV_SECTOR_SIZE);
         if (!check_lba_range(s, r->sector, r->sector_count)) {
+            block_acct_invalid(blk_get_stats(s->qdev.conf.blk),
+                               BLOCK_ACCT_UNMAP);
             scsi_check_condition(r, SENSE_CODE(LBA_OUT_OF_RANGE));
             goto done;
         }
 
+        block_acct_start(blk_get_stats(s->qdev.conf.blk), &r->acct,
+                         r->sector_count * BDRV_SECTOR_SIZE,
+                         BLOCK_ACCT_UNMAP);
+
         r->req.aiocb = blk_aio_pdiscard(s->qdev.conf.blk,
                                         r->sector * BDRV_SECTOR_SIZE,
                                         r->sector_count * BDRV_SECTOR_SIZE,
@@ -1647,10 +1653,11 @@ static void scsi_unmap_complete(void *opaque, int ret)
     r->req.aiocb = NULL;
 
     aio_context_acquire(blk_get_aio_context(s->qdev.conf.blk));
-    if (scsi_disk_req_check_error(r, ret, false)) {
+    if (scsi_disk_req_check_error(r, ret, true)) {
         scsi_req_unref(&r->req);
         g_free(data);
     } else {
+        block_acct_done(blk_get_stats(s->qdev.conf.blk), &r->acct);
         scsi_unmap_complete_noio(data, ret);
     }
     aio_context_release(blk_get_aio_context(s->qdev.conf.blk));
@@ -1682,6 +1689,7 @@ static void scsi_disk_emulate_unmap(SCSIDiskReq *r, uint8_t *inbuf)
     }
 
     if (blk_is_read_only(s->qdev.conf.blk)) {
+        block_acct_invalid(blk_get_stats(s->qdev.conf.blk), BLOCK_ACCT_UNMAP);
         scsi_check_condition(r, SENSE_CODE(WRITE_PROTECTED));
         return;
     }
@@ -1697,10 +1705,12 @@ static void scsi_disk_emulate_unmap(SCSIDiskReq *r, uint8_t *inbuf)
     return;
 
 invalid_param_len:
+    block_acct_invalid(blk_get_stats(s->qdev.conf.blk), BLOCK_ACCT_UNMAP);
     scsi_check_condition(r, SENSE_CODE(INVALID_PARAM_LEN));
     return;
 
 invalid_field:
+    block_acct_invalid(blk_get_stats(s->qdev.conf.blk), BLOCK_ACCT_UNMAP);
     scsi_check_condition(r, SENSE_CODE(INVALID_FIELD));
 }
 
-- 
2.17.1

[Qemu-devel] [PATCH v9 8/9] file-posix: account discard operations

[Anton Nefedov]

This will help to identify how many of the user-issued discard operations
(accounted on a device level) have actually suceeded down on the host file
(even though the numbers will not be exactly the same if non-raw format
driver is used (e.g. qcow2 sending metadata discards)).

Note that these numbers will not include discards triggered by
write-zeroes + MAY_UNMAP calls.

Signed-off-by: Anton Nefedov <anton.nefedov@virtuozzo.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
 block/file-posix.c | 22 +++++++++++++++++++++-
 1 file changed, 21 insertions(+), 1 deletion(-)

diff --git a/block/file-posix.c b/block/file-posix.c
index 71f168ee2f..6548dda309 100644
--- a/block/file-posix.c
+++ b/block/file-posix.c
@@ -161,6 +161,11 @@ typedef struct BDRVRawState {
     bool needs_alignment;
     bool drop_cache;
     bool check_cache_dropped;
+    struct {
+        uint64_t discard_nb_ok;
+        uint64_t discard_nb_failed;
+        uint64_t discard_bytes_ok;
+    } stats;
 
     PRManager *pr_mgr;
 } BDRVRawState;
@@ -2728,11 +2733,22 @@ static void coroutine_fn raw_co_invalidate_cache(BlockDriverState *bs,
 #endif /* !__linux__ */
 }
 
+static void raw_account_discard(BDRVRawState *s, uint64_t nbytes, int ret)
+{
+    if (ret) {
+        s->stats.discard_nb_failed++;
+    } else {
+        s->stats.discard_nb_ok++;
+        s->stats.discard_bytes_ok += nbytes;
+    }
+}
+
 static coroutine_fn int
 raw_do_pdiscard(BlockDriverState *bs, int64_t offset, int bytes, bool blkdev)
 {
     BDRVRawState *s = bs->opaque;
     RawPosixAIOData acb;
+    int ret;
 
     acb = (RawPosixAIOData) {
         .bs             = bs,
@@ -2746,7 +2762,9 @@ raw_do_pdiscard(BlockDriverState *bs, int64_t offset, int bytes, bool blkdev)
         acb.aio_type |= QEMU_AIO_BLKDEV;
     }
 
-    return raw_thread_pool_submit(bs, handle_aiocb_discard, &acb);
+    ret = raw_thread_pool_submit(bs, handle_aiocb_discard, &acb);
+    raw_account_discard(s, bytes, ret);
+    return ret;
 }
 
 static coroutine_fn int
@@ -3369,10 +3387,12 @@ static int fd_open(BlockDriverState *bs)
 static coroutine_fn int
 hdev_co_pdiscard(BlockDriverState *bs, int64_t offset, int bytes)
 {
+    BDRVRawState *s = bs->opaque;
     int ret;
 
     ret = fd_open(bs);
     if (ret < 0) {
+        raw_account_discard(s, bytes, ret);
         return ret;
     }
     return raw_do_pdiscard(bs, offset, bytes, true);
-- 
2.17.1

[Qemu-devel] [PATCH v9 9/9] qapi: query-blockstat: add driver specific file-posix stats

[Anton Nefedov]

A block driver can provide a callback to report driver-specific
statistics.

file-posix driver now reports discard statistics

Signed-off-by: Anton Nefedov <anton.nefedov@virtuozzo.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Acked-by: Markus Armbruster <armbru@redhat.com>
---
 qapi/block-core.json      | 38 ++++++++++++++++++++++++++++++++++++++
 include/block/block.h     |  1 +
 include/block/block_int.h |  1 +
 block.c                   |  9 +++++++++
 block/file-posix.c        | 32 ++++++++++++++++++++++++++++++++
 block/qapi.c              |  5 +++++
 6 files changed, 86 insertions(+)

diff --git a/qapi/block-core.json b/qapi/block-core.json
index 7d3e05891c..859acea014 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -960,6 +960,41 @@
            '*wr_latency_histogram': 'BlockLatencyHistogramInfo',
            '*flush_latency_histogram': 'BlockLatencyHistogramInfo' } }
 
+##
+# @BlockStatsSpecificFile:
+#
+# File driver statistics
+#
+# @discard-nb-ok: The number of successful discard operations performed by
+#                 the driver.
+#
+# @discard-nb-failed: The number of failed discard operations performed by
+#                     the driver.
+#
+# @discard-bytes-ok: The number of bytes discarded by the driver.
+#
+# Since: 4.2
+##
+{ 'struct': 'BlockStatsSpecificFile',
+  'data': {
+      'discard-nb-ok': 'uint64',
+      'discard-nb-failed': 'uint64',
+      'discard-bytes-ok': 'uint64' } }
+
+##
+# @BlockStatsSpecific:
+#
+# Block driver specific statistics
+#
+# Since: 4.2
+##
+{ 'union': 'BlockStatsSpecific',
+  'base': { 'driver': 'BlockdevDriver' },
+  'discriminator': 'driver',
+  'data': {
+      'file': 'BlockStatsSpecificFile',
+      'host_device': 'BlockStatsSpecificFile' } }
+
 ##
 # @BlockStats:
 #
@@ -975,6 +1010,8 @@
 #
 # @stats:  A @BlockDeviceStats for the device.
 #
+# @driver-specific: Optional driver-specific stats. (Since 4.2)
+#
 # @parent: This describes the file block device if it has one.
 #          Contains recursively the statistics of the underlying
 #          protocol (e.g. the host file for a qcow2 image). If there is
@@ -988,6 +1025,7 @@
 { 'struct': 'BlockStats',
   'data': {'*device': 'str', '*qdev': 'str', '*node-name': 'str',
            'stats': 'BlockDeviceStats',
+           '*driver-specific': 'BlockStatsSpecific',
            '*parent': 'BlockStats',
            '*backing': 'BlockStats'} }
 
diff --git a/include/block/block.h b/include/block/block.h
index 124ad40809..6c5279da99 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -503,6 +503,7 @@ int bdrv_get_flags(BlockDriverState *bs);
 int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi);
 ImageInfoSpecific *bdrv_get_specific_info(BlockDriverState *bs,
                                           Error **errp);
+BlockStatsSpecific *bdrv_get_specific_stats(BlockDriverState *bs);
 void bdrv_round_to_clusters(BlockDriverState *bs,
                             int64_t offset, int64_t bytes,
                             int64_t *cluster_offset,
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 0422acdf1c..2b113eb3c7 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -366,6 +366,7 @@ struct BlockDriver {
     int (*bdrv_get_info)(BlockDriverState *bs, BlockDriverInfo *bdi);
     ImageInfoSpecific *(*bdrv_get_specific_info)(BlockDriverState *bs,
                                                  Error **errp);
+    BlockStatsSpecific *(*bdrv_get_specific_stats)(BlockDriverState *bs);
 
     int coroutine_fn (*bdrv_save_vmstate)(BlockDriverState *bs,
                                           QEMUIOVector *qiov,
diff --git a/block.c b/block.c
index 5944124845..5d3a5a6b95 100644
--- a/block.c
+++ b/block.c
@@ -5155,6 +5155,15 @@ ImageInfoSpecific *bdrv_get_specific_info(BlockDriverState *bs,
     return NULL;
 }
 
+BlockStatsSpecific *bdrv_get_specific_stats(BlockDriverState *bs)
+{
+    BlockDriver *drv = bs->drv;
+    if (!drv || !drv->bdrv_get_specific_stats) {
+        return NULL;
+    }
+    return drv->bdrv_get_specific_stats(bs);
+}
+
 void bdrv_debug_event(BlockDriverState *bs, BlkdebugEvent event)
 {
     if (!bs || !bs->drv || !bs->drv->bdrv_debug_event) {
diff --git a/block/file-posix.c b/block/file-posix.c
index 6548dda309..767feadc21 100644
--- a/block/file-posix.c
+++ b/block/file-posix.c
@@ -2821,6 +2821,36 @@ static int raw_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
     return 0;
 }
 
+static BlockStatsSpecificFile get_blockstats_specific_file(BlockDriverState *bs)
+{
+    BDRVRawState *s = bs->opaque;
+    return (BlockStatsSpecificFile) {
+        .discard_nb_ok = s->stats.discard_nb_ok,
+        .discard_nb_failed = s->stats.discard_nb_failed,
+        .discard_bytes_ok = s->stats.discard_bytes_ok,
+    };
+}
+
+static BlockStatsSpecific *raw_get_specific_stats(BlockDriverState *bs)
+{
+    BlockStatsSpecific *stats = g_new(BlockStatsSpecific, 1);
+
+    stats->driver = BLOCKDEV_DRIVER_FILE;
+    stats->u.file = get_blockstats_specific_file(bs);
+
+    return stats;
+}
+
+static BlockStatsSpecific *hdev_get_specific_stats(BlockDriverState *bs)
+{
+    BlockStatsSpecific *stats = g_new(BlockStatsSpecific, 1);
+
+    stats->driver = BLOCKDEV_DRIVER_HOST_DEVICE;
+    stats->u.host_device = get_blockstats_specific_file(bs);
+
+    return stats;
+}
+
 static QemuOptsList raw_create_opts = {
     .name = "raw-create-opts",
     .head = QTAILQ_HEAD_INITIALIZER(raw_create_opts.head),
@@ -3028,6 +3058,7 @@ BlockDriver bdrv_file = {
     .bdrv_get_info = raw_get_info,
     .bdrv_get_allocated_file_size
                         = raw_get_allocated_file_size,
+    .bdrv_get_specific_stats = raw_get_specific_stats,
     .bdrv_check_perm = raw_check_perm,
     .bdrv_set_perm   = raw_set_perm,
     .bdrv_abort_perm_update = raw_abort_perm_update,
@@ -3506,6 +3537,7 @@ static BlockDriver bdrv_host_device = {
     .bdrv_get_info = raw_get_info,
     .bdrv_get_allocated_file_size
                         = raw_get_allocated_file_size,
+    .bdrv_get_specific_stats = hdev_get_specific_stats,
     .bdrv_check_perm = raw_check_perm,
     .bdrv_set_perm   = raw_set_perm,
     .bdrv_abort_perm_update = raw_abort_perm_update,
diff --git a/block/qapi.c b/block/qapi.c
index 3356a1dc59..54b4810efd 100644
--- a/block/qapi.c
+++ b/block/qapi.c
@@ -543,6 +543,11 @@ static BlockStats *bdrv_query_bds_stats(BlockDriverState *bs,
 
     s->stats->wr_highest_offset = stat64_get(&bs->wr_highest_offset);
 
+    s->driver_specific = bdrv_get_specific_stats(bs);
+    if (s->driver_specific) {
+        s->has_driver_specific = true;
+    }
+
     if (bs->file) {
         s->has_parent = true;
         s->parent = bdrv_query_bds_stats(bs->file->bs, blk_level);
-- 
2.17.1

Re: [Qemu-devel] [PATCH v9 7/9] scsi: account unmap operations

[Vladimir Sementsov-Ogievskiy]

06.09.2019 19:01, Anton Nefedov wrote:
> Signed-off-by: Anton Nefedov <anton.nefedov@virtuozzo.com>

Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>

> ---
>   hw/scsi/scsi-disk.c | 12 +++++++++++-
>   1 file changed, 11 insertions(+), 1 deletion(-)
> 
> diff --git a/hw/scsi/scsi-disk.c b/hw/scsi/scsi-disk.c
> index a002fdabe8..68b1675fd9 100644
> --- a/hw/scsi/scsi-disk.c
> +++ b/hw/scsi/scsi-disk.c
> @@ -1617,10 +1617,16 @@ static void scsi_unmap_complete_noio(UnmapCBData *data, int ret)
>           r->sector_count = (ldl_be_p(&data->inbuf[8]) & 0xffffffffULL)
>               * (s->qdev.blocksize / BDRV_SECTOR_SIZE);
>           if (!check_lba_range(s, r->sector, r->sector_count)) {
> +            block_acct_invalid(blk_get_stats(s->qdev.conf.blk),
> +                               BLOCK_ACCT_UNMAP);
>               scsi_check_condition(r, SENSE_CODE(LBA_OUT_OF_RANGE));
>               goto done;
>           }
>   
> +        block_acct_start(blk_get_stats(s->qdev.conf.blk), &r->acct,
> +                         r->sector_count * BDRV_SECTOR_SIZE,
> +                         BLOCK_ACCT_UNMAP);
> +
>           r->req.aiocb = blk_aio_pdiscard(s->qdev.conf.blk,
>                                           r->sector * BDRV_SECTOR_SIZE,
>                                           r->sector_count * BDRV_SECTOR_SIZE,
> @@ -1647,10 +1653,11 @@ static void scsi_unmap_complete(void *opaque, int ret)
>       r->req.aiocb = NULL;
>   
>       aio_context_acquire(blk_get_aio_context(s->qdev.conf.blk));
> -    if (scsi_disk_req_check_error(r, ret, false)) {
> +    if (scsi_disk_req_check_error(r, ret, true)) {
>           scsi_req_unref(&r->req);
>           g_free(data);
>       } else {
> +        block_acct_done(blk_get_stats(s->qdev.conf.blk), &r->acct);
>           scsi_unmap_complete_noio(data, ret);
>       }
>       aio_context_release(blk_get_aio_context(s->qdev.conf.blk));
> @@ -1682,6 +1689,7 @@ static void scsi_disk_emulate_unmap(SCSIDiskReq *r, uint8_t *inbuf)
>       }
>   
>       if (blk_is_read_only(s->qdev.conf.blk)) {
> +        block_acct_invalid(blk_get_stats(s->qdev.conf.blk), BLOCK_ACCT_UNMAP);
>           scsi_check_condition(r, SENSE_CODE(WRITE_PROTECTED));
>           return;
>       }
> @@ -1697,10 +1705,12 @@ static void scsi_disk_emulate_unmap(SCSIDiskReq *r, uint8_t *inbuf)
>       return;
>   
>   invalid_param_len:
> +    block_acct_invalid(blk_get_stats(s->qdev.conf.blk), BLOCK_ACCT_UNMAP);
>       scsi_check_condition(r, SENSE_CODE(INVALID_PARAM_LEN));
>       return;
>   
>   invalid_field:
> +    block_acct_invalid(blk_get_stats(s->qdev.conf.blk), BLOCK_ACCT_UNMAP);
>       scsi_check_condition(r, SENSE_CODE(INVALID_FIELD));
>   }
>   
> 


-- 
Best regards,
Vladimir

Re: [Qemu-devel] [PATCH v9 3/9] block: add empty account cookie type

[Alberto Garcia]

On Fri 06 Sep 2019 06:01:14 PM CEST, Anton Nefedov wrote:
> This adds some protection from accounting uninitialized cookie.
> That is, block_acct_failed/done without previous block_acct_start;
> in that case, cookie probably holds values from previous operation.
>
> (Note: it might also be uninitialized holding garbage value and there
> is still "< BLOCK_MAX_IOTYPE" assertion for that.  So
> block_acct_failed/done without previous block_acct_start should be
> used with caution.)
>
> Currently this is particularly useful in ide code where it's hard to
> keep track whether the request started accounting or not. For example,
> trim requests do the accounting separately.

Sorry if I'm understanding it wrong, but it sounds like you know that
there's a bug in the ide code (where you call block_acct_done() without
having it initialized it first), and the purpose of the this patch is to
hide the bug ?

Berto

Re: [Qemu-devel] [PATCH v9 3/9] block: add empty account cookie type

[Anton Nefedov]

On 9/9/2019 5:54 PM, Alberto Garcia wrote:
> On Fri 06 Sep 2019 06:01:14 PM CEST, Anton Nefedov wrote:
>> This adds some protection from accounting uninitialized cookie.
>> That is, block_acct_failed/done without previous block_acct_start;
>> in that case, cookie probably holds values from previous operation.
>>
>> (Note: it might also be uninitialized holding garbage value and there
>> is still "< BLOCK_MAX_IOTYPE" assertion for that.  So
>> block_acct_failed/done without previous block_acct_start should be
>> used with caution.)
>>
>> Currently this is particularly useful in ide code where it's hard to
>> keep track whether the request started accounting or not. For example,
>> trim requests do the accounting separately.
> 
> Sorry if I'm understanding it wrong, but it sounds like you know that
> there's a bug in the ide code (where you call block_acct_done() without
> having it initialized it first), and the purpose of the this patch is to
> hide the bug ?
> 

hi,

not really; in the existing code, I can't see block_acct_done() without
block_acct_start(), but there might be double-accounting though;
e.g. ide_atapi_cmd_read_dma_cb(): it can account the same operation
twice like
   ide_handle_rw_error();
   goto eot;
   block_acct_failed();

The patch should solve it.

The commit message is misleading, sorry. I'll change to:

 > Each block_acct_done/failed call is designed to correspond to a
 > previous block_acct_start call, which initializes the stats cookie.
 > However sometimes it is not the case, e.g. some error paths might
 > report the same cookie twice because it is hard to accurately track if
 > the cookie was reported yet or not.

 > This patch cleans the cookie after report.
 > (Note: block_acct_failed/done without a previous block_acct_start at
 > all should be avoided. Uninitialized cookie might hold a garbage value
 > and there is still "< BLOCK_MAX_IOTYPE" assertion for that)

 > It will be particularly useful in ide code where it's hard to
 > keep track whether the request done its accounting or not: in the
 > following patch of the series, trim requests will do the accounting
 > separately.

/Anton

Re: [PATCH v9 0/9] discard blockstats

[Max Reitz]

[-- Attachment #1.1: Type: text/plain, Size: 526 bytes --]

On 06.09.19 18:01, Anton Nefedov wrote:
> v9:
>  - fixed patch 5 so the fields are actually numbered in sectors not blocks
>  - fixed patch 7 accordingly
>  - patch 8: make stat fields unsigned
>  - qapi patches: "since 4.1" -> "since 4.2"
> 
> v8: https://lists.gnu.org/archive/html/qemu-devel/2019-05/msg03709.html

For the record: Looks OK to me, but I suppose you still wanted to change
patch 3’s commit message.

(I still don’t like patch 9 very much, but that won’t stop me from
taking it.)

Max


[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 488 bytes --]

Re: [PATCH v9 0/9] discard blockstats

[Anton Nefedov]

On 23/9/2019 1:59 PM, Max Reitz wrote:
> On 06.09.19 18:01, Anton Nefedov wrote:
>> v9:
>>   - fixed patch 5 so the fields are actually numbered in sectors not blocks
>>   - fixed patch 7 accordingly
>>   - patch 8: make stat fields unsigned
>>   - qapi patches: "since 4.1" -> "since 4.2"
>>
>> v8: https://lists.gnu.org/archive/html/qemu-devel/2019-05/msg03709.html
> 
> For the record: Looks OK to me, but I suppose you still wanted to change
> patch 3’s commit message.
> 
> (I still don’t like patch 9 very much, but that won’t stop me from
> taking it.)
> 

hi,
I've now resent the series with the updated patch 3 commit message

https://lists.nongnu.org/archive/html/qemu-devel/2019-09/msg05050.html

thanks,