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[PATCH v7 03/14] qcow2: introduce icount field for snapshots
From: |
Pavel Dovgalyuk |
Subject: |
[PATCH v7 03/14] qcow2: introduce icount field for snapshots |
Date: |
Sat, 03 Oct 2020 20:13:02 +0300 |
User-agent: |
StGit/0.17.1-dirty |
This patch introduces the icount field for saving within the snapshot.
It is required for navigation between the snapshots in record/replay mode.
Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgalyuk@ispras.ru>
Acked-by: Kevin Wolf <kwolf@redhat.com>
--
v7 changes:
- also fix the test which checks qcow2 snapshot extra data
---
block/qcow2-snapshot.c | 7 ++++++
block/qcow2.h | 3 +++
docs/interop/qcow2.txt | 5 ++++
tests/qemu-iotests/261 | 15 ++++++++-----
tests/qemu-iotests/261.out | 51 +++++++++++++++++++++++++++++---------------
5 files changed, 58 insertions(+), 23 deletions(-)
diff --git a/block/qcow2-snapshot.c b/block/qcow2-snapshot.c
index 9b68690f56..d68b25e0c5 100644
--- a/block/qcow2-snapshot.c
+++ b/block/qcow2-snapshot.c
@@ -164,6 +164,12 @@ static int qcow2_do_read_snapshots(BlockDriverState *bs,
bool repair,
sn->disk_size = bs->total_sectors * BDRV_SECTOR_SIZE;
}
+ if (sn->extra_data_size >= endof(QCowSnapshotExtraData, icount)) {
+ sn->icount = be64_to_cpu(extra.icount);
+ } else {
+ sn->icount = -1ULL;
+ }
+
if (sn->extra_data_size > sizeof(extra)) {
uint64_t extra_data_end;
size_t unknown_extra_data_size;
@@ -333,6 +339,7 @@ int qcow2_write_snapshots(BlockDriverState *bs)
memset(&extra, 0, sizeof(extra));
extra.vm_state_size_large = cpu_to_be64(sn->vm_state_size);
extra.disk_size = cpu_to_be64(sn->disk_size);
+ extra.icount = cpu_to_be64(sn->icount);
id_str_size = strlen(sn->id_str);
name_size = strlen(sn->name);
diff --git a/block/qcow2.h b/block/qcow2.h
index b71e444fca..125ea9679b 100644
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -206,6 +206,7 @@ typedef struct QEMU_PACKED QCowSnapshotHeader {
typedef struct QEMU_PACKED QCowSnapshotExtraData {
uint64_t vm_state_size_large;
uint64_t disk_size;
+ uint64_t icount;
} QCowSnapshotExtraData;
@@ -219,6 +220,8 @@ typedef struct QCowSnapshot {
uint32_t date_sec;
uint32_t date_nsec;
uint64_t vm_clock_nsec;
+ /* icount value for the moment when snapshot was taken */
+ uint64_t icount;
/* Size of all extra data, including QCowSnapshotExtraData if available */
uint32_t extra_data_size;
/* Data beyond QCowSnapshotExtraData, if any */
diff --git a/docs/interop/qcow2.txt b/docs/interop/qcow2.txt
index 7da0d81df8..0463f761ef 100644
--- a/docs/interop/qcow2.txt
+++ b/docs/interop/qcow2.txt
@@ -707,6 +707,11 @@ Snapshot table entry:
Byte 48 - 55: Virtual disk size of the snapshot in bytes
+ Byte 56 - 63: icount value which corresponds to
+ the record/replay instruction count
+ when the snapshot was taken. Set to -1
+ if icount was disabled
+
Version 3 images must include extra data at least up to
byte 55.
diff --git a/tests/qemu-iotests/261 b/tests/qemu-iotests/261
index ddcb04f285..848ffa760d 100755
--- a/tests/qemu-iotests/261
+++ b/tests/qemu-iotests/261
@@ -91,7 +91,10 @@ print_snapshot_table()
if [ $extra_len -ge 16 ]; then
echo " Disk size: $(peek_file_be "$1" $((extra_ofs + 8)) 8)"
fi
- if [ $extra_len -gt 16 ]; then
+ if [ $extra_len -ge 24 ]; then
+ echo " Icount: $(peek_file_be "$1" $((extra_ofs + 16)) 8)"
+ fi
+ if [ $extra_len -gt 24 ]; then
echo ' Unknown extra data:' \
"$(peek_file_raw "$1" $((extra_ofs + 16)) $((extra_len - 16)) \
| tr -d '\0')"
@@ -198,12 +201,12 @@ truncate -s 0 "$TEST_DIR/sn0-extra"
truncate -s $(($(snapshot_table_entry_size "$TEST_DIR/sn0-pre") - 40)) \
"$TEST_DIR/sn0-post"
-# Set sn1's extra data size to 42
-poke_file "$TEST_DIR/sn1-pre" 36 '\x00\x00\x00\x2a'
-truncate -s 42 "$TEST_DIR/sn1-extra"
-poke_file "$TEST_DIR/sn1-extra" 16 'very important data'
+# Set sn1's extra data size to 50
+poke_file "$TEST_DIR/sn1-pre" 36 '\x00\x00\x00\x32'
+truncate -s 50 "$TEST_DIR/sn1-extra"
+poke_file "$TEST_DIR/sn1-extra" 24 'very important data'
# Grow sn1-post to pad
-truncate -s $(($(snapshot_table_entry_size "$TEST_DIR/sn1-pre") - 82)) \
+truncate -s $(($(snapshot_table_entry_size "$TEST_DIR/sn1-pre") - 90)) \
"$TEST_DIR/sn1-post"
# Set sn2's extra data size to 8
diff --git a/tests/qemu-iotests/261.out b/tests/qemu-iotests/261.out
index 2600354566..612433ae40 100644
--- a/tests/qemu-iotests/261.out
+++ b/tests/qemu-iotests/261.out
@@ -12,9 +12,10 @@ Snapshots in TEST_DIR/t.IMGFMT.v2.orig:
[1]
ID: 2
Name: sn1
- Extra data size: 42
+ Extra data size: 50
VM state size: 0
Disk size: 67108864
+ Icount: 0
Unknown extra data: very important data
[2]
ID: 3
@@ -29,22 +30,25 @@ Snapshots in TEST_DIR/t.IMGFMT.v3.orig:
[0]
ID: 1
Name: sn0
- Extra data size: 16
+ Extra data size: 24
VM state size: 0
Disk size: 67108864
+ Icount: 18446744073709551615
[1]
ID: 2
Name: sn1
- Extra data size: 42
+ Extra data size: 50
VM state size: 0
Disk size: 67108864
+ Icount: 0
Unknown extra data: very important data
[2]
ID: 3
Name: sn2
- Extra data size: 16
+ Extra data size: 24
VM state size: 0
Disk size: 67108864
+ Icount: 18446744073709551615
=== Repair botched v3 ===
@@ -61,22 +65,25 @@ Snapshots in TEST_DIR/t.IMGFMT:
[0]
ID: 1
Name: sn0
- Extra data size: 16
+ Extra data size: 24
VM state size: 0
Disk size: 67108864
+ Icount: 18446744073709551615
[1]
ID: 2
Name: sn1
- Extra data size: 42
+ Extra data size: 50
VM state size: 0
Disk size: 67108864
+ Icount: 0
Unknown extra data: very important data
[2]
ID: 3
Name: sn2
- Extra data size: 16
+ Extra data size: 24
VM state size: 0
Disk size: 67108864
+ Icount: 18446744073709551615
=== Add new snapshot ===
@@ -85,28 +92,32 @@ Snapshots in TEST_DIR/t.IMGFMT:
[0]
ID: 1
Name: sn0
- Extra data size: 16
+ Extra data size: 24
VM state size: 0
Disk size: 67108864
+ Icount: 18446744073709551615
[1]
ID: 2
Name: sn1
- Extra data size: 42
+ Extra data size: 50
VM state size: 0
Disk size: 67108864
+ Icount: 0
Unknown extra data: very important data
[2]
ID: 3
Name: sn2
- Extra data size: 16
+ Extra data size: 24
VM state size: 0
Disk size: 67108864
+ Icount: 18446744073709551615
[3]
ID: 4
Name: sn3
- Extra data size: 16
+ Extra data size: 24
VM state size: 0
Disk size: 67108864
+ Icount: 0
=== Remove different snapshots ===
@@ -116,16 +127,18 @@ Snapshots in TEST_DIR/t.IMGFMT:
[0]
ID: 2
Name: sn1
- Extra data size: 42
+ Extra data size: 50
VM state size: 0
Disk size: 67108864
+ Icount: 0
Unknown extra data: very important data
[1]
ID: 3
Name: sn2
- Extra data size: 16
+ Extra data size: 24
VM state size: 0
Disk size: 67108864
+ Icount: 18446744073709551615
--- sn1 ---
No errors were found on the image.
@@ -133,15 +146,17 @@ Snapshots in TEST_DIR/t.IMGFMT:
[0]
ID: 1
Name: sn0
- Extra data size: 16
+ Extra data size: 24
VM state size: 0
Disk size: 67108864
+ Icount: 18446744073709551615
[1]
ID: 3
Name: sn2
- Extra data size: 16
+ Extra data size: 24
VM state size: 0
Disk size: 67108864
+ Icount: 18446744073709551615
--- sn2 ---
No errors were found on the image.
@@ -149,15 +164,17 @@ Snapshots in TEST_DIR/t.IMGFMT:
[0]
ID: 1
Name: sn0
- Extra data size: 16
+ Extra data size: 24
VM state size: 0
Disk size: 67108864
+ Icount: 18446744073709551615
[1]
ID: 2
Name: sn1
- Extra data size: 42
+ Extra data size: 50
VM state size: 0
Disk size: 67108864
+ Icount: 0
Unknown extra data: very important data
=== Reject too much unknown extra data ===
- [PATCH v7 00/14] Reverse debugging, Pavel Dovgalyuk, 2020/10/03
- [PATCH v7 01/14] replay: don't record interrupt poll, Pavel Dovgalyuk, 2020/10/03
- [PATCH v7 02/14] replay: provide an accessor for rr filename, Pavel Dovgalyuk, 2020/10/03
- [PATCH v7 03/14] qcow2: introduce icount field for snapshots,
Pavel Dovgalyuk <=
- [PATCH v7 04/14] migration: introduce icount field for snapshots, Pavel Dovgalyuk, 2020/10/03
- [PATCH v7 05/14] qapi: introduce replay.json for record/replay-related stuff, Pavel Dovgalyuk, 2020/10/03
- [PATCH v7 06/14] replay: introduce info hmp/qmp command, Pavel Dovgalyuk, 2020/10/03
- [PATCH v7 07/14] replay: introduce breakpoint at the specified step, Pavel Dovgalyuk, 2020/10/03
- [PATCH v7 08/14] replay: implement replay-seek command, Pavel Dovgalyuk, 2020/10/03
- [PATCH v7 09/14] replay: flush rr queue before loading the vmstate, Pavel Dovgalyuk, 2020/10/03
- [PATCH v7 10/14] gdbstub: add reverse step support in replay mode, Pavel Dovgalyuk, 2020/10/03
- [PATCH v7 11/14] gdbstub: add reverse continue support in replay mode, Pavel Dovgalyuk, 2020/10/03
- [PATCH v7 12/14] replay: describe reverse debugging in docs/replay.txt, Pavel Dovgalyuk, 2020/10/03
- [PATCH v7 13/14] replay: create temporary snapshot at debugger connection, Pavel Dovgalyuk, 2020/10/03