From bbacffc5f7a1a9318afe62f4eb20b3584acb6aa1 Mon Sep 17 00:00:00 2001 From: Pavel Dovgalyuk Date: Sat, 3 Oct 2020 20:13:02 +0300 Subject: [PATCH] qcow2: introduce icount field for snapshots 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 Acked-by: Kevin Wolf -- v7 changes: - also fix the test which checks qcow2 snapshot extra data Message-Id: <160174518284.12451.2301137308458777398.stgit@pasha-ThinkPad-X280> Signed-off-by: Paolo Bonzini --- 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 ===