diff options
Diffstat (limited to 'block/blkreplay.c')
| -rwxr-xr-x | block/blkreplay.c | 160 |
1 files changed, 160 insertions, 0 deletions
diff --git a/block/blkreplay.c b/block/blkreplay.c new file mode 100755 index 0000000000..42f1813af1 --- /dev/null +++ b/block/blkreplay.c @@ -0,0 +1,160 @@ +/* + * Block protocol for record/replay + * + * Copyright (c) 2010-2016 Institute for System Programming + * of the Russian Academy of Sciences. + * + * This work is licensed under the terms of the GNU GPL, version 2 or later. + * See the COPYING file in the top-level directory. + * + */ + +#include "qemu/osdep.h" +#include "qemu-common.h" +#include "block/block_int.h" +#include "sysemu/replay.h" +#include "qapi/error.h" + +typedef struct Request { + Coroutine *co; + QEMUBH *bh; +} Request; + +/* Next request id. + This counter is global, because requests from different + block devices should not get overlapping ids. */ +static uint64_t request_id; + +static int blkreplay_open(BlockDriverState *bs, QDict *options, int flags, + Error **errp) +{ + Error *local_err = NULL; + int ret; + + /* Open the image file */ + bs->file = bdrv_open_child(NULL, options, "image", + bs, &child_file, false, &local_err); + if (local_err) { + ret = -EINVAL; + error_propagate(errp, local_err); + goto fail; + } + + ret = 0; +fail: + if (ret < 0) { + bdrv_unref_child(bs, bs->file); + } + return ret; +} + +static void blkreplay_close(BlockDriverState *bs) +{ +} + +static int64_t blkreplay_getlength(BlockDriverState *bs) +{ + return bdrv_getlength(bs->file->bs); +} + +/* This bh is used for synchronization of return from coroutines. + It continues yielded coroutine which then finishes its execution. + BH is called adjusted to some replay checkpoint, therefore + record and replay will always finish coroutines deterministically. +*/ +static void blkreplay_bh_cb(void *opaque) +{ + Request *req = opaque; + qemu_coroutine_enter(req->co, NULL); + qemu_bh_delete(req->bh); + g_free(req); +} + +static void block_request_create(uint64_t reqid, BlockDriverState *bs, + Coroutine *co) +{ + Request *req = g_new(Request, 1); + *req = (Request) { + .co = co, + .bh = aio_bh_new(bdrv_get_aio_context(bs), blkreplay_bh_cb, req), + }; + replay_block_event(req->bh, reqid); +} + +static int coroutine_fn blkreplay_co_readv(BlockDriverState *bs, + int64_t sector_num, int nb_sectors, QEMUIOVector *qiov) +{ + uint64_t reqid = request_id++; + int ret = bdrv_co_readv(bs->file->bs, sector_num, nb_sectors, qiov); + block_request_create(reqid, bs, qemu_coroutine_self()); + qemu_coroutine_yield(); + + return ret; +} + +static int coroutine_fn blkreplay_co_writev(BlockDriverState *bs, + int64_t sector_num, int nb_sectors, QEMUIOVector *qiov) +{ + uint64_t reqid = request_id++; + int ret = bdrv_co_writev(bs->file->bs, sector_num, nb_sectors, qiov); + block_request_create(reqid, bs, qemu_coroutine_self()); + qemu_coroutine_yield(); + + return ret; +} + +static int coroutine_fn blkreplay_co_write_zeroes(BlockDriverState *bs, + int64_t sector_num, int nb_sectors, BdrvRequestFlags flags) +{ + uint64_t reqid = request_id++; + int ret = bdrv_co_write_zeroes(bs->file->bs, sector_num, nb_sectors, flags); + block_request_create(reqid, bs, qemu_coroutine_self()); + qemu_coroutine_yield(); + + return ret; +} + +static int coroutine_fn blkreplay_co_discard(BlockDriverState *bs, + int64_t sector_num, int nb_sectors) +{ + uint64_t reqid = request_id++; + int ret = bdrv_co_discard(bs->file->bs, sector_num, nb_sectors); + block_request_create(reqid, bs, qemu_coroutine_self()); + qemu_coroutine_yield(); + + return ret; +} + +static int coroutine_fn blkreplay_co_flush(BlockDriverState *bs) +{ + uint64_t reqid = request_id++; + int ret = bdrv_co_flush(bs->file->bs); + block_request_create(reqid, bs, qemu_coroutine_self()); + qemu_coroutine_yield(); + + return ret; +} + +static BlockDriver bdrv_blkreplay = { + .format_name = "blkreplay", + .protocol_name = "blkreplay", + .instance_size = 0, + + .bdrv_file_open = blkreplay_open, + .bdrv_close = blkreplay_close, + .bdrv_getlength = blkreplay_getlength, + + .bdrv_co_readv = blkreplay_co_readv, + .bdrv_co_writev = blkreplay_co_writev, + + .bdrv_co_write_zeroes = blkreplay_co_write_zeroes, + .bdrv_co_discard = blkreplay_co_discard, + .bdrv_co_flush = blkreplay_co_flush, +}; + +static void bdrv_blkreplay_init(void) +{ + bdrv_register(&bdrv_blkreplay); +} + +block_init(bdrv_blkreplay_init); |