1 files changed, 160 insertions, 0 deletions

diff --git a/qemu/block/blkreplay.c b/qemu/block/blkreplay.c
new file mode 100755
index 000000000..42f1813af
--- /dev/null
+++ b/qemu/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);