* See the COPYING file in the top-level directory.
*/
+#include "qemu/osdep.h"
+#include "qapi/error.h"
+#include "qapi/qmp/qdict.h"
+#include "qapi/qmp/qstring.h"
#include "block/block_int.h"
+#define NULL_OPT_LATENCY "latency-ns"
+#define NULL_OPT_ZEROES "read-zeroes"
+
typedef struct {
int64_t length;
+ int64_t latency_ns;
+ bool read_zeroes;
} BDRVNullState;
static QemuOptsList runtime_opts = {
.type = QEMU_OPT_SIZE,
.help = "size of the null block",
},
+ {
+ .name = NULL_OPT_LATENCY,
+ .type = QEMU_OPT_NUMBER,
+ .help = "nanoseconds (approximated) to wait "
+ "before completing request",
+ },
+ {
+ .name = NULL_OPT_ZEROES,
+ .type = QEMU_OPT_BOOL,
+ .help = "return zeroes when read",
+ },
{ /* end of list */ }
},
};
{
QemuOpts *opts;
BDRVNullState *s = bs->opaque;
+ int ret = 0;
opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
qemu_opts_absorb_qdict(opts, options, &error_abort);
s->length =
qemu_opt_get_size(opts, BLOCK_OPT_SIZE, 1 << 30);
+ s->latency_ns =
+ qemu_opt_get_number(opts, NULL_OPT_LATENCY, 0);
+ if (s->latency_ns < 0) {
+ error_setg(errp, "latency-ns is invalid");
+ ret = -EINVAL;
+ }
+ s->read_zeroes = qemu_opt_get_bool(opts, NULL_OPT_ZEROES, false);
qemu_opts_del(opts);
- return 0;
+ return ret;
}
static void null_close(BlockDriverState *bs)
return s->length;
}
+static coroutine_fn int null_co_common(BlockDriverState *bs)
+{
+ BDRVNullState *s = bs->opaque;
+
+ if (s->latency_ns) {
+ co_aio_sleep_ns(bdrv_get_aio_context(bs), QEMU_CLOCK_REALTIME,
+ s->latency_ns);
+ }
+ return 0;
+}
+
static coroutine_fn int null_co_readv(BlockDriverState *bs,
int64_t sector_num, int nb_sectors,
QEMUIOVector *qiov)
{
- return 0;
+ BDRVNullState *s = bs->opaque;
+
+ if (s->read_zeroes) {
+ qemu_iovec_memset(qiov, 0, 0, nb_sectors * BDRV_SECTOR_SIZE);
+ }
+
+ return null_co_common(bs);
}
static coroutine_fn int null_co_writev(BlockDriverState *bs,
int64_t sector_num, int nb_sectors,
QEMUIOVector *qiov)
{
- return 0;
+ return null_co_common(bs);
}
static coroutine_fn int null_co_flush(BlockDriverState *bs)
{
- return 0;
+ return null_co_common(bs);
}
typedef struct {
BlockAIOCB common;
- QEMUBH *bh;
+ QEMUTimer timer;
} NullAIOCB;
static const AIOCBInfo null_aiocb_info = {
{
NullAIOCB *acb = opaque;
acb->common.cb(acb->common.opaque, 0);
- qemu_bh_delete(acb->bh);
+ qemu_aio_unref(acb);
+}
+
+static void null_timer_cb(void *opaque)
+{
+ NullAIOCB *acb = opaque;
+ acb->common.cb(acb->common.opaque, 0);
+ timer_deinit(&acb->timer);
qemu_aio_unref(acb);
}
static inline BlockAIOCB *null_aio_common(BlockDriverState *bs,
- BlockDriverCompletionFunc *cb,
+ BlockCompletionFunc *cb,
void *opaque)
{
NullAIOCB *acb;
+ BDRVNullState *s = bs->opaque;
acb = qemu_aio_get(&null_aiocb_info, bs, cb, opaque);
- acb->bh = aio_bh_new(bdrv_get_aio_context(bs), null_bh_cb, acb);
- qemu_bh_schedule(acb->bh);
+ /* Only emulate latency after vcpu is running. */
+ if (s->latency_ns) {
+ aio_timer_init(bdrv_get_aio_context(bs), &acb->timer,
+ QEMU_CLOCK_REALTIME, SCALE_NS,
+ null_timer_cb, acb);
+ timer_mod_ns(&acb->timer,
+ qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + s->latency_ns);
+ } else {
+ aio_bh_schedule_oneshot(bdrv_get_aio_context(bs), null_bh_cb, acb);
+ }
return &acb->common;
}
static BlockAIOCB *null_aio_readv(BlockDriverState *bs,
int64_t sector_num, QEMUIOVector *qiov,
int nb_sectors,
- BlockDriverCompletionFunc *cb,
+ BlockCompletionFunc *cb,
void *opaque)
{
+ BDRVNullState *s = bs->opaque;
+
+ if (s->read_zeroes) {
+ qemu_iovec_memset(qiov, 0, 0, nb_sectors * BDRV_SECTOR_SIZE);
+ }
+
return null_aio_common(bs, cb, opaque);
}
static BlockAIOCB *null_aio_writev(BlockDriverState *bs,
int64_t sector_num, QEMUIOVector *qiov,
int nb_sectors,
- BlockDriverCompletionFunc *cb,
+ BlockCompletionFunc *cb,
void *opaque)
{
return null_aio_common(bs, cb, opaque);
}
static BlockAIOCB *null_aio_flush(BlockDriverState *bs,
- BlockDriverCompletionFunc *cb,
+ BlockCompletionFunc *cb,
void *opaque)
{
return null_aio_common(bs, cb, opaque);
}
+static int null_reopen_prepare(BDRVReopenState *reopen_state,
+ BlockReopenQueue *queue, Error **errp)
+{
+ return 0;
+}
+
+static int64_t coroutine_fn null_co_get_block_status(BlockDriverState *bs,
+ int64_t sector_num,
+ int nb_sectors, int *pnum,
+ BlockDriverState **file)
+{
+ BDRVNullState *s = bs->opaque;
+ off_t start = sector_num * BDRV_SECTOR_SIZE;
+
+ *pnum = nb_sectors;
+ *file = bs;
+
+ if (s->read_zeroes) {
+ return BDRV_BLOCK_OFFSET_VALID | start | BDRV_BLOCK_ZERO;
+ } else {
+ return BDRV_BLOCK_OFFSET_VALID | start;
+ }
+}
+
+static void null_refresh_filename(BlockDriverState *bs, QDict *opts)
+{
+ QINCREF(opts);
+ qdict_del(opts, "filename");
+
+ if (!qdict_size(opts)) {
+ snprintf(bs->exact_filename, sizeof(bs->exact_filename), "%s://",
+ bs->drv->format_name);
+ }
+
+ qdict_put_str(opts, "driver", bs->drv->format_name);
+ bs->full_open_options = opts;
+}
+
static BlockDriver bdrv_null_co = {
.format_name = "null-co",
.protocol_name = "null-co",
.bdrv_co_readv = null_co_readv,
.bdrv_co_writev = null_co_writev,
.bdrv_co_flush_to_disk = null_co_flush,
+ .bdrv_reopen_prepare = null_reopen_prepare,
+
+ .bdrv_co_get_block_status = null_co_get_block_status,
+
+ .bdrv_refresh_filename = null_refresh_filename,
};
static BlockDriver bdrv_null_aio = {
.bdrv_aio_readv = null_aio_readv,
.bdrv_aio_writev = null_aio_writev,
.bdrv_aio_flush = null_aio_flush,
+ .bdrv_reopen_prepare = null_reopen_prepare,
+
+ .bdrv_co_get_block_status = null_co_get_block_status,
+
+ .bdrv_refresh_filename = null_refresh_filename,
};
static void bdrv_null_init(void)
projects / mirror_qemu.git / blobdiff