mirror of
https://github.com/xemu-project/xemu.git
synced 2024-12-05 18:27:42 +00:00
46f5ac205a
We now have macros in place to make it less verbose to add a scalar to QDict and QList, so use them. Patch created mechanically via: spatch --sp-file scripts/coccinelle/qobject.cocci \ --macro-file scripts/cocci-macro-file.h --dir . --in-place then touched up manually to fix a couple of '?:' back to original spacing, as well as avoiding a long line in monitor.c. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20170427215821.19397-7-eblake@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
284 lines
7.7 KiB
C
284 lines
7.7 KiB
C
/*
|
|
* Null block driver
|
|
*
|
|
* Authors:
|
|
* Fam Zheng <famz@redhat.com>
|
|
*
|
|
* Copyright (C) 2014 Red Hat, Inc.
|
|
*
|
|
* 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 "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 = {
|
|
.name = "null",
|
|
.head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
|
|
.desc = {
|
|
{
|
|
.name = "filename",
|
|
.type = QEMU_OPT_STRING,
|
|
.help = "",
|
|
},
|
|
{
|
|
.name = BLOCK_OPT_SIZE,
|
|
.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 */ }
|
|
},
|
|
};
|
|
|
|
static int null_file_open(BlockDriverState *bs, QDict *options, int flags,
|
|
Error **errp)
|
|
{
|
|
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 ret;
|
|
}
|
|
|
|
static void null_close(BlockDriverState *bs)
|
|
{
|
|
}
|
|
|
|
static int64_t null_getlength(BlockDriverState *bs)
|
|
{
|
|
BDRVNullState *s = bs->opaque;
|
|
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)
|
|
{
|
|
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 null_co_common(bs);
|
|
}
|
|
|
|
static coroutine_fn int null_co_flush(BlockDriverState *bs)
|
|
{
|
|
return null_co_common(bs);
|
|
}
|
|
|
|
typedef struct {
|
|
BlockAIOCB common;
|
|
QEMUTimer timer;
|
|
} NullAIOCB;
|
|
|
|
static const AIOCBInfo null_aiocb_info = {
|
|
.aiocb_size = sizeof(NullAIOCB),
|
|
};
|
|
|
|
static void null_bh_cb(void *opaque)
|
|
{
|
|
NullAIOCB *acb = opaque;
|
|
acb->common.cb(acb->common.opaque, 0);
|
|
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,
|
|
BlockCompletionFunc *cb,
|
|
void *opaque)
|
|
{
|
|
NullAIOCB *acb;
|
|
BDRVNullState *s = bs->opaque;
|
|
|
|
acb = qemu_aio_get(&null_aiocb_info, bs, cb, opaque);
|
|
/* 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,
|
|
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,
|
|
BlockCompletionFunc *cb,
|
|
void *opaque)
|
|
{
|
|
return null_aio_common(bs, cb, opaque);
|
|
}
|
|
|
|
static BlockAIOCB *null_aio_flush(BlockDriverState *bs,
|
|
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",
|
|
.instance_size = sizeof(BDRVNullState),
|
|
|
|
.bdrv_file_open = null_file_open,
|
|
.bdrv_close = null_close,
|
|
.bdrv_getlength = null_getlength,
|
|
|
|
.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 = {
|
|
.format_name = "null-aio",
|
|
.protocol_name = "null-aio",
|
|
.instance_size = sizeof(BDRVNullState),
|
|
|
|
.bdrv_file_open = null_file_open,
|
|
.bdrv_close = null_close,
|
|
.bdrv_getlength = null_getlength,
|
|
|
|
.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)
|
|
{
|
|
bdrv_register(&bdrv_null_co);
|
|
bdrv_register(&bdrv_null_aio);
|
|
}
|
|
|
|
block_init(bdrv_null_init);
|