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Merge remote-tracking branch 'remotes/stefanha/tags/block-pull-request' into staging

Pull request

# gpg: Signature made Thu 30 Jan 2020 21:31:02 GMT
# gpg:                using RSA key 8695A8BFD3F97CDAAC35775A9CA4ABB381AB73C8
# gpg: Good signature from "Stefan Hajnoczi <stefanha@redhat.com>" [full]
# gpg:                 aka "Stefan Hajnoczi <stefanha@gmail.com>" [full]
# Primary key fingerprint: 8695 A8BF D3F9 7CDA AC35  775A 9CA4 ABB3 81AB 73C8

* remotes/stefanha/tags/block-pull-request:
  tests/qemu-iotests: use AIOMODE with various tests
  tests/qemu-iotests: enable testing with aio options
  qemu-nbd: adds option for aio engines
  qemu-img: adds option to use aio engine for benchmarking
  qemu-io: adds option to use aio engine
  block/io_uring: adds userspace completion polling
  block: add trace events for io_uring
  block/file-posix.c: extend to use io_uring
  blockdev: adds bdrv_parse_aio to use io_uring
  util/async: add aio interfaces for io_uring
  stubs: add stubs for io_uring interface
  block/io_uring: implements interfaces for io_uring
  block/block: add BDRV flag for io_uring
  qapi/block-core: add option for io_uring
  configure: permit use of io_uring
  block/io: take bs->reqs_lock in bdrv_mark_request_serialising
  block/io: wait for serialising requests when a request becomes serialising
  block: eliminate BDRV_REQ_NO_SERIALISING

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This commit is contained in:
Peter Maydell 2020-01-31 10:37:11 +00:00
commit adcd6e93b9
37 changed files with 879 additions and 173 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

9
MAINTAINERS
View file

@ -2634,6 +2634,15 @@ F: block/file-posix.c
F: block/file-win32.c
F: block/win32-aio.c
Linux io_uring
M: Aarushi Mehta <mehta.aaru20@gmail.com>
M: Julia Suvorova <jusual@redhat.com>
M: Stefan Hajnoczi <stefanha@redhat.com>
L: qemu-block@nongnu.org
S: Maintained
F: block/io_uring.c
F: stubs/io_uring.c
qcow2
M: Kevin Wolf <kwolf@redhat.com>
M: Max Reitz <mreitz@redhat.com>

22
block.c
View file

@ -845,6 +845,28 @@ static BlockdevDetectZeroesOptions bdrv_parse_detect_zeroes(QemuOpts *opts,
return detect_zeroes;
}
/**
* Set open flags for aio engine
*
* Return 0 on success, -1 if the engine specified is invalid
*/
int bdrv_parse_aio(const char *mode, int *flags)
{
if (!strcmp(mode, "threads")) {
/* do nothing, default */
} else if (!strcmp(mode, "native")) {
*flags |= BDRV_O_NATIVE_AIO;
#ifdef CONFIG_LINUX_IO_URING
} else if (!strcmp(mode, "io_uring")) {
*flags |= BDRV_O_IO_URING;
#endif
} else {
return -1;
}
return 0;
}
/**
* Set open flags for a given discard mode
*

3
block/Makefile.objs
View file

@ -18,6 +18,7 @@ block-obj-y += block-backend.o snapshot.o qapi.o
block-obj-$(CONFIG_WIN32) += file-win32.o win32-aio.o
block-obj-$(CONFIG_POSIX) += file-posix.o
block-obj-$(CONFIG_LINUX_AIO) += linux-aio.o
block-obj-$(CONFIG_LINUX_IO_URING) += io_uring.o
block-obj-y += null.o mirror.o commit.o io.o create.o
block-obj-y += throttle-groups.o
block-obj-$(CONFIG_LINUX) += nvme.o
@ -66,5 +67,7 @@ block-obj-$(if $(CONFIG_LZFSE),m,n) += dmg-lzfse.o
dmg-lzfse.o-libs := $(LZFSE_LIBS)
qcow.o-libs := -lz
linux-aio.o-libs := -laio
io_uring.o-cflags := $(LINUX_IO_URING_CFLAGS)
io_uring.o-libs := $(LINUX_IO_URING_LIBS)
parallels.o-cflags := $(LIBXML2_CFLAGS)
parallels.o-libs := $(LIBXML2_LIBS)

101
block/file-posix.c
View file

@ -156,6 +156,7 @@ typedef struct BDRVRawState {
bool has_write_zeroes:1;
bool discard_zeroes:1;
bool use_linux_aio:1;
bool use_linux_io_uring:1;
bool page_cache_inconsistent:1;
bool has_fallocate;
bool needs_alignment;
@ -444,7 +445,7 @@ static QemuOptsList raw_runtime_opts = {
{
.name = "aio",
.type = QEMU_OPT_STRING,
.help = "host AIO implementation (threads, native)",
.help = "host AIO implementation (threads, native, io_uring)",
},
{
.name = "locking",
@ -503,9 +504,16 @@ static int raw_open_common(BlockDriverState *bs, QDict *options,
goto fail;
}
aio_default = (bdrv_flags & BDRV_O_NATIVE_AIO)
? BLOCKDEV_AIO_OPTIONS_NATIVE
: BLOCKDEV_AIO_OPTIONS_THREADS;
if (bdrv_flags & BDRV_O_NATIVE_AIO) {
aio_default = BLOCKDEV_AIO_OPTIONS_NATIVE;
#ifdef CONFIG_LINUX_IO_URING
} else if (bdrv_flags & BDRV_O_IO_URING) {
aio_default = BLOCKDEV_AIO_OPTIONS_IO_URING;
#endif
} else {
aio_default = BLOCKDEV_AIO_OPTIONS_THREADS;
}
aio = qapi_enum_parse(&BlockdevAioOptions_lookup,
qemu_opt_get(opts, "aio"),
aio_default, &local_err);
@ -514,7 +522,11 @@ static int raw_open_common(BlockDriverState *bs, QDict *options,
ret = -EINVAL;
goto fail;
}
s->use_linux_aio = (aio == BLOCKDEV_AIO_OPTIONS_NATIVE);
#ifdef CONFIG_LINUX_IO_URING
s->use_linux_io_uring = (aio == BLOCKDEV_AIO_OPTIONS_IO_URING);
#endif
locking = qapi_enum_parse(&OnOffAuto_lookup,
qemu_opt_get(opts, "locking"),
@ -600,6 +612,22 @@ static int raw_open_common(BlockDriverState *bs, QDict *options,
}
#endif /* !defined(CONFIG_LINUX_AIO) */
#ifdef CONFIG_LINUX_IO_URING
if (s->use_linux_io_uring) {
if (!aio_setup_linux_io_uring(bdrv_get_aio_context(bs), errp)) {
error_prepend(errp, "Unable to use io_uring: ");
goto fail;
}
}
#else
if (s->use_linux_io_uring) {
error_setg(errp, "aio=io_uring was specified, but is not supported "
"in this build.");
ret = -EINVAL;
goto fail;
}
#endif /* !defined(CONFIG_LINUX_IO_URING) */
s->has_discard = true;
s->has_write_zeroes = true;
if ((bs->open_flags & BDRV_O_NOCACHE) != 0) {
@ -1877,21 +1905,25 @@ static int coroutine_fn raw_co_prw(BlockDriverState *bs, uint64_t offset,
return -EIO;
/*
* Check if the underlying device requires requests to be aligned,
* and if the request we are trying to submit is aligned or not.
* If this is the case tell the low-level driver that it needs
* to copy the buffer.
* When using O_DIRECT, the request must be aligned to be able to use
* either libaio or io_uring interface. If not fail back to regular thread
* pool read/write code which emulates this for us if we
* set QEMU_AIO_MISALIGNED.
*/
if (s->needs_alignment) {
if (!bdrv_qiov_is_aligned(bs, qiov)) {
type |= QEMU_AIO_MISALIGNED;
#ifdef CONFIG_LINUX_AIO
} else if (s->use_linux_aio) {
LinuxAioState *aio = aio_get_linux_aio(bdrv_get_aio_context(bs));
assert(qiov->size == bytes);
return laio_co_submit(bs, aio, s->fd, offset, qiov, type);
if (s->needs_alignment && !bdrv_qiov_is_aligned(bs, qiov)) {
type |= QEMU_AIO_MISALIGNED;
#ifdef CONFIG_LINUX_IO_URING
} else if (s->use_linux_io_uring) {
LuringState *aio = aio_get_linux_io_uring(bdrv_get_aio_context(bs));
assert(qiov->size == bytes);
return luring_co_submit(bs, aio, s->fd, offset, qiov, type);
#endif
#ifdef CONFIG_LINUX_AIO
} else if (s->use_linux_aio) {
LinuxAioState *aio = aio_get_linux_aio(bdrv_get_aio_context(bs));
assert(qiov->size == bytes);
return laio_co_submit(bs, aio, s->fd, offset, qiov, type);
#endif
}
}
acb = (RawPosixAIOData) {
@ -1927,24 +1959,36 @@ static int coroutine_fn raw_co_pwritev(BlockDriverState *bs, uint64_t offset,
static void raw_aio_plug(BlockDriverState *bs)
{
BDRVRawState __attribute__((unused)) *s = bs->opaque;
#ifdef CONFIG_LINUX_AIO
BDRVRawState *s = bs->opaque;
if (s->use_linux_aio) {
LinuxAioState *aio = aio_get_linux_aio(bdrv_get_aio_context(bs));
laio_io_plug(bs, aio);
}
#endif
#ifdef CONFIG_LINUX_IO_URING
if (s->use_linux_io_uring) {
LuringState *aio = aio_get_linux_io_uring(bdrv_get_aio_context(bs));
luring_io_plug(bs, aio);
}
#endif
}
static void raw_aio_unplug(BlockDriverState *bs)
{
BDRVRawState __attribute__((unused)) *s = bs->opaque;
#ifdef CONFIG_LINUX_AIO
BDRVRawState *s = bs->opaque;
if (s->use_linux_aio) {
LinuxAioState *aio = aio_get_linux_aio(bdrv_get_aio_context(bs));
laio_io_unplug(bs, aio);
}
#endif
#ifdef CONFIG_LINUX_IO_URING
if (s->use_linux_io_uring) {
LuringState *aio = aio_get_linux_io_uring(bdrv_get_aio_context(bs));
luring_io_unplug(bs, aio);
}
#endif
}
static int raw_co_flush_to_disk(BlockDriverState *bs)
@ -1964,14 +2008,20 @@ static int raw_co_flush_to_disk(BlockDriverState *bs)
.aio_type = QEMU_AIO_FLUSH,
};
#ifdef CONFIG_LINUX_IO_URING
if (s->use_linux_io_uring) {
LuringState *aio = aio_get_linux_io_uring(bdrv_get_aio_context(bs));
return luring_co_submit(bs, aio, s->fd, 0, NULL, QEMU_AIO_FLUSH);
}
#endif
return raw_thread_pool_submit(bs, handle_aiocb_flush, &acb);
}
static void raw_aio_attach_aio_context(BlockDriverState *bs,
AioContext *new_context)
{
BDRVRawState __attribute__((unused)) *s = bs->opaque;
#ifdef CONFIG_LINUX_AIO
BDRVRawState *s = bs->opaque;
if (s->use_linux_aio) {
Error *local_err = NULL;
if (!aio_setup_linux_aio(new_context, &local_err)) {
@ -1981,6 +2031,16 @@ static void raw_aio_attach_aio_context(BlockDriverState *bs,
}
}
#endif
#ifdef CONFIG_LINUX_IO_URING
if (s->use_linux_io_uring) {
Error *local_err;
if (!aio_setup_linux_io_uring(new_context, &local_err)) {
error_reportf_err(local_err, "Unable to use linux io_uring, "
"falling back to thread pool: ");
s->use_linux_io_uring = false;
}
}
#endif
}
static void raw_close(BlockDriverState *bs)
@ -2753,7 +2813,6 @@ raw_do_pwrite_zeroes(BlockDriverState *bs, int64_t offset, int bytes,
req->overlap_bytes = req->bytes;
bdrv_mark_request_serialising(req, bs->bl.request_alignment);
bdrv_wait_serialising_requests(req);
}
#endif

162
block/io.c
View file

@ -715,12 +715,69 @@ static void tracked_request_begin(BdrvTrackedRequest *req,
qemu_co_mutex_unlock(&bs->reqs_lock);
}
void bdrv_mark_request_serialising(BdrvTrackedRequest *req, uint64_t align)
static bool tracked_request_overlaps(BdrvTrackedRequest *req,
int64_t offset, uint64_t bytes)
{
/* aaaa bbbb */
if (offset >= req->overlap_offset + req->overlap_bytes) {
return false;
}
/* bbbb aaaa */
if (req->overlap_offset >= offset + bytes) {
return false;
}
return true;
}
static bool coroutine_fn
bdrv_wait_serialising_requests_locked(BlockDriverState *bs,
BdrvTrackedRequest *self)
{
BdrvTrackedRequest *req;
bool retry;
bool waited = false;
do {
retry = false;
QLIST_FOREACH(req, &bs->tracked_requests, list) {
if (req == self || (!req->serialising && !self->serialising)) {
continue;
}
if (tracked_request_overlaps(req, self->overlap_offset,
self->overlap_bytes))
{
/* Hitting this means there was a reentrant request, for
* example, a block driver issuing nested requests. This must
* never happen since it means deadlock.
*/
assert(qemu_coroutine_self() != req->co);
/* If the request is already (indirectly) waiting for us, or
* will wait for us as soon as it wakes up, then just go on
* (instead of producing a deadlock in the former case). */
if (!req->waiting_for) {
self->waiting_for = req;
qemu_co_queue_wait(&req->wait_queue, &bs->reqs_lock);
self->waiting_for = NULL;
retry = true;
waited = true;
break;
}
}
}
} while (retry);
return waited;
}
bool bdrv_mark_request_serialising(BdrvTrackedRequest *req, uint64_t align)
{
BlockDriverState *bs = req->bs;
int64_t overlap_offset = req->offset & ~(align - 1);
uint64_t overlap_bytes = ROUND_UP(req->offset + req->bytes, align)
- overlap_offset;
bool waited;
qemu_co_mutex_lock(&bs->reqs_lock);
if (!req->serialising) {
atomic_inc(&req->bs->serialising_in_flight);
req->serialising = true;
@ -728,18 +785,9 @@ void bdrv_mark_request_serialising(BdrvTrackedRequest *req, uint64_t align)
req->overlap_offset = MIN(req->overlap_offset, overlap_offset);
req->overlap_bytes = MAX(req->overlap_bytes, overlap_bytes);
}
static bool is_request_serialising_and_aligned(BdrvTrackedRequest *req)
{
/*
* If the request is serialising, overlap_offset and overlap_bytes are set,
* so we can check if the request is aligned. Otherwise, don't care and
* return false.
*/
return req->serialising && (req->offset == req->overlap_offset) &&
(req->bytes == req->overlap_bytes);
waited = bdrv_wait_serialising_requests_locked(bs, req);
qemu_co_mutex_unlock(&bs->reqs_lock);
return waited;
}
/**
@ -793,20 +841,6 @@ static int bdrv_get_cluster_size(BlockDriverState *bs)
}
}
static bool tracked_request_overlaps(BdrvTrackedRequest *req,
int64_t offset, uint64_t bytes)
{
/* aaaa bbbb */
if (offset >= req->overlap_offset + req->overlap_bytes) {
return false;
}
/* bbbb aaaa */
if (req->overlap_offset >= offset + bytes) {
return false;
}
return true;
}
void bdrv_inc_in_flight(BlockDriverState *bs)
{
atomic_inc(&bs->in_flight);
@ -823,48 +857,18 @@ void bdrv_dec_in_flight(BlockDriverState *bs)
bdrv_wakeup(bs);
}
bool coroutine_fn bdrv_wait_serialising_requests(BdrvTrackedRequest *self)
static bool coroutine_fn bdrv_wait_serialising_requests(BdrvTrackedRequest *self)
{
BlockDriverState *bs = self->bs;
BdrvTrackedRequest *req;
bool retry;
bool waited = false;
if (!atomic_read(&bs->serialising_in_flight)) {
return false;
}
do {
retry = false;
qemu_co_mutex_lock(&bs->reqs_lock);
QLIST_FOREACH(req, &bs->tracked_requests, list) {
if (req == self || (!req->serialising && !self->serialising)) {
continue;
}
if (tracked_request_overlaps(req, self->overlap_offset,
self->overlap_bytes))
{
/* Hitting this means there was a reentrant request, for
* example, a block driver issuing nested requests. This must
* never happen since it means deadlock.
*/
assert(qemu_coroutine_self() != req->co);
/* If the request is already (indirectly) waiting for us, or
* will wait for us as soon as it wakes up, then just go on
* (instead of producing a deadlock in the former case). */
if (!req->waiting_for) {
self->waiting_for = req;
qemu_co_queue_wait(&req->wait_queue, &bs->reqs_lock);
self->waiting_for = NULL;
retry = true;
waited = true;
break;
}
}
}
qemu_co_mutex_unlock(&bs->reqs_lock);
} while (retry);
qemu_co_mutex_lock(&bs->reqs_lock);
waited = bdrv_wait_serialising_requests_locked(bs, self);
qemu_co_mutex_unlock(&bs->reqs_lock);
return waited;
}
@ -1445,8 +1449,7 @@ static int coroutine_fn bdrv_aligned_preadv(BdrvChild *child,
* potential fallback support, if we ever implement any read flags
* to pass through to drivers. For now, there aren't any
* passthrough flags. */
assert(!(flags & ~(BDRV_REQ_NO_SERIALISING | BDRV_REQ_COPY_ON_READ |
BDRV_REQ_PREFETCH)));
assert(!(flags & ~(BDRV_REQ_COPY_ON_READ | BDRV_REQ_PREFETCH)));
/* Handle Copy on Read and associated serialisation */
if (flags & BDRV_REQ_COPY_ON_READ) {
@ -1456,12 +1459,7 @@ static int coroutine_fn bdrv_aligned_preadv(BdrvChild *child,
* it ensures that the CoR read and write operations are atomic and
* guest writes cannot interleave between them. */
bdrv_mark_request_serialising(req, bdrv_get_cluster_size(bs));
}
/* BDRV_REQ_SERIALISING is only for write operation */
assert(!(flags & BDRV_REQ_SERIALISING));
if (!(flags & BDRV_REQ_NO_SERIALISING)) {
} else {
bdrv_wait_serialising_requests(req);
}
@ -1711,7 +1709,7 @@ int coroutine_fn bdrv_co_preadv_part(BdrvChild *child,
bdrv_inc_in_flight(bs);
/* Don't do copy-on-read if we read data before write operation */
if (atomic_read(&bs->copy_on_read) && !(flags & BDRV_REQ_NO_SERIALISING)) {
if (atomic_read(&bs->copy_on_read)) {
flags |= BDRV_REQ_COPY_ON_READ;
}
@ -1852,20 +1850,24 @@ bdrv_co_write_req_prepare(BdrvChild *child, int64_t offset, uint64_t bytes,
return -EPERM;
}
/* BDRV_REQ_NO_SERIALISING is only for read operation */
assert(!(flags & BDRV_REQ_NO_SERIALISING));
assert(!(bs->open_flags & BDRV_O_INACTIVE));
assert((bs->open_flags & BDRV_O_NO_IO) == 0);
assert(!(flags & ~BDRV_REQ_MASK));
if (flags & BDRV_REQ_SERIALISING) {
bdrv_mark_request_serialising(req, bdrv_get_cluster_size(bs));
waited = bdrv_mark_request_serialising(req, bdrv_get_cluster_size(bs));
/*
* For a misaligned request we should have already waited earlier,
* because we come after bdrv_padding_rmw_read which must be called
* with the request already marked as serialising.
*/
assert(!waited ||
(req->offset == req->overlap_offset &&
req->bytes == req->overlap_bytes));
} else {
bdrv_wait_serialising_requests(req);
}
waited = bdrv_wait_serialising_requests(req);
assert(!waited || !req->serialising ||
is_request_serialising_and_aligned(req));
assert(req->overlap_offset <= offset);
assert(offset + bytes <= req->overlap_offset + req->overlap_bytes);
assert(end_sector <= bs->total_sectors || child->perm & BLK_PERM_RESIZE);
@ -2027,7 +2029,6 @@ static int coroutine_fn bdrv_co_do_zero_pwritev(BdrvChild *child,
padding = bdrv_init_padding(bs, offset, bytes, &pad);
if (padding) {
bdrv_mark_request_serialising(req, align);
bdrv_wait_serialising_requests(req);
bdrv_padding_rmw_read(child, req, &pad, true);
@ -2130,7 +2131,6 @@ int coroutine_fn bdrv_co_pwritev_part(BdrvChild *child,
if (bdrv_pad_request(bs, &qiov, &qiov_offset, &offset, &bytes, &pad)) {
bdrv_mark_request_serialising(&req, align);
bdrv_wait_serialising_requests(&req);
bdrv_padding_rmw_read(child, &req, &pad, false);
}
@ -3222,9 +3222,7 @@ static int coroutine_fn bdrv_co_copy_range_internal(
/* BDRV_REQ_SERIALISING is only for write operation */
assert(!(read_flags & BDRV_REQ_SERIALISING));
if (!(read_flags & BDRV_REQ_NO_SERIALISING)) {
bdrv_wait_serialising_requests(&req);
}
bdrv_wait_serialising_requests(&req);
ret = src->bs->drv->bdrv_co_copy_range_from(src->bs,
src, src_offset,

433
block/io_uring.c Normal file
View file

@ -0,0 +1,433 @@
/*
* Linux io_uring support.
*
* Copyright (C) 2009 IBM, Corp.
* Copyright (C) 2009 Red Hat, Inc.
* Copyright (C) 2019 Aarushi Mehta
*
* 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 <liburing.h>
#include "qemu-common.h"
#include "block/aio.h"
#include "qemu/queue.h"
#include "block/block.h"
#include "block/raw-aio.h"
#include "qemu/coroutine.h"
#include "qapi/error.h"
#include "trace.h"
/* io_uring ring size */
#define MAX_ENTRIES 128
typedef struct LuringAIOCB {
Coroutine *co;
struct io_uring_sqe sqeq;
ssize_t ret;
QEMUIOVector *qiov;
bool is_read;
QSIMPLEQ_ENTRY(LuringAIOCB) next;
/*
* Buffered reads may require resubmission, see
* luring_resubmit_short_read().
*/
int total_read;
QEMUIOVector resubmit_qiov;
} LuringAIOCB;
typedef struct LuringQueue {
int plugged;
unsigned int in_queue;
unsigned int in_flight;
bool blocked;
QSIMPLEQ_HEAD(, LuringAIOCB) submit_queue;
} LuringQueue;
typedef struct LuringState {
AioContext *aio_context;
struct io_uring ring;
/* io queue for submit at batch. Protected by AioContext lock. */
LuringQueue io_q;
/* I/O completion processing. Only runs in I/O thread. */
QEMUBH *completion_bh;
} LuringState;
/**
* luring_resubmit:
*
* Resubmit a request by appending it to submit_queue. The caller must ensure
* that ioq_submit() is called later so that submit_queue requests are started.
*/
static void luring_resubmit(LuringState *s, LuringAIOCB *luringcb)
{
QSIMPLEQ_INSERT_TAIL(&s->io_q.submit_queue, luringcb, next);
s->io_q.in_queue++;
}
/**
* luring_resubmit_short_read:
*
* Before Linux commit 9d93a3f5a0c ("io_uring: punt short reads to async
* context") a buffered I/O request with the start of the file range in the
* page cache could result in a short read. Applications need to resubmit the
* remaining read request.
*
* This is a slow path but recent kernels never take it.
*/
static void luring_resubmit_short_read(LuringState *s, LuringAIOCB *luringcb,
int nread)
{
QEMUIOVector *resubmit_qiov;
size_t remaining;
trace_luring_resubmit_short_read(s, luringcb, nread);
/* Update read position */
luringcb->total_read = nread;
remaining = luringcb->qiov->size - luringcb->total_read;
/* Shorten qiov */
resubmit_qiov = &luringcb->resubmit_qiov;
if (resubmit_qiov->iov == NULL) {
qemu_iovec_init(resubmit_qiov, luringcb->qiov->niov);
} else {
qemu_iovec_reset(resubmit_qiov);
}
qemu_iovec_concat(resubmit_qiov, luringcb->qiov, luringcb->total_read,
remaining);
/* Update sqe */
luringcb->sqeq.off = nread;
luringcb->sqeq.addr = (__u64)(uintptr_t)luringcb->resubmit_qiov.iov;
luringcb->sqeq.len = luringcb->resubmit_qiov.niov;
luring_resubmit(s, luringcb);
}
/**
* luring_process_completions:
* @s: AIO state
*
* Fetches completed I/O requests, consumes cqes and invokes their callbacks
* The function is somewhat tricky because it supports nested event loops, for
* example when a request callback invokes aio_poll().
*
* Function schedules BH completion so it can be called again in a nested
* event loop. When there are no events left to complete the BH is being
* canceled.
*
*/
static void luring_process_completions(LuringState *s)
{
struct io_uring_cqe *cqes;
int total_bytes;
/*
* Request completion callbacks can run the nested event loop.
* Schedule ourselves so the nested event loop will "see" remaining
* completed requests and process them. Without this, completion
* callbacks that wait for other requests using a nested event loop
* would hang forever.
*
* This workaround is needed because io_uring uses poll_wait, which
* is woken up when new events are added to the uring, thus polling on
* the same uring fd will block unless more events are received.
*
* Other leaf block drivers (drivers that access the data themselves)
* are networking based, so they poll sockets for data and run the
* correct coroutine.
*/
qemu_bh_schedule(s->completion_bh);
while (io_uring_peek_cqe(&s->ring, &cqes) == 0) {
LuringAIOCB *luringcb;
int ret;
if (!cqes) {
break;
}
luringcb = io_uring_cqe_get_data(cqes);
ret = cqes->res;
io_uring_cqe_seen(&s->ring, cqes);
cqes = NULL;
/* Change counters one-by-one because we can be nested. */
s->io_q.in_flight--;
trace_luring_process_completion(s, luringcb, ret);
/* total_read is non-zero only for resubmitted read requests */
total_bytes = ret + luringcb->total_read;
if (ret < 0) {
if (ret == -EINTR) {
luring_resubmit(s, luringcb);
continue;
}
} else if (!luringcb->qiov) {
goto end;
} else if (total_bytes == luringcb->qiov->size) {
ret = 0;
/* Only read/write */
} else {
/* Short Read/Write */
if (luringcb->is_read) {
if (ret > 0) {
luring_resubmit_short_read(s, luringcb, ret);
continue;
} else {
/* Pad with zeroes */
qemu_iovec_memset(luringcb->qiov, total_bytes, 0,
luringcb->qiov->size - total_bytes);
ret = 0;
}
} else {
ret = -ENOSPC;;
}
}
end:
luringcb->ret = ret;
qemu_iovec_destroy(&luringcb->resubmit_qiov);
/*
* If the coroutine is already entered it must be in ioq_submit()
* and will notice luringcb->ret has been filled in when it
* eventually runs later. Coroutines cannot be entered recursively
* so avoid doing that!
*/
if (!qemu_coroutine_entered(luringcb->co)) {
aio_co_wake(luringcb->co);
}
}
qemu_bh_cancel(s->completion_bh);
}
static int ioq_submit(LuringState *s)
{
int ret = 0;
LuringAIOCB *luringcb, *luringcb_next;
while (s->io_q.in_queue > 0) {
/*
* Try to fetch sqes from the ring for requests waiting in
* the overflow queue
*/
QSIMPLEQ_FOREACH_SAFE(luringcb, &s->io_q.submit_queue, next,
luringcb_next) {
struct io_uring_sqe *sqes = io_uring_get_sqe(&s->ring);
if (!sqes) {
break;
}
/* Prep sqe for submission */
*sqes = luringcb->sqeq;
QSIMPLEQ_REMOVE_HEAD(&s->io_q.submit_queue, next);
}
ret = io_uring_submit(&s->ring);
trace_luring_io_uring_submit(s, ret);
/* Prevent infinite loop if submission is refused */
if (ret <= 0) {
if (ret == -EAGAIN) {
continue;
}
break;
}
s->io_q.in_flight += ret;
s->io_q.in_queue -= ret;
}
s->io_q.blocked = (s->io_q.in_queue > 0);
if (s->io_q.in_flight) {
/*
* We can try to complete something just right away if there are
* still requests in-flight.
*/
luring_process_completions(s);
}
return ret;
}
static void luring_process_completions_and_submit(LuringState *s)
{
aio_context_acquire(s->aio_context);
luring_process_completions(s);
if (!s->io_q.plugged && s->io_q.in_queue > 0) {
ioq_submit(s);
}
aio_context_release(s->aio_context);
}
static void qemu_luring_completion_bh(void *opaque)
{
LuringState *s = opaque;
luring_process_completions_and_submit(s);
}
static void qemu_luring_completion_cb(void *opaque)
{
LuringState *s = opaque;
luring_process_completions_and_submit(s);
}
static bool qemu_luring_poll_cb(void *opaque)
{
LuringState *s = opaque;
struct io_uring_cqe *cqes;
if (io_uring_peek_cqe(&s->ring, &cqes) == 0) {
if (cqes) {
luring_process_completions_and_submit(s);
return true;
}
}
return false;
}
static void ioq_init(LuringQueue *io_q)
{
QSIMPLEQ_INIT(&io_q->submit_queue);
io_q->plugged = 0;
io_q->in_queue = 0;
io_q->in_flight = 0;
io_q->blocked = false;
}
void luring_io_plug(BlockDriverState *bs, LuringState *s)
{
trace_luring_io_plug(s);
s->io_q.plugged++;
}
void luring_io_unplug(BlockDriverState *bs, LuringState *s)
{
assert(s->io_q.plugged);
trace_luring_io_unplug(s, s->io_q.blocked, s->io_q.plugged,
s->io_q.in_queue, s->io_q.in_flight);
if (--s->io_q.plugged == 0 &&
!s->io_q.blocked && s->io_q.in_queue > 0) {
ioq_submit(s);
}
}
/**
* luring_do_submit:
* @fd: file descriptor for I/O
* @luringcb: AIO control block
* @s: AIO state
* @offset: offset for request
* @type: type of request
*
* Fetches sqes from ring, adds to pending queue and preps them
*
*/
static int luring_do_submit(int fd, LuringAIOCB *luringcb, LuringState *s,
uint64_t offset, int type)
{
int ret;
struct io_uring_sqe *sqes = &luringcb->sqeq;
switch (type) {
case QEMU_AIO_WRITE:
io_uring_prep_writev(sqes, fd, luringcb->qiov->iov,
luringcb->qiov->niov, offset);
break;
case QEMU_AIO_READ:
io_uring_prep_readv(sqes, fd, luringcb->qiov->iov,
luringcb->qiov->niov, offset);
break;
case QEMU_AIO_FLUSH:
io_uring_prep_fsync(sqes, fd, IORING_FSYNC_DATASYNC);
break;
default:
fprintf(stderr, "%s: invalid AIO request type, aborting 0x%x.\n",
__func__, type);
abort();
}
io_uring_sqe_set_data(sqes, luringcb);
QSIMPLEQ_INSERT_TAIL(&s->io_q.submit_queue, luringcb, next);
s->io_q.in_queue++;
trace_luring_do_submit(s, s->io_q.blocked, s->io_q.plugged,
s->io_q.in_queue, s->io_q.in_flight);
if (!s->io_q.blocked &&
(!s->io_q.plugged ||
s->io_q.in_flight + s->io_q.in_queue >= MAX_ENTRIES)) {
ret = ioq_submit(s);
trace_luring_do_submit_done(s, ret);
return ret;
}
return 0;
}
int coroutine_fn luring_co_submit(BlockDriverState *bs, LuringState *s, int fd,
uint64_t offset, QEMUIOVector *qiov, int type)
{
int ret;
LuringAIOCB luringcb = {
.co = qemu_coroutine_self(),
.ret = -EINPROGRESS,
.qiov = qiov,
.is_read = (type == QEMU_AIO_READ),
};
trace_luring_co_submit(bs, s, &luringcb, fd, offset, qiov ? qiov->size : 0,
type);
ret = luring_do_submit(fd, &luringcb, s, offset, type);
if (ret < 0) {
return ret;
}
if (luringcb.ret == -EINPROGRESS) {
qemu_coroutine_yield();
}
return luringcb.ret;
}
void luring_detach_aio_context(LuringState *s, AioContext *old_context)
{
aio_set_fd_handler(old_context, s->ring.ring_fd, false, NULL, NULL, NULL,
s);
qemu_bh_delete(s->completion_bh);
s->aio_context = NULL;
}
void luring_attach_aio_context(LuringState *s, AioContext *new_context)
{
s->aio_context = new_context;
s->completion_bh = aio_bh_new(new_context, qemu_luring_completion_bh, s);
aio_set_fd_handler(s->aio_context, s->ring.ring_fd, false,
qemu_luring_completion_cb, NULL, qemu_luring_poll_cb, s);
}
LuringState *luring_init(Error **errp)
{
int rc;
LuringState *s = g_new0(LuringState, 1);
struct io_uring *ring = &s->ring;
trace_luring_init_state(s, sizeof(*s));
rc = io_uring_queue_init(MAX_ENTRIES, ring, 0);
if (rc < 0) {
error_setg_errno(errp, errno, "failed to init linux io_uring ring");
g_free(s);
return NULL;
}
ioq_init(&s->io_q);
return s;
}
void luring_cleanup(LuringState *s)
{
io_uring_queue_exit(&s->ring);
g_free(s);
trace_luring_cleanup_state(s);
}

12
block/trace-events
View file

@ -63,6 +63,18 @@ qmp_block_stream(void *bs) "bs %p"
file_paio_submit(void *acb, void *opaque, int64_t offset, int count, int type) "acb %p opaque %p offset %"PRId64" count %d type %d"
file_copy_file_range(void *bs, int src, int64_t src_off, int dst, int64_t dst_off, int64_t bytes, int flags, int64_t ret) "bs %p src_fd %d offset %"PRIu64" dst_fd %d offset %"PRIu64" bytes %"PRIu64" flags %d ret %"PRId64
#io_uring.c
luring_init_state(void *s, size_t size) "s %p size %zu"
luring_cleanup_state(void *s) "%p freed"
luring_io_plug(void *s) "LuringState %p plug"
luring_io_unplug(void *s, int blocked, int plugged, int queued, int inflight) "LuringState %p blocked %d plugged %d queued %d inflight %d"
luring_do_submit(void *s, int blocked, int plugged, int queued, int inflight) "LuringState %p blocked %d plugged %d queued %d inflight %d"
luring_do_submit_done(void *s, int ret) "LuringState %p submitted to kernel %d"
luring_co_submit(void *bs, void *s, void *luringcb, int fd, uint64_t offset, size_t nbytes, int type) "bs %p s %p luringcb %p fd %d offset %" PRId64 " nbytes %zd type %d"
luring_process_completion(void *s, void *aiocb, int ret) "LuringState %p luringcb %p ret %d"
luring_io_uring_submit(void *s, int ret) "LuringState %p ret %d"
luring_resubmit_short_read(void *s, void *luringcb, int nread) "LuringState %p luringcb %p nread %d"
# qcow2.c
qcow2_add_task(void *co, void *bs, void *pool, const char *action, int cluster_type, uint64_t file_cluster_offset, uint64_t offset, uint64_t bytes, void *qiov, size_t qiov_offset) "co %p bs %p pool %p: %s: cluster_type %d file_cluster_offset %" PRIu64 " offset %" PRIu64 " bytes %" PRIu64 " qiov %p qiov_offset %zu"
qcow2_writev_start_req(void *co, int64_t offset, int bytes) "co %p offset 0x%" PRIx64 " bytes %d"

12
blockdev.c
View file

@ -385,13 +385,9 @@ static void extract_common_blockdev_options(QemuOpts *opts, int *bdrv_flags,
}
if ((aio = qemu_opt_get(opts, "aio")) != NULL) {
if (!strcmp(aio, "native")) {
*bdrv_flags |= BDRV_O_NATIVE_AIO;
} else if (!strcmp(aio, "threads")) {
/* this is the default */
} else {
error_setg(errp, "invalid aio option");
return;
if (bdrv_parse_aio(aio, bdrv_flags) < 0) {
error_setg(errp, "invalid aio option");
return;
}
}
}
@ -4672,7 +4668,7 @@ QemuOptsList qemu_common_drive_opts = {
},{
.name = "aio",
.type = QEMU_OPT_STRING,
.help = "host AIO implementation (threads, native)",
.help = "host AIO implementation (threads, native, io_uring)",
},{
.name = BDRV_OPT_CACHE_WB,
.type = QEMU_OPT_BOOL,

27
configure vendored
View file

@ -371,6 +371,7 @@ xen=""
xen_ctrl_version=""
xen_pci_passthrough=""
linux_aio=""
linux_io_uring=""
cap_ng=""
attr=""
libattr=""
@ -1253,6 +1254,10 @@ for opt do
;;
--enable-linux-aio) linux_aio="yes"
;;
--disable-linux-io-uring) linux_io_uring="no"
;;
--enable-linux-io-uring) linux_io_uring="yes"
;;
--disable-attr) attr="no"
;;
--enable-attr) attr="yes"
@ -1773,6 +1778,7 @@ disabled with --disable-FEATURE, default is enabled if available:
vde support for vde network
netmap support for netmap network
linux-aio Linux AIO support
linux-io-uring Linux io_uring support
cap-ng libcap-ng support
attr attr and xattr support
vhost-net vhost-net kernel acceleration support
@ -4005,6 +4011,21 @@ EOF
linux_aio=no
fi
fi
##########################################
# linux-io-uring probe
if test "$linux_io_uring" != "no" ; then
if $pkg_config liburing; then
linux_io_uring_cflags=$($pkg_config --cflags liburing)
linux_io_uring_libs=$($pkg_config --libs liburing)
linux_io_uring=yes
else
if test "$linux_io_uring" = "yes" ; then
feature_not_found "linux io_uring" "Install liburing devel"
fi
linux_io_uring=no
fi
fi
##########################################
# TPM emulation is only on POSIX
@ -6515,6 +6536,7 @@ echo "PIE $pie"
echo "vde support $vde"
echo "netmap support $netmap"
echo "Linux AIO support $linux_aio"
echo "Linux io_uring support $linux_io_uring"
echo "ATTR/XATTR support $attr"
echo "Install blobs $blobs"
echo "KVM support $kvm"
@ -7001,6 +7023,11 @@ fi
if test "$linux_aio" = "yes" ; then
echo "CONFIG_LINUX_AIO=y" >> $config_host_mak
fi
if test "$linux_io_uring" = "yes" ; then
echo "CONFIG_LINUX_IO_URING=y" >> $config_host_mak
echo "LINUX_IO_URING_CFLAGS=$linux_io_uring_cflags" >> $config_host_mak
echo "LINUX_IO_URING_LIBS=$linux_io_uring_libs" >> $config_host_mak
fi
if test "$attr" = "yes" ; then
echo "CONFIG_ATTR=y" >> $config_host_mak
fi

4
docs/interop/qemu-nbd.rst
View file

@ -108,8 +108,8 @@ driver options if ``--image-opts`` is specified.
.. option:: --aio=AIO
Set the asynchronous I/O mode between ``threads`` (the default)
and ``native`` (Linux only).
Set the asynchronous I/O mode between ``threads`` (the default),
``native`` (Linux only), and ``io_uring`` (Linux 5.1+).
.. option:: --discard=DISCARD

16
include/block/aio.h
View file

@ -49,6 +49,7 @@ typedef void IOHandler(void *opaque);
struct Coroutine;
struct ThreadPool;
struct LinuxAioState;
struct LuringState;
struct AioContext {
GSource source;
@ -117,11 +118,19 @@ struct AioContext {
struct ThreadPool *thread_pool;
#ifdef CONFIG_LINUX_AIO
/* State for native Linux AIO. Uses aio_context_acquire/release for
/*
* State for native Linux AIO. Uses aio_context_acquire/release for
* locking.
*/
struct LinuxAioState *linux_aio;
#endif
#ifdef CONFIG_LINUX_IO_URING
/*
* State for Linux io_uring. Uses aio_context_acquire/release for
* locking.
*/
struct LuringState *linux_io_uring;
#endif
/* TimerLists for calling timers - one per clock type. Has its own
* locking.
@ -386,6 +395,11 @@ struct LinuxAioState *aio_setup_linux_aio(AioContext *ctx, Error **errp);
/* Return the LinuxAioState bound to this AioContext */
struct LinuxAioState *aio_get_linux_aio(AioContext *ctx);
/* Setup the LuringState bound to this AioContext */
struct LuringState *aio_setup_linux_io_uring(AioContext *ctx, Error **errp);
/* Return the LuringState bound to this AioContext */
struct LuringState *aio_get_linux_io_uring(AioContext *ctx);
/**
* aio_timer_new_with_attrs:
* @ctx: the aio context

14
include/block/block.h
View file

@ -51,18 +51,6 @@ typedef enum {
*/
BDRV_REQ_MAY_UNMAP = 0x4,
/*
* The BDRV_REQ_NO_SERIALISING flag is only valid for reads and means that
* we don't want wait_serialising_requests() during the read operation.
*
* This flag is used for backup copy-on-write operations, when we need to
* read old data before write (write notifier triggered). It is okay since
* we already waited for other serializing requests in the initiating write
* (see bdrv_aligned_pwritev), and it is necessary if the initiating write
* is already serializing (without the flag, the read would deadlock
* waiting for the serialising write to complete).
*/
BDRV_REQ_NO_SERIALISING = 0x8,
BDRV_REQ_FUA = 0x10,
BDRV_REQ_WRITE_COMPRESSED = 0x20,
@ -126,6 +114,7 @@ typedef struct HDGeometry {
ignoring the format layer */
#define BDRV_O_NO_IO 0x10000 /* don't initialize for I/O */
#define BDRV_O_AUTO_RDONLY 0x20000 /* degrade to read-only if opening read-write fails */
#define BDRV_O_IO_URING 0x40000 /* use io_uring instead of the thread pool */
#define BDRV_O_CACHE_MASK (BDRV_O_NOCACHE | BDRV_O_NO_FLUSH)
@ -300,6 +289,7 @@ void bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top,
void bdrv_replace_node(BlockDriverState *from, BlockDriverState *to,
Error **errp);
int bdrv_parse_aio(const char *mode, int *flags);
int bdrv_parse_cache_mode(const char *mode, int *flags, bool *writethrough);
int bdrv_parse_discard_flags(const char *mode, int *flags);
BdrvChild *bdrv_open_child(const char *filename,

3
include/block/block_int.h
View file

@ -999,8 +999,7 @@ extern unsigned int bdrv_drain_all_count;
void bdrv_apply_subtree_drain(BdrvChild *child, BlockDriverState *new_parent);
void bdrv_unapply_subtree_drain(BdrvChild *child, BlockDriverState *old_parent);
bool coroutine_fn bdrv_wait_serialising_requests(BdrvTrackedRequest *self);
void bdrv_mark_request_serialising(BdrvTrackedRequest *req, uint64_t align);
bool coroutine_fn bdrv_mark_request_serialising(BdrvTrackedRequest *req, uint64_t align);
BdrvTrackedRequest *coroutine_fn bdrv_co_get_self_request(BlockDriverState *bs);
int get_tmp_filename(char *filename, int size);

12
include/block/raw-aio.h
View file

@ -57,6 +57,18 @@ void laio_attach_aio_context(LinuxAioState *s, AioContext *new_context);
void laio_io_plug(BlockDriverState *bs, LinuxAioState *s);
void laio_io_unplug(BlockDriverState *bs, LinuxAioState *s);
#endif
/* io_uring.c - Linux io_uring implementation */
#ifdef CONFIG_LINUX_IO_URING
typedef struct LuringState LuringState;
LuringState *luring_init(Error **errp);
void luring_cleanup(LuringState *s);
int coroutine_fn luring_co_submit(BlockDriverState *bs, LuringState *s, int fd,
uint64_t offset, QEMUIOVector *qiov, int type);
void luring_detach_aio_context(LuringState *s, AioContext *old_context);
void luring_attach_aio_context(LuringState *s, AioContext *new_context);
void luring_io_plug(BlockDriverState *bs, LuringState *s);
void luring_io_unplug(BlockDriverState *bs, LuringState *s);
#endif
#ifdef _WIN32
typedef struct QEMUWin32AIOState QEMUWin32AIOState;

4
qapi/block-core.json
View file

@ -2851,11 +2851,13 @@
#
# @threads: Use qemu's thread pool
# @native: Use native AIO backend (only Linux and Windows)
# @io_uring: Use linux io_uring (since 5.0)
#
# Since: 2.9
##
{ 'enum': 'BlockdevAioOptions',
'data': [ 'threads', 'native' ] }
'data': [ 'threads', 'native',
{ 'name': 'io_uring', 'if': 'defined(CONFIG_LINUX_IO_URING)' } ] }
##
# @BlockdevCacheOptions:

4
qemu-img-cmds.hx
View file

@ -20,9 +20,9 @@ STEXI
ETEXI
DEF("bench", img_bench,
"bench [-c count] [-d depth] [-f fmt] [--flush-interval=flush_interval] [-n] [--no-drain] [-o offset] [--pattern=pattern] [-q] [-s buffer_size] [-S step_size] [-t cache] [-w] [-U] filename")
"bench [-c count] [-d depth] [-f fmt] [--flush-interval=flush_interval] [-n] [--no-drain] [-o offset] [--pattern=pattern] [-q] [-s buffer_size] [-S step_size] [-t cache] [-i aio] [-w] [-U] filename")
STEXI
@item bench [-c @var{count}] [-d @var{depth}] [-f @var{fmt}] [--flush-interval=@var{flush_interval}] [-n] [--no-drain] [-o @var{offset}] [--pattern=@var{pattern}] [-q] [-s @var{buffer_size}] [-S @var{step_size}] [-t @var{cache}] [-w] [-U] @var{filename}
@item bench [-c @var{count}] [-d @var{depth}] [-f @var{fmt}] [--flush-interval=@var{flush_interval}] [-n] [--no-drain] [-o @var{offset}] [--pattern=@var{pattern}] [-q] [-s @var{buffer_size}] [-S @var{step_size}] [-t @var{cache}] [-i @var{aio}] [-w] [-U] @var{filename}
ETEXI
DEF("check", img_check,

11
qemu-img.c
View file

@ -4187,7 +4187,8 @@ static int img_bench(int argc, char **argv)
{"force-share", no_argument, 0, 'U'},
{0, 0, 0, 0}
};
c = getopt_long(argc, argv, ":hc:d:f:no:qs:S:t:wU", long_options, NULL);
c = getopt_long(argc, argv, ":hc:d:f:ni:o:qs:S:t:wU", long_options,
NULL);
if (c == -1) {
break;
}
@ -4230,6 +4231,14 @@ static int img_bench(int argc, char **argv)
case 'n':
flags |= BDRV_O_NATIVE_AIO;
break;
case 'i':
ret = bdrv_parse_aio(optarg, &flags);
if (ret < 0) {
error_report("Invalid aio option: %s", optarg);
ret = -1;
goto out;
}
break;
case 'o':
{
offset = cvtnum(optarg);

5
qemu-img.texi
View file

@ -206,7 +206,7 @@ Command description:
Amends the image format specific @var{options} for the image file
@var{filename}. Not all file formats support this operation.
@item bench [-c @var{count}] [-d @var{depth}] [-f @var{fmt}] [--flush-interval=@var{flush_interval}] [-n] [--no-drain] [-o @var{offset}] [--pattern=@var{pattern}] [-q] [-s @var{buffer_size}] [-S @var{step_size}] [-t @var{cache}] [-w] [-U] @var{filename}
@item bench [-c @var{count}] [-d @var{depth}] [-f @var{fmt}] [--flush-interval=@var{flush_interval}] [-n] [-i @var{aio}] [--no-drain] [-o @var{offset}] [--pattern=@var{pattern}] [-q] [-s @var{buffer_size}] [-S @var{step_size}] [-t @var{cache}] [-w] [-U] @var{filename}
Run a simple sequential I/O benchmark on the specified image. If @code{-w} is
specified, a write test is performed, otherwise a read test is performed.
@ -227,6 +227,9 @@ If @code{-n} is specified, the native AIO backend is used if possible. On
Linux, this option only works if @code{-t none} or @code{-t directsync} is
specified as well.
If @code{-i} is specified, aio option can be used to specify different AIO
backends: @var{threads}, @var{native} or @var{io_uring}.
For write tests, by default a buffer filled with zeros is written. This can be
overridden with a pattern byte specified by @var{pattern}.

25
qemu-io.c
View file

@ -130,7 +130,8 @@ static void open_help(void)
" -C, -- use copy-on-read\n"
" -n, -- disable host cache, short for -t none\n"
" -U, -- force shared permissions\n"
" -k, -- use kernel AIO implementation (on Linux only)\n"
" -k, -- use kernel AIO implementation (Linux only, prefer use of -i)\n"
" -i, -- use AIO mode (threads, native or io_uring)\n"
" -t, -- use the given cache mode for the image\n"
" -d, -- use the given discard mode for the image\n"
" -o, -- options to be given to the block driver"
@ -172,7 +173,7 @@ static int open_f(BlockBackend *blk, int argc, char **argv)
QDict *opts;
bool force_share = false;
while ((c = getopt(argc, argv, "snCro:kt:d:U")) != -1) {
while ((c = getopt(argc, argv, "snCro:ki:t:d:U")) != -1) {
switch (c) {
case 's':
flags |= BDRV_O_SNAPSHOT;
@ -204,6 +205,13 @@ static int open_f(BlockBackend *blk, int argc, char **argv)
return -EINVAL;
}
break;
case 'i':
if (bdrv_parse_aio(optarg, &flags) < 0) {
error_report("Invalid aio option: %s", optarg);
qemu_opts_reset(&empty_opts);
return -EINVAL;
}
break;
case 'o':
if (imageOpts) {
printf("--image-opts and 'open -o' are mutually exclusive\n");
@ -291,7 +299,9 @@ static void usage(const char *name)
" -n, --nocache disable host cache, short for -t none\n"
" -C, --copy-on-read enable copy-on-read\n"
" -m, --misalign misalign allocations for O_DIRECT\n"
" -k, --native-aio use kernel AIO implementation (on Linux only)\n"
" -k, --native-aio use kernel AIO implementation\n"
" (Linux only, prefer use of -i)\n"
" -i, --aio=MODE use AIO mode (threads, native or io_uring)\n"
" -t, --cache=MODE use the given cache mode for the image\n"
" -d, --discard=MODE use the given discard mode for the image\n"
" -T, --trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n"
@ -496,7 +506,7 @@ static QemuOptsList file_opts = {
int main(int argc, char **argv)
{
int readonly = 0;
const char *sopt = "hVc:d:f:rsnCmkt:T:U";
const char *sopt = "hVc:d:f:rsnCmki:t:T:U";
const struct option lopt[] = {
{ "help", no_argument, NULL, 'h' },
{ "version", no_argument, NULL, 'V' },
@ -508,6 +518,7 @@ int main(int argc, char **argv)
{ "copy-on-read", no_argument, NULL, 'C' },
{ "misalign", no_argument, NULL, 'm' },
{ "native-aio", no_argument, NULL, 'k' },
{ "aio", required_argument, NULL, 'i' },
{ "discard", required_argument, NULL, 'd' },
{ "cache", required_argument, NULL, 't' },
{ "trace", required_argument, NULL, 'T' },
@ -575,6 +586,12 @@ int main(int argc, char **argv)
case 'k':
flags |= BDRV_O_NATIVE_AIO;
break;
case 'i':
if (bdrv_parse_aio(optarg, &flags) < 0) {
error_report("Invalid aio option: %s", optarg);
exit(1);
}
break;
case 't':
if (bdrv_parse_cache_mode(optarg, &flags, &writethrough) < 0) {
error_report("Invalid cache option: %s", optarg);

12
qemu-nbd.c
View file

@ -135,7 +135,7 @@ static void usage(const char *name)
" '[ID_OR_NAME]'\n"
" -n, --nocache disable host cache\n"
" --cache=MODE set cache mode (none, writeback, ...)\n"
" --aio=MODE set AIO mode (native or threads)\n"
" --aio=MODE set AIO mode (native, io_uring or threads)\n"
" --discard=MODE set discard mode (ignore, unmap)\n"
" --detect-zeroes=MODE set detect-zeroes mode (off, on, unmap)\n"
" --image-opts treat FILE as a full set of image options\n"
@ -726,13 +726,9 @@ int main(int argc, char **argv)
exit(EXIT_FAILURE);
}
seen_aio = true;
if (!strcmp(optarg, "native")) {
flags |= BDRV_O_NATIVE_AIO;
} else if (!strcmp(optarg, "threads")) {
/* this is the default */
} else {
error_report("invalid aio mode `%s'", optarg);
exit(EXIT_FAILURE);
if (bdrv_parse_aio(optarg, &flags) < 0) {
error_report("Invalid aio mode '%s'", optarg);
exit(EXIT_FAILURE);
}
break;
case QEMU_NBD_OPT_DISCARD:

1
stubs/Makefile.objs
View file

@ -13,6 +13,7 @@ stub-obj-y += iothread.o
stub-obj-y += iothread-lock.o
stub-obj-y += is-daemonized.o
stub-obj-$(CONFIG_LINUX_AIO) += linux-aio.o
stub-obj-$(CONFIG_LINUX_IO_URING) += io_uring.o
stub-obj-y += machine-init-done.o
stub-obj-y += migr-blocker.o
stub-obj-y += change-state-handler.o

32
stubs/io_uring.c Normal file
View file

@ -0,0 +1,32 @@
/*
* Linux io_uring support.
*
* Copyright (C) 2009 IBM, Corp.
* Copyright (C) 2009 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 "block/aio.h"
#include "block/raw-aio.h"
void luring_detach_aio_context(LuringState *s, AioContext *old_context)
{
abort();
}
void luring_attach_aio_context(LuringState *s, AioContext *new_context)
{
abort();
}
LuringState *luring_init(Error **errp)
{
abort();
}
void luring_cleanup(LuringState *s)
{
abort();
}

2
tests/qemu-iotests/028
View file

@ -108,7 +108,7 @@ echo block-backup
echo
qemu_comm_method="monitor"
_launch_qemu -drive file="${TEST_IMG}",cache=${CACHEMODE},id=disk
_launch_qemu -drive file="${TEST_IMG}",cache=${CACHEMODE},aio=${AIOMODE},id=disk
h=$QEMU_HANDLE
if [ "${VALGRIND_QEMU}" == "y" ]; then
QEMU_COMM_TIMEOUT=7

2
tests/qemu-iotests/058
View file

@ -65,7 +65,7 @@ nbd_snapshot_img="nbd:unix:$nbd_unix_socket"
converted_image=$TEST_IMG.converted
# Use -f raw instead of -f $IMGFMT for the NBD connection
QEMU_IO_NBD="$QEMU_IO -f raw --cache=$CACHEMODE"
QEMU_IO_NBD="$QEMU_IO -f raw --cache=$CACHEMODE --aio=$AIOMODE"
echo
echo "== preparing image =="

4
tests/qemu-iotests/089
View file

@ -64,7 +64,7 @@ $QEMU_IO -c 'write -P 42 0 512' -c 'write -P 23 512 512' \
$QEMU_IMG convert -f raw -O $IMGFMT "$TEST_IMG.base" "$TEST_IMG"
$QEMU_IO_PROG --cache $CACHEMODE \
$QEMU_IO_PROG --cache $CACHEMODE --aio $AIOMODE \
-c 'read -P 42 0 512' -c 'read -P 23 512 512' \
-c 'read -P 66 1024 512' "json:{
\"driver\": \"$IMGFMT\",
@ -111,7 +111,7 @@ $QEMU_IO -c 'write -P 42 0x38000 512' "$TEST_IMG" | _filter_qemu_io
# The "image.filename" part tests whether "a": { "b": "c" } and "a.b": "c" do
# the same (which they should).
$QEMU_IO_PROG --cache $CACHEMODE \
$QEMU_IO_PROG --cache $CACHEMODE --aio $AIOMODE \
-c 'read -P 42 0x38000 512' "json:{
\"driver\": \"$IMGFMT\",
\"file\": {

4
tests/qemu-iotests/091
View file

@ -60,13 +60,13 @@ echo === Starting QEMU VM1 ===
echo
qemu_comm_method="monitor"
_launch_qemu -drive file="${TEST_IMG}",cache=${CACHEMODE},id=disk
_launch_qemu -drive file="${TEST_IMG}",cache=${CACHEMODE},aio=${AIOMODE},id=disk
h1=$QEMU_HANDLE
echo
echo === Starting QEMU VM2 ===
echo
_launch_qemu -drive file="${TEST_IMG}",cache=${CACHEMODE},id=disk \
_launch_qemu -drive file="${TEST_IMG}",cache=${CACHEMODE},aio=${AIOMODE},id=disk \
-incoming "exec: cat '${MIG_FIFO}'"
h2=$QEMU_HANDLE

2
tests/qemu-iotests/109
View file

@ -52,7 +52,7 @@ run_qemu()
local qmp_format="$3"
local qmp_event="$4"
_launch_qemu -drive file="${source_img}",format=raw,cache=${CACHEMODE},id=src
_launch_qemu -drive file="${source_img}",format=raw,cache=${CACHEMODE},aio=${AIOMODE},id=src
_send_qemu_cmd $QEMU_HANDLE "{ 'execute': 'qmp_capabilities' }" "return"
_send_qemu_cmd $QEMU_HANDLE \

5
tests/qemu-iotests/147
View file

@ -24,7 +24,7 @@ import socket
import stat
import time
import iotests
from iotests import cachemode, imgfmt, qemu_img, qemu_nbd, qemu_nbd_early_pipe
from iotests import cachemode, aiomode, imgfmt, qemu_img, qemu_nbd, qemu_nbd_early_pipe
NBD_PORT_START = 32768
NBD_PORT_END = NBD_PORT_START + 1024
@ -134,7 +134,8 @@ class BuiltinNBD(NBDBlockdevAddBase):
self.server.add_drive_raw('if=none,id=nbd-export,' +
'file=%s,' % test_img +
'format=%s,' % imgfmt +
'cache=%s' % cachemode)
'cache=%s' % cachemode +
'aio=%s' % aiomode)
self.server.launch()
def tearDown(self):

8
tests/qemu-iotests/181
View file

@ -58,20 +58,20 @@ qemu_comm_method="monitor"
if [ "$IMGOPTSSYNTAX" = "true" ]; then
_launch_qemu \
-drive "${TEST_IMG}",cache=${CACHEMODE},id=disk
-drive "${TEST_IMG}",cache=${CACHEMODE},aio=$AIOMODE,id=disk
else
_launch_qemu \
-drive file="${TEST_IMG}",cache=${CACHEMODE},driver=$IMGFMT,id=disk
-drive file="${TEST_IMG}",cache=${CACHEMODE},aio=$AIOMODE,driver=$IMGFMT,id=disk
fi
src=$QEMU_HANDLE
if [ "$IMGOPTSSYNTAX" = "true" ]; then
_launch_qemu \
-drive "${TEST_IMG}",cache=${CACHEMODE},id=disk \
-drive "${TEST_IMG}",cache=${CACHEMODE},aio=$AIOMODE,id=disk \
-incoming "unix:${MIG_SOCKET}"
else
_launch_qemu \
-drive file="${TEST_IMG}",cache=${CACHEMODE},driver=$IMGFMT,id=disk \
-drive file="${TEST_IMG}",cache=${CACHEMODE},aio=$AIOMODE,driver=$IMGFMT,id=disk \
-incoming "unix:${MIG_SOCKET}"
fi
dest=$QEMU_HANDLE

4
tests/qemu-iotests/183
View file

@ -56,12 +56,12 @@ echo
qemu_comm_method="qmp"
_launch_qemu \
-drive file="${TEST_IMG}",cache=$CACHEMODE,driver=$IMGFMT,id=disk
-drive file="${TEST_IMG}",cache=$CACHEMODE,aio=$AIOMODE,driver=$IMGFMT,id=disk
src=$QEMU_HANDLE
_send_qemu_cmd $src "{ 'execute': 'qmp_capabilities' }" 'return'
_launch_qemu \
-drive file="${TEST_IMG}.dest",cache=$CACHEMODE,driver=$IMGFMT,id=disk \
-drive file="${TEST_IMG}.dest",cache=$CACHEMODE,aio=$AIOMODE,driver=$IMGFMT,id=disk \
-incoming "unix:${MIG_SOCKET}"
dest=$QEMU_HANDLE
_send_qemu_cmd $dest "{ 'execute': 'qmp_capabilities' }" 'return'

10
tests/qemu-iotests/185
View file

@ -54,7 +54,7 @@ echo
qemu_comm_method="qmp"
_launch_qemu \
-drive file="${TEST_IMG}.base",cache=$CACHEMODE,driver=$IMGFMT,id=disk
-drive file="${TEST_IMG}.base",cache=$CACHEMODE,aio=$AIOMODE,driver=$IMGFMT,id=disk
h=$QEMU_HANDLE
_send_qemu_cmd $h "{ 'execute': 'qmp_capabilities' }" 'return'
@ -125,7 +125,7 @@ echo === Start active commit job and exit qemu ===
echo
_launch_qemu \
-drive file="${TEST_IMG}",cache=$CACHEMODE,driver=$IMGFMT,id=disk
-drive file="${TEST_IMG}",cache=$CACHEMODE,aio=$AIOMODE,driver=$IMGFMT,id=disk
h=$QEMU_HANDLE
_send_qemu_cmd $h "{ 'execute': 'qmp_capabilities' }" 'return'
@ -147,7 +147,7 @@ echo === Start mirror job and exit qemu ===
echo
_launch_qemu \
-drive file="${TEST_IMG}",cache=$CACHEMODE,driver=$IMGFMT,id=disk
-drive file="${TEST_IMG}",cache=$CACHEMODE,aio=$AIOMODE,driver=$IMGFMT,id=disk
h=$QEMU_HANDLE
_send_qemu_cmd $h "{ 'execute': 'qmp_capabilities' }" 'return'
@ -172,7 +172,7 @@ echo === Start backup job and exit qemu ===
echo
_launch_qemu \
-drive file="${TEST_IMG}",cache=$CACHEMODE,driver=$IMGFMT,id=disk
-drive file="${TEST_IMG}",cache=$CACHEMODE,aio=$AIOMODE,driver=$IMGFMT,id=disk
h=$QEMU_HANDLE
_send_qemu_cmd $h "{ 'execute': 'qmp_capabilities' }" 'return'
@ -196,7 +196,7 @@ echo === Start streaming job and exit qemu ===
echo
_launch_qemu \
-drive file="${TEST_IMG}",cache=$CACHEMODE,driver=$IMGFMT,id=disk
-drive file="${TEST_IMG}",cache=$CACHEMODE,aio=$AIOMODE,driver=$IMGFMT,id=disk
h=$QEMU_HANDLE
_send_qemu_cmd $h "{ 'execute': 'qmp_capabilities' }" 'return'

2
tests/qemu-iotests/200
View file

@ -67,7 +67,7 @@ echo === Starting QEMU VM ===
echo
qemu_comm_method="qmp"
_launch_qemu -object iothread,id=iothread0 $virtio_scsi \
-drive file="${TEST_IMG}",media=disk,if=none,cache=$CACHEMODE,id=drive_sysdisk,format=$IMGFMT \
-drive file="${TEST_IMG}",media=disk,if=none,cache=$CACHEMODE,aio=$AIOMODE,id=drive_sysdisk,format=$IMGFMT \
-device scsi-hd,drive=drive_sysdisk,bus=scsi0.0,id=sysdisk,bootindex=0
h1=$QEMU_HANDLE

8
tests/qemu-iotests/201
View file

@ -58,20 +58,20 @@ qemu_comm_method="monitor"
if [ "$IMGOPTSSYNTAX" = "true" ]; then
_launch_qemu \
-drive "${TEST_IMG}",cache=${CACHEMODE},id=disk
-drive "${TEST_IMG}",cache=${CACHEMODE},aio=$AIOMODE,id=disk
else
_launch_qemu \
-drive file="${TEST_IMG}",cache=${CACHEMODE},driver=$IMGFMT,id=disk
-drive file="${TEST_IMG}",cache=${CACHEMODE},aio=$AIOMODE,driver=$IMGFMT,id=disk
fi
src=$QEMU_HANDLE
if [ "$IMGOPTSSYNTAX" = "true" ]; then
_launch_qemu \
-drive "${TEST_IMG}",cache=${CACHEMODE},id=disk \
-drive "${TEST_IMG}",cache=${CACHEMODE},aio=$AIOMODE,id=disk \
-incoming "unix:${MIG_SOCKET}"
else
_launch_qemu \
-drive file="${TEST_IMG}",cache=${CACHEMODE},driver=$IMGFMT,id=disk \
-drive file="${TEST_IMG}",cache=${CACHEMODE},aio=$AIOMODE,driver=$IMGFMT,id=disk \
-incoming "unix:${MIG_SOCKET}"
fi
dest=$QEMU_HANDLE

15
tests/qemu-iotests/check
View file

@ -137,6 +137,7 @@ sortme=false
expunge=true
have_test_arg=false
cachemode=false
aiomode=false
tmp="${TEST_DIR}"/$$
rm -f $tmp.list $tmp.tmp $tmp.sed
@ -146,6 +147,7 @@ export IMGFMT_GENERIC=true
export IMGPROTO=file
export IMGOPTS=""
export CACHEMODE="writeback"
export AIOMODE="threads"
export QEMU_IO_OPTIONS=""
export QEMU_IO_OPTIONS_NO_FMT=""
export CACHEMODE_IS_DEFAULT=true
@ -230,6 +232,11 @@ s/ .*//p
CACHEMODE_IS_DEFAULT=false
cachemode=false
continue
elif $aiomode
then
AIOMODE="$r"
aiomode=false
continue
fi
xpand=true
@ -274,6 +281,7 @@ other options
-n show me, do not run tests
-o options -o options to pass to qemu-img create/convert
-c mode cache mode
-i mode AIO mode
-makecheck pretty print output for make check
testlist options
@ -438,10 +446,13 @@ testlist options
cachemode=true
xpand=false
;;
-i)
aiomode=true
xpand=false
;;
-T) # deprecated timestamp option
xpand=false
;;
-v)
verbose=true
xpand=false
@ -520,6 +531,8 @@ done
# Set qemu-io cache mode with $CACHEMODE we have
QEMU_IO_OPTIONS="$QEMU_IO_OPTIONS --cache $CACHEMODE"
# Set qemu-io aio mode with $AIOMODE we have
QEMU_IO_OPTIONS="$QEMU_IO_OPTIONS --aio $AIOMODE"
QEMU_IO_OPTIONS_NO_FMT="$QEMU_IO_OPTIONS"
if [ "$IMGOPTSSYNTAX" != "true" ]; then

14
tests/qemu-iotests/common.rc
View file

@ -645,6 +645,20 @@ _default_cache_mode()
return
fi
}
_supported_aio_modes()
{
for mode; do
if [ "$mode" = "$AIOMODE" ]; then
return
fi
done
_notrun "not suitable for aio mode: $AIOMODE"
}
_default_aio_mode()
{
AIOMODE="$1"
QEMU_IO="$QEMU_IO --aio $1"
}
_unsupported_imgopts()
{

12
tests/qemu-iotests/iotests.py
View file

@ -65,6 +65,7 @@
sock_dir = os.environ.get('SOCK_DIR')
output_dir = os.environ.get('OUTPUT_DIR', '.')
cachemode = os.environ.get('CACHEMODE')
aiomode = os.environ.get('AIOMODE')
qemu_default_machine = os.environ.get('QEMU_DEFAULT_MACHINE')
socket_scm_helper = os.environ.get('SOCKET_SCM_HELPER', 'socket_scm_helper')
@ -495,6 +496,7 @@ def add_drive(self, path, opts='', interface='virtio', format=imgfmt):
options.append('file=%s' % path)
options.append('format=%s' % format)
options.append('cache=%s' % cachemode)
options.append('aio=%s' % aiomode)
if opts:
options.append(opts)
@ -937,6 +939,10 @@ def verify_cache_mode(supported_cache_modes=[]):
if supported_cache_modes and (cachemode not in supported_cache_modes):
notrun('not suitable for this cache mode: %s' % cachemode)
def verify_aio_mode(supported_aio_modes=[]):
if supported_aio_modes and (aiomode not in supported_aio_modes):
notrun('not suitable for this aio mode: %s' % aiomode)
def supports_quorum():
return 'quorum' in qemu_img_pipe('--help')
@ -1023,8 +1029,9 @@ def execute_unittest(output, verbosity, debug):
def execute_test(test_function=None,
supported_fmts=[], supported_oses=['linux'],
supported_cache_modes=[], unsupported_fmts=[],
supported_protocols=[], unsupported_protocols=[]):
supported_cache_modes=[], supported_aio_modes={},
unsupported_fmts=[], supported_protocols=[],
unsupported_protocols=[]):
"""Run either unittest or script-style tests."""
# We are using TEST_DIR and QEMU_DEFAULT_MACHINE as proxies to
@ -1041,6 +1048,7 @@ def execute_test(test_function=None,
verify_protocol(supported_protocols, unsupported_protocols)
verify_platform(supported_oses)
verify_cache_mode(supported_cache_modes)
verify_aio_mode(supported_aio_modes)
if debug:
output = sys.stdout

36
util/async.c
View file

@ -276,6 +276,14 @@ aio_ctx_finalize(GSource *source)
}
#endif
#ifdef CONFIG_LINUX_IO_URING
if (ctx->linux_io_uring) {
luring_detach_aio_context(ctx->linux_io_uring, ctx);
luring_cleanup(ctx->linux_io_uring);
ctx->linux_io_uring = NULL;
}
#endif
assert(QSLIST_EMPTY(&ctx->scheduled_coroutines));
qemu_bh_delete(ctx->co_schedule_bh);
@ -340,6 +348,29 @@ LinuxAioState *aio_get_linux_aio(AioContext *ctx)
}
#endif
#ifdef CONFIG_LINUX_IO_URING
LuringState *aio_setup_linux_io_uring(AioContext *ctx, Error **errp)
{
if (ctx->linux_io_uring) {
return ctx->linux_io_uring;
}
ctx->linux_io_uring = luring_init(errp);
if (!ctx->linux_io_uring) {
return NULL;
}
luring_attach_aio_context(ctx->linux_io_uring, ctx);
return ctx->linux_io_uring;
}
LuringState *aio_get_linux_io_uring(AioContext *ctx)
{
assert(ctx->linux_io_uring);
return ctx->linux_io_uring;
}
#endif
void aio_notify(AioContext *ctx)
{
/* Write e.g. bh->scheduled before reading ctx->notify_me. Pairs
@ -434,6 +465,11 @@ AioContext *aio_context_new(Error **errp)
#ifdef CONFIG_LINUX_AIO
ctx->linux_aio = NULL;
#endif
#ifdef CONFIG_LINUX_IO_URING
ctx->linux_io_uring = NULL;
#endif
ctx->thread_pool = NULL;
qemu_rec_mutex_init(&ctx->lock);
timerlistgroup_init(&ctx->tlg, aio_timerlist_notify, ctx);