On Mon, 2019-06-10 at 19:19 +0530, Aarushi Mehta wrote:
> Signed-off-by: Aarushi Mehta <mehta.aar...@gmail.com>
> ---
> block/file-posix.c | 85 +++++++++++++++++++++++++++++++++++++---------
> 1 file changed, 69 insertions(+), 16 deletions(-)
>
> diff --git a/block/file-posix.c b/block/file-posix.c
> index d018429672..211dfe5337 100644
> --- a/block/file-posix.c
> +++ b/block/file-posix.c
> @@ -154,6 +154,7 @@ typedef struct BDRVRawState {
> bool has_write_zeroes:1;
> bool discard_zeroes:1;
> bool use_linux_aio:1;
> + bool use_linux_io_uring:1;
Maybe an enum instead?
> bool page_cache_inconsistent:1;
> bool has_fallocate;
> bool needs_alignment;
> @@ -423,7 +424,7 @@ 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",
> @@ -482,9 +483,15 @@ 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);
> @@ -493,7 +500,11 @@ 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
Same as above
>
> locking = qapi_enum_parse(&OnOffAuto_lookup,
> qemu_opt_get(opts, "locking"),
> @@ -557,7 +568,7 @@ static int raw_open_common(BlockDriverState *bs, QDict
> *options,
> s->shared_perm = BLK_PERM_ALL;
>
> #ifdef CONFIG_LINUX_AIO
> - /* Currently Linux does AIO only for files opened with O_DIRECT */
> + /* Currently Linux does AIO only for files opened with O_DIRECT */
> if (s->use_linux_aio) {
> if (!(s->open_flags & O_DIRECT)) {
> error_setg(errp, "aio=native was specified, but it requires "
> @@ -579,6 +590,22 @@ 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) {
> @@ -1875,16 +1902,20 @@ static int coroutine_fn raw_co_prw(BlockDriverState
> *bs, uint64_t offset,
> * If this is the case tell the low-level driver that it needs
> * to copy the buffer.
> */
> - if (s->needs_alignment) {
> - if (!bdrv_qiov_is_aligned(bs, qiov)) {
> - type |= QEMU_AIO_MISALIGNED;
> + if (s->needs_alignment && !bdrv_qiov_is_aligned(bs, qiov)) {
> + type |= QEMU_AIO_MISALIGNED;
indention is wrong.
> +#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);
> + } else if (s->use_linux_aio && s->needs_alignment) {
You can probably drop the s->needs_alignment here as it is set iff the file if
opened with O_DIRECT which is a requirement
for the linux aio.
Maybe while at it, maybe update that comment prior to the 's->needs_alignment
&& !bdrv_qiov_is_aligned(bs, qiov)'
since it is somewhat outdated.
I think it should state:
"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"
Or something like that.
> + 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) {
> @@ -1920,24 +1951,36 @@ 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)
> @@ -1963,8 +2006,8 @@ static int raw_co_flush_to_disk(BlockDriverState *bs)
> 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;
> if (!aio_setup_linux_aio(new_context, &local_err)) {
> @@ -1974,6 +2017,16 @@ 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)
Other that minor notes,
Reviewed-by: Maxim Levitsky <mlevi...@redhat.com>
Best regards,
Maxim Levitsky
