On Wed, Dec 18, 2019 at 04:32:21PM +0000, Stefan Hajnoczi wrote:
> From: Aarushi Mehta <mehta.aar...@gmail.com>
>
> Signed-off-by: Aarushi Mehta <mehta.aar...@gmail.com>
> Reviewed-by: Maxim Levitsky <maximlevit...@gmail.com>
> Signed-off-by: Stefan Hajnoczi <stefa...@redhat.com>
> ---
> block/file-posix.c | 95 ++++++++++++++++++++++++++++++++++++----------
> 1 file changed, 75 insertions(+), 20 deletions(-)
>
> diff --git a/block/file-posix.c b/block/file-posix.c
> index 1b805bd938..a42a90e59d 100644
> --- a/block/file-posix.c
> +++ b/block/file-posix.c
> @@ -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 +504,11 @@ 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;
> + } else {
> + aio_default = BLOCKDEV_AIO_OPTIONS_THREADS;
> + }
This is only a cosmetic change?
> aio = qapi_enum_parse(&BlockdevAioOptions_lookup,
> qemu_opt_get(opts, "aio"),
> aio_default, &local_err);
> @@ -514,7 +517,11 @@ 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"),
> @@ -578,7 +585,7 @@ 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 */
Also this is a not related fix, if you respin maybe we should split in a
new patch or say something in the commit message.
> if (s->use_linux_aio) {
> if (!(s->open_flags & O_DIRECT)) {
> error_setg(errp, "aio=native was specified, but it requires "
> @@ -600,6 +607,22 @@ 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 +1900,25 @@ 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;
> + 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);
> + } else if (s->use_linux_aio) {
This code block was executed if "s->needs_alignment" was true, now we don't
check it. Could this be a problem?
> + 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 +1954,36 @@ 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 +2003,20 @@ 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 +2026,16 @@ 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)
> --
> 2.23.0
>
>
