From c64475106909b7f53c31949657e6909b856e0ad4 Mon Sep 17 00:00:00 2001 From: Aarushi Mehta Date: Mon, 20 Jan 2020 14:18:51 +0000 Subject: [PATCH] block/file-posix.c: extend to use io_uring Signed-off-by: Aarushi Mehta Reviewed-by: Maxim Levitsky Acked-by: Stefano Garzarella Signed-off-by: Stefan Hajnoczi Message-id: 20200120141858.587874-9-stefanha@redhat.com Message-Id: <20200120141858.587874-9-stefanha@redhat.com> Signed-off-by: Stefan Hajnoczi --- block/file-posix.c | 100 ++++++++++++++++++++++++++++++++++++--------- 1 file changed, 80 insertions(+), 20 deletions(-) diff --git a/block/file-posix.c b/block/file-posix.c index 2b08b02d27..ab82ee1a67 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 +504,16 @@ 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)