From patchwork Thu Sep 14 14:00:58 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Hajnoczi X-Patchwork-Id: 13385479 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 13D45EEAA40 for ; Thu, 14 Sep 2023 14:03:29 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qgmuq-00080h-6V; Thu, 14 Sep 2023 10:01:56 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qgmuc-0007yZ-Bo for qemu-devel@nongnu.org; Thu, 14 Sep 2023 10:01:44 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qgmuV-00019T-LP for qemu-devel@nongnu.org; Thu, 14 Sep 2023 10:01:40 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1694700084; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=MAOhD67sgYXgN63nbkZvtAVWc6L847RzatreqXJJcKg=; b=OtvgMg+a2oGF0N8ViVWKlunD/vS5Yj4A3eBBtQDIX4YDtFo68Bw+M2++0hyxjpUFYuZwla oxobt6Bjn8UzvV+WQUbLxwf1tRWC4nsURKbJJHGCNfd322jdPqCyTZkqsPsvCUoiOREN1E SBrtXVUIvhIWozRR38A7SPFIqd8uKhQ= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-369-GnC-y2r4MJKOnvasmPRETg-1; Thu, 14 Sep 2023 10:01:20 -0400 X-MC-Unique: GnC-y2r4MJKOnvasmPRETg-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 34EA8857A9A; Thu, 14 Sep 2023 14:01:05 +0000 (UTC) Received: from localhost (unknown [10.39.194.105]) by smtp.corp.redhat.com (Postfix) with ESMTP id AD54E1054FC2; Thu, 14 Sep 2023 14:01:04 +0000 (UTC) From: Stefan Hajnoczi To: qemu-devel@nongnu.org Cc: Kevin Wolf , Stefan Hajnoczi , , Hanna Reitz , "Michael S. Tsirkin" Subject: [PATCH 1/4] block/file-posix: set up Linux AIO and io_uring in the current thread Date: Thu, 14 Sep 2023 10:00:58 -0400 Message-ID: <20230914140101.1065008-2-stefanha@redhat.com> In-Reply-To: <20230914140101.1065008-1-stefanha@redhat.com> References: <20230914140101.1065008-1-stefanha@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.3 Received-SPF: pass client-ip=170.10.129.124; envelope-from=stefanha@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=unavailable autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org The file-posix block driver currently only sets up Linux AIO and io_uring in the BDS's AioContext. In the multi-queue block layer we must be able to submit I/O requests in AioContexts that do not have Linux AIO and io_uring set up yet since any thread can call into the block driver. Set up Linux AIO and io_uring for the current AioContext during request submission. We lose the ability to return an error from .bdrv_file_open() when Linux AIO and io_uring setup fails (e.g. due to resource limits). Instead the user only gets warnings and we fall back to aio=threads. This is still better than a fatal error after startup. Signed-off-by: Stefan Hajnoczi Reviewed-by: Eric Blake --- block/file-posix.c | 99 ++++++++++++++++++++++------------------------ 1 file changed, 47 insertions(+), 52 deletions(-) diff --git a/block/file-posix.c b/block/file-posix.c index 4757914ac0..e9dbb87c57 100644 --- a/block/file-posix.c +++ b/block/file-posix.c @@ -713,17 +713,11 @@ static int raw_open_common(BlockDriverState *bs, QDict *options, #ifdef CONFIG_LINUX_AIO /* 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 " - "cache.direct=on, which was not specified."); - ret = -EINVAL; - goto fail; - } - if (!aio_setup_linux_aio(bdrv_get_aio_context(bs), errp)) { - error_prepend(errp, "Unable to use native AIO: "); - goto fail; - } + if (s->use_linux_aio && !(s->open_flags & O_DIRECT)) { + error_setg(errp, "aio=native was specified, but it requires " + "cache.direct=on, which was not specified."); + ret = -EINVAL; + goto fail; } #else if (s->use_linux_aio) { @@ -734,14 +728,7 @@ 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 +#ifndef CONFIG_LINUX_IO_URING if (s->use_linux_io_uring) { error_setg(errp, "aio=io_uring was specified, but is not supported " "in this build."); @@ -2442,6 +2429,44 @@ static bool bdrv_qiov_is_aligned(BlockDriverState *bs, QEMUIOVector *qiov) return true; } +static inline bool raw_check_linux_io_uring(BDRVRawState *s) +{ + Error *local_err = NULL; + AioContext *ctx; + + if (!s->use_linux_io_uring) { + return false; + } + + ctx = qemu_get_current_aio_context(); + if (unlikely(!aio_setup_linux_io_uring(ctx, &local_err))) { + error_reportf_err(local_err, "Unable to use linux io_uring, " + "falling back to thread pool: "); + s->use_linux_io_uring = false; + return false; + } + return true; +} + +static inline bool raw_check_linux_aio(BDRVRawState *s) +{ + Error *local_err = NULL; + AioContext *ctx; + + if (!s->use_linux_aio) { + return false; + } + + ctx = qemu_get_current_aio_context(); + if (unlikely(!aio_setup_linux_aio(ctx, &local_err))) { + error_reportf_err(local_err, "Unable to use Linux AIO, " + "falling back to thread pool: "); + s->use_linux_aio = false; + return false; + } + return true; +} + static int coroutine_fn raw_co_prw(BlockDriverState *bs, uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int type) { @@ -2470,13 +2495,13 @@ static int coroutine_fn raw_co_prw(BlockDriverState *bs, uint64_t offset, 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) { + } else if (raw_check_linux_io_uring(s)) { assert(qiov->size == bytes); ret = luring_co_submit(bs, s->fd, offset, qiov, type); goto out; #endif #ifdef CONFIG_LINUX_AIO - } else if (s->use_linux_aio) { + } else if (raw_check_linux_aio(s)) { assert(qiov->size == bytes); ret = laio_co_submit(s->fd, offset, qiov, type, s->aio_max_batch); @@ -2566,39 +2591,13 @@ static int coroutine_fn raw_co_flush_to_disk(BlockDriverState *bs) }; #ifdef CONFIG_LINUX_IO_URING - if (s->use_linux_io_uring) { + if (raw_check_linux_io_uring(s)) { return luring_co_submit(bs, s->fd, 0, NULL, QEMU_AIO_FLUSH); } #endif return raw_thread_pool_submit(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 - if (s->use_linux_aio) { - Error *local_err = NULL; - if (!aio_setup_linux_aio(new_context, &local_err)) { - error_reportf_err(local_err, "Unable to use native AIO, " - "falling back to thread pool: "); - s->use_linux_aio = false; - } - } -#endif -#ifdef CONFIG_LINUX_IO_URING - if (s->use_linux_io_uring) { - Error *local_err = NULL; - 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) { BDRVRawState *s = bs->opaque; @@ -3897,7 +3896,6 @@ BlockDriver bdrv_file = { .bdrv_co_copy_range_from = raw_co_copy_range_from, .bdrv_co_copy_range_to = raw_co_copy_range_to, .bdrv_refresh_limits = raw_refresh_limits, - .bdrv_attach_aio_context = raw_aio_attach_aio_context, .bdrv_co_truncate = raw_co_truncate, .bdrv_co_getlength = raw_co_getlength, @@ -4267,7 +4265,6 @@ static BlockDriver bdrv_host_device = { .bdrv_co_copy_range_from = raw_co_copy_range_from, .bdrv_co_copy_range_to = raw_co_copy_range_to, .bdrv_refresh_limits = raw_refresh_limits, - .bdrv_attach_aio_context = raw_aio_attach_aio_context, .bdrv_co_truncate = raw_co_truncate, .bdrv_co_getlength = raw_co_getlength, @@ -4403,7 +4400,6 @@ static BlockDriver bdrv_host_cdrom = { .bdrv_co_pwritev = raw_co_pwritev, .bdrv_co_flush_to_disk = raw_co_flush_to_disk, .bdrv_refresh_limits = cdrom_refresh_limits, - .bdrv_attach_aio_context = raw_aio_attach_aio_context, .bdrv_co_truncate = raw_co_truncate, .bdrv_co_getlength = raw_co_getlength, @@ -4529,7 +4525,6 @@ static BlockDriver bdrv_host_cdrom = { .bdrv_co_pwritev = raw_co_pwritev, .bdrv_co_flush_to_disk = raw_co_flush_to_disk, .bdrv_refresh_limits = cdrom_refresh_limits, - .bdrv_attach_aio_context = raw_aio_attach_aio_context, .bdrv_co_truncate = raw_co_truncate, .bdrv_co_getlength = raw_co_getlength,