From mboxrd@z Thu Jan 1 00:00:00 1970 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 497CECCD184 for ; Thu, 9 Oct 2025 16:20:52 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1v6tMx-0006L1-2M; Thu, 09 Oct 2025 12:19:55 -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 1v6tMs-0006K9-7t for qemu-devel@nongnu.org; Thu, 09 Oct 2025 12:19:50 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1v6tMh-0000bQ-Ru for qemu-devel@nongnu.org; Thu, 09 Oct 2025 12:19:48 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1760026766; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=kKfCoBWm+OS//HCHsarxXGzfMm867upCKyg0n3twxuU=; b=dUAdVruBGUTncAoJVbf1U8B+wBiyHN2cs9DTPbkZJq3iZDqW59r1KYmlGdoz7TQG/udeeI 9Tj1bdK8/cySBi6x3DiyJFri2wU6Ww4zyuHp5UAd2V1WwnRCcnKlNT1px1TlyymLRUY+HF C6W15Tq2JVW+WGkl1iN3sUx58tf2AZY= Received: from mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-630-NDPXsooKNkGMbKumYGy1Dw-1; Thu, 09 Oct 2025 12:19:24 -0400 X-MC-Unique: NDPXsooKNkGMbKumYGy1Dw-1 X-Mimecast-MFC-AGG-ID: NDPXsooKNkGMbKumYGy1Dw_1760026762 Received: from mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.12]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 7E8601800576; Thu, 9 Oct 2025 16:19:22 +0000 (UTC) Received: from redhat.com (unknown [10.44.32.99]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id EC95519560BB; Thu, 9 Oct 2025 16:19:18 +0000 (UTC) Date: Thu, 9 Oct 2025 18:19:15 +0200 From: Kevin Wolf To: Stefan Hajnoczi Cc: qemu-devel@nongnu.org, Aarushi Mehta , Fam Zheng , Stefano Garzarella , Hanna Czenczek , eblake@redhat.com, qemu-block@nongnu.org, hibriansong@gmail.com, Stefan Weil , Paolo Bonzini Subject: Re: [PATCH v4 08/12] aio-posix: gracefully handle io_uring_queue_init() failure Message-ID: References: <20250910175703.374499-1-stefanha@redhat.com> <20250910175703.374499-9-stefanha@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250910175703.374499-9-stefanha@redhat.com> X-Scanned-By: MIMEDefang 3.0 on 10.30.177.12 Received-SPF: pass client-ip=170.10.133.124; envelope-from=kwolf@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -24 X-Spam_score: -2.5 X-Spam_bar: -- X-Spam_report: (-2.5 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.438, 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_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, SPF_HELO_PASS=-0.001, T_SPF_TEMPERROR=0.01 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 Am 10.09.2025 um 19:56 hat Stefan Hajnoczi geschrieben: > io_uring may not be available at runtime due to system policies (e.g. > the io_uring_disabled sysctl) or creation could fail due to file > descriptor resource limits. > > Handle failure scenarios as follows: > > If another AioContext already has io_uring, then fail AioContext > creation so that the aio_add_sqe() API is available uniformly from all > QEMU threads. Otherwise fall back to epoll(7) if io_uring is > unavailable. > > Notes: > - Update the comment about selecting the fastest fdmon implementation. > At this point it's not about speed anymore, it's about aio_add_sqe() > API availability. > - Uppercase the error message when converting from error_report() to > error_setg_errno() for consistency (but there are instances of > lowercase in the codebase). > - It's easier to move the #ifdefs from aio-posix.h to aio-posix.c. > > Signed-off-by: Stefan Hajnoczi > Reviewed-by: Eric Blake > @@ -369,7 +370,7 @@ static const FDMonOps fdmon_io_uring_ops = { > .gsource_dispatch = fdmon_io_uring_gsource_dispatch, > }; > > -bool fdmon_io_uring_setup(AioContext *ctx) > +void fdmon_io_uring_setup(AioContext *ctx, Error **errp) > { > int ret; Same as in the previous patch, it would be more conventional to keep the bool return code in addition to the Error **. Either way: Reviewed-by: Kevin Wolf