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 54449C282DE for ; Mon, 10 Mar 2025 14:44:27 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1treMa-0000O7-Dw; Mon, 10 Mar 2025 10:44:16 -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 1treMY-0000Mv-PM for qemu-devel@nongnu.org; Mon, 10 Mar 2025 10:44:14 -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 1treMX-0002eR-1J for qemu-devel@nongnu.org; Mon, 10 Mar 2025 10:44:14 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1741617852; 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=e79LTItO9Zxn/2a/B6blpLMqcSuTSDDuVE7qNES85Ic=; b=aHvWbQNC0uS00ExYF3K7/R0VV9moCyxRt1Y73m+zcg39SAaWeoLSrzPfdIJbXI2tr+N3O1 kV1tKVdBpRAMkStR+MNtUSa1ba6PjNWxrka2bnskEsCiTJjaOuVB37C49DF0VdA7h393q6 1MKp1qqx2FB+Zo0QZv+l7q6JErlGJFw= Received: from mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-571-g4KHKMWYMzaq_Ofu-mKJPw-1; Mon, 10 Mar 2025 10:44:05 -0400 X-MC-Unique: g4KHKMWYMzaq_Ofu-mKJPw-1 X-Mimecast-MFC-AGG-ID: g4KHKMWYMzaq_Ofu-mKJPw_1741617845 Received: from mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.93]) (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-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id A5A8119560BC; Mon, 10 Mar 2025 14:44:04 +0000 (UTC) Received: from redhat.com (unknown [10.45.225.222]) by mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 1368418001E9; Mon, 10 Mar 2025 14:43:59 +0000 (UTC) Date: Mon, 10 Mar 2025 15:43:57 +0100 From: Kevin Wolf To: Stefan Hajnoczi Cc: qemu-devel@nongnu.org, Paolo Bonzini , John Snow , Fam Zheng , Peter Xu , Philippe =?iso-8859-1?Q?Mathieu-Daud=E9?= , "Michael S. Tsirkin" , qemu-block@nongnu.org, David Hildenbrand , pkrempa@redhat.com, Hanna Reitz Subject: Re: [PATCH 00/12] virtio-scsi: add iothread-vq-mapping parameter Message-ID: References: <20250213180043.713434-1-stefanha@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250213180043.713434-1-stefanha@redhat.com> X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.93 Received-SPF: pass client-ip=170.10.129.124; envelope-from=kwolf@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_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham 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 13.02.2025 um 19:00 hat Stefan Hajnoczi geschrieben: > Implement --device virtio-scsi-pci,iothread-vq-mapping= support so that > virtqueues can be assigned to different IOThreads. This improves SMP guest > scalability where I/O-intensive applications can become bottlenecked on a > single IOThread. > > The following benchmark results show the effect of iothread-vq-mapping. fio > randread 4k iodepth=64 results from a 4 vCPU guest with an Intel P4800X SSD: > iothreads IOPS > ------------------------------ > 1 189576 > 2 312698 > 4 346744 > > The virtio-scsi device model and core SCSI emulation currently assume that > requests are processed in a single AioContext. This patch series goes about > modifying this as follows: > > scsi-disk: drop unused SCSIDiskState->bh field > dma: use current AioContext for dma_blk_io() > > Make dma-helpers.c support the QEMU multi-queue block layer by using > qemu_get_current_aio_context(). > > scsi: track per-SCSIRequest AioContext > scsi: introduce requests_lock > > Make the core SCSI emulation code support processing requests in multiple > AioContexts by protecting the per-SCSIDevice requests list. > > virtio-scsi: introduce event and ctrl virtqueue locks > virtio-scsi: protect events_dropped field > virtio-scsi: perform TMFs in appropriate AioContexts > > Make the virtio-scsi emulation code support processing requests in multiple > AioContexts. The event and ctrl virtqueues can interact with multiple > AioContexts. Especially the SCSI Task Management Functions (TMFs) handled by > the ctrl virtqueue need to be made thread-safe. > > virtio-blk: extract cleanup_iothread_vq_mapping() function > virtio-blk: tidy up iothread_vq_mapping functions > virtio: extract iothread-vq-mapping.h API > virtio-scsi: add iothread-vq-mapping parameter > > Port over the iothread-vq-mapping qdev property from virtio-blk to virtio-scsi. > > virtio-scsi: handle ctrl virtqueue in main loop > > Simplify TMF handling now that there is no longer a single AioContext where all > requests are processed. > > Stefan Hajnoczi (12): > scsi-disk: drop unused SCSIDiskState->bh field > dma: use current AioContext for dma_blk_io() > scsi: track per-SCSIRequest AioContext > scsi: introduce requests_lock > virtio-scsi: introduce event and ctrl virtqueue locks > virtio-scsi: protect events_dropped field > virtio-scsi: perform TMFs in appropriate AioContexts > virtio-blk: extract cleanup_iothread_vq_mapping() function > virtio-blk: tidy up iothread_vq_mapping functions > virtio: extract iothread-vq-mapping.h API > virtio-scsi: add iothread-vq-mapping parameter > virtio-scsi: handle ctrl virtqueue in main loop Patches 1-10: Reviewed-by: Kevin Wolf