From nobody Tue Feb 10 08:03:27 2026 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org ARC-Seal: i=1; a=rsa-sha256; t=1617806222; cv=none; d=zohomail.com; s=zohoarc; b=M+4kj9ySj6Cg+1cx1jmATrXlAzBM5COai4Cm2QehasZLyEc/XUWLA/wsoLZl3o/Yttkjyl++r75igPj9CTtqsH9ZWvrUZ8jd7RTew2I6YeclRljm1kkDTRqGH04Dg0Gk3fpTlXCrcEqooU+OH0xA/hl3wS4tqAP0vofFin3ADpU= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1617806222; h=Content-Type:Content-Transfer-Encoding:Cc:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:To; bh=/vipDaGPU0WVzB1bnz+E0gw/GjyqlJcp0P7eRl4m4NE=; b=Fb++KIhn8enWir4snKSwnt7PGuhkfi7FzvjGjweXrfINyIbN3cBUYtqC4ILu7dNuveBJOJRbkba1spOhr6q6HjHh1/YsiwnJjkhpEdD0bMbTABqs6pmx6WifAh647o81yDbtx3FFN0LrP7pUf8ikFU1qylFhKplX5samPoTevy4= ARC-Authentication-Results: i=1; mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1617806222964910.1187307164089; Wed, 7 Apr 2021 07:37:02 -0700 (PDT) Received: from localhost ([::1]:59762 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lU9Ik-0001mu-8i for importer@patchew.org; Wed, 07 Apr 2021 10:37:02 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:42902) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lU9H0-0008JG-RW for qemu-devel@nongnu.org; Wed, 07 Apr 2021 10:35:14 -0400 Received: from us-smtp-delivery-44.mimecast.com ([205.139.111.44]:60230) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lU9Gz-0006NS-7H for qemu-devel@nongnu.org; Wed, 07 Apr 2021 10:35:14 -0400 Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-64-qTzJfcA9OsaiRgafA9kwKQ-1; Wed, 07 Apr 2021 10:35:10 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id B2ABB801814; Wed, 7 Apr 2021 14:35:09 +0000 (UTC) Received: from bahia.redhat.com (ovpn-114-100.ams2.redhat.com [10.36.114.100]) by smtp.corp.redhat.com (Postfix) with ESMTP id B1F4E5D9CA; Wed, 7 Apr 2021 14:35:07 +0000 (UTC) X-MC-Unique: qTzJfcA9OsaiRgafA9kwKQ-1 From: Greg Kurz To: qemu-devel@nongnu.org Subject: [for-6.1 2/4] virtio-blk: Configure all host notifiers in a single MR transaction Date: Wed, 7 Apr 2021 16:34:59 +0200 Message-Id: <20210407143501.244343-3-groug@kaod.org> In-Reply-To: <20210407143501.244343-1-groug@kaod.org> References: <20210407143501.244343-1-groug@kaod.org> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=groug@kaod.org X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: kaod.org Content-Transfer-Encoding: quoted-printable Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: softfail client-ip=205.139.111.44; envelope-from=groug@kaod.org; helo=us-smtp-delivery-44.mimecast.com X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_LOW=-0.7, SPF_HELO_NONE=0.001, SPF_SOFTFAIL=0.665 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kevin Wolf , Fam Zheng , qemu-block@nongnu.org, "Michael S. Tsirkin" , Greg Kurz , Max Reitz , Stefan Hajnoczi , Paolo Bonzini , David Gibson Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" Content-Type: text/plain; charset="utf-8" This allows the virtio-blk-pci device to batch the setup of all its host notifiers. This significantly improves boot time of VMs with a high number of vCPUs, e.g. from 3m26.186s down to 0m58.023s for a pseries machine with 384 vCPUs. Note that memory_region_transaction_commit() must be called before virtio_bus_cleanup_host_notifier() because the latter might close ioeventfds that the transaction still assumes to be around when it commits. Signed-off-by: Greg Kurz --- hw/block/dataplane/virtio-blk.c | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) diff --git a/hw/block/dataplane/virtio-blk.c b/hw/block/dataplane/virtio-bl= k.c index d7b5c95d26d9..cd81893d1d01 100644 --- a/hw/block/dataplane/virtio-blk.c +++ b/hw/block/dataplane/virtio-blk.c @@ -198,19 +198,30 @@ int virtio_blk_data_plane_start(VirtIODevice *vdev) goto fail_guest_notifiers; } =20 + memory_region_transaction_begin(); + /* Set up virtqueue notify */ for (i =3D 0; i < nvqs; i++) { r =3D virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), i, true); if (r !=3D 0) { + int j =3D i; + fprintf(stderr, "virtio-blk failed to set host notifier (%d)\n= ", r); while (i--) { virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), i, false); + } + + memory_region_transaction_commit(); + + while (j--) { virtio_bus_cleanup_host_notifier(VIRTIO_BUS(qbus), i); } goto fail_host_notifiers; } } =20 + memory_region_transaction_commit(); + s->starting =3D false; vblk->dataplane_started =3D true; trace_virtio_blk_data_plane_start(s); @@ -246,8 +257,15 @@ int virtio_blk_data_plane_start(VirtIODevice *vdev) return 0; =20 fail_aio_context: + memory_region_transaction_begin(); + for (i =3D 0; i < nvqs; i++) { virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), i, false); + } + + memory_region_transaction_commit(); + + for (i =3D 0; i < nvqs; i++) { virtio_bus_cleanup_host_notifier(VIRTIO_BUS(qbus), i); } fail_host_notifiers: @@ -312,8 +330,15 @@ void virtio_blk_data_plane_stop(VirtIODevice *vdev) =20 aio_context_release(s->ctx); =20 + memory_region_transaction_begin(); + for (i =3D 0; i < nvqs; i++) { virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), i, false); + } + + memory_region_transaction_commit(); + + for (i =3D 0; i < nvqs; i++) { virtio_bus_cleanup_host_notifier(VIRTIO_BUS(qbus), i); } =20 --=20 2.26.3