From patchwork Wed Apr 7 14:34:59 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kurz X-Patchwork-Id: 1463363 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) 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 ozlabs.org (Postfix) with ESMTPS id 4FFn5D2nkqz9sWY for ; Thu, 8 Apr 2021 00:36:16 +1000 (AEST) Received: from localhost ([::1]:56776 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lU9Hy-0000WQ-Et for incoming@patchwork.ozlabs.org; Wed, 07 Apr 2021 10:36:14 -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 X-MC-Unique: qTzJfcA9OsaiRgafA9kwKQ-1 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) 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 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+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" 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-blk.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; } + memory_region_transaction_begin(); + /* Set up virtqueue notify */ for (i = 0; i < nvqs; i++) { r = virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), i, true); if (r != 0) { + int j = 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; } } + memory_region_transaction_commit(); + s->starting = false; vblk->dataplane_started = true; trace_virtio_blk_data_plane_start(s); @@ -246,8 +257,15 @@ int virtio_blk_data_plane_start(VirtIODevice *vdev) return 0; fail_aio_context: + memory_region_transaction_begin(); + for (i = 0; i < nvqs; i++) { virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), i, false); + } + + memory_region_transaction_commit(); + + for (i = 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) aio_context_release(s->ctx); + memory_region_transaction_begin(); + for (i = 0; i < nvqs; i++) { virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), i, false); + } + + memory_region_transaction_commit(); + + for (i = 0; i < nvqs; i++) { virtio_bus_cleanup_host_notifier(VIRTIO_BUS(qbus), i); }