From nobody Sun Oct 26 01:37:18 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1516078604278305.3660048119285; Mon, 15 Jan 2018 20:56:44 -0800 (PST) Received: from localhost ([::1]:35257 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ebJIh-000762-HE for importer@patchew.org; Mon, 15 Jan 2018 23:56:43 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:47723) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ebJ9K-0007ej-Fz for qemu-devel@nongnu.org; Mon, 15 Jan 2018 23:47:03 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ebJ9J-0004h8-P8 for qemu-devel@nongnu.org; Mon, 15 Jan 2018 23:47:02 -0500 Received: from mx1.redhat.com ([209.132.183.28]:44842) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1ebJ9J-0004gk-JM for qemu-devel@nongnu.org; Mon, 15 Jan 2018 23:47:01 -0500 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 9E16B356CA; Tue, 16 Jan 2018 04:47:00 +0000 (UTC) Received: from redhat.com (ovpn-125-221.rdu2.redhat.com [10.10.125.221]) by smtp.corp.redhat.com (Postfix) with SMTP id E229C8B6D8; Tue, 16 Jan 2018 04:46:59 +0000 (UTC) Date: Tue, 16 Jan 2018 06:46:59 +0200 From: "Michael S. Tsirkin" To: qemu-devel@nongnu.org Message-ID: <1516077852-7974-9-git-send-email-mst@redhat.com> References: <1516077852-7974-1-git-send-email-mst@redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1516077852-7974-1-git-send-email-mst@redhat.com> X-Mutt-Fcc: =sent X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.30]); Tue, 16 Jan 2018 04:47:00 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PULL 08/33] virtio: improve virtio devices initialization time X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Gal Hammer , Peter Maydell , Xiaoling Gao , Sitong Liu Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Gal Hammer The loading time of a VM is quite significant when its virtio devices use a large amount of virt-queues (e.g. a virtio-serial device with max_ports=3D511). Most of the time is spend in the creation of all the required event notifiers (ioeventfd and memory regions). This patch pack all the changes to the memory regions in a single memory transaction. Reported-by: Sitong Liu Reported-by: Xiaoling Gao Signed-off-by: Gal Hammer Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- hw/virtio/virtio.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c index d6002ee..3ac3491 100644 --- a/hw/virtio/virtio.c +++ b/hw/virtio/virtio.c @@ -2574,6 +2574,7 @@ static int virtio_device_start_ioeventfd_impl(VirtIOD= evice *vdev) VirtioBusState *qbus =3D VIRTIO_BUS(qdev_get_parent_bus(DEVICE(vdev))); int n, r, err; =20 + memory_region_transaction_begin(); for (n =3D 0; n < VIRTIO_QUEUE_MAX; n++) { VirtQueue *vq =3D &vdev->vq[n]; if (!virtio_queue_get_num(vdev, n)) { @@ -2596,6 +2597,7 @@ static int virtio_device_start_ioeventfd_impl(VirtIOD= evice *vdev) } event_notifier_set(&vq->host_notifier); } + memory_region_transaction_commit(); return 0; =20 assign_error: @@ -2609,6 +2611,7 @@ assign_error: r =3D virtio_bus_set_host_notifier(qbus, n, false); assert(r >=3D 0); } + memory_region_transaction_commit(); return err; } =20 @@ -2625,6 +2628,7 @@ static void virtio_device_stop_ioeventfd_impl(VirtIOD= evice *vdev) VirtioBusState *qbus =3D VIRTIO_BUS(qdev_get_parent_bus(DEVICE(vdev))); int n, r; =20 + memory_region_transaction_begin(); for (n =3D 0; n < VIRTIO_QUEUE_MAX; n++) { VirtQueue *vq =3D &vdev->vq[n]; =20 @@ -2635,6 +2639,7 @@ static void virtio_device_stop_ioeventfd_impl(VirtIOD= evice *vdev) r =3D virtio_bus_set_host_notifier(qbus, n, false); assert(r >=3D 0); } + memory_region_transaction_commit(); } =20 void virtio_device_stop_ioeventfd(VirtIODevice *vdev) --=20 MST