From patchwork Tue Jun 5 19:08:03 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wei Xu X-Patchwork-Id: 925611 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=nongnu.org (client-ip=208.118.235.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=redhat.com Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 410hQB0Hysz9s0W for ; Wed, 6 Jun 2018 05:17:22 +1000 (AEST) Received: from localhost ([::1]:48699 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fQHSJ-0001q1-SZ for incoming@patchwork.ozlabs.org; Tue, 05 Jun 2018 15:17:19 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:42650) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fQHJs-0002Hp-U7 for qemu-devel@nongnu.org; Tue, 05 Jun 2018 15:08:37 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fQHJr-0003FN-U2 for qemu-devel@nongnu.org; Tue, 05 Jun 2018 15:08:36 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:56678 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fQHJr-0003EO-4z for qemu-devel@nongnu.org; Tue, 05 Jun 2018 15:08:35 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id CA8C880401A8; Tue, 5 Jun 2018 19:08:34 +0000 (UTC) Received: from dell-per430-12.lab.eng.pek2.redhat.com (dell-per430-12.lab.eng.pek2.redhat.com [10.73.196.55]) by smtp.corp.redhat.com (Postfix) with ESMTP id 41B032026609; Tue, 5 Jun 2018 19:08:31 +0000 (UTC) From: wexu@redhat.com To: qemu-devel@nongnu.org Date: Tue, 5 Jun 2018 15:08:03 -0400 Message-Id: <1528225683-11413-9-git-send-email-wexu@redhat.com> In-Reply-To: <1528225683-11413-1-git-send-email-wexu@redhat.com> References: <1528225683-11413-1-git-send-email-wexu@redhat.com> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.4 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.8]); Tue, 05 Jun 2018 19:08:34 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.8]); Tue, 05 Jun 2018 19:08:34 +0000 (UTC) for IP:'10.11.54.4' DOMAIN:'int-mx04.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'wexu@redhat.com' RCPT:'' X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 66.187.233.73 Subject: [Qemu-devel] [RFC v2 8/8] virtio: guest driver reload for vhost-net 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: jasowang@redhat.com, jfreimann@redhat.com, wexu@redhat.com, tiwei.bie@intel.com, mst@redhat.com Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" From: Wei Xu last_avail, avail_wrap_count, used_idx and used_wrap_count are needed to support vhost-net backend, all these are either 16 or bool variables, since state.num is 64bit wide, so here it is possible to put them to the 'num' without introducing a new case while handling ioctl. Unload/Reload test has been done successfully with a patch in vhost kernel. Signed-off-by: Wei Xu --- hw/virtio/virtio.c | 42 ++++++++++++++++++++++++++++++++++-------- 1 file changed, 34 insertions(+), 8 deletions(-) diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c index 4543974..153f6d7 100644 --- a/hw/virtio/virtio.c +++ b/hw/virtio/virtio.c @@ -2862,33 +2862,59 @@ hwaddr virtio_queue_get_used_size(VirtIODevice *vdev, int n) } } -uint16_t virtio_queue_get_last_avail_idx(VirtIODevice *vdev, int n) +uint64_t virtio_queue_get_last_avail_idx(VirtIODevice *vdev, int n) { - return vdev->vq[n].last_avail_idx; + uint64_t num; + + num = vdev->vq[n].last_avail_idx; + if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) { + num |= ((uint64_t)vdev->vq[n].avail_wrap_counter) << 16; + num |= ((uint64_t)vdev->vq[n].used_idx) << 32; + num |= ((uint64_t)vdev->vq[n].used_wrap_counter) << 48; + } + + return num; } -void virtio_queue_set_last_avail_idx(VirtIODevice *vdev, int n, uint16_t idx) +void virtio_queue_set_last_avail_idx(VirtIODevice *vdev, int n, uint64_t num) { - vdev->vq[n].last_avail_idx = idx; - vdev->vq[n].shadow_avail_idx = idx; + vdev->vq[n].shadow_avail_idx = vdev->vq[n].last_avail_idx = (uint16_t)(num); + + if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) { + vdev->vq[n].avail_wrap_counter = (uint16_t)(num >> 16); + vdev->vq[n].used_idx = (uint16_t)(num >> 32); + vdev->vq[n].used_wrap_counter = (uint16_t)(num >> 48); + } } void virtio_queue_restore_last_avail_idx(VirtIODevice *vdev, int n) { rcu_read_lock(); - if (vdev->vq[n].vring.desc) { + if (!vdev->vq[n].vring.desc) { + goto out; + } + + if (!virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) { vdev->vq[n].last_avail_idx = vring_used_idx(&vdev->vq[n]); - vdev->vq[n].shadow_avail_idx = vdev->vq[n].last_avail_idx; } + vdev->vq[n].shadow_avail_idx = vdev->vq[n].last_avail_idx; + +out: rcu_read_unlock(); } void virtio_queue_update_used_idx(VirtIODevice *vdev, int n) { rcu_read_lock(); - if (vdev->vq[n].vring.desc) { + if (!vdev->vq[n].vring.desc) { + goto out; + } + + if (!virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) { vdev->vq[n].used_idx = vring_used_idx(&vdev->vq[n]); } + +out: rcu_read_unlock(); }