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 X-Spam-Level: X-Spam-Status: No, score=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B5D2FC04AB4 for ; Fri, 17 May 2019 04:30:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8E3882083E for ; Fri, 17 May 2019 04:30:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727826AbfEQEaV (ORCPT ); Fri, 17 May 2019 00:30:21 -0400 Received: from mx1.redhat.com ([209.132.183.28]:50606 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727731AbfEQEaP (ORCPT ); Fri, 17 May 2019 00:30:15 -0400 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 357263092647; Fri, 17 May 2019 04:30:15 +0000 (UTC) Received: from hp-dl380pg8-02.lab.eng.pek2.redhat.com (hp-dl380pg8-02.lab.eng.pek2.redhat.com [10.73.8.12]) by smtp.corp.redhat.com (Postfix) with ESMTP id CC66A1001DEF; Fri, 17 May 2019 04:30:12 +0000 (UTC) From: Jason Wang To: mst@redhat.com, jasowang@redhat.com, virtualization@lists.linux-foundation.org, kvm@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Cc: pbonzini@redhat.com, stefanha@redhat.com Subject: [PATCH V2 3/4] vhost: vsock: add weight support Date: Fri, 17 May 2019 00:29:51 -0400 Message-Id: <1558067392-11740-4-git-send-email-jasowang@redhat.com> In-Reply-To: <1558067392-11740-1-git-send-email-jasowang@redhat.com> References: <1558067392-11740-1-git-send-email-jasowang@redhat.com> X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.43]); Fri, 17 May 2019 04:30:15 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch will check the weight and exit the loop if we exceeds the weight. This is useful for preventing vsock kthread from hogging cpu which is guest triggerable. The weight can help to avoid starving the request from on direction while another direction is being processed. The value of weight is picked from vhost-net. This addresses CVE-2019-3900. Cc: Stefan Hajnoczi Fixes: 433fc58e6bf2 ("VSOCK: Introduce vhost_vsock.ko") Signed-off-by: Jason Wang --- drivers/vhost/vsock.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c index 47c6d4d..814bed7 100644 --- a/drivers/vhost/vsock.c +++ b/drivers/vhost/vsock.c @@ -86,6 +86,7 @@ static struct vhost_vsock *vhost_vsock_get(u32 guest_cid) struct vhost_virtqueue *vq) { struct vhost_virtqueue *tx_vq = &vsock->vqs[VSOCK_VQ_TX]; + int pkts = 0, total_len = 0; bool added = false; bool restart_tx = false; @@ -97,7 +98,7 @@ static struct vhost_vsock *vhost_vsock_get(u32 guest_cid) /* Avoid further vmexits, we're already processing the virtqueue */ vhost_disable_notify(&vsock->dev, vq); - for (;;) { + do { struct virtio_vsock_pkt *pkt; struct iov_iter iov_iter; unsigned out, in; @@ -182,8 +183,9 @@ static struct vhost_vsock *vhost_vsock_get(u32 guest_cid) */ virtio_transport_deliver_tap_pkt(pkt); + total_len += pkt->len; virtio_transport_free_pkt(pkt); - } + } while(likely(!vhost_exceeds_weight(vq, ++pkts, total_len))); if (added) vhost_signal(&vsock->dev, vq); @@ -358,7 +360,7 @@ static void vhost_vsock_handle_tx_kick(struct vhost_work *work) struct vhost_vsock *vsock = container_of(vq->dev, struct vhost_vsock, dev); struct virtio_vsock_pkt *pkt; - int head; + int head, pkts = 0, total_len = 0; unsigned int out, in; bool added = false; @@ -368,7 +370,7 @@ static void vhost_vsock_handle_tx_kick(struct vhost_work *work) goto out; vhost_disable_notify(&vsock->dev, vq); - for (;;) { + do { u32 len; if (!vhost_vsock_more_replies(vsock)) { @@ -409,9 +411,11 @@ static void vhost_vsock_handle_tx_kick(struct vhost_work *work) else virtio_transport_free_pkt(pkt); - vhost_add_used(vq, head, sizeof(pkt->hdr) + len); + len += sizeof(pkt->hdr); + vhost_add_used(vq, head, len); + total_len += len; added = true; - } + } while(likely(!vhost_exceeds_weight(vq, ++pkts, total_len))); no_more_replies: if (added) -- 1.8.3.1