From patchwork Thu May 16 07:47:41 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jason Wang X-Patchwork-Id: 10945831 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id C24871390 for ; Thu, 16 May 2019 07:48:14 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B620228852 for ; Thu, 16 May 2019 07:48:14 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id A9665288A2; Thu, 16 May 2019 07:48:14 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4ED6A28852 for ; Thu, 16 May 2019 07:48:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726839AbfEPHsC (ORCPT ); Thu, 16 May 2019 03:48:02 -0400 Received: from mx1.redhat.com ([209.132.183.28]:54656 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726818AbfEPHsA (ORCPT ); Thu, 16 May 2019 03:48:00 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id BC2FC10C94; Thu, 16 May 2019 07:48:00 +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 6F0965D6A9; Thu, 16 May 2019 07:47:58 +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 net 3/4] vhost: vsock: add weight support Date: Thu, 16 May 2019 03:47:41 -0400 Message-Id: <1557992862-27320-4-git-send-email-jasowang@redhat.com> In-Reply-To: <1557992862-27320-1-git-send-email-jasowang@redhat.com> References: <1557992862-27320-1-git-send-email-jasowang@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Thu, 16 May 2019 07:48:00 +0000 (UTC) Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 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..1fa9deb 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; @@ -183,7 +184,8 @@ static struct vhost_vsock *vhost_vsock_get(u32 guest_cid) virtio_transport_deliver_tap_pkt(pkt); virtio_transport_free_pkt(pkt); - } + total_len += pkt->len; + } 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)