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=ham 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 85E17C04AB4 for ; Thu, 16 May 2019 07:48:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6030E20862 for ; Thu, 16 May 2019 07:48:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726902AbfEPHsH (ORCPT ); Thu, 16 May 2019 03:48:07 -0400 Received: from mx1.redhat.com ([209.132.183.28]:51626 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726864AbfEPHsD (ORCPT ); Thu, 16 May 2019 03:48:03 -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 8E4D33082135; Thu, 16 May 2019 07:48:03 +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 3CA365D6A9; Thu, 16 May 2019 07:48:00 +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 4/4] vhost: scsi: add weight support Date: Thu, 16 May 2019 03:47:42 -0400 Message-Id: <1557992862-27320-5-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 [10.5.110.42]); Thu, 16 May 2019 07:48:03 +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 scsi kthread from hogging cpu which is guest triggerable. This addresses CVE-2019-3900. Cc: Paolo Bonzini Cc: Stefan Hajnoczi Fixes: 057cbf49a1f0 ("tcm_vhost: Initial merge for vhost level target fabric driver") Signed-off-by: Jason Wang --- drivers/vhost/scsi.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c index d830579..3a59f47 100644 --- a/drivers/vhost/scsi.c +++ b/drivers/vhost/scsi.c @@ -918,7 +918,7 @@ static void vhost_scsi_submission_work(struct work_struct *work) struct iov_iter in_iter, prot_iter, data_iter; u64 tag; u32 exp_data_len, data_direction; - int ret, prot_bytes; + int ret, prot_bytes, c = 0; u16 lun; u8 task_attr; bool t10_pi = vhost_has_feature(vq, VIRTIO_SCSI_F_T10_PI); @@ -938,7 +938,7 @@ static void vhost_scsi_submission_work(struct work_struct *work) vhost_disable_notify(&vs->dev, vq); - for (;;) { + do { ret = vhost_scsi_get_desc(vs, vq, &vc); if (ret) goto err; @@ -1118,7 +1118,7 @@ static void vhost_scsi_submission_work(struct work_struct *work) break; else if (ret == -EIO) vhost_scsi_send_bad_target(vs, vq, vc.head, vc.out); - } + } while (likely(!vhost_exceeds_weight(vq, ++c, 0))); out: mutex_unlock(&vq->mutex); } @@ -1177,7 +1177,7 @@ static void vhost_scsi_submission_work(struct work_struct *work) } v_req; struct vhost_scsi_ctx vc; size_t typ_size; - int ret; + int ret, c = 0; mutex_lock(&vq->mutex); /* @@ -1191,7 +1191,7 @@ static void vhost_scsi_submission_work(struct work_struct *work) vhost_disable_notify(&vs->dev, vq); - for (;;) { + do { ret = vhost_scsi_get_desc(vs, vq, &vc); if (ret) goto err; @@ -1270,7 +1270,7 @@ static void vhost_scsi_submission_work(struct work_struct *work) break; else if (ret == -EIO) vhost_scsi_send_bad_target(vs, vq, vc.head, vc.out); - } + } while (likely(!vhost_exceeds_weight(vq, ++c, 0))); out: mutex_unlock(&vq->mutex); } -- 1.8.3.1