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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 EC0B0C7618B for ; Fri, 26 Jul 2019 11:57:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CE669218DA for ; Fri, 26 Jul 2019 11:57:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726763AbfGZL5d (ORCPT ); Fri, 26 Jul 2019 07:57:33 -0400 Received: from mx1.redhat.com ([209.132.183.28]:56310 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726115AbfGZL5d (ORCPT ); Fri, 26 Jul 2019 07:57:33 -0400 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 3785183F4C; Fri, 26 Jul 2019 11:57:33 +0000 (UTC) Received: from [10.72.12.238] (ovpn-12-238.pek2.redhat.com [10.72.12.238]) by smtp.corp.redhat.com (Postfix) with ESMTP id DC5EA60C18; Fri, 26 Jul 2019 11:57:28 +0000 (UTC) Subject: Re: [PATCH] vhost: disable metadata prefetch optimization To: "Michael S. Tsirkin" , linux-kernel@vger.kernel.org Cc: kvm@vger.kernel.org, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org References: <20190726115021.7319-1-mst@redhat.com> From: Jason Wang Message-ID: Date: Fri, 26 Jul 2019 19:57:25 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <20190726115021.7319-1-mst@redhat.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US 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 [10.5.110.27]); Fri, 26 Jul 2019 11:57:33 +0000 (UTC) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 2019/7/26 下午7:51, Michael S. Tsirkin wrote: > This seems to cause guest and host memory corruption. > Disable for now until we get a better handle on that. > > Signed-off-by: Michael S. Tsirkin > --- > > I put this in linux-next, we'll re-enable if we can fix > the outstanding issues in a short order. Btw, is this more suitable to e.g revert the 842aa64eddacd23adc6ecdbc69cb2030bec47122 and let syzbot fuzz more on the current code? I think we won't accept that patch eventually, so I suspect what syzbot reports today is a false positives. Thanks > > drivers/vhost/vhost.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h > index 819296332913..42a8c2a13ab1 100644 > --- a/drivers/vhost/vhost.h > +++ b/drivers/vhost/vhost.h > @@ -96,7 +96,7 @@ struct vhost_uaddr { > }; > > #if defined(CONFIG_MMU_NOTIFIER) && ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 0 > -#define VHOST_ARCH_CAN_ACCEL_UACCESS 1 > +#define VHOST_ARCH_CAN_ACCEL_UACCESS 0 > #else > #define VHOST_ARCH_CAN_ACCEL_UACCESS 0 > #endif