From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753155AbeDKNqE (ORCPT ); Wed, 11 Apr 2018 09:46:04 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:51348 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752598AbeDKNqD (ORCPT ); Wed, 11 Apr 2018 09:46:03 -0400 Subject: Re: [PATCH] vhost: Fix vhost_copy_to_user() To: Jason Wang , eric.auger.pro@gmail.com, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, kvm@vger.kernel.org, mst@redhat.com, kvmarm@lists.cs.columbia.edu References: <1523453438-4266-1-git-send-email-eric.auger@redhat.com> <85c033b9-b230-7ef9-744c-4e2799684609@redhat.com> Cc: stefanha@redhat.com From: Auger Eric Message-ID: <355234b2-651e-4e85-b5d2-d92bb6e33f13@redhat.com> Date: Wed, 11 Apr 2018 15:45:59 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.4.0 MIME-Version: 1.0 In-Reply-To: <85c033b9-b230-7ef9-744c-4e2799684609@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Jason, On 11/04/18 15:44, Jason Wang wrote: > > > On 2018年04月11日 21:30, Eric Auger wrote: >> vhost_copy_to_user is used to copy vring used elements to userspace. >> We should use VHOST_ADDR_USED instead of VHOST_ADDR_DESC. >> >> Fixes: f88949138058 ("vhost: introduce O(1) vq metadata cache") >> Signed-off-by: Eric Auger >> >> --- >> >> This fixes a stall observed when running an aarch64 guest with >> virtual smmu >> --- >> drivers/vhost/vhost.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c >> index bec722e..f44aead 100644 >> --- a/drivers/vhost/vhost.c >> +++ b/drivers/vhost/vhost.c >> @@ -744,7 +744,7 @@ static int vhost_copy_to_user(struct >> vhost_virtqueue *vq, void __user *to, >> struct iov_iter t; >> void __user *uaddr = vhost_vq_meta_fetch(vq, >> (u64)(uintptr_t)to, size, >> - VHOST_ADDR_DESC); >> + VHOST_ADDR_USED); >> if (uaddr) >> return __copy_to_user(uaddr, from, size); > > Acked-by: Jason Wang > > Thanks! > > Stable material I think. yes I think so. Thanks Eric