From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jason Wang Subject: Re: [PATCH] vhost: Fix vhost_copy_to_user() Date: Wed, 11 Apr 2018 21:44:45 +0800 Message-ID: <85c033b9-b230-7ef9-744c-4e2799684609@redhat.com> References: <1523453438-4266-1-git-send-email-eric.auger@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Cc: stefanha@redhat.com To: Eric Auger , 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 Return-path: In-Reply-To: <1523453438-4266-1-git-send-email-eric.auger@redhat.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org 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.