From mboxrd@z Thu Jan 1 00:00:00 1970 From: Auger Eric Subject: Re: [PATCH] vhost: Fix vhost_copy_to_user() Date: Wed, 11 Apr 2018 15:45:59 +0200 Message-ID: <355234b2-651e-4e85-b5d2-d92bb6e33f13@redhat.com> References: <1523453438-4266-1-git-send-email-eric.auger@redhat.com> <85c033b9-b230-7ef9-744c-4e2799684609@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Cc: stefanha@redhat.com 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 Return-path: In-Reply-To: <85c033b9-b230-7ef9-744c-4e2799684609@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.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