From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Xu Subject: Re: [PATCH net] vhost: correctly check the iova range when waking virtqueue Date: Fri, 24 Aug 2018 17:36:35 +0800 Message-ID: <20180824093635.GC3020@xz-x1> References: <20180824085313.21798-1-jasowang@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Cc: mst@redhat.com, kvm@vger.kernel.org, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org To: Jason Wang Return-path: Content-Disposition: inline In-Reply-To: <20180824085313.21798-1-jasowang@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org On Fri, Aug 24, 2018 at 04:53:13PM +0800, Jason Wang wrote: > We don't wakeup the virtqueue if the first byte of pending iova range > is the last byte of the range we just got updated. This will lead a > virtqueue to wait for IOTLB updating forever. Fixing by correct the > check and wake up the virtqueue in this case. > > Fixes: 6b1e6cc7855b ("vhost: new device IOTLB API") > Reported-by: Peter Xu > Signed-off-by: Jason Wang Without this patch, this command will trigger the IO hang merely every time from host to guest: netperf -H 1.2.3.4 -l 5 -t TCP_RR -- -b 100 After applying, I can run it 10 times continuously without a problem. Reviewed-by: Peter Xu Tested-by: Peter Xu Thanks, -- Peter Xu