From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jason Wang Subject: Re: vhost + multiqueue + RSS question. Date: Mon, 17 Nov 2014 13:30:06 +0800 Message-ID: <546987DE.2010701@redhat.com> References: <20141116161818.GD7589@cloudius-systems.com> <20141116185604.GA12839@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org, virtualization@lists.linux-foundation.org To: "Michael S. Tsirkin" , Gleb Natapov Return-path: In-Reply-To: <20141116185604.GA12839@redhat.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org List-Id: kvm.vger.kernel.org On 11/17/2014 02:56 AM, Michael S. Tsirkin wrote: > On Sun, Nov 16, 2014 at 06:18:18PM +0200, Gleb Natapov wrote: >> Hi Michael, >> >> I am playing with vhost multiqueue capability and have a question about >> vhost multiqueue and RSS (receive side steering). My setup has Mellanox >> ConnectX-3 NIC which supports multiqueue and RSS. Network related >> parameters for qemu are: >> >> -netdev tap,id=hn0,script=qemu-ifup.sh,vhost=on,queues=4 >> -device virtio-net-pci,netdev=hn0,id=nic1,mq=on,vectors=10 >> >> In a guest I ran "ethtool -L eth0 combined 4" to enable multiqueue. >> >> I am running one tcp stream into the guest using iperf. Since there is >> only one tcp stream I expect it to be handled by one queue only but >> this seams to be not the case. ethtool -S on a host shows that the >> stream is handled by one queue in the NIC, just like I would expect, >> but in a guest all 4 virtio-input interrupt are incremented. Am I >> missing any configuration? > I don't see anything obviously wrong with what you describe. > Maybe, somehow, same irqfd got bound to multiple MSI vectors? > To see, can you try dumping struct kvm_irqfd that's passed to kvm? > > >> -- >> Gleb. This sounds like a regression, which kernel/qemu version did you use?