From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: Re: vhost + multiqueue + RSS question. Date: Sun, 16 Nov 2014 20:56:04 +0200 Message-ID: <20141116185604.GA12839@redhat.com> References: <20141116161818.GD7589@cloudius-systems.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: Gleb Natapov Return-path: Content-Disposition: inline In-Reply-To: <20141116161818.GD7589@cloudius-systems.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 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.