On Mon, Nov 17, 2014 at 09:44:23AM +0200, Gleb Natapov wrote: > On Sun, Nov 16, 2014 at 08:56:04PM +0200, 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? > It does not look like this is what is happening judging by the way > interrupts are distributed between queues. They are not distributed > uniformly and often I see one queue gets most interrupt and others get > much less and then it changes. Weird. It would happen if you transmitted from multiple CPUs. You did pin iperf to a single CPU within guest, did you not? > -- > Gleb. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
