> From: Eric Auger [mailto:eric.au...@linaro.org] > Sent: Friday, September 19, 2014 10:23 AM > To: Gonglei (Arei); qemu list; Michael S. Tsirkin > Subject: Re: [Qemu-devel] [question] virtio-net-device and multi-queue option > > On 09/19/2014 03:42 AM, Gonglei (Arei) wrote: > >> Subject: [Qemu-devel] [question] virtio-net-device and multi-queue option > >> > >> Hi, > >> > >> > >> I am currently doing some benchmarks using virtio-net-device using > >> virtio-mmio (non PCI) with qemu_system_arm with KVM. Purpose is to > >> compare with device passthrough performance. > >> > >> I heard about the availability of a multi-queue option that greatly > >> improves the performance but I currently fail in enabling it. > >> > >> Please could someone explain me how to turn that feature on? My current > >> virtio-net options simply are: > >> > >> -netdev tap,id=tap0,ifname="tap0" \ > >> -device virtio-net-device,netdev=tap0 > >> > > > > There are some steps: > > > > 1. create multi-queue netdev device, such as tap device (you can > > use "ip tuntap" command, or libvirt), something like as below: > > ip tuntap add tap_1 mode tap multi_queue > > 2. pass corresponding parameters in QEMU command line: > > -netdev > type=tap,ifname=tap_q,id=net1,vhost=on,vhostforce=on,queues=4,script= \ > > -device virtio-net-device,netdev=net1,mq=on,vectors=9 > > Hi Gonglei, > > Thanks for your quick reply. > > Definitively I have not gone through step 1! Nethertheless I am a but > dubious about the fact the mq property does not seem to exist for my > virtio-net-device. I get > > qemu-system-arm: -device > virtio-net-device,netdev=tap0,mq=on,mac=52:54:00:12:34:56: Property > '.mq' not found > Sorry, my typo. :(
It should be "virtio-net-pci", not "virtio-net-devcie" BTW, You can use help command to get a devices properties: # ./qemu-system-x86_64 -device virtio-net-pci,? [...] virtio-net-pci.mq=on/off [...] Best regards, -Gonglei > Best Regards > > Eric > > > >> Also are there any "easy" tunings I can play with to try to reach the > >> best performance. > >> > > > > You can consider that using irq binding, core binding, vhost-net? etc.. > > > > Best regards, > > -Gonglei > > > >> Thank you in advance > >> > >> Best Regards > >> > >> Eric > >
