On 09/19/2014 04:30 AM, Gonglei (Arei) wrote: >> 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 > [...] Hi Gonglei,
I fear I can only use virtio-net-device since I only have VIRTIO-MMIO in my machine file and no PCI bus. The mq property does not seem to be supported for virtio-net-device as reported by sudo arm-softmmu/qemu-system-arm -M virt -device virtio-net-device,? virtio-net-device.tx=str virtio-net-device.x-txburst=int32 virtio-net-device.x-txtimer=uint32 virtio-net-device.bootindex=int32 virtio-net-device.netdev=netdev virtio-net-device.vlan=vlan virtio-net-device.mac=macaddr Thanks Best Regards Eric > > 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 >>> >
