Hi Paolo, Many apologies to you, I did not reply to you earlier. I somehow missed your email.
The command I used was sudo qemu-system-arm -enable-kvm -kernel zImage -machine type=virt -display none -cpu cortex-a15 -m 512 -append 'console=ttyAMA0 root=/dev/vda ip=192.168.42.24:192.168.42.1:192.168.42.1:255.255.255.0:::off rw' -serial stdio -drive file=/dev/sdb2,if=none,cache=writeback,id=foo -device virtio-blk-device,drive=foo -netdev tap,id=br0,vhost=on -device virtio-net-device,netdev=br0 Also, I had missed out on this important message among the huge kernel logs "qemu-system-arm: unable to start vhost net: 38: falling back on userspace virtio" I observed that the cause is that set_guest_notifiers is not implemented in virtio-mmio in qemu. So I guess either this has to be implemented in virtio-mmio or to use virtio-pci to move further. Thanks, Giridhar On 31 October 2013 15:19, Paolo Bonzini <pbonz...@redhat.com> wrote: > Il 31/10/2013 04:32, Giridhar Maruthy ha scritto: >> On 30 October 2013 22:12, Paolo Bonzini <pbonz...@redhat.com> wrote: >>> Il 30/10/2013 15:40, Giridhar Maruthy ha scritto: >>>> Hi All, >>>> >>>> I tried to measure the network performance of guest (mach-virt) with >>>> virtio-net on an ARM host platform (Samsung exynos). The qemu version >>>> is 1.6.50. >>>> >>>> I found that with 1GbE NIC on the host, the host iperf gave a speed of >>>> 847Mbits/sec when a local dhcp server was used as a iperf server. >>>> >>>> But the guest gave a speed of 478Mbits/sec which is around 56% compared to >>>> host. >>>> >>>> What is the typical guest network efficiency compared to host with >>>> virtio-net? >>>> Any ideas would be helpful. >>> >>> Were you using vhost? >> >> Yes, I did use vhost in the host kernel configuration and passed >> vhost=on in qemu, but there is no difference in the performance of >> guest. > > What's your command line? > > Paolo >
