I have an host machine with qemu-kvm 2.11.1 (I built it) kernel version 4.6.3-elrepo OS Centos 6

One VM acts as a router and has two bridge connections between the physical interface and the virtual network of the others VMs

I use -netdev and model virtio with vhost=on.

On some cases I see an high cpu load on the host machine of the VM acting as a router, while inside VM 99 cpu is idle.

As I understand, it`s used for emulating network. So question are :

  1. Is there any practical difference beetween model=virtio and vhost=on and virtio-pci-net ?

  2. Is it normal to have the CPU overloaded with just 6 - 7 MBit/s of traffic ( mostly UDP and http requests)

  3. Is there any reason to upgrade kernel

  4. what optimizations are possible?


  • I try virtio-net-pci and get some success results. Seems that reduce cpu consumption in virtual network, instead of using old virtio model. In same situation load average of host less – Sergey Apr 25 at 6:39

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