Re: [Qemu-devel] vhost-pci and virtio-vhost-user

[Wei Wang]

On 01/15/2018 02:56 PM, Jason Wang wrote:
> On 2018年01月12日 18:18, Stefan Hajnoczi wrote:
> >
>
> I just fail understand why we can't do software defined network or 
> storage with exist virtio device/drivers (or are there any 
> shortcomings that force us to invent new infrastructure).

Existing virtio-net works with a host central vSwitch, and it has the 
following disadvantages:
1) long code/data path;
2) poor scalability; and
3) host CPU sacrifice

Vhost-pci solves the above issues by providing a point-to-point 
communication between VMs. No matter how the control path would look 
like finally, the key point is that the data path is P2P between VMs.

Best,
Wei