Re: [Qemu-devel] [virtio-dev] [PATCH v3 0/7] Vhost-pci for inter-VM communication

["Michael S. Tsirkin" <mst@redhat.com>]

On Thu, Dec 07, 2017 at 07:54:48AM +0000, Avi Cohen (A) wrote:
> There is already a  virtio mechanism in which 2 VMs assigned a virtio device , are communicating via a veth pair  in the host .
> KVM just passes  a pointer of the page of the writer VM to the reader VM - resulting  in  excellent performance (no vSwitch in the middle)

What exactly do you refer to?

> **Question**:  What is the advantage of vhost-pci compared to this ?
> Best Regards
> Avi

I suspect what's missing in this thread is the original motivation rfc:
http://virtualization.linux-foundation.narkive.com/A7FkzAgp/rfc-vhost-user-enhancements-for-vm2vm-communication