Re: [virtio-dev] Memory sharing device

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

On Tue, Feb 12, 2019 at 09:26:10AM -0800, Frank Yang wrote:
> BTW, the other unique aspect is that the ping messages allow a _host_ pointer
> to serve as the lump of shared memory;
> then there is no need to track buffers in the guest kernel and the device
> implementation can perform specialize buffer space management.
> Because it is also host pointer shared memory, it is also physically contiguous
> and there is no scatterlist needed to process the traffic.

Yes at the moment virtio descriptors all pass addresses guest to host.

Ability to reverse that was part of the vhost-pci proposal a while ago.
BTW that also at least originally had ability to tunnel
multiple devices over a single connection.

There was nothing wrong with the proposals I think, they
just had to be polished a bit before making it into the spec.
And that runneling was dropped but I think it can be brought back
if desired, we just didn't see a use for it.

How about that? That sounds close to what you were looking for,
does it not? That would be something to look into -
if your ideas can be used to implement a virtio device
backend by code running within a VM, that would be very interesting.

-- 
MST