Re: [virtio-dev] packed ring layout proposal

[Paolo Bonzini <pbonzini@redhat.com>]

On 19/09/2016 19:22, Michael S. Tsirkin wrote:
> No but you do need to make sure that when get_buf returns
> the first buffer, all buffers are available.

Is that not the case already?  But anyway I now agree it's better to put
it in the descriptor, thanks for clarifying.

> And from the achitecture POV, I feel this is a transport
> thing, not a device specific thing.

It depends, many devices (e.g. storage) are packet-based and bursts do
not have any meaning.  So I guess it's okay, but then I would prefer to
make it a separate feature bit.

I'm mostly afraid that it would be hard for the spec to define it in
general terms (while it's easy to define something specific to rxbuf
merging).  Having device-specific descriptor flags seems like a natural
extension anyway...

Paolo