Re: [Qemu-devel] Re: [PATCH 2/3] virtio network device

[Paul Brook]

> virtio makes things a bit trickier though.  There's a shared ring queue
> between the host and guest.  The ring queue is lock-less and depends on
> the ability to atomically increment ring queue indices to be SMP safe.
> Using a copy-API wouldn't be a problem for QEMU since the host and guest
> are always running in lock-step.  A copy API is actually needed to deal
> with differing host/guest alignment and endianness.

That seems a rather poor design choice, as many architectures don't have an 
atomic increment instruction. Oh well.

Paul