Re: copyless virtio net thoughts?

[Simon Horman <horms@verge.net.au>]

On Wed, Feb 18, 2009 at 10:08:00PM +1030, Rusty Russell wrote:
> 
> 2) Direct NIC attachment This is particularly interesting with SR-IOV or
> other multiqueue nics, but for boutique cases or benchmarks, could be for
> normal NICs.  So far I have some very sketched-out patches: for the
> attached nic dev_alloc_skb() gets an skb from the guest (which supplies
> them via some kind of AIO interface), and a branch in netif_receive_skb()
> which returned it to the guest.  This bypasses all firewalling in the
> host though; we're basically having the guest process drive the NIC
> directly.

Hi Rusty,

Can I clarify that the idea with utilising SR-IOV would be to assign
virtual functions to guests? That is, something conceptually similar to
PCI pass-through in Xen (although I'm not sure that anyone has virtual
function pass-through working yet). If so, wouldn't this also be useful
on machines that have multiple NICs?

-- 
Simon Horman
  VA Linux Systems Japan K.K., Sydney, Australia Satellite Office
  H: www.vergenet.net/~horms/             W: www.valinux.co.jp/en