[ipxe-devel] [PATCH 4/4] [virtio] Add virtio-net 1.0 support

[Michael S. Tsirkin]

On Fri, Mar 11, 2016 at 02:43:23AM +0200, Michael S. Tsirkin wrote:
> On Thu, Mar 10, 2016 at 04:04:31PM +0100, Ladi Prosek wrote:
> > On Thu, Mar 10, 2016 at 3:12 PM, Michael S. Tsirkin <mst at redhat.com> wrote:
> > > On Wed, Mar 09, 2016 at 07:20:03PM +0100, Ladi Prosek wrote:
> > >> +     /* Enable PCI bus master and reset NIC */
> > >> +     adjust_pci_device ( pci );
> > >
> > > At the moment, this enables memory and io unconditionally.  But I think
> > > it should check BAR is assigned before enabling and using it, since
> > > e.g. pci express devices might not have their BARs assigned.
> > >
> > > I'm also not sure 64 bit BAR values will work under ipxe -
> > > if not it's preferably to fall back on io or cfg access.
> > 
> > Hmm.. 64-bit BARs are indeed not supported. It would be better to
> > always use the cfg cap then and remove all that BAR mapping business.
> > Less code and fewer assumptions for the win.
> 
> Much slower though.

Thinking more about it, I think it's a good idea to
leave the mapping infrastructure in place, but
maybe only do the CFG approach as the first step.

Once code is upstream and works, we can add
faster BAR/IO support later.

Cc Gerd who worked on similar issues for virtio blk.

Gerd, what did you do there?

> > > --
> > > MST