[Qemu-devel] Re: [PATCH 0/2] fix virtio_blk serial pci config breakage

[Avi Kivity]

On 09/29/2009 03:51 PM, Anthony Liguori wrote:
> > The change this patch implements is passing of the
> > identify data through a mapping established by
> > PCI BAR #5 rather than the PCI config area, the
> > latter of which resulted in the above breakage.
>
>
> This is a massive layering violation.  The virtio-blk ABI cannot make 
> demands of the transport.

True.

> The better solution would be to move the entire virtio-pci config 
> space to a separate BAR that's an MMIO region.  Then there is no 
> practical limit on the size of the config area.

Don't some fast-paths accesses go through the config space?  Using mmio 
will slow them down.

--
error compiling committee.c: too many arguments to function