Subject: Re: [PATCH 0/2][RFC] virtio_net: MAC filtering

From: Alex Williamson <[email-masked]>
Date: Wed, 07 Jan 2009 11:28:25 -0700

On Wed, 2009-01-07 at 12:14 -0600, Anthony Liguori wrote:
> Alex Williamson wrote:
> >
> > As noted in the RFC thread adding the kvm/qemu backing, this does
> > increase the size of the virtio-net device I/O port space, up to 1kB
> > with PCI rounding if we add a 4k entry VLAN bitmap.  A 64 device limit
> > is still pretty high for a VM, but maybe we should think about adding
> > MMIO space for virtio-pci.  Thanks,
> >   
> 
> I'm not quite sure the best way to address this.  Maybe another control 
> queue for sending commands to control this sort of stuff?  What are your 
> thoughts Rusty?

This is also a good time to decide if a fixed 16 entry MAC filter table
is sufficient.  Should the size be programmed into the config space?
There's plenty of room to make it a bigger fixed size and still stay at
1kB of I/O port space with the VLAN table.  This implementation is a
little wasteful of space in using 8 bytes to store the MAC and a valid
bit, but I suspect there's some endian issues I'm ignoring and a
standard data type might make that easier later.

Alex

-- 
Alex Williamson                             HP Open Source & Linux Org.