Re: [Qemu-devel] [PATCH 00/16] Add a -netdev option

[Edgar E. Iglesias]

On Fri, Oct 09, 2009 at 08:09:35AM +0100, Mark McLoughlin wrote:
> Hi Stefan,
> 
> On Thu, 2009-10-08 at 22:29 +0200, Stefan Weil wrote:
> 
> > Hi Mark,
> > 
> > today, qemu's ethernet devices are a fixed combination of
> > MAC (Media Access Controller) and PHY (Physical Layer).
> > 
> > Real hardware is different: the controllers provide a MAC,
> > and many provide a PHY, too, but all controllers allow
> > one or even several external PHY(s).
> > 
> > Most (or all?) controllers use the same standard interface
> > to address their PHY (internal or external), something
> > which is completely missing today in qemu.
> > 
> > A better solution would use separate code for MAC and
> > PHY, so the controllers could share common code for the
> > PHY.
> > 
> > Configuration of a different PHY should be possible,
> > so users can run a system emulation of different
> > MAC-PHY combinations.
> > 
> > In addition to the PHY type, a PHY needs attributes
> > (link speed and link status).
> > 
> > Maybe you can address these requirements in your
> > redesign.
> 
> Doesn't that sound like something purely for the device model itself, as
> opposed to the core packet handling code?

Right, this kind of PHY emulation is purely for emulated control not
for packet data paths.

Cheers