Re: [Qemu-devel] emulated lance device crashes in debian-sparc32

[Mark Glines <mark@glines.org>]

On Sun, 20 May 2007 10:10:20 +0300
"Blue Swirl" <blauwirbel@gmail.com> wrote:

> > I've verified your patch fixes the crash for me.  But I'm curious,
> > have I been running qemu in a nonstandard fashion, then?  (Should I
> > be specifying more than just "-net user", normally?)
> >
> > If so, I can make up a patch to amend the documentation.
> 
> I think Qemu should reject -net user only. Currently that seems to
> mean that there is no nic, but still the vlan is connected to slirp
> stack. That does not make any sense.

In my past experience, -net user implies -net nic. Your patch brings
sparc in line with the way x86 behaves - -net user implies -net nic
and the guest machine ends up with a network card, of whatever model is
default for that platform.

Hmm.  -net performs 2 separate functions.  First, it sets up the
network card in the guest machine (nic, model, and macaddr). Second, it
specifies how that card behaves on the host side of things (vlan, user,
tap, or socket).

If the host behavior implies a default card in the guest, then this
should occur for "-net tap" and "-net socket" as well as "-net user".
This has been my experience of what happens currently.  (And my sparc
bug report was the result of qemu violating my expectation that this is
how things should work.)  Are you saying it shouldn't be, and that "-net
nic" should be required before host-behavior parameters are valid?  If
so, I think the host-behavior parameters (all of them, not just -net
user) should result in an error message, in the absense of a guest card
parameter.

Mark