Re: [Qemu-devel] [BUGFIX][PATCH for 2.2 v3 1/1] -machine vmport=auto: Fix handling of VMWare ioport emulation for xen

[Eduardo Habkost]

On Thu, Nov 20, 2014 at 12:00:19PM +0100, Paolo Bonzini wrote:
> 
> 
> On 20/11/2014 11:00, Dr. David Alan Gilbert wrote:
> >> > I'm still not sure why the configuration should differ for "-M pc"
> >> > depending on whether xen is enabled.
> > I think this goes back to:
> > 
> > commit 1611977c3d8fdbdac6090cbd1f5555cee4aed6d9
> > Author: Anthony PERARD <address@hidden>
> > Date:   Tue May 3 17:06:54 2011 +0100
> > 
> >     pc, Disable vmport initialisation with Xen.
> >     
> >     This is because there is not synchronisation of the vcpu register
> >     between Xen and QEMU, so vmport can't work properly.
> >     
> >     This patch introduces no_vmport parameter to pc_basic_device_init.
> >     
> >     Signed-off-by: Anthony PERARD <address@hidden>
> >     Signed-off-by: Alexander Graf <address@hidden>
> 
> Yes, but Xen has since implemented vmport (commit 37f9e258).  It's fine
> to have a conservative default for "-M xenfv" and possibly "-M pc-2.1",
> but "-M pc" can require the latest hypervisor.

Are there any ABI stability expectations when using -machine
pc-2.1,accel=xen? I guess there aren't any, and in this case the first
patch (the one changing default_machine_opts) would be enough.

-- 
Eduardo