Re: [Qemu-devel] [patch 2/2] QEMU BOCHS bios patches to use maxcpus value.

[Alexander Graf]

On 14.07.2009, at 11:32, Gleb Natapov wrote:

> On Tue, Jul 14, 2009 at 11:21:53AM +0200, Filip Navara wrote:
> > On Tue, Jul 14, 2009 at 10:38 AM, Jes Sorensen<address@hidden> wrote:
> > > On 07/09/2009 11:57 PM, Anthony Liguori wrote:
> > > > These changes make my Ubuntu server guest very unhappy.  I get a  
> > > > bunch
> > > > of messages about "Not responding." on startup.
> > > >
> > > > If nothing else, maxcpus ==smp_cpus under QEMU because we don't  
> > > > do CPU
> > > > hotplug (and I don't think we should).
> > >
> > > Anthony,
> > >
> > > Sorry haven't gotten back to you earlier as I was on vacation. Are  
> > > you
> > > saying the Ubuntu kernel doesn't like having more CPU entries in the
> > > ACPI table than it actually boots on?
> > >
> > > Does the same guest boot using an older KVM setup? Curious since  
> > > it does
> > > have the larger CPU table in the DSDT.
> > >
> > > Cheers,
> > > Jes
> >
> > BTW, many other guests complain when ACPI describes more processors
> > than actually present in machine. That's why I implemented the  
> > dynamic
> > DSDT generation in Bochs BIOS in the first place. One that comes to
> > mind is MacOS X, or the Darwin kernel respectively.
> There is nothing wrong in describing more processors than actually
> present. The disable flag is defined by ACPI for a reason. My real HW
> IBM server does this.

Yeah, last time I tried MacOS X was happy with more CPU descriptions  
than actual CPUs too as long as they were in disabled state. Has  
anything changed there I should know about?

Alex