Re: [Qemu-devel] [PATCH RFC] memory: drop _overlap variant

[Michael S. Tsirkin]

On Thu, Feb 14, 2013 at 08:23:04PM +0200, Avi Kivity wrote:
> On Thu, Feb 14, 2013 at 8:12 PM, Michael S. Tsirkin <address@hidden> wrote:
> >>
> >> Is there an actual real problem that needs fixing?
> >
> > Yes. Guests sometimes cause device BARs to temporary overlap
> > the APIC range during BAR sizing. It works fine on a physical
> > system but fails on KVM since pci has same priority.
> >
> > See the report:
> > [BUG] Guest OS hangs on boot when 64bit BAR present
> >
> 
> Is PCI_COMMAND_MEMORY set while this is going on?

I think Linux never clears PCI_COMMAND_MEMORY because
it's buggy in some devices.