Re: Xen regression, Was: [PATCH] x86/irq: Probe for PIC presence before allocating descs for legacy IRQs

[Boris Ostrovsky]

On 04/12/2016 07:15 PM, Stefano Stabellini wrote:
> On Tue, 12 Apr 2016, Boris Ostrovsky wrote:
> > On 04/12/2016 05:56 PM, Stefano Stabellini wrote:
> > >    I am not sure, maybe you didn't have CONFIG_SPARSE_IRQ?
> > > But I am certain that 4.6-rc2, with the attached config, fails as Dom0
> > > on QEMU with the following sequence of calls:
> > I did have CONFIG_SPARSE_IRQ and I just rebuilt 4.5.0 with your config
> > (4.6-rc3 doesn't build for me for some reason) and that booted dom0 as well.
> >
> > BTW, what do you mean by "dom0 on QEMU"?
>   
> I am running Xen and Linux inside a QEMU x86_64 emulated machine (nested
> virt).

This I, of course, never tried.

But given that things work in a single-level virt, doesn't this imply 
that perhaps there is something in the emulation that's not quite right?

-boris