Re: Xen 4.18.5 PV dbregs fail

[Manuel Bouyer <bouyer@xxxxxxxxxxxxxxx>]

On Mon, May 26, 2025 at 09:30:53PM +0100, Andrew Cooper wrote:
> On 26/05/2025 9:13 pm, Manuel Bouyer wrote:
> > On Mon, May 26, 2025 at 07:50:14PM +0100, Andrew Cooper wrote:
> >> [...]
> >> Well, that range does include the aforementioned commit.
> >>
> >> Can you bisect around d32c77f471fb8400b6512c171a14cdd58f04f0a3 which is
> >> the backport of ^ in 4.18 ?
> > Sure,
> > with 0d5f15e and d32c77f the test pass, with cecee35 it fails.
> >
> 
> Oh interesting, so the basic forwarding of #DB back into a guest
> (d32c77f) works fine, but the changes to emulated debug exceptions
> (cecee35) break.
> 
> Anyway, I think I've spotted a logical error.  We do indeed end up
> calling x86_merge_dr6() twice, because of the TODO just out of context. 
> Does this help?

Yes, it works for cecee35; now testing with 4.18.5

-- 
Manuel Bouyer <bouyer@xxxxxxxxxxxxxxx>
     NetBSD: 26 ans d'experience feront toujours la difference
--