Re: [PATCH v2 5/8] x86/mtrr: revert commit 90b926e68f50

From: Christian Kujau
Date: Mon Feb 13 2023 - 06:46:27 EST


On Mon, 13 Feb 2023, Juergen Gross wrote:
> On 10.02.23 19:59, Linux regression tracking (Thorsten Leemhuis) wrote:
> > Hi, this is your Linux kernel regression tracker.
> >
> > On 09.02.23 08:22, Juergen Gross wrote:
> > > Commit 90b926e68f50 ("x86/pat: Fix pat_x_mtrr_type() for MTRR disabled
> > > case") has introduced a regression with Xen.
> > >
> > > Revert the patch.
> >
> > That regression you refer to is afaics one I'm tracking[1] that was
> > introduced this cycle. That makes me wonder: could this patch be applied
> > directly to fix the issue quickly? Or are patches 1 to 4 needed as well
> > (or the whole series?) to avoid other problems?
>
> Patches 1-4 are needed, too, as otherwise the issue claimed to be fixed
> with patch 5 would show up again.

The (last?) -rc8 version was released yesterday. Would it be possible to
include at least (only) the revert in mainline so that 6.2 will be
released with a working storage configuration under Xen?

Otherwise one would have to carry around that single revert manually until
this patch series has landed in mainline, or convince all the
distributions to do so :-\

Anyway, thanks for fixing this problem, I did not expect this to be such a
complicated issue when I reported that thing :-)

Christian.
--
BOFH excuse #52:

Smell from unhygienic janitorial staff wrecked the tape heads