Re: [PATCH 3/4] x86, AMD: Fix crash as Xen Dom0 on AMD Trinity systems

["H. Peter Anvin" <hpa@zytor.com>]

On 06/01/2012 07:52 AM, Borislav Petkov wrote:
> From: Andre Przywara <andre.przywara@amd.com>
> 
> f7f286a910221 ("x86/amd: Re-enable CPU topology extensions in case BIOS
> has disabled it") wrongfully added code which used the AMD-specific
> {rd,wr}msr variants for no real reason.
> 
> This caused boot panics on xen which wasn't initializing the
> {rd,wr}msr_safe_regs pv_ops members properly.
> 
> This, in turn, caused a heated discussion leading to us reviewing all
> uses of the AMD-specific variants and removing them where unneeded
> (almost everywhere except an obscure K8 BIOS fix, see 6b0f43ddfa358).
> 
> Finally, this patch switches to the standard {rd,wr}msr*_safe* variants
> which should've been used in the first place anyway and avoided unneeded
> excitation with xen.
> 
> Signed-off-by: Andre Przywara <andre.przywara@amd.com>
> Cc: Andreas Herrmann <andreas.herrmann3@amd.com>
> Cc: stable@vger.kernel.org # 3.4+
> Link: <http://lkml.kernel.org/r/1338383402-3838-1-git-send-email-andre.przywara@amd.com>
> [Boris: correct and expand commit message]
> Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>

Why -stable?  I though we had agreed that we didn't have an active
problem (unclean hack, yes, but not an active problem) in 3.4/3.5 as it
currently sits?

	-hpa

-- 
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel.  I don't speak on their behalf.