Re: [PATCH] x86, msr: Better document AMD "tweak MSRs", rename MSR_F15H_IC_CFG

[Denys Vlasenko]

On 04/25/2017 01:59 PM, Borislav Petkov wrote:
> On Tue, Apr 25, 2017 at 01:45:41PM +0200, Denys Vlasenko wrote:
> > Before this patch, we have a define for MSR 0xc0011021: MSR_F15H_IC_CFG.
> > But it exists starting from K8, so it's not really a Fam15h MSR only.
> >
> > Lat's call it MSR_AMD64_IC_CFG.
>
> Except that we name only those MSRs with "AMD64" which are
> architectural. See "Appendix A MSR Cross-Reference" in APM vol 2.

Yes, APM vol 2 has none of c001_1xxx MSRs.

However, all IBS registers are in this range. DRi_ADDR_MASK
are in this range - and these are very useful, likely to stay.

In the arch/x86/include/asm/msr-index.h file we already have
three "tweak" MSRs defined with "AMD64":

#define MSR_AMD64_LS_CFG               0xc0011020
#define MSR_AMD64_DC_CFG               0xc0011022
#define MSR_AMD64_BU_CFG2              0xc001102a

I just noticed that we have a fourth one in
arch/x86/kernel/cpu/amd.c:

#define MSR_AMD64_DE_CFG       0xC0011029