[PATCH] x86/cpu: Fix the AMD Fam 17h, Fam 19h, Zen2 and Zen4 enumerations

From: Ingo Molnar
Date: Thu Oct 12 2023 - 14:12:11 EST



* Borislav Petkov <bp@xxxxxxxxx> wrote:

> On Wed, Oct 11, 2023 at 11:28:26PM +0200, Ingo Molnar wrote:
> > While in reality:
> >
> > Zen 2 == Fam 17h
> > Zen 4 == Fam 19h
>
> If only were that easy...
>
> family 0x17 is Zen1 and 2, family 0x19 is spread around Zen 3 and 4.
>
...
> See above. The MSRs are per Zen generation while the family is per
> family. Yes, it is confusing. :-\

Fun!

> IOW, you want to have this as the end product:
>
> /* Zen4 */
> #define MSR_ZEN4_BP_CFG 0xc001102e
> #define MSR_ZEN4_BP_CFG_SHARED_BTB_FIX_BIT 5
>
> /* Fam 19h MSRs */
> #define MSR_F19H_UMC_PERF_CTL 0xc0010800
> #define MSR_F19H_UMC_PERF_CTR 0xc0010801
>
> /* Zen 2 */
> #define MSR_ZEN2_SPECTRAL_CHICKEN 0xc00110e3
> #define MSR_ZEN2_SPECTRAL_CHICKEN_BIT BIT_ULL(1)
>
> /* Fam 17h MSRs */
> #define MSR_F17H_IRPERF 0xc00000e9

Ok, thanks - I've distilled your enumeration order into the separate
patch below - there's more commits in perf/core meanwhile, and maybe
it isn't even bad there's a bit of a spotlight on the naming
scheme here.

I've turned your above grouping & comments into a patch, created a
changelog and added your SOB, see the perf/core commit below.
Lemme know if that's not OK to you.

Thanks,

Ingo

=============>
From: Borislav Petkov <bp@xxxxxxxxx>
Date: Thu, 12 Oct 2023 20:01:59 +0200
Subject: [PATCH] x86/cpu: Fix the AMD Fam 17h, Fam 19h, Zen2 and Zen4 MSR enumerations

The comments introduced in <asm/msr-index.h> in the merge conflict fixup in:

8f4156d58713 ("Merge branch 'x86/urgent' into perf/core, to resolve conflict")

... aren't right: AMD naming schemes are more complex than implied,
family 0x17 is Zen1 and 2, family 0x19 is spread around Zen 3 and 4.

So there's indeed four separate MSR namespaces for:

MSR_F17H_
MSR_F19H_
MSR_ZEN2_
MSR_ZEN4_

... and the namespaces cannot be merged.

Fix it up. No change in functionality.

Signed-off-by: Borislav Petkov (AMD) <bp@xxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/D99589F4-BC5D-430B-87B2-72C20370CF57@xxxxxxxxxxxxx
---
arch/x86/include/asm/msr-index.h | 20 +++++++++++---------
1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h
index 0ad9ba8baa8a..f8b502867dd1 100644
--- a/arch/x86/include/asm/msr-index.h
+++ b/arch/x86/include/asm/msr-index.h
@@ -637,18 +637,20 @@
/* AMD Last Branch Record MSRs */
#define MSR_AMD64_LBR_SELECT 0xc000010e

-/* Fam 19h (Zen 4) MSRs */
-#define MSR_F19H_UMC_PERF_CTL 0xc0010800
-#define MSR_F19H_UMC_PERF_CTR 0xc0010801
-
-#define MSR_ZEN4_BP_CFG 0xc001102e
+/* Zen4 */
+#define MSR_ZEN4_BP_CFG 0xc001102e
#define MSR_ZEN4_BP_CFG_SHARED_BTB_FIX_BIT 5

-/* Fam 17h (Zen 2) MSRs */
-#define MSR_F17H_IRPERF 0xc00000e9
+/* Fam 19h MSRs */
+#define MSR_F19H_UMC_PERF_CTL 0xc0010800
+#define MSR_F19H_UMC_PERF_CTR 0xc0010801

-#define MSR_ZEN2_SPECTRAL_CHICKEN 0xc00110e3
-#define MSR_ZEN2_SPECTRAL_CHICKEN_BIT BIT_ULL(1)
+/* Zen 2 */
+#define MSR_ZEN2_SPECTRAL_CHICKEN 0xc00110e3
+#define MSR_ZEN2_SPECTRAL_CHICKEN_BIT BIT_ULL(1)
+
+/* Fam 17h MSRs */
+#define MSR_F17H_IRPERF 0xc00000e9

/* Fam 16h MSRs */
#define MSR_F16H_L2I_PERF_CTL 0xc0010230