turbostat always used the same logic to read the microcode patch level,
which is correct for Intel but not for AMD/Hygon.
While Intel stores the patch level in the upper 32 bits of MSR, AMD
stores it in the lower 32 bits, which causes turbostat to report the
microcode version as 0x0 on AMD/Hygon.

Fix by shifting right by 32 for non-AMD/Hygon, preserving the existing
behavior for Intel and unknown vendors.

Signed-off-by: Serhii Pievniev <spevnev16@gmail.com>
---
v1 -> v2: Changed to single MSR path with conditional shift

v1: https://lore.kernel.org/linux-pm/20260224023719.65165-1-spevnev16@gmail.com
---
 tools/power/x86/turbostat/turbostat.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/tools/power/x86/turbostat/turbostat.c b/tools/power/x86/turbostat/turbostat.c
index 1a2671c2820..7545142b3a6 100644
--- a/tools/power/x86/turbostat/turbostat.c
+++ b/tools/power/x86/turbostat/turbostat.c
@@ -9122,10 +9122,13 @@ void process_cpuid()
 	cpuid_has_hv = ecx_flags & (1 << 31);
 
 	if (!no_msr) {
-		if (get_msr(sched_getcpu(), MSR_IA32_UCODE_REV, &ucode_patch))
+		if (get_msr(sched_getcpu(), MSR_IA32_UCODE_REV, &ucode_patch)) {
 			warnx("get_msr(UCODE)");
-		else
+		} else {
 			ucode_patch_valid = true;
+			if (!authentic_amd && !hygon_genuine)
+				ucode_patch >>= 32;
+		}
 	}
 
 	/*
@@ -9139,7 +9142,7 @@ void process_cpuid()
 	if (!quiet) {
 		fprintf(outf, "CPUID(1): family:model:stepping 0x%x:%x:%x (%d:%d:%d)", family, model, stepping, family, model, stepping);
 		if (ucode_patch_valid)
-			fprintf(outf, " microcode 0x%x", (unsigned int)((ucode_patch >> 32) & 0xFFFFFFFF));
+			fprintf(outf, " microcode 0x%x", (unsigned int)ucode_patch);
 		fputc('\n', outf);
 
 		fprintf(outf, "CPUID(0x80000000): max_extended_levels: 0x%x\n", max_extended_level);
-- 
2.53.0

Applied, thanks!

ps. I added a Fixes tag...
Fixes: 3e4048466c39 ("tools/power turbostat: Add --no-msr option")

That is in Linux-6.9, where this cleanly applies.  Technically the logic
was already broken before that in an earlier 6.9 patch, and the original code
was broken years before that, but I expect going back 2-years is more
than sufficient.

On Wed, Feb 25, 2026 at 6:16 PM Serhii Pievniev <spevnev16@gmail.com> wrote:
>
> turbostat always used the same logic to read the microcode patch level,
> which is correct for Intel but not for AMD/Hygon.
> While Intel stores the patch level in the upper 32 bits of MSR, AMD
> stores it in the lower 32 bits, which causes turbostat to report the
> microcode version as 0x0 on AMD/Hygon.
>
> Fix by shifting right by 32 for non-AMD/Hygon, preserving the existing
> behavior for Intel and unknown vendors.
>
> Signed-off-by: Serhii Pievniev <spevnev16@gmail.com>
> ---
> v1 -> v2: Changed to single MSR path with conditional shift
>
> v1: https://lore.kernel.org/linux-pm/20260224023719.65165-1-spevnev16@gmail.com
> ---
>  tools/power/x86/turbostat/turbostat.c | 9 ++++++---
>  1 file changed, 6 insertions(+), 3 deletions(-)
>
> diff --git a/tools/power/x86/turbostat/turbostat.c b/tools/power/x86/turbostat/turbostat.c
> index 1a2671c2820..7545142b3a6 100644
> --- a/tools/power/x86/turbostat/turbostat.c
> +++ b/tools/power/x86/turbostat/turbostat.c
> @@ -9122,10 +9122,13 @@ void process_cpuid()
>         cpuid_has_hv = ecx_flags & (1 << 31);
>
>         if (!no_msr) {
> -               if (get_msr(sched_getcpu(), MSR_IA32_UCODE_REV, &ucode_patch))
> +               if (get_msr(sched_getcpu(), MSR_IA32_UCODE_REV, &ucode_patch)) {
>                         warnx("get_msr(UCODE)");
> -               else
> +               } else {
>                         ucode_patch_valid = true;
> +                       if (!authentic_amd && !hygon_genuine)
> +                               ucode_patch >>= 32;
> +               }
>         }
>
>         /*
> @@ -9139,7 +9142,7 @@ void process_cpuid()
>         if (!quiet) {
>                 fprintf(outf, "CPUID(1): family:model:stepping 0x%x:%x:%x (%d:%d:%d)", family, model, stepping, family, model, stepping);
>                 if (ucode_patch_valid)
> -                       fprintf(outf, " microcode 0x%x", (unsigned int)((ucode_patch >> 32) & 0xFFFFFFFF));
> +                       fprintf(outf, " microcode 0x%x", (unsigned int)ucode_patch);
>                 fputc('\n', outf);
>
>                 fprintf(outf, "CPUID(0x80000000): max_extended_levels: 0x%x\n", max_extended_level);
> --
> 2.53.0
>


-- 
Len Brown, Intel Open Source Technology Center