Re: [PATCH] x86/CPU/AMD: Add additional fixed microcode for SB-7055

[Borislav Petkov]

On Fri, Nov 14, 2025 at 12:37:58PM +0000, Andrew Cooper wrote:
> Linux-firmware says the min revision for loading this ucode is 0x02, but
> there's no row for it in needs_sha_check().

Author: Borislav Petkov (AMD) <bp@xxxxxxxxx>
Date:   Fri Nov 14 14:01:14 2025 +0100

    x86/microcode/AMD: Add Zen5 model 0x44, stepping 0x1 minrev
    
    Add the minimum Entrysign revision for that model+stepping to the list
    of minimum revisions.
    
    Fixes: 50cef76d5cb0 ("x86/microcode/AMD: Load only SHA256-checksummed patches")
    Reported-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
    Signed-off-by: Borislav Petkov (AMD) <bp@xxxxxxxxx>
    Cc: <stable@xxxxxxxxxx>
    Link: https://lore.kernel.org/r/e94dd76b-4911-482f-8500-5c848a3df026@xxxxxxxxxx

diff --git a/arch/x86/kernel/cpu/microcode/amd.c b/arch/x86/kernel/cpu/microcode/amd.c
index dc82153009da..a881bf4c2011 100644
--- a/arch/x86/kernel/cpu/microcode/amd.c
+++ b/arch/x86/kernel/cpu/microcode/amd.c
@@ -224,6 +224,7 @@ static bool need_sha_check(u32 cur_rev)
 	case 0xb1010: return cur_rev <= 0xb101046; break;
 	case 0xb2040: return cur_rev <= 0xb204031; break;
 	case 0xb4040: return cur_rev <= 0xb404031; break;
+	case 0xb4041: return cur_rev <= 0xb404101; break;
 	case 0xb6000: return cur_rev <= 0xb600031; break;
 	case 0xb6080: return cur_rev <= 0xb608031; break;
 	case 0xb7000: return cur_rev <= 0xb700031; break;


-- 
Regards/Gruss,
    Boris.

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