From faac2abe895d200615a91acb63a709feb3dac1c2 Mon Sep 17 00:00:00 2001 From: "Borislav Petkov (AMD)" Date: Fri, 11 Jul 2025 21:18:44 +0200 Subject: [PATCH] x86/CPU/AMD: Properly check the TSA microcode In order to simplify backports, I resorted to an older version of the microcode revision checking which didn't pull in the whole struct x86_cpu_id matching machinery. My simpler method, however, forgot to add the extended CPU model to the patch revision, which lead to mismatches when determining whether TSA mitigation support is present. So add that forgotten extended model. This is a stable-only fix and the preference is to do it this way because it is a lot simpler. Also, the Fixes: tag below points to the respective stable patch. Fixes: 7a0395f6607a ("x86/bugs: Add a Transient Scheduler Attacks mitigation") Reported-by: Thomas Voegtle Signed-off-by: Borislav Petkov (AMD) Tested-by: Thomas Voegtle Message-ID: <04ea0a8e-edb0-c59e-ce21-5f3d5d167af3@lio96.de> Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/cpu/amd.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c index 8a740e92e483e..b42307200e98f 100644 --- a/arch/x86/kernel/cpu/amd.c +++ b/arch/x86/kernel/cpu/amd.c @@ -376,6 +376,7 @@ static bool amd_check_tsa_microcode(void) p.ext_fam = c->x86 - 0xf; p.model = c->x86_model; + p.ext_model = c->x86_model >> 4; p.stepping = c->x86_stepping; if (cpu_has(c, X86_FEATURE_ZEN3) || -- 2.47.3