linux-kernel - [PATCH v3] x86/cpu: Clear TME feature flag if TME is not enabled by BIOS

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Date: Tue, 12 Mar 2024 18:35:34 +0800
From: Bingsong Si <sibs@...natelecom.cn>
To: kai.huang@...el.com,
	Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...hat.com>,
	Borislav Petkov <bp@...en8.de>,
	Dave Hansen <dave.hansen@...ux.intel.com>,
	x86@...nel.org,
	"H. Peter Anvin" <hpa@...or.com>
Cc: linux-kernel@...r.kernel.org,
	sibs@...natelecom.cn
Subject: [PATCH v3] x86/cpu: Clear TME feature flag if TME is not enabled by BIOS

When TME is disabled by BIOS, dmesg output is "x86/tme: not enabled by
BIOS" but the TME feature is still shown in the output of/proc/cpuinfo.

Signed-off-by: Bingsong Si <sibs@...natelecom.cn>
---
 arch/x86/kernel/cpu/intel.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index 40dec9b56f87..119ae291573b 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -228,6 +228,7 @@ static void detect_tme_early(struct cpuinfo_x86 *c)
 	if (!TME_ACTIVATE_LOCKED(tme_activate) || !TME_ACTIVATE_ENABLED(tme_activate)) {
 		pr_info_once("x86/tme: not enabled by BIOS\n");
 		mktme_status = MKTME_DISABLED;
+		clear_cpu_cap(c, X86_FEATURE_TME);
 		return;
 	}
 
-- 
2.34.1