From: Mario Limonciello <mario.limonciello@amd.com>
To: Borislav Petkov <bp@alien8.de>,
"maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)"
<x86@kernel.org>
Cc: Kees Cook <keescook@chromium.org>,
Thomas Lendacky <Thomas.Lendacky@amd.com>, <hughsient@gmail.com>,
Martin Fernandez <martin.fernandez@eclypsium.com>,
<linux-kernel@vger.kernel.org>,
"Brijesh Singh" <brijesh.singh@amd.com>,
Mario Limonciello <mario.limonciello@amd.com>
Subject: [PATCH v2 4/4] x86/cpu: clear SEV/SEV_ES features when not in use
Date: Fri, 11 Feb 2022 15:02:55 -0600 [thread overview]
Message-ID: <20220211210255.9820-5-mario.limonciello@amd.com> (raw)
In-Reply-To: <20220211210255.9820-1-mario.limonciello@amd.com>
As there are no consumers for these feature flags in the kernel,
don't export these flags to userspace unless the feature has been
enabled by the guest.
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
arch/x86/kernel/cpu/amd.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 9cea774344cb..6623a4995df1 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -614,12 +614,19 @@ static void early_detect_mem_encrypt(struct cpuinfo_x86 *c)
if (!(msr & MSR_K7_HWCR_SMMLOCK))
goto clear_sev;
+ if (!(sev_status & MSR_AMD64_SEV_ENABLED))
+ goto clear_sev;
+
+ if (!(sev_status & MSR_AMD64_SEV_ES_ENABLED))
+ goto clear_sev_es;
+
return;
clear_all:
setup_clear_cpu_cap(X86_FEATURE_SME);
clear_sev:
setup_clear_cpu_cap(X86_FEATURE_SEV);
+clear_sev_es:
setup_clear_cpu_cap(X86_FEATURE_SEV_ES);
}
}
--
2.34.1
next prev parent reply other threads:[~2022-02-11 21:06 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-11 21:02 [PATCH v2 0/4] Only export SME/SEV/SEV_ES features when activated Mario Limonciello
2022-02-11 21:02 ` [PATCH v2 1/4] crypto: ccp: Use cc_platform_has to determine SEV presence Mario Limonciello
2022-02-11 21:02 ` [PATCH v2 2/4] KVM: SVM: Use cc_platform_has instead of CPU feature flags Mario Limonciello
2022-02-11 21:02 ` [PATCH v2 3/4] x86/cpu: clear SME features when not in use Mario Limonciello
2022-02-11 21:17 ` Tom Lendacky
2022-02-11 21:02 ` Mario Limonciello [this message]
2022-02-11 21:13 ` [PATCH v2 0/4] Only export SME/SEV/SEV_ES features when activated Tom Lendacky
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