linux-kernel - [PATCH, RESEND] x86/sev: Fix SEV check in sev_map_percpu

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Message-ID: <20240124130317.495519-1-kirill.shutemov@linux.intel.com>
Date: Wed, 24 Jan 2024 15:03:17 +0200
From: "Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>
To: Paolo Bonzini <pbonzini@...hat.com>,
	Wanpeng Li <wanpengli@...cent.com>,
	Vitaly Kuznetsov <vkuznets@...hat.com>,
	Sean Christopherson <seanjc@...gle.com>,
	Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...hat.com>,
	Borislav Petkov <bp@...en8.de>,
	Dave Hansen <dave.hansen@...ux.intel.com>,
	Tom Lendacky <thomas.lendacky@....com>
Cc: x86@...nel.org,
	kvm@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	"Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>,
	David Rientjes <rientjes@...gle.com>
Subject: [PATCH, RESEND] x86/sev: Fix SEV check in sev_map_percpu_data()

The function sev_map_percpu_data() checks if it is running on an SEV
platform by checking the CC_ATTR_GUEST_MEM_ENCRYPT attribute. However,
this attribute is also defined for TDX.

To avoid false positives, add a cc_vendor check.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@...ux.intel.com>
Fixes: 4d96f9109109 ("x86/sev: Replace occurrences of sev_active() with cc_platform_has()")
Suggested-by: Borislav Petkov (AMD) <bp@...en8.de>
Acked-by: David Rientjes <rientjes@...gle.com>
---
 arch/x86/kernel/kvm.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
index dfe9945b9bec..428ee74002e1 100644
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -434,7 +434,8 @@ static void __init sev_map_percpu_data(void)
 {
 	int cpu;
 
-	if (!cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT))
+	if (cc_vendor != CC_VENDOR_AMD ||
+	    !cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT))
 		return;
 
 	for_each_possible_cpu(cpu) {
-- 
2.43.0