[PATCH, RESEND] x86/sev: Fix SEV check in sev_map_percpu_data()

From: Kirill A. Shutemov
Date: Wed Jan 24 2024 - 08:09:20 EST


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@xxxxxxxxxxxxxxx>
Fixes: 4d96f9109109 ("x86/sev: Replace occurrences of sev_active() with cc_platform_has()")
Suggested-by: Borislav Petkov (AMD) <bp@xxxxxxxxx>
Acked-by: David Rientjes <rientjes@xxxxxxxxxx>
---
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