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* [PATCH] x86/sev: Fix SEV check in sev_map_percpu_data()
@ 2024-01-02 13:37 Kirill A. Shutemov
  2024-01-02 14:31 ` Borislav Petkov
  2024-01-02 18:27 ` David Rientjes
  0 siblings, 2 replies; 3+ messages in thread
From: Kirill A. Shutemov @ 2024-01-02 13:37 UTC (permalink / raw)
  To: Paolo Bonzini, Wanpeng Li, Vitaly Kuznetsov, Sean Christopherson,
	Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen,
	Tom Lendacky
  Cc: x86, kvm, linux-kernel, Kirill A. Shutemov

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@linux.intel.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 0ddb3bd0f1aa..5b495cfc79bc 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) {
-- 
2.41.0


^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH] x86/sev: Fix SEV check in sev_map_percpu_data()
  2024-01-02 13:37 [PATCH] x86/sev: Fix SEV check in sev_map_percpu_data() Kirill A. Shutemov
@ 2024-01-02 14:31 ` Borislav Petkov
  2024-01-02 18:27 ` David Rientjes
  1 sibling, 0 replies; 3+ messages in thread
From: Borislav Petkov @ 2024-01-02 14:31 UTC (permalink / raw)
  To: Kirill A. Shutemov
  Cc: Paolo Bonzini, Wanpeng Li, Vitaly Kuznetsov, Sean Christopherson,
	Thomas Gleixner, Ingo Molnar, Dave Hansen, Tom Lendacky, x86,
	kvm, linux-kernel

On Tue, Jan 02, 2024 at 04:37:47PM +0300, Kirill A. Shutemov wrote:
> 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@linux.intel.com>

Fixes: 4d96f9109109 ("x86/sev: Replace occurrences of sev_active() with cc_platform_has()")
Suggested-by: Borislav Petkov (AMD) <bp@alien8.de>

Thx.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH] x86/sev: Fix SEV check in sev_map_percpu_data()
  2024-01-02 13:37 [PATCH] x86/sev: Fix SEV check in sev_map_percpu_data() Kirill A. Shutemov
  2024-01-02 14:31 ` Borislav Petkov
@ 2024-01-02 18:27 ` David Rientjes
  1 sibling, 0 replies; 3+ messages in thread
From: David Rientjes @ 2024-01-02 18:27 UTC (permalink / raw)
  To: Kirill A. Shutemov
  Cc: Paolo Bonzini, Wanpeng Li, Vitaly Kuznetsov, Sean Christopherson,
	Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen,
	Tom Lendacky, x86, kvm, linux-kernel

On Tue, 2 Jan 2024, Kirill A. Shutemov wrote:

> 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@linux.intel.com>

Acked-by: David Rientjes <rientjes@google.com>

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2024-01-02 18:27 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2024-01-02 13:37 [PATCH] x86/sev: Fix SEV check in sev_map_percpu_data() Kirill A. Shutemov
2024-01-02 14:31 ` Borislav Petkov
2024-01-02 18:27 ` David Rientjes

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