[5/6] KVM: x86: Advertise LASS CPUID to user space

Message ID 20230420133724.11398-6-guang.zeng@intel.com
State New
Headers
Series LASS KVM virtualization support |

Commit Message

Zeng Guang April 20, 2023, 1:37 p.m. UTC
  LASS (Linear-address space separation) is an independent mechanism
to enforce the mode-based protection that can prevent user-mode
accesses to supervisor-mode addresses, and vice versa. Because the
LASS protections are applied before paging, malicious software can
not acquire any paging-based timing information to compromise the
security of system.

The CPUID bit definition to support LASS:
CPUID.(EAX=07H.ECX=1):EAX.LASS[bit 6]

Advertise LASS to user space to support LASS virtualization.

Signed-off-by: Zeng Guang <guang.zeng@intel.com>
---
 arch/x86/kvm/cpuid.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
  

Patch

diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index ba7f7abc8964..5facb8037140 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -663,8 +663,8 @@  void kvm_set_cpu_caps(void)
 		kvm_cpu_cap_set(X86_FEATURE_SPEC_CTRL_SSBD);
 
 	kvm_cpu_cap_mask(CPUID_7_1_EAX,
-		F(AVX_VNNI) | F(AVX512_BF16) | F(CMPCCXADD) | F(AMX_FP16) |
-		F(AVX_IFMA)
+		F(AVX_VNNI) | F(AVX512_BF16) | F(LASS) | F(CMPCCXADD) |
+		F(AMX_FP16) | F(AVX_IFMA)
 	);
 
 	kvm_cpu_cap_init_kvm_defined(CPUID_7_1_EDX,