From: Zeng Guang <guang.zeng@xxxxxxxxx> Linear address space separation (LASS) 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. Note: KVM LASS feature exposure also depends on cpuid capability held by host kernel. It will be masked to guest if host vsyscall is in emulate mode which actually disables LASS. Signed-off-by: Zeng Guang <guang.zeng@xxxxxxxxx> Signed-off-by: Binbin Wu <binbin.wu@xxxxxxxxxxxxxxx> Tested-by: Xuelian Guo <xuelian.guo@xxxxxxxxx> --- arch/x86/kvm/cpuid.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index a0db266bab73..81a52218c20f 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -675,7 +675,7 @@ 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(AVX_VNNI) | F(AVX512_BF16) | F(LASS) | F(CMPCCXADD) | F(FZRM) | F(FSRS) | F(FSRC) | F(AMX_FP16) | F(AVX_IFMA) | F(LAM) ); -- 2.25.1
