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[v5,5/5] KVM: x86: LAM: Expose LAM CPUID to user space VMM

Message ID 20230227084547.404871-6-robert.hu@linux.intel.com (mailing list archive)
State New, archived
Headers show
Series Linear Address Masking (LAM) KVM Enabling | expand

Commit Message

Robert Hoo Feb. 27, 2023, 8:45 a.m. UTC 
LAM feature is enumerated by (EAX=07H, ECX=01H):EAX.LAM[bit26].

Signed-off-by: Robert Hoo <robert.hu@linux.intel.com>
Reviewed-by: Jingqi Liu <jingqi.liu@intel.com>
---
 arch/x86/kvm/cpuid.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Chao Gao March 3, 2023, 6:46 a.m. UTC | #1 
On Mon, Feb 27, 2023 at 04:45:47PM +0800, Robert Hoo wrote:
>LAM feature is enumerated by (EAX=07H, ECX=01H):EAX.LAM[bit26].

Please add some high-level introduction about LAM.

Maybe also call out that LAM's CR3 bits, CR4 bit and the modified
canonicality check are virtualized already. As the last step,
advertise LAM support to user space.

>
>Signed-off-by: Robert Hoo <robert.hu@linux.intel.com>
>Reviewed-by: Jingqi Liu <jingqi.liu@intel.com>
>---
> 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 b14653b61470..79f45cbe587e 100644
>--- a/arch/x86/kvm/cpuid.c
>+++ b/arch/x86/kvm/cpuid.c
>@@ -664,7 +664,7 @@ void kvm_set_cpu_caps(void)
> 
> 	kvm_cpu_cap_mask(CPUID_7_1_EAX,
> 		F(AVX_VNNI) | F(AVX512_BF16) | F(CMPCCXADD) | F(AMX_FP16) |
>-		F(AVX_IFMA)
>+		F(AVX_IFMA) | F(LAM)
> 	);
> 
> 	kvm_cpu_cap_init_kvm_defined(CPUID_7_1_EDX,
>-- 
>2.31.1
>
diff mbox series

Patch

diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index b14653b61470..79f45cbe587e 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -664,7 +664,7 @@  void kvm_set_cpu_caps(void)
 
 	kvm_cpu_cap_mask(CPUID_7_1_EAX,
 		F(AVX_VNNI) | F(AVX512_BF16) | F(CMPCCXADD) | F(AMX_FP16) |
-		F(AVX_IFMA)
+		F(AVX_IFMA) | F(LAM)
 	);
 
 	kvm_cpu_cap_init_kvm_defined(CPUID_7_1_EDX,