[v8,3/8] x86/cpu, kvm: Add the NO_NESTED_DATA_BP feature

Message ID 20230123225700.2224063-4-kim.phillips@amd.com
State New
Headers
Series x86/cpu, kvm: Support AMD Automatic IBRS |

Commit Message

Kim Phillips Jan. 23, 2023, 10:56 p.m. UTC
  The "Processor ignores nested data breakpoints" feature was being
open-coded for KVM.  Add the feature to its newly introduced
CPUID leaf 0x80000021 EAX proper.

Signed-off-by: Kim Phillips <kim.phillips@amd.com>
---
 arch/x86/include/asm/cpufeatures.h | 3 +++
 arch/x86/kvm/cpuid.c               | 2 +-
 2 files changed, 4 insertions(+), 1 deletion(-)
  

Patch

diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
index a84536876794..7f0fb894e432 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -428,6 +428,9 @@ 
 #define X86_FEATURE_V_TSC_AUX		(19*32+ 9) /* "" Virtual TSC_AUX */
 #define X86_FEATURE_SME_COHERENT	(19*32+10) /* "" AMD hardware-enforced cache coherency */
 
+/* AMD-defined Extended Feature 2 EAX, CPUID level 0x80000021 (EAX), word 20 */
+#define X86_FEATURE_NO_NESTED_DATA_BP	(20*32+ 0) /* "" No Nested Data Breakpoints */
+
 /*
  * BUG word(s)
  */
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 3930452bf06e..13bd2769fa5a 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -742,7 +742,7 @@  void kvm_set_cpu_caps(void)
 		F(SME_COHERENT));
 
 	kvm_cpu_cap_mask(CPUID_8000_0021_EAX,
-		BIT(0) /* NO_NESTED_DATA_BP */ | 0 /* SmmPgCfgLock */ |
+		F(NO_NESTED_DATA_BP) | 0 /* SmmPgCfgLock */ |
 		BIT(6) /* NULL_SEL_CLR_BASE */ | 0 /* PrefetchCtlMsr */
 	);
 	if (cpu_feature_enabled(X86_FEATURE_LFENCE_RDTSC))