Page modification logging(PML) is a hardware feature designed to track
guest modified memory pages. PML enables the hypervisor to identify which
pages in a guest's memory have been changed since the last checkpoint or
during live migration.
The PML feature is advertised via CPUID leaf 0x8000000A ECX[4] bit.
Signed-off-by: Nikunj A Dadhania <nikunj@xxxxxxx>
---
arch/x86/include/asm/cpufeatures.h | 1 +
arch/x86/kernel/cpu/scattered.c | 1 +
2 files changed, 2 insertions(+)
diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
index 286d509f9363..069c0e17113a 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -227,6 +227,7 @@
#define X86_FEATURE_PVUNLOCK ( 8*32+20) /* PV unlock function */
#define X86_FEATURE_VCPUPREEMPT ( 8*32+21) /* PV vcpu_is_preempted function */
#define X86_FEATURE_TDX_GUEST ( 8*32+22) /* "tdx_guest" Intel Trust Domain Extensions Guest */
+#define X86_FEATURE_PML ( 8*32+23) /* AMD Page Modification logging */
/* Intel-defined CPU features, CPUID level 0x00000007:0 (EBX), word 9 */
#define X86_FEATURE_FSGSBASE ( 9*32+ 0) /* "fsgsbase" RDFSBASE, WRFSBASE, RDGSBASE, WRGSBASE instructions*/
diff --git a/arch/x86/kernel/cpu/scattered.c b/arch/x86/kernel/cpu/scattered.c
index b4a1f6732a3a..02fc16b28bc9 100644
--- a/arch/x86/kernel/cpu/scattered.c
+++ b/arch/x86/kernel/cpu/scattered.c
@@ -48,6 +48,7 @@ static const struct cpuid_bit cpuid_bits[] = {
{ X86_FEATURE_PROC_FEEDBACK, CPUID_EDX, 11, 0x80000007, 0 },
{ X86_FEATURE_AMD_FAST_CPPC, CPUID_EDX, 15, 0x80000007, 0 },
{ X86_FEATURE_MBA, CPUID_EBX, 6, 0x80000008, 0 },
+ { X86_FEATURE_PML, CPUID_ECX, 4, 0x8000000A, 0 },
{ X86_FEATURE_SMBA, CPUID_EBX, 2, 0x80000020, 0 },
{ X86_FEATURE_BMEC, CPUID_EBX, 3, 0x80000020, 0 },
{ X86_FEATURE_TSA_SQ_NO, CPUID_ECX, 1, 0x80000021, 0 },
--
2.43.0
