Adds the new AMD feature X86_FEATURE_SMBA. With this feature, the QOS enforcement policies can be applied to external slow memory connected to the host. QOS enforcement is accomplished by assigning a Class Of Service (COS) to a processor and specifying allocations or limits for that COS for each resource to be allocated. This feature is identified by the CPUID Function 8000_0020_EBX_x0. CPUID Fn8000_0020_EBX_x0 AMD Bandwidth Enforcement Feature Identifiers (ECX=0) Bits Field Name Description 2 L3SBE L3 external slow memory bandwidth enforcement Feature description is available in the specification, "AMD64 Technology Platform Quality of Service Extensions, Revision: 1.03 Publication # 56375 Revision: 1.03 Issue Date: February 2022". Link: https://www.amd.com/en/support/tech-docs/amd64-technology-platform-quality-service-extensions Link: https://bugzilla.kernel.org/show_bug.cgi?id=206537 Signed-off-by: Babu Moger <babu.moger@xxxxxxx> Reviewed-by: Ingo Molnar <mingo@xxxxxxxxxx> --- 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 235dc85c91c3..1815435c9c88 100644 --- a/arch/x86/include/asm/cpufeatures.h +++ b/arch/x86/include/asm/cpufeatures.h @@ -304,6 +304,7 @@ #define X86_FEATURE_UNRET (11*32+15) /* "" AMD BTB untrain return */ #define X86_FEATURE_USE_IBPB_FW (11*32+16) /* "" Use IBPB during runtime firmware calls */ #define X86_FEATURE_RSB_VMEXIT_LITE (11*32+17) /* "" Fill RSB on VM exit when EIBRS is enabled */ +#define X86_FEATURE_SMBA (11*32+18) /* SLOW Memory Bandwidth Allocation */ /* Intel-defined CPU features, CPUID level 0x00000007:1 (EAX), word 12 */ #define X86_FEATURE_AVX_VNNI (12*32+ 4) /* AVX VNNI instructions */ diff --git a/arch/x86/kernel/cpu/scattered.c b/arch/x86/kernel/cpu/scattered.c index fd44b54c90d5..885ecf46abb2 100644 --- a/arch/x86/kernel/cpu/scattered.c +++ b/arch/x86/kernel/cpu/scattered.c @@ -44,6 +44,7 @@ static const struct cpuid_bit cpuid_bits[] = { { X86_FEATURE_CPB, CPUID_EDX, 9, 0x80000007, 0 }, { X86_FEATURE_PROC_FEEDBACK, CPUID_EDX, 11, 0x80000007, 0 }, { X86_FEATURE_MBA, CPUID_EBX, 6, 0x80000008, 0 }, + { X86_FEATURE_SMBA, CPUID_EBX, 2, 0x80000020, 0 }, { X86_FEATURE_PERFMON_V2, CPUID_EAX, 0, 0x80000022, 0 }, { 0, 0, 0, 0, 0 } };
