Thread (60 messages) 60 messages, 5 authors, 2022-12-13

RE: [PATCH v8 01/13] x86/cpufeatures: Add Slow Memory Bandwidth Allocation feature flag

From: Yu, Fenghua <hidden>
Date: 2022-11-23 18:21:46
Also in: lkml

Hi, Babu,
quoted hunk ↗ jump to hunk
diff --git a/arch/x86/include/asm/cpufeatures.h
b/arch/x86/include/asm/cpufeatures.h
index aefd0816a333..d68b4c9c181d 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -305,6 +305,7 @@
 #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_CALL_DEPTH		(11*32+18) /* "" Call depth
tracking for RSB stuffing */
+#define X86_FEATURE_SMBA		(11*32+19) /* 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 fc01f81f6e2a..5a5f17ed69a2 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 },
 	{ X86_FEATURE_AMD_LBR_V2,	CPUID_EAX,  1, 0x80000022, 0 },
 	{ 0, 0, 0, 0, 0 }
Shouldn't X86_FEATURE_SMBA depend on X86_FEATURE_MBA? Need to add the
dependency in cpuid-deps.c

Thanks.

-Fenghua
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