From 3d8f61bf8bcd69bcd397276d53aa18f7ca8347f9 Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Tue, 24 Jan 2023 19:45:19 +0000 Subject: [PATCH] x86: KVM: Add common feature flag for AMD's PSFD Use a common X86_FEATURE_* flag for AMD's PSFD, and suppress it from /proc/cpuinfo via the standard method of an empty string instead of hacking in a one-off "private" #define in KVM. The request that led to KVM defining its own flag was really just that the feature not show up in /proc/cpuinfo, and additional patches+discussions in the interim have clarified that defining flags in cpufeatures.h purely so that KVM can advertise features to userspace is ok so long as the kernel already uses a word to track the associated CPUID leaf. No functional change intended. Link: https://lore.kernel.org/all/d1b1e0da-29f0-c443-6c86-9549bbe1c79d@redhat.como Link: https://lore.kernel.org/all/YxGZH7aOXQF7Pu5q@nazgul.tnic Link: https://lore.kernel.org/all/Y3O7UYWfOLfJkwM%2F@zn.tnic Reviewed-by: Paolo Bonzini Link: https://lore.kernel.org/r/20230124194519.2893234-1-seanjc@google.com Signed-off-by: Sean Christopherson --- arch/x86/include/asm/cpufeatures.h | 1 + arch/x86/kvm/cpuid.c | 8 +------- 2 files changed, 2 insertions(+), 7 deletions(-) diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h index 73c9672c123b..42abcd3db7a7 100644 --- a/arch/x86/include/asm/cpufeatures.h +++ b/arch/x86/include/asm/cpufeatures.h @@ -337,6 +337,7 @@ #define X86_FEATURE_VIRT_SSBD (13*32+25) /* Virtualized Speculative Store Bypass Disable */ #define X86_FEATURE_AMD_SSB_NO (13*32+26) /* "" Speculative Store Bypass is fixed in hardware. */ #define X86_FEATURE_CPPC (13*32+27) /* Collaborative Processor Performance Control */ +#define X86_FEATURE_AMD_PSFD (13*32+28) /* "" Predictive Store Forwarding Disable */ #define X86_FEATURE_BTC_NO (13*32+29) /* "" Not vulnerable to Branch Type Confusion */ #define X86_FEATURE_BRS (13*32+31) /* Branch Sampling available */ diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index 1ad3bde72526..6972e0be60fa 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -60,12 +60,6 @@ u32 xstate_required_size(u64 xstate_bv, bool compacted) return ret; } -/* - * This one is tied to SSB in the user API, and not - * visible in /proc/cpuinfo. - */ -#define KVM_X86_FEATURE_AMD_PSFD (13*32+28) /* Predictive Store Forwarding Disable */ - #define F feature_bit /* Scattered Flag - For features that are scattered by cpufeatures.h. */ @@ -715,7 +709,7 @@ void kvm_set_cpu_caps(void) F(CLZERO) | F(XSAVEERPTR) | F(WBNOINVD) | F(AMD_IBPB) | F(AMD_IBRS) | F(AMD_SSBD) | F(VIRT_SSBD) | F(AMD_SSB_NO) | F(AMD_STIBP) | F(AMD_STIBP_ALWAYS_ON) | - __feature_bit(KVM_X86_FEATURE_AMD_PSFD) + F(AMD_PSFD) ); /* -- 2.42.0