5.15-stable review patch. If anyone has any objections, please let me know.
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From: Sean Christopherson seanjc@google.com
commit 047c7229906152fb85c23dc18fd25a00cd7cb4de upstream.
Rename kvm_cpu_cap_init_scattered() to kvm_cpu_cap_init_kvm_defined() in anticipation of adding KVM-only CPUID leafs that aren't recognized by the kernel and thus not scattered, i.e. for leafs that are 100% KVM-defined.
Adjust/add comments to kvm_only_cpuid_leafs and KVM_X86_FEATURE to document how to create new kvm_only_cpuid_leafs entries for scattered features as well as features that are entirely unknown to the kernel.
No functional change intended.
Signed-off-by: Sean Christopherson seanjc@google.com Message-Id: 20221125125845.1182922-3-jiaxi.chen@linux.intel.com Signed-off-by: Paolo Bonzini pbonzini@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/x86/kvm/cpuid.c | 8 ++++---- arch/x86/kvm/reverse_cpuid.h | 18 +++++++++++++++--- 2 files changed, 19 insertions(+), 7 deletions(-)
--- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -355,9 +355,9 @@ static __always_inline void __kvm_cpu_ca }
static __always_inline -void kvm_cpu_cap_init_scattered(enum kvm_only_cpuid_leafs leaf, u32 mask) +void kvm_cpu_cap_init_kvm_defined(enum kvm_only_cpuid_leafs leaf, u32 mask) { - /* Use kvm_cpu_cap_mask for non-scattered leafs. */ + /* Use kvm_cpu_cap_mask for leafs that aren't KVM-only. */ BUILD_BUG_ON(leaf < NCAPINTS);
kvm_cpu_caps[leaf] = mask; @@ -367,7 +367,7 @@ void kvm_cpu_cap_init_scattered(enum kvm
static __always_inline void kvm_cpu_cap_mask(enum cpuid_leafs leaf, u32 mask) { - /* Use kvm_cpu_cap_init_scattered for scattered leafs. */ + /* Use kvm_cpu_cap_init_kvm_defined for KVM-only leafs. */ BUILD_BUG_ON(leaf >= NCAPINTS);
kvm_cpu_caps[leaf] &= mask; @@ -473,7 +473,7 @@ void kvm_set_cpu_caps(void) F(XSAVEOPT) | F(XSAVEC) | F(XGETBV1) | F(XSAVES) );
- kvm_cpu_cap_init_scattered(CPUID_12_EAX, + kvm_cpu_cap_init_kvm_defined(CPUID_12_EAX, SF(SGX1) | SF(SGX2) );
--- a/arch/x86/kvm/reverse_cpuid.h +++ b/arch/x86/kvm/reverse_cpuid.h @@ -7,9 +7,9 @@ #include <asm/cpufeatures.h>
/* - * Hardware-defined CPUID leafs that are scattered in the kernel, but need to - * be directly used by KVM. Note, these word values conflict with the kernel's - * "bug" caps, but KVM doesn't use those. + * Hardware-defined CPUID leafs that are either scattered by the kernel or are + * unknown to the kernel, but need to be directly used by KVM. Note, these + * word values conflict with the kernel's "bug" caps, but KVM doesn't use those. */ enum kvm_only_cpuid_leafs { CPUID_12_EAX = NCAPINTS, @@ -18,6 +18,18 @@ enum kvm_only_cpuid_leafs { NKVMCAPINTS = NR_KVM_CPU_CAPS - NCAPINTS, };
+/* + * Define a KVM-only feature flag. + * + * For features that are scattered by cpufeatures.h, __feature_translate() also + * needs to be updated to translate the kernel-defined feature into the + * KVM-defined feature. + * + * For features that are 100% KVM-only, i.e. not defined by cpufeatures.h, + * forego the intermediate KVM_X86_FEATURE and directly define X86_FEATURE_* so + * that X86_FEATURE_* can be used in KVM. No __feature_translate() handling is + * needed in this case. + */ #define KVM_X86_FEATURE(w, f) ((w)*32 + (f))
/* Intel-defined SGX sub-features, CPUID level 0x12 (EAX). */