diff options
| author | Kim Phillips <kim.phillips@amd.com> | 2025-09-09 20:28:24 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-10-02 13:39:00 +0200 |
| commit | 2fab1e2af6c598bbfa796350668c626cfda0353e (patch) | |
| tree | 4a5b8d17fe63e61906688ac796e1f7f858a7e8e9 /arch/x86 | |
| parent | 7429b8b9bfbc276fd304fbaebc405f46b421fedf (diff) | |
KVM: x86: Move open-coded CPUID leaf 0x80000021 EAX bit propagation code
Commit c35ac8c4bf600ee23bacb20f863aa7830efb23fb upstream
Move code from __do_cpuid_func() to kvm_set_cpu_caps() in preparation for adding
the features in their native leaf.
Also drop the bit description comments as it will be more self-describing once
the individual features are added.
Whilst there, switch to using the more efficient cpu_feature_enabled() instead
of static_cpu_has().
Note, LFENCE_RDTSC and "NULL selector clears base" are currently synthetic,
Linux-defined feature flags as Linux tracking of the features predates AMD's
definition. Keep the manual propagation of the flags from their synthetic
counterparts until the kernel fully converts to AMD's definition, otherwise KVM
would stop synthesizing the flags as intended.
Signed-off-by: Kim Phillips <kim.phillips@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20230124163319.2277355-3-kim.phillips@amd.com
Move setting of VERW_CLEAR bit to the new
kvm_cpu_cap_mask(CPUID_8000_0021_EAX, ...) site.
Cc: <stable@vger.kernel.org> # 5.15.y
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/kvm/cpuid.c | 25 |
1 files changed, 12 insertions, 13 deletions
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index 3bdb522d48bc..f85a1f7b7582 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -544,6 +544,17 @@ void kvm_set_cpu_caps(void) 0 /* SME */ | F(SEV) | 0 /* VM_PAGE_FLUSH */ | F(SEV_ES) | F(SME_COHERENT)); + kvm_cpu_cap_mask(CPUID_8000_0021_EAX, + BIT(0) /* NO_NESTED_DATA_BP */ | + BIT(2) /* LFENCE Always serializing */ | 0 /* SmmPgCfgLock */ | + BIT(5) /* The memory form of VERW mitigates TSA */ | + BIT(6) /* NULL_SEL_CLR_BASE */ | 0 /* PrefetchCtlMsr */ + ); + if (cpu_feature_enabled(X86_FEATURE_LFENCE_RDTSC)) + kvm_cpu_caps[CPUID_8000_0021_EAX] |= BIT(2) /* LFENCE Always serializing */; + if (!static_cpu_has_bug(X86_BUG_NULL_SEG)) + kvm_cpu_caps[CPUID_8000_0021_EAX] |= BIT(6) /* NULL_SEL_CLR_BASE */; + kvm_cpu_cap_mask(CPUID_C000_0001_EDX, F(XSTORE) | F(XSTORE_EN) | F(XCRYPT) | F(XCRYPT_EN) | F(ACE2) | F(ACE2_EN) | F(PHE) | F(PHE_EN) | @@ -553,8 +564,6 @@ void kvm_set_cpu_caps(void) if (cpu_feature_enabled(X86_FEATURE_SRSO_NO)) kvm_cpu_cap_set(X86_FEATURE_SRSO_NO); - kvm_cpu_cap_mask(CPUID_8000_0021_EAX, F(VERW_CLEAR)); - kvm_cpu_cap_init_kvm_defined(CPUID_8000_0021_ECX, F(TSA_SQ_NO) | F(TSA_L1_NO) ); @@ -1006,17 +1015,7 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function) break; case 0x80000021: entry->ebx = entry->ecx = entry->edx = 0; - /* - * Pass down these bits: - * EAX 0 NNDBP, Processor ignores nested data breakpoints - * EAX 2 LAS, LFENCE always serializing - * EAX 6 NSCB, Null selector clear base - * - * Other defined bits are for MSRs that KVM does not expose: - * EAX 3 SPCL, SMM page configuration lock - * EAX 13 PCMSR, Prefetch control MSR - */ - entry->eax &= BIT(0) | BIT(2) | BIT(6); + cpuid_entry_override(entry, CPUID_8000_0021_EAX); break; /*Add support for Centaur's CPUID instruction*/ case 0xC0000000: |