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Peter Anvin" , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Jamie Liu Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" CPUID faulting via MSR_MISC_FEATURES_ENABLES_CPUID_FAULT is only used on Intel CPUs. The mechanism virtualized by this change is used on AMD CPUs. See arch/x86/kernel/cpu/amd.c:bsp_init_amd(), arch/x86/kernel/process.c:set_cpuid_faulting(). Signed-off-by: Jamie Liu --- arch/x86/include/asm/msr-index.h | 1 + arch/x86/kvm/cpuid.c | 2 +- arch/x86/kvm/cpuid.h | 28 +++++++++++++++++----------- arch/x86/kvm/x86.c | 14 +++++++++----- 4 files changed, 28 insertions(+), 17 deletions(-) diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-in= dex.h index 3d0a0950d20a..79600fb551cf 100644 --- a/arch/x86/include/asm/msr-index.h +++ b/arch/x86/include/asm/msr-index.h @@ -880,6 +880,7 @@ #define MSR_K7_HWCR_IRPERF_EN_BIT 30 #define MSR_K7_HWCR_IRPERF_EN BIT_ULL(MSR_K7_HWCR_IRPERF_EN_BIT) #define MSR_K7_HWCR_CPUID_USER_DIS_BIT 35 +#define MSR_K7_HWCR_CPUID_USER_DIS BIT_ULL(MSR_K7_HWCR_CPUID_USER_DIS_BIT) #define MSR_K7_FID_VID_CTL 0xc0010041 #define MSR_K7_FID_VID_STATUS 0xc0010042 #define MSR_K7_HWCR_CPB_DIS_BIT 25 diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index 88a5426674a1..1dba0982e543 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -1221,7 +1221,7 @@ void kvm_set_cpu_caps(void) F(PREFETCHI), EMULATED_F(NO_SMM_CTL_MSR), /* PrefetchCtlMsr */ - /* GpOnUserCpuid */ + EMULATED_F(GP_ON_USER_CPUID), /* EPSF */ SYNTHESIZED_F(SBPB), SYNTHESIZED_F(IBPB_BRTYPE), diff --git a/arch/x86/kvm/cpuid.h b/arch/x86/kvm/cpuid.h index d3f5ae15a7ca..9ca8321762fb 100644 --- a/arch/x86/kvm/cpuid.h +++ b/arch/x86/kvm/cpuid.h @@ -173,17 +173,6 @@ static inline int guest_cpuid_stepping(struct kvm_vcpu= *vcpu) return x86_stepping(best->eax); } =20 -static inline bool supports_cpuid_fault(struct kvm_vcpu *vcpu) -{ - return vcpu->arch.msr_platform_info & MSR_PLATFORM_INFO_CPUID_FAULT; -} - -static inline bool cpuid_fault_enabled(struct kvm_vcpu *vcpu) -{ - return vcpu->arch.msr_misc_features_enables & - MSR_MISC_FEATURES_ENABLES_CPUID_FAULT; -} - static __always_inline void kvm_cpu_cap_clear(unsigned int x86_feature) { unsigned int x86_leaf =3D __feature_leaf(x86_feature); @@ -267,6 +256,23 @@ static __always_inline bool guest_cpu_cap_has(struct k= vm_vcpu *vcpu, return vcpu->arch.cpu_caps[x86_leaf] & __feature_bit(x86_feature); } =20 +static inline bool supports_cpuid_fault_intel(struct kvm_vcpu *vcpu) +{ + return vcpu->arch.msr_platform_info & MSR_PLATFORM_INFO_CPUID_FAULT; +} + +static inline bool supports_cpuid_fault_amd(struct kvm_vcpu *vcpu) +{ + return guest_cpu_cap_has(vcpu, X86_FEATURE_GP_ON_USER_CPUID); +} + +static inline bool cpuid_fault_enabled(struct kvm_vcpu *vcpu) +{ + return (vcpu->arch.msr_misc_features_enables & + MSR_MISC_FEATURES_ENABLES_CPUID_FAULT) || + (vcpu->arch.msr_hwcr & MSR_K7_HWCR_CPUID_USER_DIS); +} + static inline bool kvm_vcpu_is_legal_cr3(struct kvm_vcpu *vcpu, unsigned l= ong cr3) { if (guest_cpu_cap_has(vcpu, X86_FEATURE_LAM)) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 72d37c8930ad..9140f66b21c6 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3992,14 +3992,18 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struc= t msr_data *msr_info) data &=3D ~(u64)0x8; /* ignore TLB cache disable */ =20 /* - * Allow McStatusWrEn and TscFreqSel. (Linux guests from v3.2 - * through at least v6.6 whine if TscFreqSel is clear, - * depending on F/M/S. + * Allow McStatusWrEn, TscFreqSel, and CpuidUserDis. (Linux + * guests from v3.2 through at least v6.6 whine if TscFreqSel + * is clear, depending on F/M/S.) */ - if (data & ~(BIT_ULL(18) | BIT_ULL(24))) { + if (data & ~(BIT_ULL(18) | BIT_ULL(24) | + MSR_K7_HWCR_CPUID_USER_DIS)) { kvm_pr_unimpl_wrmsr(vcpu, msr, data); return 1; } + if (data & MSR_K7_HWCR_CPUID_USER_DIS && + !supports_cpuid_fault_amd(vcpu)) + return 1; vcpu->arch.msr_hwcr =3D data; break; case MSR_FAM10H_MMIO_CONF_BASE: @@ -4248,7 +4252,7 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct = msr_data *msr_info) case MSR_MISC_FEATURES_ENABLES: if (data & ~MSR_MISC_FEATURES_ENABLES_CPUID_FAULT || (data & MSR_MISC_FEATURES_ENABLES_CPUID_FAULT && - !supports_cpuid_fault(vcpu))) + !supports_cpuid_fault_intel(vcpu))) return 1; vcpu->arch.msr_misc_features_enables =3D data; break; --=20 2.53.0.239.g8d8fc8a987-goog