On Mon, Sep 14, 2020 at 03:15:37PM -0500, Tom Lendacky wrote: > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index 6f5988c305e1..5e5f1e8fed3a 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -1033,6 +1033,26 @@ int kvm_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4) > } > EXPORT_SYMBOL_GPL(kvm_set_cr4); > > +int kvm_track_cr4(struct kvm_vcpu *vcpu, unsigned long cr4) > +{ > + unsigned long old_cr4 = kvm_read_cr4(vcpu); > + unsigned long pdptr_bits = X86_CR4_PGE | X86_CR4_PSE | X86_CR4_PAE | > + X86_CR4_SMEP | X86_CR4_SMAP | X86_CR4_PKE; > + > + if (kvm_x86_ops.set_cr4(vcpu, cr4)) > + return 1; Pretty much all the same comments as EFER and CR0, e.g. call svm_set_cr4() directly instead of bouncing through kvm_x86_ops. And with that, this can be called __kvm_set_cr4() to be consistent with __kvm_set_cr0(). > + > + if (((cr4 ^ old_cr4) & pdptr_bits) || > + (!(cr4 & X86_CR4_PCIDE) && (old_cr4 & X86_CR4_PCIDE))) > + kvm_mmu_reset_context(vcpu); > + > + if ((cr4 ^ old_cr4) & (X86_CR4_OSXSAVE | X86_CR4_PKE)) > + kvm_update_cpuid_runtime(vcpu); > + > + return 0; > +} > +EXPORT_SYMBOL_GPL(kvm_track_cr4); > + > int kvm_set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3) > { > bool skip_tlb_flush = false; > -- > 2.28.0 >