Re: [PATCH v3 13/17] KVM: x86/tdp_mmu: Support mirror root for TDP MMU

[Yan Zhao]

On Wed, Jun 19, 2024 at 03:36:10PM -0700, Rick Edgecombe wrote:
> diff --git a/arch/x86/kvm/mmu/tdp_mmu.h b/arch/x86/kvm/mmu/tdp_mmu.h
> index b887c225ff24..2903f03a34be 100644
> --- a/arch/x86/kvm/mmu/tdp_mmu.h
> +++ b/arch/x86/kvm/mmu/tdp_mmu.h
> @@ -10,7 +10,7 @@
>  void kvm_mmu_init_tdp_mmu(struct kvm *kvm);
>  void kvm_mmu_uninit_tdp_mmu(struct kvm *kvm);
>  
> -void kvm_tdp_mmu_alloc_root(struct kvm_vcpu *vcpu);
> +void kvm_tdp_mmu_alloc_root(struct kvm_vcpu *vcpu, bool private);
>  
>  __must_check static inline bool kvm_tdp_mmu_get_root(struct kvm_mmu_page *root)
This function name is very similar to below tdp_mmu_get_root().

> +static inline struct kvm_mmu_page *tdp_mmu_get_root_for_fault(struct kvm_vcpu *vcpu,
> +							      struct kvm_page_fault *fault)
> +{
> +	if (unlikely(!kvm_is_addr_direct(vcpu->kvm, fault->addr)))
> +		return root_to_sp(vcpu->arch.mmu->mirror_root_hpa);
> +
> +	return root_to_sp(vcpu->arch.mmu->root.hpa);
> +}
> +
> +static inline struct kvm_mmu_page *tdp_mmu_get_root(struct kvm_vcpu *vcpu,
> +						    enum kvm_tdp_mmu_root_types type)
> +{
> +	if (unlikely(type == KVM_MIRROR_ROOTS))
> +		return root_to_sp(vcpu->arch.mmu->mirror_root_hpa);
> +
> +	return root_to_sp(vcpu->arch.mmu->root.hpa);
> +}
No need to put the two functions in tdp_mmu.h as they are not called in mmu.c.

Could we move them to tdp_mmu.c and rename them to something like
tdp_mmu_type_to_root() and tdp_mmu_fault_to_root() ?