linux-kernel - Re: [PATCH 57/61] KVM: x86/mmu: Merge kvm_{enable,disable}

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Message-ID: <87eeuilp24.fsf@vitty.brq.redhat.com>
Date:   Tue, 25 Feb 2020 15:27:47 +0100
From:   Vitaly Kuznetsov <vkuznets@...hat.com>
To:     Sean Christopherson <sean.j.christopherson@...el.com>
Cc:     Paolo Bonzini <pbonzini@...hat.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Jim Mattson <jmattson@...gle.com>,
        Joerg Roedel <joro@...tes.org>, kvm@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH 57/61] KVM: x86/mmu: Merge kvm_{enable,disable}_tdp() into a common function

Sean Christopherson <sean.j.christopherson@...el.com> writes:

> Combine kvm_enable_tdp() and kvm_disable_tdp() into a single function,
> kvm_configure_mmu(), in preparation for doing additional configuration
> during hardware setup.  And because having separate helpers is silly.
>
> No functional change intended.
>
> Signed-off-by: Sean Christopherson <sean.j.christopherson@...el.com>
> ---
>  arch/x86/include/asm/kvm_host.h |  3 +--
>  arch/x86/kvm/mmu/mmu.c          | 13 +++----------
>  arch/x86/kvm/svm.c              |  5 +----
>  arch/x86/kvm/vmx/vmx.c          |  4 +---
>  4 files changed, 6 insertions(+), 19 deletions(-)
>
> diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
> index a8bae9d88bce..1a13a53bbaeb 100644
> --- a/arch/x86/include/asm/kvm_host.h
> +++ b/arch/x86/include/asm/kvm_host.h
> @@ -1494,8 +1494,7 @@ void kvm_mmu_invlpg(struct kvm_vcpu *vcpu, gva_t gva);
>  void kvm_mmu_invpcid_gva(struct kvm_vcpu *vcpu, gva_t gva, unsigned long pcid);
>  void kvm_mmu_new_cr3(struct kvm_vcpu *vcpu, gpa_t new_cr3, bool skip_tlb_flush);
>  
> -void kvm_enable_tdp(void);
> -void kvm_disable_tdp(void);
> +void kvm_configure_mmu(bool enable_tdp);
>  
>  static inline gpa_t translate_gpa(struct kvm_vcpu *vcpu, gpa_t gpa, u32 access,
>  				  struct x86_exception *exception)
> diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
> index 84eeb61d06aa..08c80c7c88d4 100644
> --- a/arch/x86/kvm/mmu/mmu.c
> +++ b/arch/x86/kvm/mmu/mmu.c
> @@ -5541,18 +5541,11 @@ void kvm_mmu_invpcid_gva(struct kvm_vcpu *vcpu, gva_t gva, unsigned long pcid)
>  }
>  EXPORT_SYMBOL_GPL(kvm_mmu_invpcid_gva);
>  
> -void kvm_enable_tdp(void)
> +void kvm_configure_mmu(bool enable_tdp)
>  {
> -	tdp_enabled = true;
> +	tdp_enabled = enable_tdp;
>  }
> -EXPORT_SYMBOL_GPL(kvm_enable_tdp);
> -
> -void kvm_disable_tdp(void)
> -{
> -	tdp_enabled = false;
> -}
> -EXPORT_SYMBOL_GPL(kvm_disable_tdp);
> -
> +EXPORT_SYMBOL_GPL(kvm_configure_mmu);
>  
>  /* The return value indicates if tlb flush on all vcpus is needed. */
>  typedef bool (*slot_level_handler) (struct kvm *kvm, struct kvm_rmap_head *rmap_head);
> diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
> index 80962c1eea8f..19dc74ae1efb 100644
> --- a/arch/x86/kvm/svm.c
> +++ b/arch/x86/kvm/svm.c
> @@ -1443,10 +1443,7 @@ static __init int svm_hardware_setup(void)
>  	if (npt_enabled && !npt)
>  		npt_enabled = false;
>  
> -	if (npt_enabled)
> -		kvm_enable_tdp();
> -	else
> -		kvm_disable_tdp();
> +	kvm_configure_mmu(npt_enabled);
>  	pr_info("kvm: Nested Paging %sabled\n", npt_enabled ? "en" : "dis");
>  
>  	if (nrips) {
> diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
> index e6284b6aac56..59206c22b5e1 100644
> --- a/arch/x86/kvm/vmx/vmx.c
> +++ b/arch/x86/kvm/vmx/vmx.c
> @@ -5295,7 +5295,6 @@ static void vmx_enable_tdp(void)
>  		VMX_EPT_RWX_MASK, 0ull);
>  
>  	ept_set_mmio_spte_mask();
> -	kvm_enable_tdp();
>  }
>  
>  /*
> @@ -7678,8 +7677,7 @@ static __init int hardware_setup(void)
>  
>  	if (enable_ept)
>  		vmx_enable_tdp();
> -	else
> -		kvm_disable_tdp();
> +	kvm_configure_mmu(enable_ept);
>  
>  	/*
>  	 * Only enable PML when hardware supports PML feature, and both EPT

Reviewed-by: Vitaly Kuznetsov <vkuznets@...hat.com>

-- 
Vitaly