linux-kernel - Re: [PATCH 03/10] KVM: VMX: Handle INVVPID fallback logic in vpid_sync_vcpu

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Date:   Fri, 21 Feb 2020 14:26:45 +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 03/10] KVM: VMX: Handle INVVPID fallback logic in vpid_sync_vcpu_addr()

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

> Directly invoke vpid_sync_context() to do a global INVVPID when the
> individual address variant is not supported instead of deferring such
> behavior to the caller.  This allows for additional consolidation of
> code as the logic is basically identical to the emulation of the
> individual address variant in handle_invvpid().
>
> No functional change intended.
>
> Signed-off-by: Sean Christopherson <sean.j.christopherson@...el.com>
> ---
>  arch/x86/kvm/vmx/ops.h | 12 +++++-------
>  arch/x86/kvm/vmx/vmx.c |  3 +--
>  2 files changed, 6 insertions(+), 9 deletions(-)
>
> diff --git a/arch/x86/kvm/vmx/ops.h b/arch/x86/kvm/vmx/ops.h
> index a2b0689e65e3..612df1bdb26b 100644
> --- a/arch/x86/kvm/vmx/ops.h
> +++ b/arch/x86/kvm/vmx/ops.h
> @@ -276,17 +276,15 @@ static inline void vpid_sync_context(int vpid)
>  		vpid_sync_vcpu_global();
>  }
>  
> -static inline bool vpid_sync_vcpu_addr(int vpid, gva_t addr)
> +static inline void vpid_sync_vcpu_addr(int vpid, gva_t addr)
>  {
>  	if (vpid == 0)
> -		return true;
> +		return;
>  
> -	if (cpu_has_vmx_invvpid_individual_addr()) {
> +	if (cpu_has_vmx_invvpid_individual_addr())
>  		__invvpid(VMX_VPID_EXTENT_INDIVIDUAL_ADDR, vpid, addr);
> -		return true;
> -	}
> -
> -	return false;
> +	else
> +		vpid_sync_context(vpid);
>  }
>  
>  static inline void ept_sync_global(void)
> diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
> index 9a6664886f2e..349a6e054e0e 100644
> --- a/arch/x86/kvm/vmx/vmx.c
> +++ b/arch/x86/kvm/vmx/vmx.c
> @@ -2826,8 +2826,7 @@ static void vmx_flush_tlb_gva(struct kvm_vcpu *vcpu, gva_t addr)
>  {
>  	int vpid = to_vmx(vcpu)->vpid;
>  
> -	if (!vpid_sync_vcpu_addr(vpid, addr))
> -		vpid_sync_context(vpid);
> +	vpid_sync_vcpu_addr(vpid, addr);
>  
>  	/*
>  	 * If VPIDs are not supported or enabled, then the above is a no-op.

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

-- 
Vitaly