Re: [PATCH] do not call gva_to_gpa on physical address

[Avi Kivity <avi@redhat.com>]

On 07/14/2010 06:38 PM, Gleb Natapov wrote:
> When tdp is enabled cr2 passed to emulator is pga not gva, so no need to
> call gva_to_gpa on it.
>
> Signed-off-by: Gleb Natapov<gleb@redhat.com>
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index fb08316..721bf0a 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -3944,10 +3944,13 @@ static bool reexecute_instruction(struct kvm_vcpu *vcpu, gva_t gva)
>   	if (kvm_mmu_unprotect_page_virt(vcpu, gva))
>   		return true;
>
> -	gpa = kvm_mmu_gva_to_gpa_system(vcpu, gva, NULL);
> +	if (!tdp_enabled) {
> +		gpa = kvm_mmu_gva_to_gpa_system(vcpu, gva, NULL);
>
> -	if (gpa == UNMAPPED_GVA)
> -		return true; /* let cpu generate fault */
> +		if (gpa == UNMAPPED_GVA)
> +			return true; /* let cpu generate fault */
> +	} else
> +		gpa = gva;
>
>   	if (!kvm_is_error_hva(gfn_to_hva(vcpu->kvm, gpa>>  PAGE_SHIFT)))
>   		return true;
>    

Why not

     if (tdp_enabled)
               return false;

at the top?  Is there any reason ever to reexecute an instruction with 
tdp enabled?

-- 
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.