Re: [RFC PATCH v2 44/69] KVM: x86/mmu: Refactor shadow walk in __direct_map() to reduce indentation

[Paolo Bonzini]

On 03/07/21 00:04, isaku.yamahata@xxxxxxxxx wrote:
> From: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
>
> Employ a 'continue' to reduce the indentation for linking a new shadow
> page during __direct_map() in preparation for linking private pages.
>
> Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
> Signed-off-by: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
> ---
>   arch/x86/kvm/mmu/mmu.c | 19 +++++++++----------
>   1 file changed, 9 insertions(+), 10 deletions(-)
>
> diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
> index 1c40dfd05979..0259781cee6a 100644
> --- a/arch/x86/kvm/mmu/mmu.c
> +++ b/arch/x86/kvm/mmu/mmu.c
> @@ -2910,16 +2910,15 @@ static int __direct_map(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code,
>   			break;
>   
>   		drop_large_spte(vcpu, it.sptep);
> -		if (!is_shadow_present_pte(*it.sptep)) {
> -			sp = __kvm_mmu_get_page(vcpu, base_gfn,
> -						gfn_stolen_bits, it.addr,
> -						it.level - 1, true, ACC_ALL);
> -
> -			link_shadow_page(vcpu, it.sptep, sp);
> -			if (is_tdp && huge_page_disallowed &&
> -			    req_level >= it.level)
> -				account_huge_nx_page(vcpu->kvm, sp);
> -		}
> +		if (is_shadow_present_pte(*it.sptep))
> +			continue;
> +
> +		sp = __kvm_mmu_get_page(vcpu, base_gfn, gfn_stolen_bits,
> +					it.addr, it.level - 1, true, ACC_ALL);
> +
> +		link_shadow_page(vcpu, it.sptep, sp);
> +		if (is_tdp && huge_page_disallowed && req_level >= it.level)
> +			account_huge_nx_page(vcpu->kvm, sp);
>   	}
>   
>   	ret = mmu_set_spte(vcpu, it.sptep, ACC_ALL,

Reviewed-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>