Re: [PATCH 12/14] KVM: x86/mmu: Fold max_mapping_level() into kvm_mmu_hugepage_adjust()

Paolo Bonzini
2020-01-21T15:12:59Z

On 08/01/20 21:24, Sean Christopherson wrote:
> - level = host_pfn_mapping_level(vcpu, gfn, pfn);
> + slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);
> + if (!memslot_valid_for_gpte(slot, true))
> + return PT_PAGE_TABLE_LEVEL;

Following up on my remark to patch 7, this can also use
gfn_to_memslot_dirty_bitmap.

Paolo

> +
> + max_level = min(max_level, kvm_x86_ops->get_lpage_level());
> + for ( ; max_level > PT_PAGE_TABLE_LEVEL; max_level--) {
> + if (!__mmu_gfn_lpage_is_disallowed(gfn, max_level, slot))
> + break;
> + }
> +
> + if (max_level == PT_PAGE_TABLE_LEVEL)
> + return PT_PAGE_TABLE_LEVEL;
> +
> + level = host_pfn_mapping_level(vcpu, gfn, pfn, slot);
> if (level == PT_PAGE_TABLE_LEVEL)
> return level;
>
> @@ -4182,8 +4172,6 @@ static int direct_page_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code,
> if (lpage_disallowed)
> max_level = PT_PAGE_TABLE_LEVEL;
>
> - max_level = max_mapping_level(vcpu, gfn, max_level);
> -
> if (fast_page_fault(vcpu, gpa, error_code))
> return RET_PF_RETRY;
>
> diff --git a/arch/x86/kvm/mmu/paging_tmpl.h b/arch/x86/kvm/mmu/paging_tmpl.h
> index 0560982eda8b..ea174d85700a 100644
> --- a/arch/x86/kvm/mmu/paging_tmpl.h
> +++ b/arch/x86/kvm/mmu/paging_tmpl.h
> @@ -817,8 +817,6 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gpa_t addr, u32 error_code,
> else
> max_level = walker.level;
>
> - max_level = max_mapping_level(vcpu, walker.gfn, max_level);
> -
> mmu_seq = vcpu->kvm->mmu_notifier_seq;
> smp_rmb();
>
>