Commit cb9b88c6 authored by Sean Christopherson's avatar Sean Christopherson Committed by Paolo Bonzini
Browse files

KVM: x86/mmu: Refactor handling of cache consistency with TDP 



Pre-calculate the max level for a TDP page with respect to MTRR cache
consistency in preparation of replacing force_pt_level with max_level,
and eventually combining the bulk of nonpaging_page_fault() and
tdp_page_fault() into a common helper.

No functional change intended.

Signed-off-by: default avatarSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 9f1a8526

arch/x86/kvm/mmu/mmu.c

+14 −16
Original line number Diff line number Diff line
@@ -4271,16 +4271,6 @@ int kvm_handle_page_fault(struct kvm_vcpu *vcpu, u64 error_code, 
}

EXPORT_SYMBOL_GPL(kvm_handle_page_fault);



static bool

check_hugepage_cache_consistency(struct kvm_vcpu *vcpu, gfn_t gfn, int level)

{

	int page_num = KVM_PAGES_PER_HPAGE(level);



	gfn &= ~(page_num - 1);



	return kvm_mtrr_check_gfn_range_consistency(vcpu, gfn, page_num);

}



static int tdp_page_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code,

			  bool prefault)

{
@@ -4294,6 +4284,7 @@ static int tdp_page_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code, 
	bool map_writable;

	bool lpage_disallowed = (error_code & PFERR_FETCH_MASK) &&

				is_nx_huge_page_enabled();

	int max_level;



	MMU_WARN_ON(!VALID_PAGE(vcpu->arch.mmu->root_hpa));
@@ -4304,14 +4295,21 @@ static int tdp_page_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code, 
	if (r)

		return r;



	force_pt_level =

		lpage_disallowed ||

		!check_hugepage_cache_consistency(vcpu, gfn, PT_DIRECTORY_LEVEL);

	for (max_level = PT_MAX_HUGEPAGE_LEVEL;

	     max_level > PT_PAGE_TABLE_LEVEL;

	     max_level--) {

		int page_num = KVM_PAGES_PER_HPAGE(max_level);

		gfn_t base = gfn & ~(page_num - 1);



		if (kvm_mtrr_check_gfn_range_consistency(vcpu, base, page_num))

			break;

	}



	force_pt_level = lpage_disallowed || max_level == PT_PAGE_TABLE_LEVEL;

	level = mapping_level(vcpu, gfn, &force_pt_level);

	if (likely(!force_pt_level)) {

		if (level > PT_DIRECTORY_LEVEL &&

		    !check_hugepage_cache_consistency(vcpu, gfn, level))

			level = PT_DIRECTORY_LEVEL;

		if (level > max_level)

			level = max_level;

		gfn &= ~(KVM_PAGES_PER_HPAGE(level) - 1);

	}