Commit 1b6d9d9e authored by Sean Christopherson's avatar Sean Christopherson Committed by Paolo Bonzini
Browse files

KVM: x86/mmu: Split out max mapping level calculation to helper 



Factor out the logic for determining the maximum mapping level given a
memslot and a gpa.  The helper will be used when zapping collapsible
SPTEs when disabling dirty logging, e.g. to avoid zapping SPTEs that
can't possibly be rebuilt as hugepages.

No functional change intended.

Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
Message-Id: <20210213005015.1651772-4-seanjc@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent c060c72f

arch/x86/kvm/mmu/mmu.c

+22 −15
Original line number Diff line number Diff line
@@ -2756,8 +2756,8 @@ static void direct_pte_prefetch(struct kvm_vcpu *vcpu, u64 *sptep) 
	__direct_pte_prefetch(vcpu, sp, sptep);

}



static int host_pfn_mapping_level(struct kvm_vcpu *vcpu, gfn_t gfn,

				  kvm_pfn_t pfn, struct kvm_memory_slot *slot)

static int host_pfn_mapping_level(struct kvm *kvm, gfn_t gfn, kvm_pfn_t pfn,

				  struct kvm_memory_slot *slot)

{

	unsigned long hva;

	pte_t *pte;
@@ -2776,19 +2776,36 @@ static int host_pfn_mapping_level(struct kvm_vcpu *vcpu, gfn_t gfn, 
	 */

	hva = __gfn_to_hva_memslot(slot, gfn);



	pte = lookup_address_in_mm(vcpu->kvm->mm, hva, &level);

	pte = lookup_address_in_mm(kvm->mm, hva, &level);

	if (unlikely(!pte))

		return PG_LEVEL_4K;



	return level;

}



int kvm_mmu_max_mapping_level(struct kvm *kvm, struct kvm_memory_slot *slot,

			      gfn_t gfn, kvm_pfn_t pfn, int max_level)

{

	struct kvm_lpage_info *linfo;



	max_level = min(max_level, max_huge_page_level);

	for ( ; max_level > PG_LEVEL_4K; max_level--) {

		linfo = lpage_info_slot(gfn, slot, max_level);

		if (!linfo->disallow_lpage)

			break;

	}



	if (max_level == PG_LEVEL_4K)

		return PG_LEVEL_4K;



	return host_pfn_mapping_level(kvm, gfn, pfn, slot);

}



int kvm_mmu_hugepage_adjust(struct kvm_vcpu *vcpu, gfn_t gfn,

			    int max_level, kvm_pfn_t *pfnp,

			    bool huge_page_disallowed, int *req_level)

{

	struct kvm_memory_slot *slot;

	struct kvm_lpage_info *linfo;

	kvm_pfn_t pfn = *pfnp;

	kvm_pfn_t mask;

	int level;
@@ -2805,17 +2822,7 @@ int kvm_mmu_hugepage_adjust(struct kvm_vcpu *vcpu, gfn_t gfn, 
	if (!slot)

		return PG_LEVEL_4K;



	max_level = min(max_level, max_huge_page_level);

	for ( ; max_level > PG_LEVEL_4K; max_level--) {

		linfo = lpage_info_slot(gfn, slot, max_level);

		if (!linfo->disallow_lpage)

			break;

	}



	if (max_level == PG_LEVEL_4K)

		return PG_LEVEL_4K;



	level = host_pfn_mapping_level(vcpu, gfn, pfn, slot);

	level = kvm_mmu_max_mapping_level(vcpu->kvm, slot, gfn, pfn, max_level);

	if (level == PG_LEVEL_4K)

		return level;

arch/x86/kvm/mmu/mmu_internal.h

+2 −0
Original line number Diff line number Diff line
@@ -138,6 +138,8 @@ enum { 
#define SET_SPTE_NEED_REMOTE_TLB_FLUSH	BIT(1)

#define SET_SPTE_SPURIOUS		BIT(2)



int kvm_mmu_max_mapping_level(struct kvm *kvm, struct kvm_memory_slot *slot,

			      gfn_t gfn, kvm_pfn_t pfn, int max_level);

int kvm_mmu_hugepage_adjust(struct kvm_vcpu *vcpu, gfn_t gfn,

			    int max_level, kvm_pfn_t *pfnp,

			    bool huge_page_disallowed, int *req_level);