kvm: rename pfn_t to kvm_pfn_t

To date, we have implemented two I/O usage models for persistent memory,
PMEM (a persistent "ram disk") and DAX (mmap persistent memory into
userspace).  This series adds a third, DAX-GUP, that allows DAX mappings
to be the target of direct-i/o.  It allows userspace to coordinate
DMA/RDMA from/to persistent memory.

The implementation leverages the ZONE_DEVICE mm-zone that went into
4.3-rc1 (also discussed at kernel summit) to flag pages that are owned
and dynamically mapped by a device driver.  The pmem driver, after
mapping a persistent memory range into the system memmap via
devm_memremap_pages(), arranges for DAX to distinguish pfn-only versus
page-backed pmem-pfns via flags in the new pfn_t type.

The DAX code, upon seeing a PFN_DEV+PFN_MAP flagged pfn, flags the
resulting pte(s) inserted into the process page tables with a new
_PAGE_DEVMAP flag.  Later, when get_user_pages() is walking ptes it keys
off _PAGE_DEVMAP to pin the device hosting the page range active.
Finally, get_page() and put_page() are modified to take references
against the device driver established page mapping.

Finally, this need for "struct page" for persistent memory requires
memory capacity to store the memmap array.  Given the memmap array for a
large pool of persistent may exhaust available DRAM introduce a
mechanism to allocate the memmap from persistent memory.  The new
"struct vmem_altmap *" parameter to devm_memremap_pages() enables
arch_add_memory() to use reserved pmem capacity rather than the page
allocator.

This patch (of 18):

The core has developed a need for a "pfn_t" type [1].  Move the existing
pfn_t in KVM to kvm_pfn_t [2].

[1]: https://lists.01.org/pipermail/linux-nvdimm/2015-September/002199.html
[2]: https://lists.01.org/pipermail/linux-nvdimm/2015-September/002218.html

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

23 files changed, 110 insertions, 104 deletions

diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h
index 9203c21b4673..a520b7987a29 100644
--- a/arch/arm/include/asm/kvm_mmu.h
+++ b/arch/arm/include/asm/kvm_mmu.h
@@ -182,7 +182,8 @@ static inline bool vcpu_has_cache_enabled(struct kvm_vcpu *vcpu)
 	return (vcpu->arch.cp15[c1_SCTLR] & 0b101) == 0b101;
 }
 
-static inline void __coherent_cache_guest_page(struct kvm_vcpu *vcpu, pfn_t pfn,
+static inline void __coherent_cache_guest_page(struct kvm_vcpu *vcpu,
+					       kvm_pfn_t pfn,
 					       unsigned long size,
 					       bool ipa_uncached)
 {
@@ -246,7 +247,7 @@ static inline void __kvm_flush_dcache_pte(pte_t pte)
 static inline void __kvm_flush_dcache_pmd(pmd_t pmd)
 {
 	unsigned long size = PMD_SIZE;
-	pfn_t pfn = pmd_pfn(pmd);
+	kvm_pfn_t pfn = pmd_pfn(pmd);
 
 	while (size) {
 		void *va = kmap_atomic_pfn(pfn);
diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c
index 22f7fa0124ec..aba61fd3697a 100644
--- a/arch/arm/kvm/mmu.c
+++ b/arch/arm/kvm/mmu.c
@@ -992,9 +992,9 @@ out:
 	return ret;
 }
 
-static bool transparent_hugepage_adjust(pfn_t *pfnp, phys_addr_t *ipap)
+static bool transparent_hugepage_adjust(kvm_pfn_t *pfnp, phys_addr_t *ipap)
 {
-	pfn_t pfn = *pfnp;
+	kvm_pfn_t pfn = *pfnp;
 	gfn_t gfn = *ipap >> PAGE_SHIFT;
 
 	if (PageTransCompound(pfn_to_page(pfn))) {
@@ -1201,7 +1201,7 @@ void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm,
 	kvm_mmu_write_protect_pt_masked(kvm, slot, gfn_offset, mask);
 }
 
-static void coherent_cache_guest_page(struct kvm_vcpu *vcpu, pfn_t pfn,
+static void coherent_cache_guest_page(struct kvm_vcpu *vcpu, kvm_pfn_t pfn,
 				      unsigned long size, bool uncached)
 {
 	__coherent_cache_guest_page(vcpu, pfn, size, uncached);
@@ -1218,7 +1218,7 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
 	struct kvm *kvm = vcpu->kvm;
 	struct kvm_mmu_memory_cache *memcache = &vcpu->arch.mmu_page_cache;
 	struct vm_area_struct *vma;
-	pfn_t pfn;
+	kvm_pfn_t pfn;
 	pgprot_t mem_type = PAGE_S2;
 	bool fault_ipa_uncached;
 	bool logging_active = memslot_is_logging(memslot);
@@ -1346,7 +1346,7 @@ static void handle_access_fault(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa)
 {
 	pmd_t *pmd;
 	pte_t *pte;
-	pfn_t pfn;
+	kvm_pfn_t pfn;
 	bool pfn_valid = false;
 
 	trace_kvm_access_fault(fault_ipa);
diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h
index 0bf8b4320a91..736433912a1e 100644
--- a/arch/arm64/include/asm/kvm_mmu.h
+++ b/arch/arm64/include/asm/kvm_mmu.h
@@ -230,7 +230,8 @@ static inline bool vcpu_has_cache_enabled(struct kvm_vcpu *vcpu)
 	return (vcpu_sys_reg(vcpu, SCTLR_EL1) & 0b101) == 0b101;
 }
 
-static inline void __coherent_cache_guest_page(struct kvm_vcpu *vcpu, pfn_t pfn,
+static inline void __coherent_cache_guest_page(struct kvm_vcpu *vcpu,
+					       kvm_pfn_t pfn,
 					       unsigned long size,
 					       bool ipa_uncached)
 {
diff --git a/arch/mips/include/asm/kvm_host.h b/arch/mips/include/asm/kvm_host.h
index 6ded8d347af9..7c191443c7ea 100644
--- a/arch/mips/include/asm/kvm_host.h
+++ b/arch/mips/include/asm/kvm_host.h
@@ -101,9 +101,9 @@
 #define CAUSEF_DC			(_ULCAST_(1) << 27)
 
 extern atomic_t kvm_mips_instance;
-extern pfn_t(*kvm_mips_gfn_to_pfn) (struct kvm *kvm, gfn_t gfn);
-extern void (*kvm_mips_release_pfn_clean) (pfn_t pfn);
-extern bool(*kvm_mips_is_error_pfn) (pfn_t pfn);
+extern kvm_pfn_t (*kvm_mips_gfn_to_pfn)(struct kvm *kvm, gfn_t gfn);
+extern void (*kvm_mips_release_pfn_clean)(kvm_pfn_t pfn);
+extern bool (*kvm_mips_is_error_pfn)(kvm_pfn_t pfn);
 
 struct kvm_vm_stat {
 	u32 remote_tlb_flush;
diff --git a/arch/mips/kvm/emulate.c b/arch/mips/kvm/emulate.c
index 41b1b090f56f..1b675c7ce89f 100644
--- a/arch/mips/kvm/emulate.c
+++ b/arch/mips/kvm/emulate.c
@@ -1525,7 +1525,7 @@ int kvm_mips_sync_icache(unsigned long va, struct kvm_vcpu *vcpu)
 	struct kvm *kvm = vcpu->kvm;
 	unsigned long pa;
 	gfn_t gfn;
-	pfn_t pfn;
+	kvm_pfn_t pfn;
 
 	gfn = va >> PAGE_SHIFT;
 
diff --git a/arch/mips/kvm/tlb.c b/arch/mips/kvm/tlb.c
index aed0ac2a4972..570479c03bdc 100644
--- a/arch/mips/kvm/tlb.c
+++ b/arch/mips/kvm/tlb.c
@@ -38,13 +38,13 @@ atomic_t kvm_mips_instance;
 EXPORT_SYMBOL(kvm_mips_instance);
 
 /* These function pointers are initialized once the KVM module is loaded */
-pfn_t (*kvm_mips_gfn_to_pfn)(struct kvm *kvm, gfn_t gfn);
+kvm_pfn_t (*kvm_mips_gfn_to_pfn)(struct kvm *kvm, gfn_t gfn);
 EXPORT_SYMBOL(kvm_mips_gfn_to_pfn);
 
-void (*kvm_mips_release_pfn_clean)(pfn_t pfn);
+void (*kvm_mips_release_pfn_clean)(kvm_pfn_t pfn);
 EXPORT_SYMBOL(kvm_mips_release_pfn_clean);
 
-bool (*kvm_mips_is_error_pfn)(pfn_t pfn);
+bool (*kvm_mips_is_error_pfn)(kvm_pfn_t pfn);
 EXPORT_SYMBOL(kvm_mips_is_error_pfn);
 
 uint32_t kvm_mips_get_kernel_asid(struct kvm_vcpu *vcpu)
@@ -144,7 +144,7 @@ EXPORT_SYMBOL(kvm_mips_dump_guest_tlbs);
 static int kvm_mips_map_page(struct kvm *kvm, gfn_t gfn)
 {
 	int srcu_idx, err = 0;
-	pfn_t pfn;
+	kvm_pfn_t pfn;
 
 	if (kvm->arch.guest_pmap[gfn] != KVM_INVALID_PAGE)
 		return 0;
@@ -262,7 +262,7 @@ int kvm_mips_handle_kseg0_tlb_fault(unsigned long badvaddr,
 				    struct kvm_vcpu *vcpu)
 {
 	gfn_t gfn;
-	pfn_t pfn0, pfn1;
+	kvm_pfn_t pfn0, pfn1;
 	unsigned long vaddr = 0;
 	unsigned long entryhi = 0, entrylo0 = 0, entrylo1 = 0;
 	int even;
@@ -313,7 +313,7 @@ EXPORT_SYMBOL(kvm_mips_handle_kseg0_tlb_fault);
 int kvm_mips_handle_commpage_tlb_fault(unsigned long badvaddr,
 	struct kvm_vcpu *vcpu)
 {
-	pfn_t pfn0, pfn1;
+	kvm_pfn_t pfn0, pfn1;
 	unsigned long flags, old_entryhi = 0, vaddr = 0;
 	unsigned long entrylo0 = 0, entrylo1 = 0;
 
@@ -360,7 +360,7 @@ int kvm_mips_handle_mapped_seg_tlb_fault(struct kvm_vcpu *vcpu,
 {
 	unsigned long entryhi = 0, entrylo0 = 0, entrylo1 = 0;
 	struct kvm *kvm = vcpu->kvm;
-	pfn_t pfn0, pfn1;
+	kvm_pfn_t pfn0, pfn1;
 
 	if ((tlb->tlb_hi & VPN2_MASK) == 0) {
 		pfn0 = 0;
diff --git a/arch/powerpc/include/asm/kvm_book3s.h b/arch/powerpc/include/asm/kvm_book3s.h
index 9fac01cb89c1..8f39796c9da8 100644
--- a/arch/powerpc/include/asm/kvm_book3s.h
+++ b/arch/powerpc/include/asm/kvm_book3s.h
@@ -154,8 +154,8 @@ extern void kvmppc_set_bat(struct kvm_vcpu *vcpu, struct kvmppc_bat *bat,
 			   bool upper, u32 val);
 extern void kvmppc_giveup_ext(struct kvm_vcpu *vcpu, ulong msr);
 extern int kvmppc_emulate_paired_single(struct kvm_run *run, struct kvm_vcpu *vcpu);
-extern pfn_t kvmppc_gpa_to_pfn(struct kvm_vcpu *vcpu, gpa_t gpa, bool writing,
-			bool *writable);
+extern kvm_pfn_t kvmppc_gpa_to_pfn(struct kvm_vcpu *vcpu, gpa_t gpa,
+			bool writing, bool *writable);
 extern void kvmppc_add_revmap_chain(struct kvm *kvm, struct revmap_entry *rev,
 			unsigned long *rmap, long pte_index, int realmode);
 extern void kvmppc_update_rmap_change(unsigned long *rmap, unsigned long psize);
diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
index c6ef05bd0765..2241d5357129 100644
--- a/arch/powerpc/include/asm/kvm_ppc.h
+++ b/arch/powerpc/include/asm/kvm_ppc.h
@@ -515,7 +515,7 @@ void kvmppc_claim_lpid(long lpid);
 void kvmppc_free_lpid(long lpid);
 void kvmppc_init_lpid(unsigned long nr_lpids);
 
-static inline void kvmppc_mmu_flush_icache(pfn_t pfn)
+static inline void kvmppc_mmu_flush_icache(kvm_pfn_t pfn)
 {
 	struct page *page;
 	/*
diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c
index 099c79d8c160..638c6d9be9e0 100644
--- a/arch/powerpc/kvm/book3s.c
+++ b/arch/powerpc/kvm/book3s.c
@@ -366,7 +366,7 @@ int kvmppc_core_prepare_to_enter(struct kvm_vcpu *vcpu)
 }
 EXPORT_SYMBOL_GPL(kvmppc_core_prepare_to_enter);
 
-pfn_t kvmppc_gpa_to_pfn(struct kvm_vcpu *vcpu, gpa_t gpa, bool writing,
+kvm_pfn_t kvmppc_gpa_to_pfn(struct kvm_vcpu *vcpu, gpa_t gpa, bool writing,
 			bool *writable)
 {
 	ulong mp_pa = vcpu->arch.magic_page_pa & KVM_PAM;
@@ -379,9 +379,9 @@ pfn_t kvmppc_gpa_to_pfn(struct kvm_vcpu *vcpu, gpa_t gpa, bool writing,
 	gpa &= ~0xFFFULL;
 	if (unlikely(mp_pa) && unlikely((gpa & KVM_PAM) == mp_pa)) {
 		ulong shared_page = ((ulong)vcpu->arch.shared) & PAGE_MASK;
-		pfn_t pfn;
+		kvm_pfn_t pfn;
 
-		pfn = (pfn_t)virt_to_phys((void*)shared_page) >> PAGE_SHIFT;
+		pfn = (kvm_pfn_t)virt_to_phys((void*)shared_page) >> PAGE_SHIFT;
 		get_page(pfn_to_page(pfn));
 		if (writable)
 			*writable = true;
diff --git a/arch/powerpc/kvm/book3s_32_mmu_host.c b/arch/powerpc/kvm/book3s_32_mmu_host.c
index d5c9bfeb0c9c..55c4d51ea3e2 100644
--- a/arch/powerpc/kvm/book3s_32_mmu_host.c
+++ b/arch/powerpc/kvm/book3s_32_mmu_host.c
@@ -142,7 +142,7 @@ extern char etext[];
 int kvmppc_mmu_map_page(struct kvm_vcpu *vcpu, struct kvmppc_pte *orig_pte,
 			bool iswrite)
 {
-	pfn_t hpaddr;
+	kvm_pfn_t hpaddr;
 	u64 vpn;
 	u64 vsid;
 	struct kvmppc_sid_map *map;
diff --git a/arch/powerpc/kvm/book3s_64_mmu_host.c b/arch/powerpc/kvm/book3s_64_mmu_host.c
index 79ad35abd196..913cd2198fa6 100644
--- a/arch/powerpc/kvm/book3s_64_mmu_host.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_host.c
@@ -83,7 +83,7 @@ int kvmppc_mmu_map_page(struct kvm_vcpu *vcpu, struct kvmppc_pte *orig_pte,
 			bool iswrite)
 {
 	unsigned long vpn;
-	pfn_t hpaddr;
+	kvm_pfn_t hpaddr;
 	ulong hash, hpteg;
 	u64 vsid;
 	int ret;
diff --git a/arch/powerpc/kvm/e500.h b/arch/powerpc/kvm/e500.h
index 72920bed3ac6..94f04fcb373e 100644
--- a/arch/powerpc/kvm/e500.h
+++ b/arch/powerpc/kvm/e500.h
@@ -41,7 +41,7 @@ enum vcpu_ftr {
 #define E500_TLB_MAS2_ATTR	(0x7f)
 
 struct tlbe_ref {
-	pfn_t pfn;		/* valid only for TLB0, except briefly */
+	kvm_pfn_t pfn;		/* valid only for TLB0, except briefly */
 	unsigned int flags;	/* E500_TLB_* */
 };
 
diff --git a/arch/powerpc/kvm/e500_mmu_host.c b/arch/powerpc/kvm/e500_mmu_host.c
index 34c43fff4adb..b0333cc737dd 100644
--- a/arch/powerpc/kvm/e500_mmu_host.c
+++ b/arch/powerpc/kvm/e500_mmu_host.c
@@ -163,9 +163,9 @@ void kvmppc_map_magic(struct kvm_vcpu *vcpu)
 	struct kvm_book3e_206_tlb_entry magic;
 	ulong shared_page = ((ulong)vcpu->arch.shared) & PAGE_MASK;
 	unsigned int stid;
-	pfn_t pfn;
+	kvm_pfn_t pfn;
 
-	pfn = (pfn_t)virt_to_phys((void *)shared_page) >> PAGE_SHIFT;
+	pfn = (kvm_pfn_t)virt_to_phys((void *)shared_page) >> PAGE_SHIFT;
 	get_page(pfn_to_page(pfn));
 
 	preempt_disable();
@@ -246,7 +246,7 @@ static inline int tlbe_is_writable(struct kvm_book3e_206_tlb_entry *tlbe)
 
 static inline void kvmppc_e500_ref_setup(struct tlbe_ref *ref,
 					 struct kvm_book3e_206_tlb_entry *gtlbe,
-					 pfn_t pfn, unsigned int wimg)
+					 kvm_pfn_t pfn, unsigned int wimg)
 {
 	ref->pfn = pfn;
 	ref->flags = E500_TLB_VALID;
@@ -309,7 +309,7 @@ static void kvmppc_e500_setup_stlbe(
 	int tsize, struct tlbe_ref *ref, u64 gvaddr,
 	struct kvm_book3e_206_tlb_entry *stlbe)
 {
-	pfn_t pfn = ref->pfn;
+	kvm_pfn_t pfn = ref->pfn;
 	u32 pr = vcpu->arch.shared->msr & MSR_PR;
 
 	BUG_ON(!(ref->flags & E500_TLB_VALID));
diff --git a/arch/powerpc/kvm/trace_pr.h b/arch/powerpc/kvm/trace_pr.h
index 810507cb688a..d44f324184fb 100644
--- a/arch/powerpc/kvm/trace_pr.h
+++ b/arch/powerpc/kvm/trace_pr.h
@@ -30,7 +30,7 @@ TRACE_EVENT(kvm_book3s_reenter,
 #ifdef CONFIG_PPC_BOOK3S_64
 
 TRACE_EVENT(kvm_book3s_64_mmu_map,
-	TP_PROTO(int rflags, ulong hpteg, ulong va, pfn_t hpaddr,
+	TP_PROTO(int rflags, ulong hpteg, ulong va, kvm_pfn_t hpaddr,
 		 struct kvmppc_pte *orig_pte),
 	TP_ARGS(rflags, hpteg, va, hpaddr, orig_pte),
 
diff --git a/arch/x86/kvm/iommu.c b/arch/x86/kvm/iommu.c
index 5c520ebf6343..a22a488b4622 100644
--- a/arch/x86/kvm/iommu.c
+++ b/arch/x86/kvm/iommu.c
@@ -43,11 +43,11 @@ static int kvm_iommu_unmap_memslots(struct kvm *kvm);
 static void kvm_iommu_put_pages(struct kvm *kvm,
 				gfn_t base_gfn, unsigned long npages);
 
-static pfn_t kvm_pin_pages(struct kvm_memory_slot *slot, gfn_t gfn,
+static kvm_pfn_t kvm_pin_pages(struct kvm_memory_slot *slot, gfn_t gfn,
 			   unsigned long npages)
 {
 	gfn_t end_gfn;
-	pfn_t pfn;
+	kvm_pfn_t pfn;
 
 	pfn     = gfn_to_pfn_memslot(slot, gfn);
 	end_gfn = gfn + npages;
@@ -62,7 +62,8 @@ static pfn_t kvm_pin_pages(struct kvm_memory_slot *slot, gfn_t gfn,
 	return pfn;
 }
 
-static void kvm_unpin_pages(struct kvm *kvm, pfn_t pfn, unsigned long npages)
+static void kvm_unpin_pages(struct kvm *kvm, kvm_pfn_t pfn,
+		unsigned long npages)
 {
 	unsigned long i;
 
@@ -73,7 +74,7 @@ static void kvm_unpin_pages(struct kvm *kvm, pfn_t pfn, unsigned long npages)
 int kvm_iommu_map_pages(struct kvm *kvm, struct kvm_memory_slot *slot)
 {
 	gfn_t gfn, end_gfn;
-	pfn_t pfn;
+	kvm_pfn_t pfn;
 	int r = 0;
 	struct iommu_domain *domain = kvm->arch.iommu_domain;
 	int flags;
@@ -275,7 +276,7 @@ static void kvm_iommu_put_pages(struct kvm *kvm,
 {
 	struct iommu_domain *domain;
 	gfn_t end_gfn, gfn;
-	pfn_t pfn;
+	kvm_pfn_t pfn;
 	u64 phys;
 
 	domain  = kvm->arch.iommu_domain;
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 420a5ca3c0ee..95a955de5964 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -259,7 +259,7 @@ static unsigned get_mmio_spte_access(u64 spte)
 }
 
 static bool set_mmio_spte(struct kvm_vcpu *vcpu, u64 *sptep, gfn_t gfn,
-			  pfn_t pfn, unsigned access)
+			  kvm_pfn_t pfn, unsigned access)
 {
 	if (unlikely(is_noslot_pfn(pfn))) {
 		mark_mmio_spte(vcpu, sptep, gfn, access);
@@ -320,7 +320,7 @@ static int is_last_spte(u64 pte, int level)
 	return 0;
 }
 
-static pfn_t spte_to_pfn(u64 pte)
+static kvm_pfn_t spte_to_pfn(u64 pte)
 {
 	return (pte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT;
 }
@@ -582,7 +582,7 @@ static bool mmu_spte_update(u64 *sptep, u64 new_spte)
  */
 static int mmu_spte_clear_track_bits(u64 *sptep)
 {
-	pfn_t pfn;
+	kvm_pfn_t pfn;
 	u64 old_spte = *sptep;
 
 	if (!spte_has_volatile_bits(old_spte))
@@ -1372,7 +1372,7 @@ static int kvm_set_pte_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head,
 	int need_flush = 0;
 	u64 new_spte;
 	pte_t *ptep = (pte_t *)data;
-	pfn_t new_pfn;
+	kvm_pfn_t new_pfn;
 
 	WARN_ON(pte_huge(*ptep));
 	new_pfn = pte_pfn(*ptep);
@@ -2450,7 +2450,7 @@ static int mmu_need_write_protect(struct kvm_vcpu *vcpu, gfn_t gfn,
 	return 0;
 }
 
-static bool kvm_is_mmio_pfn(pfn_t pfn)
+static bool kvm_is_mmio_pfn(kvm_pfn_t pfn)
 {
 	if (pfn_valid(pfn))
 		return !is_zero_pfn(pfn) && PageReserved(pfn_to_page(pfn));
@@ -2460,7 +2460,7 @@ static bool kvm_is_mmio_pfn(pfn_t pfn)
 
 static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep,
 		    unsigned pte_access, int level,
-		    gfn_t gfn, pfn_t pfn, bool speculative,
+		    gfn_t gfn, kvm_pfn_t pfn, bool speculative,
 		    bool can_unsync, bool host_writable)
 {
 	u64 spte;
@@ -2539,7 +2539,7 @@ done:
 }
 
 static bool mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep, unsigned pte_access,
-			 int write_fault, int level, gfn_t gfn, pfn_t pfn,
+			 int write_fault, int level, gfn_t gfn, kvm_pfn_t pfn,
 			 bool speculative, bool host_writable)
 {
 	int was_rmapped = 0;
@@ -2602,7 +2602,7 @@ static bool mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep, unsigned pte_access,
 	return emulate;
 }
 
-static pfn_t pte_prefetch_gfn_to_pfn(struct kvm_vcpu *vcpu, gfn_t gfn,
+static kvm_pfn_t pte_prefetch_gfn_to_pfn(struct kvm_vcpu *vcpu, gfn_t gfn,
 				     bool no_dirty_log)
 {
 	struct kvm_memory_slot *slot;
@@ -2684,7 +2684,7 @@ static void direct_pte_prefetch(struct kvm_vcpu *vcpu, u64 *sptep)
 }
 
 static int __direct_map(struct kvm_vcpu *vcpu, int write, int map_writable,
-			int level, gfn_t gfn, pfn_t pfn, bool prefault)
+			int level, gfn_t gfn, kvm_pfn_t pfn, bool prefault)
 {
 	struct kvm_shadow_walk_iterator iterator;
 	struct kvm_mmu_page *sp;
@@ -2732,7 +2732,7 @@ static void kvm_send_hwpoison_signal(unsigned long address, struct task_struct *
 	send_sig_info(SIGBUS, &info, tsk);
 }
 
-static int kvm_handle_bad_page(struct kvm_vcpu *vcpu, gfn_t gfn, pfn_t pfn)
+static int kvm_handle_bad_page(struct kvm_vcpu *vcpu, gfn_t gfn, kvm_pfn_t pfn)
 {
 	/*
 	 * Do not cache the mmio info caused by writing the readonly gfn
@@ -2752,9 +2752,10 @@ static int kvm_handle_bad_page(struct kvm_vcpu *vcpu, gfn_t gfn, pfn_t pfn)
 }
 
 static void transparent_hugepage_adjust(struct kvm_vcpu *vcpu,
-					gfn_t *gfnp, pfn_t *pfnp, int *levelp)
+					gfn_t *gfnp, kvm_pfn_t *pfnp,
+					int *levelp)
 {
-	pfn_t pfn = *pfnp;
+	kvm_pfn_t pfn = *pfnp;
 	gfn_t gfn = *gfnp;
 	int level = *levelp;
 
@@ -2793,7 +2794,7 @@ static void transparent_hugepage_adjust(struct kvm_vcpu *vcpu,
 }
 
 static bool handle_abnormal_pfn(struct kvm_vcpu *vcpu, gva_t gva, gfn_t gfn,
-				pfn_t pfn, unsigned access, int *ret_val)
+				kvm_pfn_t pfn, unsigned access, int *ret_val)
 {
 	bool ret = true;
 
@@ -2947,7 +2948,7 @@ exit:
 }
 
 static bool try_async_pf(struct kvm_vcpu *vcpu, bool prefault, gfn_t gfn,
-			 gva_t gva, pfn_t *pfn, bool write, bool *writable);
+			 gva_t gva, kvm_pfn_t *pfn, bool write, bool *writable);
 static void make_mmu_pages_available(struct kvm_vcpu *vcpu);
 
 static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, u32 error_code,
@@ -2956,7 +2957,7 @@ static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, u32 error_code,
 	int r;
 	int level;
 	bool force_pt_level = false;
-	pfn_t pfn;
+	kvm_pfn_t pfn;
 	unsigned long mmu_seq;
 	bool map_writable, write = error_code & PFERR_WRITE_MASK;
 
@@ -3410,7 +3411,7 @@ static bool can_do_async_pf(struct kvm_vcpu *vcpu)
 }
 
 static bool try_async_pf(struct kvm_vcpu *vcpu, bool prefault, gfn_t gfn,
-			 gva_t gva, pfn_t *pfn, bool write, bool *writable)
+			 gva_t gva, kvm_pfn_t *pfn, bool write, bool *writable)
 {
 	struct kvm_memory_slot *slot;
 	bool async;
@@ -3448,7 +3449,7 @@ check_hugepage_cache_consistency(struct kvm_vcpu *vcpu, gfn_t gfn, int level)
 static int tdp_page_fault(struct kvm_vcpu *vcpu, gva_t gpa, u32 error_code,
 			  bool prefault)
 {
-	pfn_t pfn;
+	kvm_pfn_t pfn;
 	int r;
 	int level;
 	bool force_pt_level;
@@ -4601,7 +4602,7 @@ static bool kvm_mmu_zap_collapsible_spte(struct kvm *kvm,
 	u64 *sptep;
 	struct rmap_iterator iter;
 	int need_tlb_flush = 0;
-	pfn_t pfn;
+	kvm_pfn_t pfn;
 	struct kvm_mmu_page *sp;
 
 restart:
diff --git a/arch/x86/kvm/mmu_audit.c b/arch/x86/kvm/mmu_audit.c
index 1cee3ec20dd2..dcce533d420c 100644
--- a/arch/x86/kvm/mmu_audit.c
+++ b/arch/x86/kvm/mmu_audit.c
@@ -97,7 +97,7 @@ static void audit_mappings(struct kvm_vcpu *vcpu, u64 *sptep, int level)
 {
 	struct kvm_mmu_page *sp;
 	gfn_t gfn;
-	pfn_t pfn;
+	kvm_pfn_t pfn;
 	hpa_t hpa;
 
 	sp = page_header(__pa(sptep));
diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index 91e939b486d1..6c9fed957cce 100644
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -456,7 +456,7 @@ FNAME(prefetch_gpte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,
 {
 	unsigned pte_access;
 	gfn_t gfn;
-	pfn_t pfn;
+	kvm_pfn_t pfn;
 
 	if (FNAME(prefetch_invalid_gpte)(vcpu, sp, spte, gpte))
 		return false;
@@ -551,7 +551,7 @@ static void FNAME(pte_prefetch)(struct kvm_vcpu *vcpu, struct guest_walker *gw,
 static int FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
 			 struct guest_walker *gw,
 			 int write_fault, int hlevel,
-			 pfn_t pfn, bool map_writable, bool prefault)
+			 kvm_pfn_t pfn, bool map_writable, bool prefault)
 {
 	struct kvm_mmu_page *sp = NULL;
 	struct kvm_shadow_walk_iterator it;
@@ -694,7 +694,7 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr, u32 error_code,
 	int user_fault = error_code & PFERR_USER_MASK;
 	struct guest_walker walker;
 	int r;
-	pfn_t pfn;
+	kvm_pfn_t pfn;
 	int level = PT_PAGE_TABLE_LEVEL;
 	bool force_pt_level = false;
 	unsigned long mmu_seq;
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 04d61d496b14..e2951b6edbbc 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -4251,7 +4251,7 @@ out:
 static int init_rmode_identity_map(struct kvm *kvm)
 {
 	int i, idx, r = 0;
-	pfn_t identity_map_pfn;
+	kvm_pfn_t identity_map_pfn;
 	u32 tmp;
 
 	if (!enable_ept)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index f53f5b13c677..4244c2baf57d 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -5148,7 +5148,7 @@ static bool reexecute_instruction(struct kvm_vcpu *vcpu, gva_t cr2,
 				  int emulation_type)
 {
 	gpa_t gpa = cr2;
-	pfn_t pfn;
+	kvm_pfn_t pfn;
 
 	if (emulation_type & EMULTYPE_NO_REEXECUTE)
 		return false;
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index f707f74055c3..861f690aa791 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -66,7 +66,7 @@
  * error pfns indicate that the gfn is in slot but faild to
  * translate it to pfn on host.
  */
-static inline bool is_error_pfn(pfn_t pfn)
+static inline bool is_error_pfn(kvm_pfn_t pfn)
 {
 	return !!(pfn & KVM_PFN_ERR_MASK);
 }
@@ -76,13 +76,13 @@ static inline bool is_error_pfn(pfn_t pfn)
  * translated to pfn - it is not in slot or failed to
  * translate it to pfn.
  */
-static inline bool is_error_noslot_pfn(pfn_t pfn)
+static inline bool is_error_noslot_pfn(kvm_pfn_t pfn)
 {
 	return !!(pfn & KVM_PFN_ERR_NOSLOT_MASK);
 }
 
 /* noslot pfn indicates that the gfn is not in slot. */
-static inline bool is_noslot_pfn(pfn_t pfn)
+static inline bool is_noslot_pfn(kvm_pfn_t pfn)
 {
 	return pfn == KVM_PFN_NOSLOT;
 }
@@ -591,19 +591,20 @@ void kvm_release_page_clean(struct page *page);
 void kvm_release_page_dirty(struct page *page);
 void kvm_set_page_accessed(struct page *page);
 
-pfn_t gfn_to_pfn_atomic(struct kvm *kvm, gfn_t gfn);
-pfn_t gfn_to_pfn(struct kvm *kvm, gfn_t gfn);
-pfn_t gfn_to_pfn_prot(struct kvm *kvm, gfn_t gfn, bool write_fault,
+kvm_pfn_t gfn_to_pfn_atomic(struct kvm *kvm, gfn_t gfn);
+kvm_pfn_t gfn_to_pfn(struct kvm *kvm, gfn_t gfn);
+kvm_pfn_t gfn_to_pfn_prot(struct kvm *kvm, gfn_t gfn, bool write_fault,
 		      bool *writable);
-pfn_t gfn_to_pfn_memslot(struct kvm_memory_slot *slot, gfn_t gfn);
-pfn_t gfn_to_pfn_memslot_atomic(struct kvm_memory_slot *slot, gfn_t gfn);
-pfn_t __gfn_to_pfn_memslot(struct kvm_memory_slot *slot, gfn_t gfn, bool atomic,
-			   bool *async, bool write_fault, bool *writable);
+kvm_pfn_t gfn_to_pfn_memslot(struct kvm_memory_slot *slot, gfn_t gfn);
+kvm_pfn_t gfn_to_pfn_memslot_atomic(struct kvm_memory_slot *slot, gfn_t gfn);
+kvm_pfn_t __gfn_to_pfn_memslot(struct kvm_memory_slot *slot, gfn_t gfn,
+			       bool atomic, bool *async, bool write_fault,
+			       bool *writable);
 
-void kvm_release_pfn_clean(pfn_t pfn);
-void kvm_set_pfn_dirty(pfn_t pfn);
-void kvm_set_pfn_accessed(pfn_t pfn);
-void kvm_get_pfn(pfn_t pfn);
+void kvm_release_pfn_clean(kvm_pfn_t pfn);
+void kvm_set_pfn_dirty(kvm_pfn_t pfn);
+void kvm_set_pfn_accessed(kvm_pfn_t pfn);
+void kvm_get_pfn(kvm_pfn_t pfn);
 
 int kvm_read_guest_page(struct kvm *kvm, gfn_t gfn, void *data, int offset,
 			int len);
@@ -629,8 +630,8 @@ void mark_page_dirty(struct kvm *kvm, gfn_t gfn);
 
 struct kvm_memslots *kvm_vcpu_memslots(struct kvm_vcpu *vcpu);
 struct kvm_memory_slot *kvm_vcpu_gfn_to_memslot(struct kvm_vcpu *vcpu, gfn_t gfn);
-pfn_t kvm_vcpu_gfn_to_pfn_atomic(struct kvm_vcpu *vcpu, gfn_t gfn);
-pfn_t kvm_vcpu_gfn_to_pfn(struct kvm_vcpu *vcpu, gfn_t gfn);
+kvm_pfn_t kvm_vcpu_gfn_to_pfn_atomic(struct kvm_vcpu *vcpu, gfn_t gfn);
+kvm_pfn_t kvm_vcpu_gfn_to_pfn(struct kvm_vcpu *vcpu, gfn_t gfn);
 struct page *kvm_vcpu_gfn_to_page(struct kvm_vcpu *vcpu, gfn_t gfn);
 unsigned long kvm_vcpu_gfn_to_hva(struct kvm_vcpu *vcpu, gfn_t gfn);
 unsigned long kvm_vcpu_gfn_to_hva_prot(struct kvm_vcpu *vcpu, gfn_t gfn, bool *writable);
@@ -811,7 +812,7 @@ void kvm_arch_sync_events(struct kvm *kvm);
 int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu);
 void kvm_vcpu_kick(struct kvm_vcpu *vcpu);
 
-bool kvm_is_reserved_pfn(pfn_t pfn);
+bool kvm_is_reserved_pfn(kvm_pfn_t pfn);
 
 struct kvm_irq_ack_notifier {
 	struct hlist_node link;
@@ -965,7 +966,7 @@ static inline gfn_t gpa_to_gfn(gpa_t gpa)
 	return (gfn_t)(gpa >> PAGE_SHIFT);
 }
 
-static inline hpa_t pfn_to_hpa(pfn_t pfn)
+static inline hpa_t pfn_to_hpa(kvm_pfn_t pfn)
 {
 	return (hpa_t)pfn << PAGE_SHIFT;
 }
diff --git a/include/linux/kvm_types.h b/include/linux/kvm_types.h
index 1b47a185c2f0..8bf259dae9f6 100644
--- a/include/linux/kvm_types.h
+++ b/include/linux/kvm_types.h
@@ -53,7 +53,7 @@ typedef unsigned long  hva_t;
 typedef u64            hpa_t;
 typedef u64            hfn_t;
 
-typedef hfn_t pfn_t;
+typedef hfn_t kvm_pfn_t;
 
 struct gfn_to_hva_cache {
 	u64 generation;
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 314c7774652e..a11cfd20a6a0 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -111,7 +111,7 @@ static void hardware_disable_all(void);
 
 static void kvm_io_bus_destroy(struct kvm_io_bus *bus);
 
-static void kvm_release_pfn_dirty(pfn_t pfn);
+static void kvm_release_pfn_dirty(kvm_pfn_t pfn);
 static void mark_page_dirty_in_slot(struct kvm_memory_slot *memslot, gfn_t gfn);
 
 __visible bool kvm_rebooting;
@@ -119,7 +119,7 @@ EXPORT_SYMBOL_GPL(kvm_rebooting);
 
 static bool largepages_enabled = true;
 
-bool kvm_is_reserved_pfn(pfn_t pfn)
+bool kvm_is_reserved_pfn(kvm_pfn_t pfn)
 {
 	if (pfn_valid(pfn))
 		return PageReserved(pfn_to_page(pfn));
@@ -1289,7 +1289,7 @@ static inline int check_user_page_hwpoison(unsigned long addr)
  * true indicates success, otherwise false is returned.
  */
 static bool hva_to_pfn_fast(unsigned long addr, bool atomic, bool *async,
-			    bool write_fault, bool *writable, pfn_t *pfn)
+			    bool write_fault, bool *writable, kvm_pfn_t *pfn)
 {
 	struct page *page[1];
 	int npages;
@@ -1322,7 +1322,7 @@ static bool hva_to_pfn_fast(unsigned long addr, bool atomic, bool *async,
  * 1 indicates success, -errno is returned if error is detected.
  */
 static int hva_to_pfn_slow(unsigned long addr, bool *async, bool write_fault,
-			   bool *writable, pfn_t *pfn)
+			   bool *writable, kvm_pfn_t *pfn)
 {
 	struct page *page[1];
 	int npages = 0;
@@ -1386,11 +1386,11 @@ static bool vma_is_valid(struct vm_area_struct *vma, bool write_fault)
  * 2): @write_fault = false && @writable, @writable will tell the caller
  *     whether the mapping is writable.
  */
-static pfn_t hva_to_pfn(unsigned long addr, bool atomic, bool *async,
+static kvm_pfn_t hva_to_pfn(unsigned long addr, bool atomic, bool *async,
 			bool write_fault, bool *writable)
 {
 	struct vm_area_struct *vma;
-	pfn_t pfn = 0;
+	kvm_pfn_t pfn = 0;
 	int npages;
 
 	/* we can do it either atomically or asynchronously, not both */
@@ -1431,8 +1431,9 @@ exit:
 	return pfn;
 }
 
-pfn_t __gfn_to_pfn_memslot(struct kvm_memory_slot *slot, gfn_t gfn, bool atomic,
-			   bool *async, bool write_fault, bool *writable)
+kvm_pfn_t __gfn_to_pfn_memslot(struct kvm_memory_slot *slot, gfn_t gfn,
+			       bool atomic, bool *async, bool write_fault,
+			       bool *writable)
 {
 	unsigned long addr = __gfn_to_hva_many(slot, gfn, NULL, write_fault);
 
@@ -1453,7 +1454,7 @@ pfn_t __gfn_to_pfn_memslot(struct kvm_memory_slot *slot, gfn_t gfn, bool atomic,
 }
 EXPORT_SYMBOL_GPL(__gfn_to_pfn_memslot);
 
-pfn_t gfn_to_pfn_prot(struct kvm *kvm, gfn_t gfn, bool write_fault,
+kvm_pfn_t gfn_to_pfn_prot(struct kvm *kvm, gfn_t gfn, bool write_fault,
 		      bool *writable)
 {
 	return __gfn_to_pfn_memslot(gfn_to_memslot(kvm, gfn), gfn, false, NULL,
@@ -1461,37 +1462,37 @@ pfn_t gfn_to_pfn_prot(struct kvm *kvm, gfn_t gfn, bool write_fault,
 }
 EXPORT_SYMBOL_GPL(gfn_to_pfn_prot);
 
-pfn_t gfn_to_pfn_memslot(struct kvm_memory_slot *slot, gfn_t gfn)
+kvm_pfn_t gfn_to_pfn_memslot(struct kvm_memory_slot *slot, gfn_t gfn)
 {
 	return __gfn_to_pfn_memslot(slot, gfn, false, NULL, true, NULL);
 }
 EXPORT_SYMBOL_GPL(gfn_to_pfn_memslot);
 
-pfn_t gfn_to_pfn_memslot_atomic(struct kvm_memory_slot *slot, gfn_t gfn)
+kvm_pfn_t gfn_to_pfn_memslot_atomic(struct kvm_memory_slot *slot, gfn_t gfn)
 {
 	return __gfn_to_pfn_memslot(slot, gfn, true, NULL, true, NULL);
 }
 EXPORT_SYMBOL_GPL(gfn_to_pfn_memslot_atomic);
 
-pfn_t gfn_to_pfn_atomic(struct kvm *kvm, gfn_t gfn)
+kvm_pfn_t gfn_to_pfn_atomic(struct kvm *kvm, gfn_t gfn)
 {
 	return gfn_to_pfn_memslot_atomic(gfn_to_memslot(kvm, gfn), gfn);
 }
 EXPORT_SYMBOL_GPL(gfn_to_pfn_atomic);
 
-pfn_t kvm_vcpu_gfn_to_pfn_atomic(struct kvm_vcpu *vcpu, gfn_t gfn)
+kvm_pfn_t kvm_vcpu_gfn_to_pfn_atomic(struct kvm_vcpu *vcpu, gfn_t gfn)
 {
 	return gfn_to_pfn_memslot_atomic(kvm_vcpu_gfn_to_memslot(vcpu, gfn), gfn);
 }
 EXPORT_SYMBOL_GPL(kvm_vcpu_gfn_to_pfn_atomic);
 
-pfn_t gfn_to_pfn(struct kvm *kvm, gfn_t gfn)
+kvm_pfn_t gfn_to_pfn(struct kvm *kvm, gfn_t gfn)
 {
 	return gfn_to_pfn_memslot(gfn_to_memslot(kvm, gfn), gfn);
 }
 EXPORT_SYMBOL_GPL(gfn_to_pfn);
 
-pfn_t kvm_vcpu_gfn_to_pfn(struct kvm_vcpu *vcpu, gfn_t gfn)
+kvm_pfn_t kvm_vcpu_gfn_to_pfn(struct kvm_vcpu *vcpu, gfn_t gfn)
 {
 	return gfn_to_pfn_memslot(kvm_vcpu_gfn_to_memslot(vcpu, gfn), gfn);
 }
@@ -1514,7 +1515,7 @@ int gfn_to_page_many_atomic(struct kvm_memory_slot *slot, gfn_t gfn,
 }
 EXPORT_SYMBOL_GPL(gfn_to_page_many_atomic);
 
-static struct page *kvm_pfn_to_page(pfn_t pfn)
+static struct page *kvm_pfn_to_page(kvm_pfn_t pfn)
 {
 	if (is_error_noslot_pfn(pfn))
 		return KVM_ERR_PTR_BAD_PAGE;
@@ -1529,7 +1530,7 @@ static struct page *kvm_pfn_to_page(pfn_t pfn)
 
 struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn)
 {
-	pfn_t pfn;
+	kvm_pfn_t pfn;
 
 	pfn = gfn_to_pfn(kvm, gfn);
 
@@ -1539,7 +1540,7 @@ EXPORT_SYMBOL_GPL(gfn_to_page);
 
 struct page *kvm_vcpu_gfn_to_page(struct kvm_vcpu *vcpu, gfn_t gfn)
 {
-	pfn_t pfn;
+	kvm_pfn_t pfn;
 
 	pfn = kvm_vcpu_gfn_to_pfn(vcpu, gfn);
 
@@ -1555,7 +1556,7 @@ void kvm_release_page_clean(struct page *page)
 }
 EXPORT_SYMBOL_GPL(kvm_release_page_clean);
 
-void kvm_release_pfn_clean(pfn_t pfn)
+void kvm_release_pfn_clean(kvm_pfn_t pfn)
 {
 	if (!is_error_noslot_pfn(pfn) && !kvm_is_reserved_pfn(pfn))
 		put_page(pfn_to_page(pfn));
@@ -1570,13 +1571,13 @@ void kvm_release_page_dirty(struct page *page)
 }
 EXPORT_SYMBOL_GPL(kvm_release_page_dirty);
 
-static void kvm_release_pfn_dirty(pfn_t pfn)
+static void kvm_release_pfn_dirty(kvm_pfn_t pfn)
 {
 	kvm_set_pfn_dirty(pfn);
 	kvm_release_pfn_clean(pfn);
 }
 
-void kvm_set_pfn_dirty(pfn_t pfn)
+void kvm_set_pfn_dirty(kvm_pfn_t pfn)
 {
 	if (!kvm_is_reserved_pfn(pfn)) {
 		struct page *page = pfn_to_page(pfn);
@@ -1587,14 +1588,14 @@ void kvm_set_pfn_dirty(pfn_t pfn)
 }
 EXPORT_SYMBOL_GPL(kvm_set_pfn_dirty);
 
-void kvm_set_pfn_accessed(pfn_t pfn)
+void kvm_set_pfn_accessed(kvm_pfn_t pfn)
 {
 	if (!kvm_is_reserved_pfn(pfn))
 		mark_page_accessed(pfn_to_page(pfn));
 }
 EXPORT_SYMBOL_GPL(kvm_set_pfn_accessed);
 
-void kvm_get_pfn(pfn_t pfn)
+void kvm_get_pfn(kvm_pfn_t pfn)
 {
 	if (!kvm_is_reserved_pfn(pfn))
 		get_page(pfn_to_page(pfn));