Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1492 insertions, 0 deletions

diff --git a/arch/powerpc/kvm/book3s_64_mmu_radix.c b/arch/powerpc/kvm/book3s_64_mmu_radix.c
new file mode 100644
index 0000000000..10aacbf924
--- /dev/null
+++ b/arch/powerpc/kvm/book3s_64_mmu_radix.c
@@ -0,0 +1,1492 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *
+ * Copyright 2016 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
+ */
+
+#include <linux/types.h>
+#include <linux/string.h>
+#include <linux/kvm.h>
+#include <linux/kvm_host.h>
+#include <linux/anon_inodes.h>
+#include <linux/file.h>
+#include <linux/debugfs.h>
+#include <linux/pgtable.h>
+
+#include <asm/kvm_ppc.h>
+#include <asm/kvm_book3s.h>
+#include "book3s_hv.h"
+#include <asm/page.h>
+#include <asm/mmu.h>
+#include <asm/pgalloc.h>
+#include <asm/pte-walk.h>
+#include <asm/ultravisor.h>
+#include <asm/kvm_book3s_uvmem.h>
+#include <asm/plpar_wrappers.h>
+#include <asm/firmware.h>
+
+/*
+ * Supported radix tree geometry.
+ * Like p9, we support either 5 or 9 bits at the first (lowest) level,
+ * for a page size of 64k or 4k.
+ */
+static int p9_supported_radix_bits[4] = { 5, 9, 9, 13 };
+
+unsigned long __kvmhv_copy_tofrom_guest_radix(int lpid, int pid,
+					      gva_t eaddr, void *to, void *from,
+					      unsigned long n)
+{
+	int old_pid, old_lpid;
+	unsigned long quadrant, ret = n;
+	bool is_load = !!to;
+
+	/* Can't access quadrants 1 or 2 in non-HV mode, call the HV to do it */
+	if (kvmhv_on_pseries())
+		return plpar_hcall_norets(H_COPY_TOFROM_GUEST, lpid, pid, eaddr,
+					  (to != NULL) ? __pa(to): 0,
+					  (from != NULL) ? __pa(from): 0, n);
+
+	if (eaddr & (0xFFFUL << 52))
+		return ret;
+
+	quadrant = 1;
+	if (!pid)
+		quadrant = 2;
+	if (is_load)
+		from = (void *) (eaddr | (quadrant << 62));
+	else
+		to = (void *) (eaddr | (quadrant << 62));
+
+	preempt_disable();
+
+	asm volatile("hwsync" ::: "memory");
+	isync();
+	/* switch the lpid first to avoid running host with unallocated pid */
+	old_lpid = mfspr(SPRN_LPID);
+	if (old_lpid != lpid)
+		mtspr(SPRN_LPID, lpid);
+	if (quadrant == 1) {
+		old_pid = mfspr(SPRN_PID);
+		if (old_pid != pid)
+			mtspr(SPRN_PID, pid);
+	}
+	isync();
+
+	pagefault_disable();
+	if (is_load)
+		ret = __copy_from_user_inatomic(to, (const void __user *)from, n);
+	else
+		ret = __copy_to_user_inatomic((void __user *)to, from, n);
+	pagefault_enable();
+
+	asm volatile("hwsync" ::: "memory");
+	isync();
+	/* switch the pid first to avoid running host with unallocated pid */
+	if (quadrant == 1 && pid != old_pid)
+		mtspr(SPRN_PID, old_pid);
+	if (lpid != old_lpid)
+		mtspr(SPRN_LPID, old_lpid);
+	isync();
+
+	preempt_enable();
+
+	return ret;
+}
+
+static long kvmhv_copy_tofrom_guest_radix(struct kvm_vcpu *vcpu, gva_t eaddr,
+					  void *to, void *from, unsigned long n)
+{
+	int lpid = vcpu->kvm->arch.lpid;
+	int pid = vcpu->arch.pid;
+
+	/* This would cause a data segment intr so don't allow the access */
+	if (eaddr & (0x3FFUL << 52))
+		return -EINVAL;
+
+	/* Should we be using the nested lpid */
+	if (vcpu->arch.nested)
+		lpid = vcpu->arch.nested->shadow_lpid;
+
+	/* If accessing quadrant 3 then pid is expected to be 0 */
+	if (((eaddr >> 62) & 0x3) == 0x3)
+		pid = 0;
+
+	eaddr &= ~(0xFFFUL << 52);
+
+	return __kvmhv_copy_tofrom_guest_radix(lpid, pid, eaddr, to, from, n);
+}
+
+long kvmhv_copy_from_guest_radix(struct kvm_vcpu *vcpu, gva_t eaddr, void *to,
+				 unsigned long n)
+{
+	long ret;
+
+	ret = kvmhv_copy_tofrom_guest_radix(vcpu, eaddr, to, NULL, n);
+	if (ret > 0)
+		memset(to + (n - ret), 0, ret);
+
+	return ret;
+}
+
+long kvmhv_copy_to_guest_radix(struct kvm_vcpu *vcpu, gva_t eaddr, void *from,
+			       unsigned long n)
+{
+	return kvmhv_copy_tofrom_guest_radix(vcpu, eaddr, NULL, from, n);
+}
+
+int kvmppc_mmu_walk_radix_tree(struct kvm_vcpu *vcpu, gva_t eaddr,
+			       struct kvmppc_pte *gpte, u64 root,
+			       u64 *pte_ret_p)
+{
+	struct kvm *kvm = vcpu->kvm;
+	int ret, level, ps;
+	unsigned long rts, bits, offset, index;
+	u64 pte, base, gpa;
+	__be64 rpte;
+
+	rts = ((root & RTS1_MASK) >> (RTS1_SHIFT - 3)) |
+		((root & RTS2_MASK) >> RTS2_SHIFT);
+	bits = root & RPDS_MASK;
+	base = root & RPDB_MASK;
+
+	offset = rts + 31;
+
+	/* Current implementations only support 52-bit space */
+	if (offset != 52)
+		return -EINVAL;
+
+	/* Walk each level of the radix tree */
+	for (level = 3; level >= 0; --level) {
+		u64 addr;
+		/* Check a valid size */
+		if (level && bits != p9_supported_radix_bits[level])
+			return -EINVAL;
+		if (level == 0 && !(bits == 5 || bits == 9))
+			return -EINVAL;
+		offset -= bits;
+		index = (eaddr >> offset) & ((1UL << bits) - 1);
+		/* Check that low bits of page table base are zero */
+		if (base & ((1UL << (bits + 3)) - 1))
+			return -EINVAL;
+		/* Read the entry from guest memory */
+		addr = base + (index * sizeof(rpte));
+
+		kvm_vcpu_srcu_read_lock(vcpu);
+		ret = kvm_read_guest(kvm, addr, &rpte, sizeof(rpte));
+		kvm_vcpu_srcu_read_unlock(vcpu);
+		if (ret) {
+			if (pte_ret_p)
+				*pte_ret_p = addr;
+			return ret;
+		}
+		pte = __be64_to_cpu(rpte);
+		if (!(pte & _PAGE_PRESENT))
+			return -ENOENT;
+		/* Check if a leaf entry */
+		if (pte & _PAGE_PTE)
+			break;
+		/* Get ready to walk the next level */
+		base = pte & RPDB_MASK;
+		bits = pte & RPDS_MASK;
+	}
+
+	/* Need a leaf at lowest level; 512GB pages not supported */
+	if (level < 0 || level == 3)
+		return -EINVAL;
+
+	/* We found a valid leaf PTE */
+	/* Offset is now log base 2 of the page size */
+	gpa = pte & 0x01fffffffffff000ul;
+	if (gpa & ((1ul << offset) - 1))
+		return -EINVAL;
+	gpa |= eaddr & ((1ul << offset) - 1);
+	for (ps = MMU_PAGE_4K; ps < MMU_PAGE_COUNT; ++ps)
+		if (offset == mmu_psize_defs[ps].shift)
+			break;
+	gpte->page_size = ps;
+	gpte->page_shift = offset;
+
+	gpte->eaddr = eaddr;
+	gpte->raddr = gpa;
+
+	/* Work out permissions */
+	gpte->may_read = !!(pte & _PAGE_READ);
+	gpte->may_write = !!(pte & _PAGE_WRITE);
+	gpte->may_execute = !!(pte & _PAGE_EXEC);
+
+	gpte->rc = pte & (_PAGE_ACCESSED | _PAGE_DIRTY);
+
+	if (pte_ret_p)
+		*pte_ret_p = pte;
+
+	return 0;
+}
+
+/*
+ * Used to walk a partition or process table radix tree in guest memory
+ * Note: We exploit the fact that a partition table and a process
+ * table have the same layout, a partition-scoped page table and a
+ * process-scoped page table have the same layout, and the 2nd
+ * doubleword of a partition table entry has the same layout as
+ * the PTCR register.
+ */
+int kvmppc_mmu_radix_translate_table(struct kvm_vcpu *vcpu, gva_t eaddr,
+				     struct kvmppc_pte *gpte, u64 table,
+				     int table_index, u64 *pte_ret_p)
+{
+	struct kvm *kvm = vcpu->kvm;
+	int ret;
+	unsigned long size, ptbl, root;
+	struct prtb_entry entry;
+
+	if ((table & PRTS_MASK) > 24)
+		return -EINVAL;
+	size = 1ul << ((table & PRTS_MASK) + 12);
+
+	/* Is the table big enough to contain this entry? */
+	if ((table_index * sizeof(entry)) >= size)
+		return -EINVAL;
+
+	/* Read the table to find the root of the radix tree */
+	ptbl = (table & PRTB_MASK) + (table_index * sizeof(entry));
+	kvm_vcpu_srcu_read_lock(vcpu);
+	ret = kvm_read_guest(kvm, ptbl, &entry, sizeof(entry));
+	kvm_vcpu_srcu_read_unlock(vcpu);
+	if (ret)
+		return ret;
+
+	/* Root is stored in the first double word */
+	root = be64_to_cpu(entry.prtb0);
+
+	return kvmppc_mmu_walk_radix_tree(vcpu, eaddr, gpte, root, pte_ret_p);
+}
+
+int kvmppc_mmu_radix_xlate(struct kvm_vcpu *vcpu, gva_t eaddr,
+			   struct kvmppc_pte *gpte, bool data, bool iswrite)
+{
+	u32 pid;
+	u64 pte;
+	int ret;
+
+	/* Work out effective PID */
+	switch (eaddr >> 62) {
+	case 0:
+		pid = vcpu->arch.pid;
+		break;
+	case 3:
+		pid = 0;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	ret = kvmppc_mmu_radix_translate_table(vcpu, eaddr, gpte,
+				vcpu->kvm->arch.process_table, pid, &pte);
+	if (ret)
+		return ret;
+
+	/* Check privilege (applies only to process scoped translations) */
+	if (kvmppc_get_msr(vcpu) & MSR_PR) {
+		if (pte & _PAGE_PRIVILEGED) {
+			gpte->may_read = 0;
+			gpte->may_write = 0;
+			gpte->may_execute = 0;
+		}
+	} else {
+		if (!(pte & _PAGE_PRIVILEGED)) {
+			/* Check AMR/IAMR to see if strict mode is in force */
+			if (kvmppc_get_amr_hv(vcpu) & (1ul << 62))
+				gpte->may_read = 0;
+			if (kvmppc_get_amr_hv(vcpu) & (1ul << 63))
+				gpte->may_write = 0;
+			if (vcpu->arch.iamr & (1ul << 62))
+				gpte->may_execute = 0;
+		}
+	}
+
+	return 0;
+}
+
+void kvmppc_radix_tlbie_page(struct kvm *kvm, unsigned long addr,
+			     unsigned int pshift, unsigned int lpid)
+{
+	unsigned long psize = PAGE_SIZE;
+	int psi;
+	long rc;
+	unsigned long rb;
+
+	if (pshift)
+		psize = 1UL << pshift;
+	else
+		pshift = PAGE_SHIFT;
+
+	addr &= ~(psize - 1);
+
+	if (!kvmhv_on_pseries()) {
+		radix__flush_tlb_lpid_page(lpid, addr, psize);
+		return;
+	}
+
+	psi = shift_to_mmu_psize(pshift);
+
+	if (!firmware_has_feature(FW_FEATURE_RPT_INVALIDATE)) {
+		rb = addr | (mmu_get_ap(psi) << PPC_BITLSHIFT(58));
+		rc = plpar_hcall_norets(H_TLB_INVALIDATE, H_TLBIE_P1_ENC(0, 0, 1),
+					lpid, rb);
+	} else {
+		rc = pseries_rpt_invalidate(lpid, H_RPTI_TARGET_CMMU,
+					    H_RPTI_TYPE_NESTED |
+					    H_RPTI_TYPE_TLB,
+					    psize_to_rpti_pgsize(psi),
+					    addr, addr + psize);
+	}
+
+	if (rc)
+		pr_err("KVM: TLB page invalidation hcall failed, rc=%ld\n", rc);
+}
+
+static void kvmppc_radix_flush_pwc(struct kvm *kvm, unsigned int lpid)
+{
+	long rc;
+
+	if (!kvmhv_on_pseries()) {
+		radix__flush_pwc_lpid(lpid);
+		return;
+	}
+
+	if (!firmware_has_feature(FW_FEATURE_RPT_INVALIDATE))
+		rc = plpar_hcall_norets(H_TLB_INVALIDATE, H_TLBIE_P1_ENC(1, 0, 1),
+					lpid, TLBIEL_INVAL_SET_LPID);
+	else
+		rc = pseries_rpt_invalidate(lpid, H_RPTI_TARGET_CMMU,
+					    H_RPTI_TYPE_NESTED |
+					    H_RPTI_TYPE_PWC, H_RPTI_PAGE_ALL,
+					    0, -1UL);
+	if (rc)
+		pr_err("KVM: TLB PWC invalidation hcall failed, rc=%ld\n", rc);
+}
+
+static unsigned long kvmppc_radix_update_pte(struct kvm *kvm, pte_t *ptep,
+				      unsigned long clr, unsigned long set,
+				      unsigned long addr, unsigned int shift)
+{
+	return __radix_pte_update(ptep, clr, set);
+}
+
+static void kvmppc_radix_set_pte_at(struct kvm *kvm, unsigned long addr,
+			     pte_t *ptep, pte_t pte)
+{
+	radix__set_pte_at(kvm->mm, addr, ptep, pte, 0);
+}
+
+static struct kmem_cache *kvm_pte_cache;
+static struct kmem_cache *kvm_pmd_cache;
+
+static pte_t *kvmppc_pte_alloc(void)
+{
+	pte_t *pte;
+
+	pte = kmem_cache_alloc(kvm_pte_cache, GFP_KERNEL);
+	/* pmd_populate() will only reference _pa(pte). */
+	kmemleak_ignore(pte);
+
+	return pte;
+}
+
+static void kvmppc_pte_free(pte_t *ptep)
+{
+	kmem_cache_free(kvm_pte_cache, ptep);
+}
+
+static pmd_t *kvmppc_pmd_alloc(void)
+{
+	pmd_t *pmd;
+
+	pmd = kmem_cache_alloc(kvm_pmd_cache, GFP_KERNEL);
+	/* pud_populate() will only reference _pa(pmd). */
+	kmemleak_ignore(pmd);
+
+	return pmd;
+}
+
+static void kvmppc_pmd_free(pmd_t *pmdp)
+{
+	kmem_cache_free(kvm_pmd_cache, pmdp);
+}
+
+/* Called with kvm->mmu_lock held */
+void kvmppc_unmap_pte(struct kvm *kvm, pte_t *pte, unsigned long gpa,
+		      unsigned int shift,
+		      const struct kvm_memory_slot *memslot,
+		      unsigned int lpid)
+
+{
+	unsigned long old;
+	unsigned long gfn = gpa >> PAGE_SHIFT;
+	unsigned long page_size = PAGE_SIZE;
+	unsigned long hpa;
+
+	old = kvmppc_radix_update_pte(kvm, pte, ~0UL, 0, gpa, shift);
+	kvmppc_radix_tlbie_page(kvm, gpa, shift, lpid);
+
+	/* The following only applies to L1 entries */
+	if (lpid != kvm->arch.lpid)
+		return;
+
+	if (!memslot) {
+		memslot = gfn_to_memslot(kvm, gfn);
+		if (!memslot)
+			return;
+	}
+	if (shift) { /* 1GB or 2MB page */
+		page_size = 1ul << shift;
+		if (shift == PMD_SHIFT)
+			kvm->stat.num_2M_pages--;
+		else if (shift == PUD_SHIFT)
+			kvm->stat.num_1G_pages--;
+	}
+
+	gpa &= ~(page_size - 1);
+	hpa = old & PTE_RPN_MASK;
+	kvmhv_remove_nest_rmap_range(kvm, memslot, gpa, hpa, page_size);
+
+	if ((old & _PAGE_DIRTY) && memslot->dirty_bitmap)
+		kvmppc_update_dirty_map(memslot, gfn, page_size);
+}
+
+/*
+ * kvmppc_free_p?d are used to free existing page tables, and recursively
+ * descend and clear and free children.
+ * Callers are responsible for flushing the PWC.
+ *
+ * When page tables are being unmapped/freed as part of page fault path
+ * (full == false), valid ptes are generally not expected; however, there
+ * is one situation where they arise, which is when dirty page logging is
+ * turned off for a memslot while the VM is running.  The new memslot
+ * becomes visible to page faults before the memslot commit function
+ * gets to flush the memslot, which can lead to a 2MB page mapping being
+ * installed for a guest physical address where there are already 64kB
+ * (or 4kB) mappings (of sub-pages of the same 2MB page).
+ */
+static void kvmppc_unmap_free_pte(struct kvm *kvm, pte_t *pte, bool full,
+				  unsigned int lpid)
+{
+	if (full) {
+		memset(pte, 0, sizeof(long) << RADIX_PTE_INDEX_SIZE);
+	} else {
+		pte_t *p = pte;
+		unsigned long it;
+
+		for (it = 0; it < PTRS_PER_PTE; ++it, ++p) {
+			if (pte_val(*p) == 0)
+				continue;
+			kvmppc_unmap_pte(kvm, p,
+					 pte_pfn(*p) << PAGE_SHIFT,
+					 PAGE_SHIFT, NULL, lpid);
+		}
+	}
+
+	kvmppc_pte_free(pte);
+}
+
+static void kvmppc_unmap_free_pmd(struct kvm *kvm, pmd_t *pmd, bool full,
+				  unsigned int lpid)
+{
+	unsigned long im;
+	pmd_t *p = pmd;
+
+	for (im = 0; im < PTRS_PER_PMD; ++im, ++p) {
+		if (!pmd_present(*p))
+			continue;
+		if (pmd_is_leaf(*p)) {
+			if (full) {
+				pmd_clear(p);
+			} else {
+				WARN_ON_ONCE(1);
+				kvmppc_unmap_pte(kvm, (pte_t *)p,
+					 pte_pfn(*(pte_t *)p) << PAGE_SHIFT,
+					 PMD_SHIFT, NULL, lpid);
+			}
+		} else {
+			pte_t *pte;
+
+			pte = pte_offset_kernel(p, 0);
+			kvmppc_unmap_free_pte(kvm, pte, full, lpid);
+			pmd_clear(p);
+		}
+	}
+	kvmppc_pmd_free(pmd);
+}
+
+static void kvmppc_unmap_free_pud(struct kvm *kvm, pud_t *pud,
+				  unsigned int lpid)
+{
+	unsigned long iu;
+	pud_t *p = pud;
+
+	for (iu = 0; iu < PTRS_PER_PUD; ++iu, ++p) {
+		if (!pud_present(*p))
+			continue;
+		if (pud_is_leaf(*p)) {
+			pud_clear(p);
+		} else {
+			pmd_t *pmd;
+
+			pmd = pmd_offset(p, 0);
+			kvmppc_unmap_free_pmd(kvm, pmd, true, lpid);
+			pud_clear(p);
+		}
+	}
+	pud_free(kvm->mm, pud);
+}
+
+void kvmppc_free_pgtable_radix(struct kvm *kvm, pgd_t *pgd, unsigned int lpid)
+{
+	unsigned long ig;
+
+	for (ig = 0; ig < PTRS_PER_PGD; ++ig, ++pgd) {
+		p4d_t *p4d = p4d_offset(pgd, 0);
+		pud_t *pud;
+
+		if (!p4d_present(*p4d))
+			continue;
+		pud = pud_offset(p4d, 0);
+		kvmppc_unmap_free_pud(kvm, pud, lpid);
+		p4d_clear(p4d);
+	}
+}
+
+void kvmppc_free_radix(struct kvm *kvm)
+{
+	if (kvm->arch.pgtable) {
+		kvmppc_free_pgtable_radix(kvm, kvm->arch.pgtable,
+					  kvm->arch.lpid);
+		pgd_free(kvm->mm, kvm->arch.pgtable);
+		kvm->arch.pgtable = NULL;
+	}
+}
+
+static void kvmppc_unmap_free_pmd_entry_table(struct kvm *kvm, pmd_t *pmd,
+					unsigned long gpa, unsigned int lpid)
+{
+	pte_t *pte = pte_offset_kernel(pmd, 0);
+
+	/*
+	 * Clearing the pmd entry then flushing the PWC ensures that the pte
+	 * page no longer be cached by the MMU, so can be freed without
+	 * flushing the PWC again.
+	 */
+	pmd_clear(pmd);
+	kvmppc_radix_flush_pwc(kvm, lpid);
+
+	kvmppc_unmap_free_pte(kvm, pte, false, lpid);
+}
+
+static void kvmppc_unmap_free_pud_entry_table(struct kvm *kvm, pud_t *pud,
+					unsigned long gpa, unsigned int lpid)
+{
+	pmd_t *pmd = pmd_offset(pud, 0);
+
+	/*
+	 * Clearing the pud entry then flushing the PWC ensures that the pmd
+	 * page and any children pte pages will no longer be cached by the MMU,
+	 * so can be freed without flushing the PWC again.
+	 */
+	pud_clear(pud);
+	kvmppc_radix_flush_pwc(kvm, lpid);
+
+	kvmppc_unmap_free_pmd(kvm, pmd, false, lpid);
+}
+
+/*
+ * There are a number of bits which may differ between different faults to
+ * the same partition scope entry. RC bits, in the course of cleaning and
+ * aging. And the write bit can change, either the access could have been
+ * upgraded, or a read fault could happen concurrently with a write fault
+ * that sets those bits first.
+ */
+#define PTE_BITS_MUST_MATCH (~(_PAGE_WRITE | _PAGE_DIRTY | _PAGE_ACCESSED))
+
+int kvmppc_create_pte(struct kvm *kvm, pgd_t *pgtable, pte_t pte,
+		      unsigned long gpa, unsigned int level,
+		      unsigned long mmu_seq, unsigned int lpid,
+		      unsigned long *rmapp, struct rmap_nested **n_rmap)
+{
+	pgd_t *pgd;
+	p4d_t *p4d;
+	pud_t *pud, *new_pud = NULL;
+	pmd_t *pmd, *new_pmd = NULL;
+	pte_t *ptep, *new_ptep = NULL;
+	int ret;
+
+	/* Traverse the guest's 2nd-level tree, allocate new levels needed */
+	pgd = pgtable + pgd_index(gpa);
+	p4d = p4d_offset(pgd, gpa);
+
+	pud = NULL;
+	if (p4d_present(*p4d))
+		pud = pud_offset(p4d, gpa);
+	else
+		new_pud = pud_alloc_one(kvm->mm, gpa);
+
+	pmd = NULL;
+	if (pud && pud_present(*pud) && !pud_is_leaf(*pud))
+		pmd = pmd_offset(pud, gpa);
+	else if (level <= 1)
+		new_pmd = kvmppc_pmd_alloc();
+
+	if (level == 0 && !(pmd && pmd_present(*pmd) && !pmd_is_leaf(*pmd)))
+		new_ptep = kvmppc_pte_alloc();
+
+	/* Check if we might have been invalidated; let the guest retry if so */
+	spin_lock(&kvm->mmu_lock);
+	ret = -EAGAIN;
+	if (mmu_invalidate_retry(kvm, mmu_seq))
+		goto out_unlock;
+
+	/* Now traverse again under the lock and change the tree */
+	ret = -ENOMEM;
+	if (p4d_none(*p4d)) {
+		if (!new_pud)
+			goto out_unlock;
+		p4d_populate(kvm->mm, p4d, new_pud);
+		new_pud = NULL;
+	}
+	pud = pud_offset(p4d, gpa);
+	if (pud_is_leaf(*pud)) {
+		unsigned long hgpa = gpa & PUD_MASK;
+
+		/* Check if we raced and someone else has set the same thing */
+		if (level == 2) {
+			if (pud_raw(*pud) == pte_raw(pte)) {
+				ret = 0;
+				goto out_unlock;
+			}
+			/* Valid 1GB page here already, add our extra bits */
+			WARN_ON_ONCE((pud_val(*pud) ^ pte_val(pte)) &
+							PTE_BITS_MUST_MATCH);
+			kvmppc_radix_update_pte(kvm, (pte_t *)pud,
+					      0, pte_val(pte), hgpa, PUD_SHIFT);
+			ret = 0;
+			goto out_unlock;
+		}
+		/*
+		 * If we raced with another CPU which has just put
+		 * a 1GB pte in after we saw a pmd page, try again.
+		 */
+		if (!new_pmd) {
+			ret = -EAGAIN;
+			goto out_unlock;
+		}
+		/* Valid 1GB page here already, remove it */
+		kvmppc_unmap_pte(kvm, (pte_t *)pud, hgpa, PUD_SHIFT, NULL,
+				 lpid);
+	}
+	if (level == 2) {
+		if (!pud_none(*pud)) {
+			/*
+			 * There's a page table page here, but we wanted to
+			 * install a large page, so remove and free the page
+			 * table page.
+			 */
+			kvmppc_unmap_free_pud_entry_table(kvm, pud, gpa, lpid);
+		}
+		kvmppc_radix_set_pte_at(kvm, gpa, (pte_t *)pud, pte);
+		if (rmapp && n_rmap)
+			kvmhv_insert_nest_rmap(kvm, rmapp, n_rmap);
+		ret = 0;
+		goto out_unlock;
+	}
+	if (pud_none(*pud)) {
+		if (!new_pmd)
+			goto out_unlock;
+		pud_populate(kvm->mm, pud, new_pmd);
+		new_pmd = NULL;
+	}
+	pmd = pmd_offset(pud, gpa);
+	if (pmd_is_leaf(*pmd)) {
+		unsigned long lgpa = gpa & PMD_MASK;
+
+		/* Check if we raced and someone else has set the same thing */
+		if (level == 1) {
+			if (pmd_raw(*pmd) == pte_raw(pte)) {
+				ret = 0;
+				goto out_unlock;
+			}
+			/* Valid 2MB page here already, add our extra bits */
+			WARN_ON_ONCE((pmd_val(*pmd) ^ pte_val(pte)) &
+							PTE_BITS_MUST_MATCH);
+			kvmppc_radix_update_pte(kvm, pmdp_ptep(pmd),
+					0, pte_val(pte), lgpa, PMD_SHIFT);
+			ret = 0;
+			goto out_unlock;
+		}
+
+		/*
+		 * If we raced with another CPU which has just put
+		 * a 2MB pte in after we saw a pte page, try again.
+		 */
+		if (!new_ptep) {
+			ret = -EAGAIN;
+			goto out_unlock;
+		}
+		/* Valid 2MB page here already, remove it */
+		kvmppc_unmap_pte(kvm, pmdp_ptep(pmd), lgpa, PMD_SHIFT, NULL,
+				 lpid);
+	}
+	if (level == 1) {
+		if (!pmd_none(*pmd)) {
+			/*
+			 * There's a page table page here, but we wanted to
+			 * install a large page, so remove and free the page
+			 * table page.
+			 */
+			kvmppc_unmap_free_pmd_entry_table(kvm, pmd, gpa, lpid);
+		}
+		kvmppc_radix_set_pte_at(kvm, gpa, pmdp_ptep(pmd), pte);
+		if (rmapp && n_rmap)
+			kvmhv_insert_nest_rmap(kvm, rmapp, n_rmap);
+		ret = 0;
+		goto out_unlock;
+	}
+	if (pmd_none(*pmd)) {
+		if (!new_ptep)
+			goto out_unlock;
+		pmd_populate(kvm->mm, pmd, new_ptep);
+		new_ptep = NULL;
+	}
+	ptep = pte_offset_kernel(pmd, gpa);
+	if (pte_present(*ptep)) {
+		/* Check if someone else set the same thing */
+		if (pte_raw(*ptep) == pte_raw(pte)) {
+			ret = 0;
+			goto out_unlock;
+		}
+		/* Valid page here already, add our extra bits */
+		WARN_ON_ONCE((pte_val(*ptep) ^ pte_val(pte)) &
+							PTE_BITS_MUST_MATCH);
+		kvmppc_radix_update_pte(kvm, ptep, 0, pte_val(pte), gpa, 0);
+		ret = 0;
+		goto out_unlock;
+	}
+	kvmppc_radix_set_pte_at(kvm, gpa, ptep, pte);
+	if (rmapp && n_rmap)
+		kvmhv_insert_nest_rmap(kvm, rmapp, n_rmap);
+	ret = 0;
+
+ out_unlock:
+	spin_unlock(&kvm->mmu_lock);
+	if (new_pud)
+		pud_free(kvm->mm, new_pud);
+	if (new_pmd)
+		kvmppc_pmd_free(new_pmd);
+	if (new_ptep)
+		kvmppc_pte_free(new_ptep);
+	return ret;
+}
+
+bool kvmppc_hv_handle_set_rc(struct kvm *kvm, bool nested, bool writing,
+			     unsigned long gpa, unsigned int lpid)
+{
+	unsigned long pgflags;
+	unsigned int shift;
+	pte_t *ptep;
+
+	/*
+	 * Need to set an R or C bit in the 2nd-level tables;
+	 * since we are just helping out the hardware here,
+	 * it is sufficient to do what the hardware does.
+	 */
+	pgflags = _PAGE_ACCESSED;
+	if (writing)
+		pgflags |= _PAGE_DIRTY;
+
+	if (nested)
+		ptep = find_kvm_nested_guest_pte(kvm, lpid, gpa, &shift);
+	else
+		ptep = find_kvm_secondary_pte(kvm, gpa, &shift);
+
+	if (ptep && pte_present(*ptep) && (!writing || pte_write(*ptep))) {
+		kvmppc_radix_update_pte(kvm, ptep, 0, pgflags, gpa, shift);
+		return true;
+	}
+	return false;
+}
+
+int kvmppc_book3s_instantiate_page(struct kvm_vcpu *vcpu,
+				   unsigned long gpa,
+				   struct kvm_memory_slot *memslot,
+				   bool writing, bool kvm_ro,
+				   pte_t *inserted_pte, unsigned int *levelp)
+{
+	struct kvm *kvm = vcpu->kvm;
+	struct page *page = NULL;
+	unsigned long mmu_seq;
+	unsigned long hva, gfn = gpa >> PAGE_SHIFT;
+	bool upgrade_write = false;
+	bool *upgrade_p = &upgrade_write;
+	pte_t pte, *ptep;
+	unsigned int shift, level;
+	int ret;
+	bool large_enable;
+
+	/* used to check for invalidations in progress */
+	mmu_seq = kvm->mmu_invalidate_seq;
+	smp_rmb();
+
+	/*
+	 * Do a fast check first, since __gfn_to_pfn_memslot doesn't
+	 * do it with !atomic && !async, which is how we call it.
+	 * We always ask for write permission since the common case
+	 * is that the page is writable.
+	 */
+	hva = gfn_to_hva_memslot(memslot, gfn);
+	if (!kvm_ro && get_user_page_fast_only(hva, FOLL_WRITE, &page)) {
+		upgrade_write = true;
+	} else {
+		unsigned long pfn;
+
+		/* Call KVM generic code to do the slow-path check */
+		pfn = __gfn_to_pfn_memslot(memslot, gfn, false, false, NULL,
+					   writing, upgrade_p, NULL);
+		if (is_error_noslot_pfn(pfn))
+			return -EFAULT;
+		page = NULL;
+		if (pfn_valid(pfn)) {
+			page = pfn_to_page(pfn);
+			if (PageReserved(page))
+				page = NULL;
+		}
+	}
+
+	/*
+	 * Read the PTE from the process' radix tree and use that
+	 * so we get the shift and attribute bits.
+	 */
+	spin_lock(&kvm->mmu_lock);
+	ptep = find_kvm_host_pte(kvm, mmu_seq, hva, &shift);
+	pte = __pte(0);
+	if (ptep)
+		pte = READ_ONCE(*ptep);
+	spin_unlock(&kvm->mmu_lock);
+	/*
+	 * If the PTE disappeared temporarily due to a THP
+	 * collapse, just return and let the guest try again.
+	 */
+	if (!pte_present(pte)) {
+		if (page)
+			put_page(page);
+		return RESUME_GUEST;
+	}
+
+	/* If we're logging dirty pages, always map single pages */
+	large_enable = !(memslot->flags & KVM_MEM_LOG_DIRTY_PAGES);
+
+	/* Get pte level from shift/size */
+	if (large_enable && shift == PUD_SHIFT &&
+	    (gpa & (PUD_SIZE - PAGE_SIZE)) ==
+	    (hva & (PUD_SIZE - PAGE_SIZE))) {
+		level = 2;
+	} else if (large_enable && shift == PMD_SHIFT &&
+		   (gpa & (PMD_SIZE - PAGE_SIZE)) ==
+		   (hva & (PMD_SIZE - PAGE_SIZE))) {
+		level = 1;
+	} else {
+		level = 0;
+		if (shift > PAGE_SHIFT) {
+			/*
+			 * If the pte maps more than one page, bring over
+			 * bits from the virtual address to get the real
+			 * address of the specific single page we want.
+			 */
+			unsigned long rpnmask = (1ul << shift) - PAGE_SIZE;
+			pte = __pte(pte_val(pte) | (hva & rpnmask));
+		}
+	}
+
+	pte = __pte(pte_val(pte) | _PAGE_EXEC | _PAGE_ACCESSED);
+	if (writing || upgrade_write) {
+		if (pte_val(pte) & _PAGE_WRITE)
+			pte = __pte(pte_val(pte) | _PAGE_DIRTY);
+	} else {
+		pte = __pte(pte_val(pte) & ~(_PAGE_WRITE | _PAGE_DIRTY));
+	}
+
+	/* Allocate space in the tree and write the PTE */
+	ret = kvmppc_create_pte(kvm, kvm->arch.pgtable, pte, gpa, level,
+				mmu_seq, kvm->arch.lpid, NULL, NULL);
+	if (inserted_pte)
+		*inserted_pte = pte;
+	if (levelp)
+		*levelp = level;
+
+	if (page) {
+		if (!ret && (pte_val(pte) & _PAGE_WRITE))
+			set_page_dirty_lock(page);
+		put_page(page);
+	}
+
+	/* Increment number of large pages if we (successfully) inserted one */
+	if (!ret) {
+		if (level == 1)
+			kvm->stat.num_2M_pages++;
+		else if (level == 2)
+			kvm->stat.num_1G_pages++;
+	}
+
+	return ret;
+}
+
+int kvmppc_book3s_radix_page_fault(struct kvm_vcpu *vcpu,
+				   unsigned long ea, unsigned long dsisr)
+{
+	struct kvm *kvm = vcpu->kvm;
+	unsigned long gpa, gfn;
+	struct kvm_memory_slot *memslot;
+	long ret;
+	bool writing = !!(dsisr & DSISR_ISSTORE);
+	bool kvm_ro = false;
+
+	/* Check for unusual errors */
+	if (dsisr & DSISR_UNSUPP_MMU) {
+		pr_err("KVM: Got unsupported MMU fault\n");
+		return -EFAULT;
+	}
+	if (dsisr & DSISR_BADACCESS) {
+		/* Reflect to the guest as DSI */
+		pr_err("KVM: Got radix HV page fault with DSISR=%lx\n", dsisr);
+		kvmppc_core_queue_data_storage(vcpu,
+				kvmppc_get_msr(vcpu) & SRR1_PREFIXED,
+				ea, dsisr);
+		return RESUME_GUEST;
+	}
+
+	/* Translate the logical address */
+	gpa = vcpu->arch.fault_gpa & ~0xfffUL;
+	gpa &= ~0xF000000000000000ul;
+	gfn = gpa >> PAGE_SHIFT;
+	if (!(dsisr & DSISR_PRTABLE_FAULT))
+		gpa |= ea & 0xfff;
+
+	if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE)
+		return kvmppc_send_page_to_uv(kvm, gfn);
+
+	/* Get the corresponding memslot */
+	memslot = gfn_to_memslot(kvm, gfn);
+
+	/* No memslot means it's an emulated MMIO region */
+	if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID)) {
+		if (dsisr & (DSISR_PRTABLE_FAULT | DSISR_BADACCESS |
+			     DSISR_SET_RC)) {
+			/*
+			 * Bad address in guest page table tree, or other
+			 * unusual error - reflect it to the guest as DSI.
+			 */
+			kvmppc_core_queue_data_storage(vcpu,
+					kvmppc_get_msr(vcpu) & SRR1_PREFIXED,
+					ea, dsisr);
+			return RESUME_GUEST;
+		}
+		return kvmppc_hv_emulate_mmio(vcpu, gpa, ea, writing);
+	}
+
+	if (memslot->flags & KVM_MEM_READONLY) {
+		if (writing) {
+			/* give the guest a DSI */
+			kvmppc_core_queue_data_storage(vcpu,
+					kvmppc_get_msr(vcpu) & SRR1_PREFIXED,
+					ea, DSISR_ISSTORE | DSISR_PROTFAULT);
+			return RESUME_GUEST;
+		}
+		kvm_ro = true;
+	}
+
+	/* Failed to set the reference/change bits */
+	if (dsisr & DSISR_SET_RC) {
+		spin_lock(&kvm->mmu_lock);
+		if (kvmppc_hv_handle_set_rc(kvm, false, writing,
+					    gpa, kvm->arch.lpid))
+			dsisr &= ~DSISR_SET_RC;
+		spin_unlock(&kvm->mmu_lock);
+
+		if (!(dsisr & (DSISR_BAD_FAULT_64S | DSISR_NOHPTE |
+			       DSISR_PROTFAULT | DSISR_SET_RC)))
+			return RESUME_GUEST;
+	}
+
+	/* Try to insert a pte */
+	ret = kvmppc_book3s_instantiate_page(vcpu, gpa, memslot, writing,
+					     kvm_ro, NULL, NULL);
+
+	if (ret == 0 || ret == -EAGAIN)
+		ret = RESUME_GUEST;
+	return ret;
+}
+
+/* Called with kvm->mmu_lock held */
+void kvm_unmap_radix(struct kvm *kvm, struct kvm_memory_slot *memslot,
+		     unsigned long gfn)
+{
+	pte_t *ptep;
+	unsigned long gpa = gfn << PAGE_SHIFT;
+	unsigned int shift;
+
+	if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE) {
+		uv_page_inval(kvm->arch.lpid, gpa, PAGE_SHIFT);
+		return;
+	}
+
+	ptep = find_kvm_secondary_pte(kvm, gpa, &shift);
+	if (ptep && pte_present(*ptep))
+		kvmppc_unmap_pte(kvm, ptep, gpa, shift, memslot,
+				 kvm->arch.lpid);
+}
+
+/* Called with kvm->mmu_lock held */
+bool kvm_age_radix(struct kvm *kvm, struct kvm_memory_slot *memslot,
+		   unsigned long gfn)
+{
+	pte_t *ptep;
+	unsigned long gpa = gfn << PAGE_SHIFT;
+	unsigned int shift;
+	bool ref = false;
+	unsigned long old, *rmapp;
+
+	if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE)
+		return ref;
+
+	ptep = find_kvm_secondary_pte(kvm, gpa, &shift);
+	if (ptep && pte_present(*ptep) && pte_young(*ptep)) {
+		old = kvmppc_radix_update_pte(kvm, ptep, _PAGE_ACCESSED, 0,
+					      gpa, shift);
+		/* XXX need to flush tlb here? */
+		/* Also clear bit in ptes in shadow pgtable for nested guests */
+		rmapp = &memslot->arch.rmap[gfn - memslot->base_gfn];
+		kvmhv_update_nest_rmap_rc_list(kvm, rmapp, _PAGE_ACCESSED, 0,
+					       old & PTE_RPN_MASK,
+					       1UL << shift);
+		ref = true;
+	}
+	return ref;
+}
+
+/* Called with kvm->mmu_lock held */
+bool kvm_test_age_radix(struct kvm *kvm, struct kvm_memory_slot *memslot,
+			unsigned long gfn)
+
+{
+	pte_t *ptep;
+	unsigned long gpa = gfn << PAGE_SHIFT;
+	unsigned int shift;
+	bool ref = false;
+
+	if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE)
+		return ref;
+
+	ptep = find_kvm_secondary_pte(kvm, gpa, &shift);
+	if (ptep && pte_present(*ptep) && pte_young(*ptep))
+		ref = true;
+	return ref;
+}
+
+/* Returns the number of PAGE_SIZE pages that are dirty */
+static int kvm_radix_test_clear_dirty(struct kvm *kvm,
+				struct kvm_memory_slot *memslot, int pagenum)
+{
+	unsigned long gfn = memslot->base_gfn + pagenum;
+	unsigned long gpa = gfn << PAGE_SHIFT;
+	pte_t *ptep, pte;
+	unsigned int shift;
+	int ret = 0;
+	unsigned long old, *rmapp;
+
+	if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE)
+		return ret;
+
+	/*
+	 * For performance reasons we don't hold kvm->mmu_lock while walking the
+	 * partition scoped table.
+	 */
+	ptep = find_kvm_secondary_pte_unlocked(kvm, gpa, &shift);
+	if (!ptep)
+		return 0;
+
+	pte = READ_ONCE(*ptep);
+	if (pte_present(pte) && pte_dirty(pte)) {
+		spin_lock(&kvm->mmu_lock);
+		/*
+		 * Recheck the pte again
+		 */
+		if (pte_val(pte) != pte_val(*ptep)) {
+			/*
+			 * We have KVM_MEM_LOG_DIRTY_PAGES enabled. Hence we can
+			 * only find PAGE_SIZE pte entries here. We can continue
+			 * to use the pte addr returned by above page table
+			 * walk.
+			 */
+			if (!pte_present(*ptep) || !pte_dirty(*ptep)) {
+				spin_unlock(&kvm->mmu_lock);
+				return 0;
+			}
+		}
+
+		ret = 1;
+		VM_BUG_ON(shift);
+		old = kvmppc_radix_update_pte(kvm, ptep, _PAGE_DIRTY, 0,
+					      gpa, shift);
+		kvmppc_radix_tlbie_page(kvm, gpa, shift, kvm->arch.lpid);
+		/* Also clear bit in ptes in shadow pgtable for nested guests */
+		rmapp = &memslot->arch.rmap[gfn - memslot->base_gfn];
+		kvmhv_update_nest_rmap_rc_list(kvm, rmapp, _PAGE_DIRTY, 0,
+					       old & PTE_RPN_MASK,
+					       1UL << shift);
+		spin_unlock(&kvm->mmu_lock);
+	}
+	return ret;
+}
+
+long kvmppc_hv_get_dirty_log_radix(struct kvm *kvm,
+			struct kvm_memory_slot *memslot, unsigned long *map)
+{
+	unsigned long i, j;
+	int npages;
+
+	for (i = 0; i < memslot->npages; i = j) {
+		npages = kvm_radix_test_clear_dirty(kvm, memslot, i);
+
+		/*
+		 * Note that if npages > 0 then i must be a multiple of npages,
+		 * since huge pages are only used to back the guest at guest
+		 * real addresses that are a multiple of their size.
+		 * Since we have at most one PTE covering any given guest
+		 * real address, if npages > 1 we can skip to i + npages.
+		 */
+		j = i + 1;
+		if (npages) {
+			set_dirty_bits(map, i, npages);
+			j = i + npages;
+		}
+	}
+	return 0;
+}
+
+void kvmppc_radix_flush_memslot(struct kvm *kvm,
+				const struct kvm_memory_slot *memslot)
+{
+	unsigned long n;
+	pte_t *ptep;
+	unsigned long gpa;
+	unsigned int shift;
+
+	if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_START)
+		kvmppc_uvmem_drop_pages(memslot, kvm, true);
+
+	if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE)
+		return;
+
+	gpa = memslot->base_gfn << PAGE_SHIFT;
+	spin_lock(&kvm->mmu_lock);
+	for (n = memslot->npages; n; --n) {
+		ptep = find_kvm_secondary_pte(kvm, gpa, &shift);
+		if (ptep && pte_present(*ptep))
+			kvmppc_unmap_pte(kvm, ptep, gpa, shift, memslot,
+					 kvm->arch.lpid);
+		gpa += PAGE_SIZE;
+	}
+	/*
+	 * Increase the mmu notifier sequence number to prevent any page
+	 * fault that read the memslot earlier from writing a PTE.
+	 */
+	kvm->mmu_invalidate_seq++;
+	spin_unlock(&kvm->mmu_lock);
+}
+
+static void add_rmmu_ap_encoding(struct kvm_ppc_rmmu_info *info,
+				 int psize, int *indexp)
+{
+	if (!mmu_psize_defs[psize].shift)
+		return;
+	info->ap_encodings[*indexp] = mmu_psize_defs[psize].shift |
+		(mmu_psize_defs[psize].ap << 29);
+	++(*indexp);
+}
+
+int kvmhv_get_rmmu_info(struct kvm *kvm, struct kvm_ppc_rmmu_info *info)
+{
+	int i;
+
+	if (!radix_enabled())
+		return -EINVAL;
+	memset(info, 0, sizeof(*info));
+
+	/* 4k page size */
+	info->geometries[0].page_shift = 12;
+	info->geometries[0].level_bits[0] = 9;
+	for (i = 1; i < 4; ++i)
+		info->geometries[0].level_bits[i] = p9_supported_radix_bits[i];
+	/* 64k page size */
+	info->geometries[1].page_shift = 16;
+	for (i = 0; i < 4; ++i)
+		info->geometries[1].level_bits[i] = p9_supported_radix_bits[i];
+
+	i = 0;
+	add_rmmu_ap_encoding(info, MMU_PAGE_4K, &i);
+	add_rmmu_ap_encoding(info, MMU_PAGE_64K, &i);
+	add_rmmu_ap_encoding(info, MMU_PAGE_2M, &i);
+	add_rmmu_ap_encoding(info, MMU_PAGE_1G, &i);
+
+	return 0;
+}
+
+int kvmppc_init_vm_radix(struct kvm *kvm)
+{
+	kvm->arch.pgtable = pgd_alloc(kvm->mm);
+	if (!kvm->arch.pgtable)
+		return -ENOMEM;
+	return 0;
+}
+
+static void pte_ctor(void *addr)
+{
+	memset(addr, 0, RADIX_PTE_TABLE_SIZE);
+}
+
+static void pmd_ctor(void *addr)
+{
+	memset(addr, 0, RADIX_PMD_TABLE_SIZE);
+}
+
+struct debugfs_radix_state {
+	struct kvm	*kvm;
+	struct mutex	mutex;
+	unsigned long	gpa;
+	int		lpid;
+	int		chars_left;
+	int		buf_index;
+	char		buf[128];
+	u8		hdr;
+};
+
+static int debugfs_radix_open(struct inode *inode, struct file *file)
+{
+	struct kvm *kvm = inode->i_private;
+	struct debugfs_radix_state *p;
+
+	p = kzalloc(sizeof(*p), GFP_KERNEL);
+	if (!p)
+		return -ENOMEM;
+
+	kvm_get_kvm(kvm);
+	p->kvm = kvm;
+	mutex_init(&p->mutex);
+	file->private_data = p;
+
+	return nonseekable_open(inode, file);
+}
+
+static int debugfs_radix_release(struct inode *inode, struct file *file)
+{
+	struct debugfs_radix_state *p = file->private_data;
+
+	kvm_put_kvm(p->kvm);
+	kfree(p);
+	return 0;
+}
+
+static ssize_t debugfs_radix_read(struct file *file, char __user *buf,
+				 size_t len, loff_t *ppos)
+{
+	struct debugfs_radix_state *p = file->private_data;
+	ssize_t ret, r;
+	unsigned long n;
+	struct kvm *kvm;
+	unsigned long gpa;
+	pgd_t *pgt;
+	struct kvm_nested_guest *nested;
+	pgd_t *pgdp;
+	p4d_t p4d, *p4dp;
+	pud_t pud, *pudp;
+	pmd_t pmd, *pmdp;
+	pte_t *ptep;
+	int shift;
+	unsigned long pte;
+
+	kvm = p->kvm;
+	if (!kvm_is_radix(kvm))
+		return 0;
+
+	ret = mutex_lock_interruptible(&p->mutex);
+	if (ret)
+		return ret;
+
+	if (p->chars_left) {
+		n = p->chars_left;
+		if (n > len)
+			n = len;
+		r = copy_to_user(buf, p->buf + p->buf_index, n);
+		n -= r;
+		p->chars_left -= n;
+		p->buf_index += n;
+		buf += n;
+		len -= n;
+		ret = n;
+		if (r) {
+			if (!n)
+				ret = -EFAULT;
+			goto out;
+		}
+	}
+
+	gpa = p->gpa;
+	nested = NULL;
+	pgt = NULL;
+	while (len != 0 && p->lpid >= 0) {
+		if (gpa >= RADIX_PGTABLE_RANGE) {
+			gpa = 0;
+			pgt = NULL;
+			if (nested) {
+				kvmhv_put_nested(nested);
+				nested = NULL;
+			}
+			p->lpid = kvmhv_nested_next_lpid(kvm, p->lpid);
+			p->hdr = 0;
+			if (p->lpid < 0)
+				break;
+		}
+		if (!pgt) {
+			if (p->lpid == 0) {
+				pgt = kvm->arch.pgtable;
+			} else {
+				nested = kvmhv_get_nested(kvm, p->lpid, false);
+				if (!nested) {
+					gpa = RADIX_PGTABLE_RANGE;
+					continue;
+				}
+				pgt = nested->shadow_pgtable;
+			}
+		}
+		n = 0;
+		if (!p->hdr) {
+			if (p->lpid > 0)
+				n = scnprintf(p->buf, sizeof(p->buf),
+					      "\nNested LPID %d: ", p->lpid);
+			n += scnprintf(p->buf + n, sizeof(p->buf) - n,
+				      "pgdir: %lx\n", (unsigned long)pgt);
+			p->hdr = 1;
+			goto copy;
+		}
+
+		pgdp = pgt + pgd_index(gpa);
+		p4dp = p4d_offset(pgdp, gpa);
+		p4d = READ_ONCE(*p4dp);
+		if (!(p4d_val(p4d) & _PAGE_PRESENT)) {
+			gpa = (gpa & P4D_MASK) + P4D_SIZE;
+			continue;
+		}
+
+		pudp = pud_offset(&p4d, gpa);
+		pud = READ_ONCE(*pudp);
+		if (!(pud_val(pud) & _PAGE_PRESENT)) {
+			gpa = (gpa & PUD_MASK) + PUD_SIZE;
+			continue;
+		}
+		if (pud_val(pud) & _PAGE_PTE) {
+			pte = pud_val(pud);
+			shift = PUD_SHIFT;
+			goto leaf;
+		}
+
+		pmdp = pmd_offset(&pud, gpa);
+		pmd = READ_ONCE(*pmdp);
+		if (!(pmd_val(pmd) & _PAGE_PRESENT)) {
+			gpa = (gpa & PMD_MASK) + PMD_SIZE;
+			continue;
+		}
+		if (pmd_val(pmd) & _PAGE_PTE) {
+			pte = pmd_val(pmd);
+			shift = PMD_SHIFT;
+			goto leaf;
+		}
+
+		ptep = pte_offset_kernel(&pmd, gpa);
+		pte = pte_val(READ_ONCE(*ptep));
+		if (!(pte & _PAGE_PRESENT)) {
+			gpa += PAGE_SIZE;
+			continue;
+		}
+		shift = PAGE_SHIFT;
+	leaf:
+		n = scnprintf(p->buf, sizeof(p->buf),
+			      " %lx: %lx %d\n", gpa, pte, shift);
+		gpa += 1ul << shift;
+	copy:
+		p->chars_left = n;
+		if (n > len)
+			n = len;
+		r = copy_to_user(buf, p->buf, n);
+		n -= r;
+		p->chars_left -= n;
+		p->buf_index = n;
+		buf += n;
+		len -= n;
+		ret += n;
+		if (r) {
+			if (!ret)
+				ret = -EFAULT;
+			break;
+		}
+	}
+	p->gpa = gpa;
+	if (nested)
+		kvmhv_put_nested(nested);
+
+ out:
+	mutex_unlock(&p->mutex);
+	return ret;
+}
+
+static ssize_t debugfs_radix_write(struct file *file, const char __user *buf,
+			   size_t len, loff_t *ppos)
+{
+	return -EACCES;
+}
+
+static const struct file_operations debugfs_radix_fops = {
+	.owner	 = THIS_MODULE,
+	.open	 = debugfs_radix_open,
+	.release = debugfs_radix_release,
+	.read	 = debugfs_radix_read,
+	.write	 = debugfs_radix_write,
+	.llseek	 = generic_file_llseek,
+};
+
+void kvmhv_radix_debugfs_init(struct kvm *kvm)
+{
+	debugfs_create_file("radix", 0400, kvm->debugfs_dentry, kvm,
+			    &debugfs_radix_fops);
+}
+
+int kvmppc_radix_init(void)
+{
+	unsigned long size = sizeof(void *) << RADIX_PTE_INDEX_SIZE;
+
+	kvm_pte_cache = kmem_cache_create("kvm-pte", size, size, 0, pte_ctor);
+	if (!kvm_pte_cache)
+		return -ENOMEM;
+
+	size = sizeof(void *) << RADIX_PMD_INDEX_SIZE;
+
+	kvm_pmd_cache = kmem_cache_create("kvm-pmd", size, size, 0, pmd_ctor);
+	if (!kvm_pmd_cache) {
+		kmem_cache_destroy(kvm_pte_cache);
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+void kvmppc_radix_exit(void)
+{
+	kmem_cache_destroy(kvm_pte_cache);
+	kmem_cache_destroy(kvm_pmd_cache);
+}