Adding upstream version 4.19.249.upstream/4.19.249upstream

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

1 files changed, 901 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 000000000..df0f08cb8
--- /dev/null
+++ b/arch/powerpc/kvm/book3s_64_mmu_radix.c
@@ -0,0 +1,901 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2, as
+ * published by the Free Software Foundation.
+ *
+ * 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 <asm/kvm_ppc.h>
+#include <asm/kvm_book3s.h>
+#include <asm/page.h>
+#include <asm/mmu.h>
+#include <asm/pgtable.h>
+#include <asm/pgalloc.h>
+#include <asm/pte-walk.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 };
+
+int kvmppc_mmu_radix_xlate(struct kvm_vcpu *vcpu, gva_t eaddr,
+			   struct kvmppc_pte *gpte, bool data, bool iswrite)
+{
+	struct kvm *kvm = vcpu->kvm;
+	u32 pid;
+	int ret, level, ps;
+	__be64 prte, rpte;
+	unsigned long ptbl;
+	unsigned long root, pte, index;
+	unsigned long rts, bits, offset;
+	unsigned long gpa;
+	unsigned long proc_tbl_size;
+
+	/* Work out effective PID */
+	switch (eaddr >> 62) {
+	case 0:
+		pid = vcpu->arch.pid;
+		break;
+	case 3:
+		pid = 0;
+		break;
+	default:
+		return -EINVAL;
+	}
+	proc_tbl_size = 1 << ((kvm->arch.process_table & PRTS_MASK) + 12);
+	if (pid * 16 >= proc_tbl_size)
+		return -EINVAL;
+
+	/* Read partition table to find root of tree for effective PID */
+	ptbl = (kvm->arch.process_table & PRTB_MASK) + (pid * 16);
+	ret = kvm_read_guest(kvm, ptbl, &prte, sizeof(prte));
+	if (ret)
+		return ret;
+
+	root = be64_to_cpu(prte);
+	rts = ((root & RTS1_MASK) >> (RTS1_SHIFT - 3)) |
+		((root & RTS2_MASK) >> RTS2_SHIFT);
+	bits = root & RPDS_MASK;
+	root = root & RPDB_MASK;
+
+	offset = rts + 31;
+
+	/* current implementations only support 52-bit space */
+	if (offset != 52)
+		return -EINVAL;
+
+	for (level = 3; level >= 0; --level) {
+		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 (root & ((1UL << (bits + 3)) - 1))
+			return -EINVAL;
+		ret = kvm_read_guest(kvm, root + index * 8,
+				     &rpte, sizeof(rpte));
+		if (ret)
+			return ret;
+		pte = __be64_to_cpu(rpte);
+		if (!(pte & _PAGE_PRESENT))
+			return -ENOENT;
+		if (pte & _PAGE_PTE)
+			break;
+		bits = pte & 0x1f;
+		root = pte & 0x0fffffffffffff00ul;
+	}
+	/* need a leaf at lowest level; 512GB pages not supported */
+	if (level < 0 || level == 3)
+		return -EINVAL;
+
+	/* 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->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);
+	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 (vcpu->arch.amr & (1ul << 62))
+				gpte->may_read = 0;
+			if (vcpu->arch.amr & (1ul << 63))
+				gpte->may_write = 0;
+			if (vcpu->arch.iamr & (1ul << 62))
+				gpte->may_execute = 0;
+		}
+	}
+
+	return 0;
+}
+
+static void kvmppc_radix_tlbie_page(struct kvm *kvm, unsigned long addr,
+				    unsigned int pshift)
+{
+	unsigned long psize = PAGE_SIZE;
+
+	if (pshift)
+		psize = 1UL << pshift;
+
+	addr &= ~(psize - 1);
+	radix__flush_tlb_lpid_page(kvm->arch.lpid, addr, psize);
+}
+
+static void kvmppc_radix_flush_pwc(struct kvm *kvm)
+{
+	radix__flush_pwc_lpid(kvm->arch.lpid);
+}
+
+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);
+}
+
+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);
+}
+
+/* Like pmd_huge() and pmd_large(), but works regardless of config options */
+static inline int pmd_is_leaf(pmd_t pmd)
+{
+	return !!(pmd_val(pmd) & _PAGE_PTE);
+}
+
+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);
+}
+
+static void kvmppc_unmap_pte(struct kvm *kvm, pte_t *pte,
+			     unsigned long gpa, unsigned int shift)
+
+{
+	unsigned long page_size = 1ul << shift;
+	unsigned long old;
+
+	old = kvmppc_radix_update_pte(kvm, pte, ~0UL, 0, gpa, shift);
+	kvmppc_radix_tlbie_page(kvm, gpa, shift);
+	if (old & _PAGE_DIRTY) {
+		unsigned long gfn = gpa >> PAGE_SHIFT;
+		struct kvm_memory_slot *memslot;
+
+		memslot = gfn_to_memslot(kvm, gfn);
+		if (memslot && 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), ptes are not expected. There is code to unmap them
+ * and emit a warning if encountered, but there may already be data
+ * corruption due to the unexpected mappings.
+ */
+static void kvmppc_unmap_free_pte(struct kvm *kvm, pte_t *pte, bool full)
+{
+	if (full) {
+		memset(pte, 0, sizeof(long) << 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;
+			WARN_ON_ONCE(1);
+			kvmppc_unmap_pte(kvm, p,
+					 pte_pfn(*p) << PAGE_SHIFT,
+					 PAGE_SHIFT);
+		}
+	}
+
+	kvmppc_pte_free(pte);
+}
+
+static void kvmppc_unmap_free_pmd(struct kvm *kvm, pmd_t *pmd, bool full)
+{
+	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);
+			}
+		} else {
+			pte_t *pte;
+
+			pte = pte_offset_map(p, 0);
+			kvmppc_unmap_free_pte(kvm, pte, full);
+			pmd_clear(p);
+		}
+	}
+	kvmppc_pmd_free(pmd);
+}
+
+static void kvmppc_unmap_free_pud(struct kvm *kvm, pud_t *pud)
+{
+	unsigned long iu;
+	pud_t *p = pud;
+
+	for (iu = 0; iu < PTRS_PER_PUD; ++iu, ++p) {
+		if (!pud_present(*p))
+			continue;
+		if (pud_huge(*p)) {
+			pud_clear(p);
+		} else {
+			pmd_t *pmd;
+
+			pmd = pmd_offset(p, 0);
+			kvmppc_unmap_free_pmd(kvm, pmd, true);
+			pud_clear(p);
+		}
+	}
+	pud_free(kvm->mm, pud);
+}
+
+void kvmppc_free_radix(struct kvm *kvm)
+{
+	unsigned long ig;
+	pgd_t *pgd;
+
+	if (!kvm->arch.pgtable)
+		return;
+	pgd = kvm->arch.pgtable;
+	for (ig = 0; ig < PTRS_PER_PGD; ++ig, ++pgd) {
+		pud_t *pud;
+
+		if (!pgd_present(*pgd))
+			continue;
+		pud = pud_offset(pgd, 0);
+		kvmppc_unmap_free_pud(kvm, pud);
+		pgd_clear(pgd);
+	}
+	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)
+{
+	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);
+
+	kvmppc_unmap_free_pte(kvm, pte, false);
+}
+
+static void kvmppc_unmap_free_pud_entry_table(struct kvm *kvm, pud_t *pud,
+					unsigned long gpa)
+{
+	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);
+
+	kvmppc_unmap_free_pmd(kvm, pmd, false);
+}
+
+/*
+ * 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))
+
+static int kvmppc_create_pte(struct kvm *kvm, pte_t pte, unsigned long gpa,
+			     unsigned int level, unsigned long mmu_seq)
+{
+	pgd_t *pgd;
+	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 = kvm->arch.pgtable + pgd_index(gpa);
+	pud = NULL;
+	if (pgd_present(*pgd))
+		pud = pud_offset(pgd, gpa);
+	else
+		new_pud = pud_alloc_one(kvm->mm, gpa);
+
+	pmd = NULL;
+	if (pud && pud_present(*pud) && !pud_huge(*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_notifier_retry(kvm, mmu_seq))
+		goto out_unlock;
+
+	/* Now traverse again under the lock and change the tree */
+	ret = -ENOMEM;
+	if (pgd_none(*pgd)) {
+		if (!new_pud)
+			goto out_unlock;
+		pgd_populate(kvm->mm, pgd, new_pud);
+		new_pud = NULL;
+	}
+	pud = pud_offset(pgd, gpa);
+	if (pud_huge(*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);
+	}
+	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);
+		}
+		kvmppc_radix_set_pte_at(kvm, gpa, (pte_t *)pud, pte);
+		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);
+	}
+	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);
+		}
+		kvmppc_radix_set_pte_at(kvm, gpa, pmdp_ptep(pmd), pte);
+		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);
+	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;
+}
+
+int kvmppc_book3s_radix_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu,
+				   unsigned long ea, unsigned long dsisr)
+{
+	struct kvm *kvm = vcpu->kvm;
+	unsigned long mmu_seq;
+	unsigned long gpa, gfn, hva;
+	struct kvm_memory_slot *memslot;
+	struct page *page = NULL;
+	long ret;
+	bool writing;
+	bool upgrade_write = false;
+	bool *upgrade_p = &upgrade_write;
+	pte_t pte, *ptep;
+	unsigned long pgflags;
+	unsigned int shift, level;
+
+	/* 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, ea, dsisr);
+		return RESUME_GUEST;
+	}
+
+	/* Translate the logical address and get the page */
+	gpa = vcpu->arch.fault_gpa & ~0xfffUL;
+	gpa &= ~0xF000000000000000ul;
+	gfn = gpa >> PAGE_SHIFT;
+	if (!(dsisr & DSISR_PRTABLE_FAULT))
+		gpa |= ea & 0xfff;
+	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, ea, dsisr);
+			return RESUME_GUEST;
+		}
+		return kvmppc_hv_emulate_mmio(run, vcpu, gpa, ea,
+					      dsisr & DSISR_ISSTORE);
+	}
+
+	writing = (dsisr & DSISR_ISSTORE) != 0;
+	if (memslot->flags & KVM_MEM_READONLY) {
+		if (writing) {
+			/* give the guest a DSI */
+			dsisr = DSISR_ISSTORE | DSISR_PROTFAULT;
+			kvmppc_core_queue_data_storage(vcpu, ea, dsisr);
+			return RESUME_GUEST;
+		}
+		upgrade_p = NULL;
+	}
+
+	if (dsisr & DSISR_SET_RC) {
+		/*
+		 * 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;
+		/*
+		 * We are walking the secondary page table here. We can do this
+		 * without disabling irq.
+		 */
+		spin_lock(&kvm->mmu_lock);
+		ptep = __find_linux_pte(kvm->arch.pgtable,
+					gpa, NULL, &shift);
+		if (ptep && pte_present(*ptep) &&
+		    (!writing || pte_write(*ptep))) {
+			kvmppc_radix_update_pte(kvm, ptep, 0, pgflags,
+						gpa, shift);
+			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;
+	}
+
+	/* used to check for invalidations in progress */
+	mmu_seq = kvm->mmu_notifier_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 (upgrade_p && __get_user_pages_fast(hva, 1, 1, &page) == 1) {
+		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, NULL,
+					   writing, upgrade_p);
+		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.
+	 */
+	local_irq_disable();
+	ptep = __find_linux_pte(vcpu->arch.pgdir, hva, NULL, &shift);
+	/*
+	 * If the PTE disappeared temporarily due to a THP
+	 * collapse, just return and let the guest try again.
+	 */
+	if (!ptep) {
+		local_irq_enable();
+		if (page)
+			put_page(page);
+		return RESUME_GUEST;
+	}
+	pte = *ptep;
+	local_irq_enable();
+
+	/* Get pte level from shift/size */
+	if (shift == PUD_SHIFT &&
+	    (gpa & (PUD_SIZE - PAGE_SIZE)) ==
+	    (hva & (PUD_SIZE - PAGE_SIZE))) {
+		level = 2;
+	} else if (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, pte, gpa, level, mmu_seq);
+
+	if (page) {
+		if (!ret && (pte_val(pte) & _PAGE_WRITE))
+			set_page_dirty_lock(page);
+		put_page(page);
+	}
+
+	if (ret == 0 || ret == -EAGAIN)
+		ret = RESUME_GUEST;
+	return ret;
+}
+
+/* Called with kvm->lock held */
+int 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;
+	unsigned long old;
+
+	ptep = __find_linux_pte(kvm->arch.pgtable, gpa, NULL, &shift);
+	if (ptep && pte_present(*ptep)) {
+		old = kvmppc_radix_update_pte(kvm, ptep, ~0UL, 0,
+					      gpa, shift);
+		kvmppc_radix_tlbie_page(kvm, gpa, shift);
+		if ((old & _PAGE_DIRTY) && memslot->dirty_bitmap) {
+			unsigned long psize = PAGE_SIZE;
+			if (shift)
+				psize = 1ul << shift;
+			kvmppc_update_dirty_map(memslot, gfn, psize);
+		}
+	}
+	return 0;				
+}
+
+/* Called with kvm->lock held */
+int 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;
+	int ref = 0;
+
+	ptep = __find_linux_pte(kvm->arch.pgtable, gpa, NULL, &shift);
+	if (ptep && pte_present(*ptep) && pte_young(*ptep)) {
+		kvmppc_radix_update_pte(kvm, ptep, _PAGE_ACCESSED, 0,
+					gpa, shift);
+		/* XXX need to flush tlb here? */
+		ref = 1;
+	}
+	return ref;
+}
+
+/* Called with kvm->lock held */
+int 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;
+	int ref = 0;
+
+	ptep = __find_linux_pte(kvm->arch.pgtable, gpa, NULL, &shift);
+	if (ptep && pte_present(*ptep) && pte_young(*ptep))
+		ref = 1;
+	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;
+	unsigned int shift;
+	int ret = 0;
+
+	ptep = __find_linux_pte(kvm->arch.pgtable, gpa, NULL, &shift);
+	if (ptep && pte_present(*ptep) && pte_dirty(*ptep)) {
+		ret = 1;
+		if (shift)
+			ret = 1 << (shift - PAGE_SHIFT);
+		kvmppc_radix_update_pte(kvm, ptep, _PAGE_DIRTY, 0,
+					gpa, shift);
+		kvmppc_radix_tlbie_page(kvm, gpa, shift);
+	}
+	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;
+}
+
+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);
+}
+
+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);
+}