1 files changed, 221 insertions, 127 deletions

diff --git a/arch/powerpc/kvm/book3s_64_mmu_radix.c b/arch/powerpc/kvm/book3s_64_mmu_radix.c
index 481da8f..176f911 100644
--- a/arch/powerpc/kvm/book3s_64_mmu_radix.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_radix.c
@@ -139,44 +139,24 @@ int kvmppc_mmu_radix_xlate(struct kvm_vcpu *vcpu, gva_t eaddr,
 	return 0;
 }
 
-#ifdef CONFIG_PPC_64K_PAGES
-#define MMU_BASE_PSIZE	MMU_PAGE_64K
-#else
-#define MMU_BASE_PSIZE	MMU_PAGE_4K
-#endif
-
 static void kvmppc_radix_tlbie_page(struct kvm *kvm, unsigned long addr,
 				    unsigned int pshift)
 {
-	int psize = MMU_BASE_PSIZE;
-
-	if (pshift >= PUD_SHIFT)
-		psize = MMU_PAGE_1G;
-	else if (pshift >= PMD_SHIFT)
-		psize = MMU_PAGE_2M;
-	addr &= ~0xfffUL;
-	addr |= mmu_psize_defs[psize].ap << 5;
-	asm volatile("ptesync": : :"memory");
-	asm volatile(PPC_TLBIE_5(%0, %1, 0, 0, 1)
-		     : : "r" (addr), "r" (kvm->arch.lpid) : "memory");
-	if (cpu_has_feature(CPU_FTR_P9_TLBIE_BUG))
-		asm volatile(PPC_TLBIE_5(%0, %1, 0, 0, 1)
-			     : : "r" (addr), "r" (kvm->arch.lpid) : "memory");
-	asm volatile("eieio ; tlbsync ; ptesync": : :"memory");
+	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, unsigned long addr)
+static void kvmppc_radix_flush_pwc(struct kvm *kvm)
 {
-	unsigned long rb = 0x2 << PPC_BITLSHIFT(53); /* IS = 2 */
-
-	asm volatile("ptesync": : :"memory");
-	/* RIC=1 PRS=0 R=1 IS=2 */
-	asm volatile(PPC_TLBIE_5(%0, %1, 1, 0, 1)
-		     : : "r" (rb), "r" (kvm->arch.lpid) : "memory");
-	asm volatile("eieio ; tlbsync ; ptesync": : :"memory");
+	radix__flush_pwc_lpid(kvm->arch.lpid);
 }
 
-unsigned long kvmppc_radix_update_pte(struct kvm *kvm, pte_t *ptep,
+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)
 {
@@ -228,6 +208,167 @@ 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)
 {
@@ -235,7 +376,6 @@ static int kvmppc_create_pte(struct kvm *kvm, pte_t pte, unsigned long gpa,
 	pud_t *pud, *new_pud = NULL;
 	pmd_t *pmd, *new_pmd = NULL;
 	pte_t *ptep, *new_ptep = NULL;
-	unsigned long old;
 	int ret;
 
 	/* Traverse the guest's 2nd-level tree, allocate new levels needed */
@@ -273,42 +413,39 @@ static int kvmppc_create_pte(struct kvm *kvm, pte_t pte, unsigned long 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 (level <= 1 && !new_pmd) {
+		if (!new_pmd) {
 			ret = -EAGAIN;
 			goto out_unlock;
 		}
-		/* Check if we raced and someone else has set the same thing */
-		if (level == 2 && pud_raw(*pud) == pte_raw(pte)) {
-			ret = 0;
-			goto out_unlock;
-		}
 		/* Valid 1GB page here already, remove it */
-		old = kvmppc_radix_update_pte(kvm, (pte_t *)pud,
-					      ~0UL, 0, hgpa, PUD_SHIFT);
-		kvmppc_radix_tlbie_page(kvm, hgpa, PUD_SHIFT);
-		if (old & _PAGE_DIRTY) {
-			unsigned long gfn = hgpa >> PAGE_SHIFT;
-			struct kvm_memory_slot *memslot;
-			memslot = gfn_to_memslot(kvm, gfn);
-			if (memslot && memslot->dirty_bitmap)
-				kvmppc_update_dirty_map(memslot,
-							gfn, PUD_SIZE);
-		}
+		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.  new_pmd will be NULL since level == 2.
+			 * table page.
 			 */
-			new_pmd = pmd_offset(pud, 0);
-			pud_clear(pud);
-			kvmppc_radix_flush_pwc(kvm, gpa);
+			kvmppc_unmap_free_pud_entry_table(kvm, pud, gpa);
 		}
 		kvmppc_radix_set_pte_at(kvm, gpa, (pte_t *)pud, pte);
 		ret = 0;
@@ -324,42 +461,40 @@ static int kvmppc_create_pte(struct kvm *kvm, pte_t pte, unsigned long 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 (level == 0 && !new_ptep) {
+		if (!new_ptep) {
 			ret = -EAGAIN;
 			goto out_unlock;
 		}
-		/* Check if we raced and someone else has set the same thing */
-		if (level == 1 && pmd_raw(*pmd) == pte_raw(pte)) {
-			ret = 0;
-			goto out_unlock;
-		}
 		/* Valid 2MB page here already, remove it */
-		old = kvmppc_radix_update_pte(kvm, pmdp_ptep(pmd),
-					      ~0UL, 0, lgpa, PMD_SHIFT);
-		kvmppc_radix_tlbie_page(kvm, lgpa, PMD_SHIFT);
-		if (old & _PAGE_DIRTY) {
-			unsigned long gfn = lgpa >> PAGE_SHIFT;
-			struct kvm_memory_slot *memslot;
-			memslot = gfn_to_memslot(kvm, gfn);
-			if (memslot && memslot->dirty_bitmap)
-				kvmppc_update_dirty_map(memslot,
-							gfn, PMD_SIZE);
-		}
+		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.  new_ptep will be NULL since level == 1.
+			 * table page.
 			 */
-			new_ptep = pte_offset_kernel(pmd, 0);
-			pmd_clear(pmd);
-			kvmppc_radix_flush_pwc(kvm, gpa);
+			kvmppc_unmap_free_pmd_entry_table(kvm, pmd, gpa);
 		}
 		kvmppc_radix_set_pte_at(kvm, gpa, pmdp_ptep(pmd), pte);
 		ret = 0;
@@ -378,12 +513,12 @@ static int kvmppc_create_pte(struct kvm *kvm, pte_t pte, unsigned long gpa,
 			ret = 0;
 			goto out_unlock;
 		}
-		/* PTE was previously valid, so invalidate it */
-		old = kvmppc_radix_update_pte(kvm, ptep, _PAGE_PRESENT,
-					      0, gpa, 0);
-		kvmppc_radix_tlbie_page(kvm, gpa, 0);
-		if (old & _PAGE_DIRTY)
-			mark_page_dirty(kvm, gpa >> PAGE_SHIFT);
+		/* 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;
@@ -565,9 +700,13 @@ int kvmppc_book3s_radix_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu,
 			unsigned long mask = (1ul << shift) - PAGE_SIZE;
 			pte = __pte(pte_val(pte) | (hva & mask));
 		}
-		if (!(writing || upgrade_write))
-			pte = __pte(pte_val(pte) & ~ _PAGE_WRITE);
-		pte = __pte(pte_val(pte) | _PAGE_EXEC);
+		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 */
@@ -734,51 +873,6 @@ int kvmppc_init_vm_radix(struct kvm *kvm)
 	return 0;
 }
 
-void kvmppc_free_radix(struct kvm *kvm)
-{
-	unsigned long ig, iu, im;
-	pte_t *pte;
-	pmd_t *pmd;
-	pud_t *pud;
-	pgd_t *pgd;
-
-	if (!kvm->arch.pgtable)
-		return;
-	pgd = kvm->arch.pgtable;
-	for (ig = 0; ig < PTRS_PER_PGD; ++ig, ++pgd) {
-		if (!pgd_present(*pgd))
-			continue;
-		pud = pud_offset(pgd, 0);
-		for (iu = 0; iu < PTRS_PER_PUD; ++iu, ++pud) {
-			if (!pud_present(*pud))
-				continue;
-			if (pud_huge(*pud)) {
-				pud_clear(pud);
-				continue;
-			}
-			pmd = pmd_offset(pud, 0);
-			for (im = 0; im < PTRS_PER_PMD; ++im, ++pmd) {
-				if (pmd_is_leaf(*pmd)) {
-					pmd_clear(pmd);
-					continue;
-				}
-				if (!pmd_present(*pmd))
-					continue;
-				pte = pte_offset_map(pmd, 0);
-				memset(pte, 0, sizeof(long) << PTE_INDEX_SIZE);
-				kvmppc_pte_free(pte);
-				pmd_clear(pmd);
-			}
-			kvmppc_pmd_free(pmd_offset(pud, 0));
-			pud_clear(pud);
-		}
-		pud_free(kvm->mm, pud_offset(pgd, 0));
-		pgd_clear(pgd);
-	}
-	pgd_free(kvm->mm, kvm->arch.pgtable);
-	kvm->arch.pgtable = NULL;
-}
-
 static void pte_ctor(void *addr)
 {
 	memset(addr, 0, RADIX_PTE_TABLE_SIZE);