Merge tag 'kvm-arm-for-3.18-take-2' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm

Pull second batch of changes for KVM/{arm,arm64} from Marc Zyngier:
 "The most obvious thing is the sizeable MMU changes to support 48bit
  VAs on arm64.

  Summary:

   - support for 48bit IPA and VA (EL2)
   - a number of fixes for devices mapped into guests
   - yet another VGIC fix for BE
   - a fix for CPU hotplug
   - a few compile fixes (disabled VGIC, strict mm checks)"

[ I'm pulling directly from Marc at the request of Paolo Bonzini, whose
  backpack was stolen at Düsseldorf airport and will do new keys and
  rebuild his web of trust.    - Linus ]

* tag 'kvm-arm-for-3.18-take-2' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm:
  arm/arm64: KVM: Fix BE accesses to GICv2 EISR and ELRSR regs
  arm: kvm: STRICT_MM_TYPECHECKS fix for user_mem_abort
  arm/arm64: KVM: Ensure memslots are within KVM_PHYS_SIZE
  arm64: KVM: Implement 48 VA support for KVM EL2 and Stage-2
  arm/arm64: KVM: map MMIO regions at creation time
  arm64: kvm: define PAGE_S2_DEVICE as read-only by default
  ARM: kvm: define PAGE_S2_DEVICE as read-only by default
  arm/arm64: KVM: add 'writable' parameter to kvm_phys_addr_ioremap
  arm/arm64: KVM: fix potential NULL dereference in user_mem_abort()
  arm/arm64: KVM: use __GFP_ZERO not memset() to get zeroed pages
  ARM: KVM: fix vgic-disabled build
  arm: kvm: fix CPU hotplug

3 files changed, 207 insertions, 40 deletions

diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index 779605122f32..9e193c8a959e 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -409,7 +409,7 @@ static void update_vttbr(struct kvm *kvm)
 	kvm_next_vmid++;
 
 	/* update vttbr to be used with the new vmid */
-	pgd_phys = virt_to_phys(kvm->arch.pgd);
+	pgd_phys = virt_to_phys(kvm_get_hwpgd(kvm));
 	BUG_ON(pgd_phys & ~VTTBR_BADDR_MASK);
 	vmid = ((u64)(kvm->arch.vmid) << VTTBR_VMID_SHIFT) & VTTBR_VMID_MASK;
 	kvm->arch.vttbr = pgd_phys | vmid;
@@ -808,7 +808,8 @@ static int hyp_init_cpu_notify(struct notifier_block *self,
 	switch (action) {
 	case CPU_STARTING:
 	case CPU_STARTING_FROZEN:
-		cpu_init_hyp_mode(NULL);
+		if (__hyp_get_vectors() == hyp_default_vectors)
+			cpu_init_hyp_mode(NULL);
 		break;
 	}
 
diff --git a/arch/arm/kvm/interrupts_head.S b/arch/arm/kvm/interrupts_head.S
index 98c8c5b9a87f..14d488388480 100644
--- a/arch/arm/kvm/interrupts_head.S
+++ b/arch/arm/kvm/interrupts_head.S
@@ -433,10 +433,17 @@ ARM_BE8(rev	r10, r10	)
 	str	r3, [r11, #VGIC_V2_CPU_HCR]
 	str	r4, [r11, #VGIC_V2_CPU_VMCR]
 	str	r5, [r11, #VGIC_V2_CPU_MISR]
+#ifdef CONFIG_CPU_ENDIAN_BE8
+	str	r6, [r11, #(VGIC_V2_CPU_EISR + 4)]
+	str	r7, [r11, #VGIC_V2_CPU_EISR]
+	str	r8, [r11, #(VGIC_V2_CPU_ELRSR + 4)]
+	str	r9, [r11, #VGIC_V2_CPU_ELRSR]
+#else
 	str	r6, [r11, #VGIC_V2_CPU_EISR]
 	str	r7, [r11, #(VGIC_V2_CPU_EISR + 4)]
 	str	r8, [r11, #VGIC_V2_CPU_ELRSR]
 	str	r9, [r11, #(VGIC_V2_CPU_ELRSR + 4)]
+#endif
 	str	r10, [r11, #VGIC_V2_CPU_APR]
 
 	/* Clear GICH_HCR */
diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c
index eea03069161b..57a403a5c22b 100644
--- a/arch/arm/kvm/mmu.c
+++ b/arch/arm/kvm/mmu.c
@@ -42,7 +42,7 @@ static unsigned long hyp_idmap_start;
 static unsigned long hyp_idmap_end;
 static phys_addr_t hyp_idmap_vector;
 
-#define pgd_order get_order(PTRS_PER_PGD * sizeof(pgd_t))
+#define hyp_pgd_order get_order(PTRS_PER_PGD * sizeof(pgd_t))
 
 #define kvm_pmd_huge(_x)	(pmd_huge(_x) || pmd_trans_huge(_x))
 
@@ -134,7 +134,7 @@ static void unmap_ptes(struct kvm *kvm, pmd_t *pmd,
 		}
 	} while (pte++, addr += PAGE_SIZE, addr != end);
 
-	if (kvm_pte_table_empty(start_pte))
+	if (kvm_pte_table_empty(kvm, start_pte))
 		clear_pmd_entry(kvm, pmd, start_addr);
 }
 
@@ -158,7 +158,7 @@ static void unmap_pmds(struct kvm *kvm, pud_t *pud,
 		}
 	} while (pmd++, addr = next, addr != end);
 
-	if (kvm_pmd_table_empty(start_pmd))
+	if (kvm_pmd_table_empty(kvm, start_pmd))
 		clear_pud_entry(kvm, pud, start_addr);
 }
 
@@ -182,7 +182,7 @@ static void unmap_puds(struct kvm *kvm, pgd_t *pgd,
 		}
 	} while (pud++, addr = next, addr != end);
 
-	if (kvm_pud_table_empty(start_pud))
+	if (kvm_pud_table_empty(kvm, start_pud))
 		clear_pgd_entry(kvm, pgd, start_addr);
 }
 
@@ -306,7 +306,7 @@ void free_boot_hyp_pgd(void)
 	if (boot_hyp_pgd) {
 		unmap_range(NULL, boot_hyp_pgd, hyp_idmap_start, PAGE_SIZE);
 		unmap_range(NULL, boot_hyp_pgd, TRAMPOLINE_VA, PAGE_SIZE);
-		free_pages((unsigned long)boot_hyp_pgd, pgd_order);
+		free_pages((unsigned long)boot_hyp_pgd, hyp_pgd_order);
 		boot_hyp_pgd = NULL;
 	}
 
@@ -343,7 +343,7 @@ void free_hyp_pgds(void)
 		for (addr = VMALLOC_START; is_vmalloc_addr((void*)addr); addr += PGDIR_SIZE)
 			unmap_range(NULL, hyp_pgd, KERN_TO_HYP(addr), PGDIR_SIZE);
 
-		free_pages((unsigned long)hyp_pgd, pgd_order);
+		free_pages((unsigned long)hyp_pgd, hyp_pgd_order);
 		hyp_pgd = NULL;
 	}
 
@@ -401,13 +401,46 @@ static int create_hyp_pmd_mappings(pud_t *pud, unsigned long start,
 	return 0;
 }
 
+static int create_hyp_pud_mappings(pgd_t *pgd, unsigned long start,
+				   unsigned long end, unsigned long pfn,
+				   pgprot_t prot)
+{
+	pud_t *pud;
+	pmd_t *pmd;
+	unsigned long addr, next;
+	int ret;
+
+	addr = start;
+	do {
+		pud = pud_offset(pgd, addr);
+
+		if (pud_none_or_clear_bad(pud)) {
+			pmd = pmd_alloc_one(NULL, addr);
+			if (!pmd) {
+				kvm_err("Cannot allocate Hyp pmd\n");
+				return -ENOMEM;
+			}
+			pud_populate(NULL, pud, pmd);
+			get_page(virt_to_page(pud));
+			kvm_flush_dcache_to_poc(pud, sizeof(*pud));
+		}
+
+		next = pud_addr_end(addr, end);
+		ret = create_hyp_pmd_mappings(pud, addr, next, pfn, prot);
+		if (ret)
+			return ret;
+		pfn += (next - addr) >> PAGE_SHIFT;
+	} while (addr = next, addr != end);
+
+	return 0;
+}
+
 static int __create_hyp_mappings(pgd_t *pgdp,
 				 unsigned long start, unsigned long end,
 				 unsigned long pfn, pgprot_t prot)
 {
 	pgd_t *pgd;
 	pud_t *pud;
-	pmd_t *pmd;
 	unsigned long addr, next;
 	int err = 0;
 
@@ -416,22 +449,21 @@ static int __create_hyp_mappings(pgd_t *pgdp,
 	end = PAGE_ALIGN(end);
 	do {
 		pgd = pgdp + pgd_index(addr);
-		pud = pud_offset(pgd, addr);
 
-		if (pud_none_or_clear_bad(pud)) {
-			pmd = pmd_alloc_one(NULL, addr);
-			if (!pmd) {
-				kvm_err("Cannot allocate Hyp pmd\n");
+		if (pgd_none(*pgd)) {
+			pud = pud_alloc_one(NULL, addr);
+			if (!pud) {
+				kvm_err("Cannot allocate Hyp pud\n");
 				err = -ENOMEM;
 				goto out;
 			}
-			pud_populate(NULL, pud, pmd);
-			get_page(virt_to_page(pud));
-			kvm_flush_dcache_to_poc(pud, sizeof(*pud));
+			pgd_populate(NULL, pgd, pud);
+			get_page(virt_to_page(pgd));
+			kvm_flush_dcache_to_poc(pgd, sizeof(*pgd));
 		}
 
 		next = pgd_addr_end(addr, end);
-		err = create_hyp_pmd_mappings(pud, addr, next, pfn, prot);
+		err = create_hyp_pud_mappings(pgd, addr, next, pfn, prot);
 		if (err)
 			goto out;
 		pfn += (next - addr) >> PAGE_SHIFT;
@@ -521,6 +553,7 @@ int create_hyp_io_mappings(void *from, void *to, phys_addr_t phys_addr)
  */
 int kvm_alloc_stage2_pgd(struct kvm *kvm)
 {
+	int ret;
 	pgd_t *pgd;
 
 	if (kvm->arch.pgd != NULL) {
@@ -528,15 +561,38 @@ int kvm_alloc_stage2_pgd(struct kvm *kvm)
 		return -EINVAL;
 	}
 
-	pgd = (pgd_t *)__get_free_pages(GFP_KERNEL, S2_PGD_ORDER);
+	if (KVM_PREALLOC_LEVEL > 0) {
+		/*
+		 * Allocate fake pgd for the page table manipulation macros to
+		 * work.  This is not used by the hardware and we have no
+		 * alignment requirement for this allocation.
+		 */
+		pgd = (pgd_t *)kmalloc(PTRS_PER_S2_PGD * sizeof(pgd_t),
+				       GFP_KERNEL | __GFP_ZERO);
+	} else {
+		/*
+		 * Allocate actual first-level Stage-2 page table used by the
+		 * hardware for Stage-2 page table walks.
+		 */
+		pgd = (pgd_t *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, S2_PGD_ORDER);
+	}
+
 	if (!pgd)
 		return -ENOMEM;
 
-	memset(pgd, 0, PTRS_PER_S2_PGD * sizeof(pgd_t));
+	ret = kvm_prealloc_hwpgd(kvm, pgd);
+	if (ret)
+		goto out_err;
+
 	kvm_clean_pgd(pgd);
 	kvm->arch.pgd = pgd;
-
 	return 0;
+out_err:
+	if (KVM_PREALLOC_LEVEL > 0)
+		kfree(pgd);
+	else
+		free_pages((unsigned long)pgd, S2_PGD_ORDER);
+	return ret;
 }
 
 /**
@@ -572,19 +628,39 @@ void kvm_free_stage2_pgd(struct kvm *kvm)
 		return;
 
 	unmap_stage2_range(kvm, 0, KVM_PHYS_SIZE);
-	free_pages((unsigned long)kvm->arch.pgd, S2_PGD_ORDER);
+	kvm_free_hwpgd(kvm);
+	if (KVM_PREALLOC_LEVEL > 0)
+		kfree(kvm->arch.pgd);
+	else
+		free_pages((unsigned long)kvm->arch.pgd, S2_PGD_ORDER);
 	kvm->arch.pgd = NULL;
 }
 
-static pmd_t *stage2_get_pmd(struct kvm *kvm, struct kvm_mmu_memory_cache *cache,
+static pud_t *stage2_get_pud(struct kvm *kvm, struct kvm_mmu_memory_cache *cache,
 			     phys_addr_t addr)
 {
 	pgd_t *pgd;
 	pud_t *pud;
-	pmd_t *pmd;
 
 	pgd = kvm->arch.pgd + pgd_index(addr);
-	pud = pud_offset(pgd, addr);
+	if (WARN_ON(pgd_none(*pgd))) {
+		if (!cache)
+			return NULL;
+		pud = mmu_memory_cache_alloc(cache);
+		pgd_populate(NULL, pgd, pud);
+		get_page(virt_to_page(pgd));
+	}
+
+	return pud_offset(pgd, addr);
+}
+
+static pmd_t *stage2_get_pmd(struct kvm *kvm, struct kvm_mmu_memory_cache *cache,
+			     phys_addr_t addr)
+{
+	pud_t *pud;
+	pmd_t *pmd;
+
+	pud = stage2_get_pud(kvm, cache, addr);
 	if (pud_none(*pud)) {
 		if (!cache)
 			return NULL;
@@ -630,7 +706,7 @@ static int stage2_set_pte(struct kvm *kvm, struct kvm_mmu_memory_cache *cache,
 	pmd_t *pmd;
 	pte_t *pte, old_pte;
 
-	/* Create stage-2 page table mapping - Level 1 */
+	/* Create stage-2 page table mapping - Levels 0 and 1 */
 	pmd = stage2_get_pmd(kvm, cache, addr);
 	if (!pmd) {
 		/*
@@ -675,7 +751,7 @@ static int stage2_set_pte(struct kvm *kvm, struct kvm_mmu_memory_cache *cache,
  * @size:	The size of the mapping
  */
 int kvm_phys_addr_ioremap(struct kvm *kvm, phys_addr_t guest_ipa,
-			  phys_addr_t pa, unsigned long size)
+			  phys_addr_t pa, unsigned long size, bool writable)
 {
 	phys_addr_t addr, end;
 	int ret = 0;
@@ -688,7 +764,11 @@ int kvm_phys_addr_ioremap(struct kvm *kvm, phys_addr_t guest_ipa,
 	for (addr = guest_ipa; addr < end; addr += PAGE_SIZE) {
 		pte_t pte = pfn_pte(pfn, PAGE_S2_DEVICE);
 
-		ret = mmu_topup_memory_cache(&cache, 2, 2);
+		if (writable)
+			kvm_set_s2pte_writable(&pte);
+
+		ret = mmu_topup_memory_cache(&cache, KVM_MMU_CACHE_MIN_PAGES,
+						KVM_NR_MEM_OBJS);
 		if (ret)
 			goto out;
 		spin_lock(&kvm->mmu_lock);
@@ -777,6 +857,12 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
 	/* Let's check if we will get back a huge page backed by hugetlbfs */
 	down_read(&current->mm->mmap_sem);
 	vma = find_vma_intersection(current->mm, hva, hva + 1);
+	if (unlikely(!vma)) {
+		kvm_err("Failed to find VMA for hva 0x%lx\n", hva);
+		up_read(&current->mm->mmap_sem);
+		return -EFAULT;
+	}
+
 	if (is_vm_hugetlb_page(vma)) {
 		hugetlb = true;
 		gfn = (fault_ipa & PMD_MASK) >> PAGE_SHIFT;
@@ -797,7 +883,8 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
 	up_read(&current->mm->mmap_sem);
 
 	/* We need minimum second+third level pages */
-	ret = mmu_topup_memory_cache(memcache, 2, KVM_NR_MEM_OBJS);
+	ret = mmu_topup_memory_cache(memcache, KVM_MMU_CACHE_MIN_PAGES,
+				     KVM_NR_MEM_OBJS);
 	if (ret)
 		return ret;
 
@@ -843,7 +930,7 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
 		}
 		coherent_cache_guest_page(vcpu, hva, PAGE_SIZE);
 		ret = stage2_set_pte(kvm, memcache, fault_ipa, &new_pte,
-				     mem_type == PAGE_S2_DEVICE);
+			pgprot_val(mem_type) == pgprot_val(PAGE_S2_DEVICE));
 	}
 
 
@@ -916,6 +1003,9 @@ int kvm_handle_guest_abort(struct kvm_vcpu *vcpu, struct kvm_run *run)
 		goto out_unlock;
 	}
 
+	/* Userspace should not be able to register out-of-bounds IPAs */
+	VM_BUG_ON(fault_ipa >= KVM_PHYS_SIZE);
+
 	ret = user_mem_abort(vcpu, fault_ipa, memslot, hva, fault_status);
 	if (ret == 0)
 		ret = 1;
@@ -1072,8 +1162,8 @@ int kvm_mmu_init(void)
 			 (unsigned long)phys_base);
 	}
 
-	hyp_pgd = (pgd_t *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, pgd_order);
-	boot_hyp_pgd = (pgd_t *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, pgd_order);
+	hyp_pgd = (pgd_t *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, hyp_pgd_order);
+	boot_hyp_pgd = (pgd_t *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, hyp_pgd_order);
 
 	if (!hyp_pgd || !boot_hyp_pgd) {
 		kvm_err("Hyp mode PGD not allocated\n");
@@ -1126,13 +1216,6 @@ void kvm_arch_commit_memory_region(struct kvm *kvm,
 				   const struct kvm_memory_slot *old,
 				   enum kvm_mr_change change)
 {
-	gpa_t gpa = old->base_gfn << PAGE_SHIFT;
-	phys_addr_t size = old->npages << PAGE_SHIFT;
-	if (change == KVM_MR_DELETE || change == KVM_MR_MOVE) {
-		spin_lock(&kvm->mmu_lock);
-		unmap_stage2_range(kvm, gpa, size);
-		spin_unlock(&kvm->mmu_lock);
-	}
 }
 
 int kvm_arch_prepare_memory_region(struct kvm *kvm,
@@ -1140,7 +1223,77 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm,
 				   struct kvm_userspace_memory_region *mem,
 				   enum kvm_mr_change change)
 {
-	return 0;
+	hva_t hva = mem->userspace_addr;
+	hva_t reg_end = hva + mem->memory_size;
+	bool writable = !(mem->flags & KVM_MEM_READONLY);
+	int ret = 0;
+
+	if (change != KVM_MR_CREATE && change != KVM_MR_MOVE)
+		return 0;
+
+	/*
+	 * Prevent userspace from creating a memory region outside of the IPA
+	 * space addressable by the KVM guest IPA space.
+	 */
+	if (memslot->base_gfn + memslot->npages >=
+	    (KVM_PHYS_SIZE >> PAGE_SHIFT))
+		return -EFAULT;
+
+	/*
+	 * A memory region could potentially cover multiple VMAs, and any holes
+	 * between them, so iterate over all of them to find out if we can map
+	 * any of them right now.
+	 *
+	 *     +--------------------------------------------+
+	 * +---------------+----------------+   +----------------+
+	 * |   : VMA 1     |      VMA 2     |   |    VMA 3  :    |
+	 * +---------------+----------------+   +----------------+
+	 *     |               memory region                |
+	 *     +--------------------------------------------+
+	 */
+	do {
+		struct vm_area_struct *vma = find_vma(current->mm, hva);
+		hva_t vm_start, vm_end;
+
+		if (!vma || vma->vm_start >= reg_end)
+			break;
+
+		/*
+		 * Mapping a read-only VMA is only allowed if the
+		 * memory region is configured as read-only.
+		 */
+		if (writable && !(vma->vm_flags & VM_WRITE)) {
+			ret = -EPERM;
+			break;
+		}
+
+		/*
+		 * Take the intersection of this VMA with the memory region
+		 */
+		vm_start = max(hva, vma->vm_start);
+		vm_end = min(reg_end, vma->vm_end);
+
+		if (vma->vm_flags & VM_PFNMAP) {
+			gpa_t gpa = mem->guest_phys_addr +
+				    (vm_start - mem->userspace_addr);
+			phys_addr_t pa = (vma->vm_pgoff << PAGE_SHIFT) +
+					 vm_start - vma->vm_start;
+
+			ret = kvm_phys_addr_ioremap(kvm, gpa, pa,
+						    vm_end - vm_start,
+						    writable);
+			if (ret)
+				break;
+		}
+		hva = vm_end;
+	} while (hva < reg_end);
+
+	if (ret) {
+		spin_lock(&kvm->mmu_lock);
+		unmap_stage2_range(kvm, mem->guest_phys_addr, mem->memory_size);
+		spin_unlock(&kvm->mmu_lock);
+	}
+	return ret;
 }
 
 void kvm_arch_free_memslot(struct kvm *kvm, struct kvm_memory_slot *free,
@@ -1165,4 +1318,10 @@ void kvm_arch_flush_shadow_all(struct kvm *kvm)
 void kvm_arch_flush_shadow_memslot(struct kvm *kvm,
 				   struct kvm_memory_slot *slot)
 {
+	gpa_t gpa = slot->base_gfn << PAGE_SHIFT;
+	phys_addr_t size = slot->npages << PAGE_SHIFT;
+
+	spin_lock(&kvm->mmu_lock);
+	unmap_stage2_range(kvm, gpa, size);
+	spin_unlock(&kvm->mmu_lock);
 }