diff options
Diffstat (limited to 'arch/arm64/kvm/mmu.c')
| -rw-r--r-- | arch/arm64/kvm/mmu.c | 2798 |
1 files changed, 2798 insertions, 0 deletions
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c new file mode 100644 index 000000000..9ba86450f --- /dev/null +++ b/arch/arm64/kvm/mmu.c @@ -0,0 +1,2798 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2012 - Virtual Open Systems and Columbia University + * Author: Christoffer Dall <c.dall@virtualopensystems.com> + */ + +#include <linux/acpi.h> +#include <linux/mman.h> +#include <linux/kvm_host.h> +#include <linux/io.h> +#include <linux/hugetlb.h> +#include <linux/sched/signal.h> +#include <trace/events/kvm.h> +#include <asm/acpi.h> +#include <asm/pgalloc.h> +#include <asm/cacheflush.h> +#include <asm/kvm_arm.h> +#include <asm/kvm_mmu.h> +#include <asm/kvm_pgtable.h> +#include <asm/kvm_pkvm.h> +#include <asm/kvm_asm.h> +#include <asm/kvm_emulate.h> +#include <asm/virt.h> + +#include "trace.h" + +static struct kvm_pgtable *hyp_pgtable; +static DEFINE_MUTEX(kvm_hyp_pgd_mutex); + +static unsigned long __ro_after_init hyp_idmap_start; +static unsigned long __ro_after_init hyp_idmap_end; +static phys_addr_t __ro_after_init hyp_idmap_vector; + +u32 __ro_after_init __hyp_va_bits; + +static unsigned long __ro_after_init io_map_base; + +#define KVM_PGT_FN(fn) (!is_protected_kvm_enabled() ? fn : p ## fn) + +static phys_addr_t __stage2_range_addr_end(phys_addr_t addr, phys_addr_t end, + phys_addr_t size) +{ + phys_addr_t boundary = ALIGN_DOWN(addr + size, size); + + return (boundary - 1 < end - 1) ? boundary : end; +} + +static phys_addr_t stage2_range_addr_end(phys_addr_t addr, phys_addr_t end) +{ + phys_addr_t size = kvm_granule_size(KVM_PGTABLE_MIN_BLOCK_LEVEL); + + return __stage2_range_addr_end(addr, end, size); +} + +/* + * Release kvm_mmu_lock periodically if the memory region is large. Otherwise, + * we may see kernel panics with CONFIG_DETECT_HUNG_TASK, + * CONFIG_LOCKUP_DETECTOR, CONFIG_LOCKDEP. Additionally, holding the lock too + * long will also starve other vCPUs. We have to also make sure that the page + * tables are not freed while we released the lock. + */ +static int stage2_apply_range(struct kvm_s2_mmu *mmu, phys_addr_t addr, + phys_addr_t end, + int (*fn)(struct kvm_pgtable *, u64, u64), + bool resched) +{ + struct kvm *kvm = kvm_s2_mmu_to_kvm(mmu); + int ret; + u64 next; + + do { + struct kvm_pgtable *pgt = mmu->pgt; + if (!pgt) + return -EINVAL; + + next = stage2_range_addr_end(addr, end); + ret = fn(pgt, addr, next - addr); + if (ret) + break; + + if (resched && next != end) + cond_resched_rwlock_write(&kvm->mmu_lock); + } while (addr = next, addr != end); + + return ret; +} + +#define stage2_apply_range_resched(mmu, addr, end, fn) \ + stage2_apply_range(mmu, addr, end, fn, true) + +/* + * Get the maximum number of page-tables pages needed to split a range + * of blocks into PAGE_SIZE PTEs. It assumes the range is already + * mapped at level 2, or at level 1 if allowed. + */ +static int kvm_mmu_split_nr_page_tables(u64 range) +{ + int n = 0; + + if (KVM_PGTABLE_MIN_BLOCK_LEVEL < 2) + n += DIV_ROUND_UP(range, PUD_SIZE); + n += DIV_ROUND_UP(range, PMD_SIZE); + return n; +} + +static bool need_split_memcache_topup_or_resched(struct kvm *kvm) +{ + struct kvm_mmu_memory_cache *cache; + u64 chunk_size, min; + + if (need_resched() || rwlock_needbreak(&kvm->mmu_lock)) + return true; + + chunk_size = kvm->arch.mmu.split_page_chunk_size; + min = kvm_mmu_split_nr_page_tables(chunk_size); + cache = &kvm->arch.mmu.split_page_cache; + return kvm_mmu_memory_cache_nr_free_objects(cache) < min; +} + +static int kvm_mmu_split_huge_pages(struct kvm *kvm, phys_addr_t addr, + phys_addr_t end) +{ + struct kvm_mmu_memory_cache *cache; + struct kvm_pgtable *pgt; + int ret, cache_capacity; + u64 next, chunk_size; + + lockdep_assert_held_write(&kvm->mmu_lock); + + chunk_size = kvm->arch.mmu.split_page_chunk_size; + cache_capacity = kvm_mmu_split_nr_page_tables(chunk_size); + + if (chunk_size == 0) + return 0; + + cache = &kvm->arch.mmu.split_page_cache; + + do { + if (need_split_memcache_topup_or_resched(kvm)) { + write_unlock(&kvm->mmu_lock); + cond_resched(); + /* Eager page splitting is best-effort. */ + ret = __kvm_mmu_topup_memory_cache(cache, + cache_capacity, + cache_capacity); + write_lock(&kvm->mmu_lock); + if (ret) + break; + } + + pgt = kvm->arch.mmu.pgt; + if (!pgt) + return -EINVAL; + + next = __stage2_range_addr_end(addr, end, chunk_size); + ret = KVM_PGT_FN(kvm_pgtable_stage2_split)(pgt, addr, next - addr, cache); + if (ret) + break; + } while (addr = next, addr != end); + + return ret; +} + +static bool memslot_is_logging(struct kvm_memory_slot *memslot) +{ + return memslot->dirty_bitmap && !(memslot->flags & KVM_MEM_READONLY); +} + +/** + * kvm_arch_flush_remote_tlbs() - flush all VM TLB entries for v7/8 + * @kvm: pointer to kvm structure. + * + * Interface to HYP function to flush all VM TLB entries + */ +int kvm_arch_flush_remote_tlbs(struct kvm *kvm) +{ + if (is_protected_kvm_enabled()) + kvm_call_hyp_nvhe(__pkvm_tlb_flush_vmid, kvm->arch.pkvm.handle); + else + kvm_call_hyp(__kvm_tlb_flush_vmid, &kvm->arch.mmu); + return 0; +} + +int kvm_arch_flush_remote_tlbs_range(struct kvm *kvm, + gfn_t gfn, u64 nr_pages) +{ + u64 size = nr_pages << PAGE_SHIFT; + u64 addr = gfn << PAGE_SHIFT; + + if (is_protected_kvm_enabled()) + kvm_call_hyp_nvhe(__pkvm_tlb_flush_vmid, kvm->arch.pkvm.handle); + else + kvm_tlb_flush_vmid_range(&kvm->arch.mmu, addr, size); + return 0; +} + +static void *stage2_memcache_zalloc_page(void *arg) +{ + struct kvm_mmu_memory_cache *mc = arg; + void *virt; + + /* Allocated with __GFP_ZERO, so no need to zero */ + virt = kvm_mmu_memory_cache_alloc(mc); + if (virt) + kvm_account_pgtable_pages(virt, 1); + return virt; +} + +static void *kvm_host_zalloc_pages_exact(size_t size) +{ + return alloc_pages_exact(size, GFP_KERNEL_ACCOUNT | __GFP_ZERO); +} + +static void *kvm_s2_zalloc_pages_exact(size_t size) +{ + void *virt = kvm_host_zalloc_pages_exact(size); + + if (virt) + kvm_account_pgtable_pages(virt, (size >> PAGE_SHIFT)); + return virt; +} + +static void kvm_s2_free_pages_exact(void *virt, size_t size) +{ + kvm_account_pgtable_pages(virt, -(size >> PAGE_SHIFT)); + free_pages_exact(virt, size); +} + +static struct kvm_pgtable_mm_ops kvm_s2_mm_ops; + +static void stage2_free_unlinked_table_rcu_cb(struct rcu_head *head) +{ + struct page *page = container_of(head, struct page, rcu_head); + void *pgtable = page_to_virt(page); + s8 level = page_private(page); + + KVM_PGT_FN(kvm_pgtable_stage2_free_unlinked)(&kvm_s2_mm_ops, pgtable, level); +} + +static void stage2_free_unlinked_table(void *addr, s8 level) +{ + struct page *page = virt_to_page(addr); + + set_page_private(page, (unsigned long)level); + call_rcu(&page->rcu_head, stage2_free_unlinked_table_rcu_cb); +} + +static void kvm_host_get_page(void *addr) +{ + get_page(virt_to_page(addr)); +} + +static void kvm_host_put_page(void *addr) +{ + put_page(virt_to_page(addr)); +} + +static void kvm_s2_put_page(void *addr) +{ + struct page *p = virt_to_page(addr); + /* Dropping last refcount, the page will be freed */ + if (page_count(p) == 1) + kvm_account_pgtable_pages(addr, -1); + put_page(p); +} + +static int kvm_host_page_count(void *addr) +{ + return page_count(virt_to_page(addr)); +} + +static phys_addr_t kvm_host_pa(void *addr) +{ + return __pa(addr); +} + +static void *kvm_host_va(phys_addr_t phys) +{ + return __va(phys); +} + +static void clean_dcache_guest_page(void *va, size_t size) +{ + __clean_dcache_guest_page(va, size); +} + +static void invalidate_icache_guest_page(void *va, size_t size) +{ + __invalidate_icache_guest_page(va, size); +} + +/* + * Unmapping vs dcache management: + * + * If a guest maps certain memory pages as uncached, all writes will + * bypass the data cache and go directly to RAM. However, the CPUs + * can still speculate reads (not writes) and fill cache lines with + * data. + * + * Those cache lines will be *clean* cache lines though, so a + * clean+invalidate operation is equivalent to an invalidate + * operation, because no cache lines are marked dirty. + * + * Those clean cache lines could be filled prior to an uncached write + * by the guest, and the cache coherent IO subsystem would therefore + * end up writing old data to disk. + * + * This is why right after unmapping a page/section and invalidating + * the corresponding TLBs, we flush to make sure the IO subsystem will + * never hit in the cache. + * + * This is all avoided on systems that have ARM64_HAS_STAGE2_FWB, as + * we then fully enforce cacheability of RAM, no matter what the guest + * does. + */ +/** + * __unmap_stage2_range -- Clear stage2 page table entries to unmap a range + * @mmu: The KVM stage-2 MMU pointer + * @start: The intermediate physical base address of the range to unmap + * @size: The size of the area to unmap + * @may_block: Whether or not we are permitted to block + * + * Clear a range of stage-2 mappings, lowering the various ref-counts. Must + * be called while holding mmu_lock (unless for freeing the stage2 pgd before + * destroying the VM), otherwise another faulting VCPU may come in and mess + * with things behind our backs. + */ +static void __unmap_stage2_range(struct kvm_s2_mmu *mmu, phys_addr_t start, u64 size, + bool may_block) +{ + struct kvm *kvm = kvm_s2_mmu_to_kvm(mmu); + phys_addr_t end = start + size; + + lockdep_assert_held_write(&kvm->mmu_lock); + WARN_ON(size & ~PAGE_MASK); + WARN_ON(stage2_apply_range(mmu, start, end, KVM_PGT_FN(kvm_pgtable_stage2_unmap), + may_block)); +} + +void kvm_stage2_unmap_range(struct kvm_s2_mmu *mmu, phys_addr_t start, + u64 size, bool may_block) +{ + if (kvm_vm_is_protected(kvm_s2_mmu_to_kvm(mmu))) + return; + + __unmap_stage2_range(mmu, start, size, may_block); +} + +void kvm_stage2_flush_range(struct kvm_s2_mmu *mmu, phys_addr_t addr, phys_addr_t end) +{ + stage2_apply_range_resched(mmu, addr, end, KVM_PGT_FN(kvm_pgtable_stage2_flush)); +} + +static void stage2_flush_memslot(struct kvm *kvm, + struct kvm_memory_slot *memslot) +{ + phys_addr_t addr = memslot->base_gfn << PAGE_SHIFT; + phys_addr_t end = addr + PAGE_SIZE * memslot->npages; + + kvm_stage2_flush_range(&kvm->arch.mmu, addr, end); +} + +/** + * stage2_flush_vm - Invalidate cache for pages mapped in stage 2 + * @kvm: The struct kvm pointer + * + * Go through the stage 2 page tables and invalidate any cache lines + * backing memory already mapped to the VM. + */ +static void stage2_flush_vm(struct kvm *kvm) +{ + struct kvm_memslots *slots; + struct kvm_memory_slot *memslot; + int idx, bkt; + + idx = srcu_read_lock(&kvm->srcu); + write_lock(&kvm->mmu_lock); + + slots = kvm_memslots(kvm); + kvm_for_each_memslot(memslot, bkt, slots) + stage2_flush_memslot(kvm, memslot); + + kvm_nested_s2_flush(kvm); + + write_unlock(&kvm->mmu_lock); + srcu_read_unlock(&kvm->srcu, idx); +} + +/** + * free_hyp_pgds - free Hyp-mode page tables + */ +void __init free_hyp_pgds(void) +{ + mutex_lock(&kvm_hyp_pgd_mutex); + if (hyp_pgtable) { + kvm_pgtable_hyp_destroy(hyp_pgtable); + kfree(hyp_pgtable); + hyp_pgtable = NULL; + } + mutex_unlock(&kvm_hyp_pgd_mutex); +} + +static bool kvm_host_owns_hyp_mappings(void) +{ + if (is_kernel_in_hyp_mode()) + return false; + + if (static_branch_likely(&kvm_protected_mode_initialized)) + return false; + + /* + * This can happen at boot time when __create_hyp_mappings() is called + * after the hyp protection has been enabled, but the static key has + * not been flipped yet. + */ + if (!hyp_pgtable && is_protected_kvm_enabled()) + return false; + + WARN_ON(!hyp_pgtable); + + return true; +} + +int __create_hyp_mappings(unsigned long start, unsigned long size, + unsigned long phys, enum kvm_pgtable_prot prot) +{ + int err; + + if (WARN_ON(!kvm_host_owns_hyp_mappings())) + return -EINVAL; + + mutex_lock(&kvm_hyp_pgd_mutex); + err = kvm_pgtable_hyp_map(hyp_pgtable, start, size, phys, prot); + mutex_unlock(&kvm_hyp_pgd_mutex); + + return err; +} + +static phys_addr_t kvm_kaddr_to_phys(void *kaddr) +{ + if (!is_vmalloc_addr(kaddr)) { + BUG_ON(!virt_addr_valid(kaddr)); + return __pa(kaddr); + } else { + return page_to_phys(vmalloc_to_page(kaddr)) + + offset_in_page(kaddr); + } +} + +struct hyp_shared_pfn { + u64 pfn; + int count; + struct rb_node node; +}; + +static DEFINE_MUTEX(hyp_shared_pfns_lock); +static struct rb_root hyp_shared_pfns = RB_ROOT; + +static struct hyp_shared_pfn *find_shared_pfn(u64 pfn, struct rb_node ***node, + struct rb_node **parent) +{ + struct hyp_shared_pfn *this; + + *node = &hyp_shared_pfns.rb_node; + *parent = NULL; + while (**node) { + this = container_of(**node, struct hyp_shared_pfn, node); + *parent = **node; + if (this->pfn < pfn) + *node = &((**node)->rb_left); + else if (this->pfn > pfn) + *node = &((**node)->rb_right); + else + return this; + } + + return NULL; +} + +static int share_pfn_hyp(u64 pfn) +{ + struct rb_node **node, *parent; + struct hyp_shared_pfn *this; + int ret = 0; + + mutex_lock(&hyp_shared_pfns_lock); + this = find_shared_pfn(pfn, &node, &parent); + if (this) { + this->count++; + goto unlock; + } + + this = kzalloc_obj(*this); + if (!this) { + ret = -ENOMEM; + goto unlock; + } + + this->pfn = pfn; + this->count = 1; + rb_link_node(&this->node, parent, node); + rb_insert_color(&this->node, &hyp_shared_pfns); + ret = kvm_call_hyp_nvhe(__pkvm_host_share_hyp, pfn); + if (ret) { + rb_erase(&this->node, &hyp_shared_pfns); + kfree(this); + } +unlock: + mutex_unlock(&hyp_shared_pfns_lock); + + return ret; +} + +static int unshare_pfn_hyp(u64 pfn) +{ + struct rb_node **node, *parent; + struct hyp_shared_pfn *this; + int ret = 0; + + mutex_lock(&hyp_shared_pfns_lock); + this = find_shared_pfn(pfn, &node, &parent); + if (WARN_ON(!this)) { + ret = -ENOENT; + goto unlock; + } + + if (this->count > 1) { + this->count--; + goto unlock; + } + + ret = kvm_call_hyp_nvhe(__pkvm_host_unshare_hyp, pfn); + if (ret) + goto unlock; + + rb_erase(&this->node, &hyp_shared_pfns); + kfree(this); +unlock: + mutex_unlock(&hyp_shared_pfns_lock); + + return ret; +} + +int kvm_share_hyp(void *from, void *to) +{ + phys_addr_t start, end, cur; + int ret = 0; + u64 pfn; + + if (is_kernel_in_hyp_mode()) + return 0; + + /* + * The share hcall maps things in the 'fixed-offset' region of the hyp + * VA space, so we can only share physically contiguous data-structures + * for now. + */ + if (is_vmalloc_or_module_addr(from) || is_vmalloc_or_module_addr(to)) + return -EINVAL; + + if (kvm_host_owns_hyp_mappings()) + return create_hyp_mappings(from, to, PAGE_HYP); + + start = ALIGN_DOWN(__pa(from), PAGE_SIZE); + end = PAGE_ALIGN(__pa(to)); + for (cur = start; cur < end; cur += PAGE_SIZE) { + pfn = __phys_to_pfn(cur); + ret = share_pfn_hyp(pfn); + if (ret) + break; + } + + if (!ret) + return 0; + + /* + * Roll back the pages shared by this call. A failed unshare leaks + * the page (it stays shared with the hypervisor and is no longer + * reusable for pKVM) but breaks no isolation guarantee, so warn and + * continue. Not expected in practice. + */ + for (end = cur, cur = start; cur < end; cur += PAGE_SIZE) { + pfn = __phys_to_pfn(cur); + WARN_ON(unshare_pfn_hyp(pfn)); + } + + return ret; +} + +void kvm_unshare_hyp(void *from, void *to) +{ + phys_addr_t start, end, cur; + u64 pfn; + + if (is_kernel_in_hyp_mode() || kvm_host_owns_hyp_mappings() || !from) + return; + + start = ALIGN_DOWN(__pa(from), PAGE_SIZE); + end = PAGE_ALIGN(__pa(to)); + for (cur = start; cur < end; cur += PAGE_SIZE) { + pfn = __phys_to_pfn(cur); + /* + * A failed unshare leaks the page: it stays shared with the + * hypervisor and is no longer reusable for pKVM. No isolation + * guarantee is broken, and this is not expected in practice. + */ + WARN_ON(unshare_pfn_hyp(pfn)); + } +} + +/** + * create_hyp_mappings - duplicate a kernel virtual address range in Hyp mode + * @from: The virtual kernel start address of the range + * @to: The virtual kernel end address of the range (exclusive) + * @prot: The protection to be applied to this range + * + * The same virtual address as the kernel virtual address is also used + * in Hyp-mode mapping (modulo HYP_PAGE_OFFSET) to the same underlying + * physical pages. + */ +int create_hyp_mappings(void *from, void *to, enum kvm_pgtable_prot prot) +{ + phys_addr_t phys_addr; + unsigned long virt_addr; + unsigned long start = kern_hyp_va((unsigned long)from); + unsigned long end = kern_hyp_va((unsigned long)to); + + if (is_kernel_in_hyp_mode()) + return 0; + + if (!kvm_host_owns_hyp_mappings()) + return -EPERM; + + start = start & PAGE_MASK; + end = PAGE_ALIGN(end); + + for (virt_addr = start; virt_addr < end; virt_addr += PAGE_SIZE) { + int err; + + phys_addr = kvm_kaddr_to_phys(from + virt_addr - start); + err = __create_hyp_mappings(virt_addr, PAGE_SIZE, phys_addr, + prot); + if (err) + return err; + } + + return 0; +} + +static int __hyp_alloc_private_va_range(unsigned long base) +{ + lockdep_assert_held(&kvm_hyp_pgd_mutex); + + if (!PAGE_ALIGNED(base)) + return -EINVAL; + + /* + * Verify that BIT(VA_BITS - 1) hasn't been flipped by + * allocating the new area, as it would indicate we've + * overflowed the idmap/IO address range. + */ + if ((base ^ io_map_base) & BIT(VA_BITS - 1)) + return -ENOMEM; + + io_map_base = base; + + return 0; +} + +/** + * hyp_alloc_private_va_range - Allocates a private VA range. + * @size: The size of the VA range to reserve. + * @haddr: The hypervisor virtual start address of the allocation. + * + * The private virtual address (VA) range is allocated below io_map_base + * and aligned based on the order of @size. + * + * Return: 0 on success or negative error code on failure. + */ +int hyp_alloc_private_va_range(size_t size, unsigned long *haddr) +{ + unsigned long base; + int ret = 0; + + mutex_lock(&kvm_hyp_pgd_mutex); + + /* + * This assumes that we have enough space below the idmap + * page to allocate our VAs. If not, the check in + * __hyp_alloc_private_va_range() will kick. A potential + * alternative would be to detect that overflow and switch + * to an allocation above the idmap. + * + * The allocated size is always a multiple of PAGE_SIZE. + */ + size = PAGE_ALIGN(size); + base = io_map_base - size; + ret = __hyp_alloc_private_va_range(base); + + mutex_unlock(&kvm_hyp_pgd_mutex); + + if (!ret) + *haddr = base; + + return ret; +} + +static int __create_hyp_private_mapping(phys_addr_t phys_addr, size_t size, + unsigned long *haddr, + enum kvm_pgtable_prot prot) +{ + unsigned long addr; + int ret = 0; + + if (!kvm_host_owns_hyp_mappings()) { + addr = kvm_call_hyp_nvhe(__pkvm_create_private_mapping, + phys_addr, size, prot); + if (IS_ERR_VALUE(addr)) + return addr; + *haddr = addr; + + return 0; + } + + size = PAGE_ALIGN(size + offset_in_page(phys_addr)); + ret = hyp_alloc_private_va_range(size, &addr); + if (ret) + return ret; + + ret = __create_hyp_mappings(addr, size, phys_addr, prot); + if (ret) + return ret; + + *haddr = addr + offset_in_page(phys_addr); + return ret; +} + +int create_hyp_stack(phys_addr_t phys_addr, unsigned long *haddr) +{ + unsigned long base; + size_t size; + int ret; + + mutex_lock(&kvm_hyp_pgd_mutex); + /* + * Efficient stack verification using the NVHE_STACK_SHIFT bit implies + * an alignment of our allocation on the order of the size. + */ + size = NVHE_STACK_SIZE * 2; + base = ALIGN_DOWN(io_map_base - size, size); + + ret = __hyp_alloc_private_va_range(base); + + mutex_unlock(&kvm_hyp_pgd_mutex); + + if (ret) { + kvm_err("Cannot allocate hyp stack guard page\n"); + return ret; + } + + /* + * Since the stack grows downwards, map the stack to the page + * at the higher address and leave the lower guard page + * unbacked. + * + * Any valid stack address now has the NVHE_STACK_SHIFT bit as 1 + * and addresses corresponding to the guard page have the + * NVHE_STACK_SHIFT bit as 0 - this is used for overflow detection. + */ + ret = __create_hyp_mappings(base + NVHE_STACK_SIZE, NVHE_STACK_SIZE, + phys_addr, PAGE_HYP); + if (ret) + kvm_err("Cannot map hyp stack\n"); + + *haddr = base + size; + + return ret; +} + +/** + * create_hyp_io_mappings - Map IO into both kernel and HYP + * @phys_addr: The physical start address which gets mapped + * @size: Size of the region being mapped + * @kaddr: Kernel VA for this mapping + * @haddr: HYP VA for this mapping + */ +int create_hyp_io_mappings(phys_addr_t phys_addr, size_t size, + void __iomem **kaddr, + void __iomem **haddr) +{ + unsigned long addr; + int ret; + + if (is_protected_kvm_enabled()) + return -EPERM; + + *kaddr = ioremap(phys_addr, size); + if (!*kaddr) + return -ENOMEM; + + if (is_kernel_in_hyp_mode()) { + *haddr = *kaddr; + return 0; + } + + ret = __create_hyp_private_mapping(phys_addr, size, + &addr, PAGE_HYP_DEVICE); + if (ret) { + iounmap(*kaddr); + *kaddr = NULL; + *haddr = NULL; + return ret; + } + + *haddr = (void __iomem *)addr; + return 0; +} + +/** + * create_hyp_exec_mappings - Map an executable range into HYP + * @phys_addr: The physical start address which gets mapped + * @size: Size of the region being mapped + * @haddr: HYP VA for this mapping + */ +int create_hyp_exec_mappings(phys_addr_t phys_addr, size_t size, + void **haddr) +{ + unsigned long addr; + int ret; + + BUG_ON(is_kernel_in_hyp_mode()); + + ret = __create_hyp_private_mapping(phys_addr, size, + &addr, PAGE_HYP_EXEC); + if (ret) { + *haddr = NULL; + return ret; + } + + *haddr = (void *)addr; + return 0; +} + +static struct kvm_pgtable_mm_ops kvm_user_mm_ops = { + /* We shouldn't need any other callback to walk the PT */ + .phys_to_virt = kvm_host_va, +}; + +static int get_user_mapping_size(struct kvm *kvm, u64 addr) +{ + struct kvm_pgtable pgt = { + .pgd = (kvm_pteref_t)kvm->mm->pgd, + .ia_bits = vabits_actual, + .start_level = (KVM_PGTABLE_LAST_LEVEL - + ARM64_HW_PGTABLE_LEVELS(pgt.ia_bits) + 1), + .mm_ops = &kvm_user_mm_ops, + }; + unsigned long flags; + kvm_pte_t pte = 0; /* Keep GCC quiet... */ + s8 level = S8_MAX; + int ret; + + /* + * Disable IRQs so that we hazard against a concurrent + * teardown of the userspace page tables (which relies on + * IPI-ing threads). + */ + local_irq_save(flags); + ret = kvm_pgtable_get_leaf(&pgt, addr, &pte, &level); + local_irq_restore(flags); + + if (ret) + return ret; + + /* + * Not seeing an error, but not updating level? Something went + * deeply wrong... + */ + if (WARN_ON(level > KVM_PGTABLE_LAST_LEVEL)) + return -EFAULT; + if (WARN_ON(level < KVM_PGTABLE_FIRST_LEVEL)) + return -EFAULT; + + /* Oops, the userspace PTs are gone... Replay the fault */ + if (!kvm_pte_valid(pte)) + return -EAGAIN; + + return BIT(ARM64_HW_PGTABLE_LEVEL_SHIFT(level)); +} + +static struct kvm_pgtable_mm_ops kvm_s2_mm_ops = { + .zalloc_page = stage2_memcache_zalloc_page, + .zalloc_pages_exact = kvm_s2_zalloc_pages_exact, + .free_pages_exact = kvm_s2_free_pages_exact, + .free_unlinked_table = stage2_free_unlinked_table, + .get_page = kvm_host_get_page, + .put_page = kvm_s2_put_page, + .page_count = kvm_host_page_count, + .phys_to_virt = kvm_host_va, + .virt_to_phys = kvm_host_pa, + .dcache_clean_inval_poc = clean_dcache_guest_page, + .icache_inval_pou = invalidate_icache_guest_page, +}; + +static int kvm_init_ipa_range(struct kvm_s2_mmu *mmu, unsigned long type) +{ + u32 kvm_ipa_limit = get_kvm_ipa_limit(); + u64 mmfr0, mmfr1; + u32 phys_shift; + + phys_shift = KVM_VM_TYPE_ARM_IPA_SIZE(type); + if (is_protected_kvm_enabled()) { + phys_shift = kvm_ipa_limit; + } else if (phys_shift) { + if (phys_shift > kvm_ipa_limit || + phys_shift < ARM64_MIN_PARANGE_BITS) + return -EINVAL; + } else { + phys_shift = KVM_PHYS_SHIFT; + if (phys_shift > kvm_ipa_limit) { + pr_warn_once("%s using unsupported default IPA limit, upgrade your VMM\n", + current->comm); + return -EINVAL; + } + } + + mmfr0 = read_sanitised_ftr_reg(SYS_ID_AA64MMFR0_EL1); + mmfr1 = read_sanitised_ftr_reg(SYS_ID_AA64MMFR1_EL1); + mmu->vtcr = kvm_get_vtcr(mmfr0, mmfr1, phys_shift); + + return 0; +} + +/* + * Assume that @pgt is valid and unlinked from the KVM MMU to free the + * page-table without taking the kvm_mmu_lock and without performing any + * TLB invalidations. + * + * Also, the range of addresses can be large enough to cause need_resched + * warnings, for instance on CONFIG_PREEMPT_NONE kernels. Hence, invoke + * cond_resched() periodically to prevent hogging the CPU for a long time + * and schedule something else, if required. + */ +static void stage2_destroy_range(struct kvm_pgtable *pgt, phys_addr_t addr, + phys_addr_t end) +{ + u64 next; + + do { + next = stage2_range_addr_end(addr, end); + KVM_PGT_FN(kvm_pgtable_stage2_destroy_range)(pgt, addr, + next - addr); + if (next != end) + cond_resched(); + } while (addr = next, addr != end); +} + +static void kvm_stage2_destroy(struct kvm_pgtable *pgt) +{ + unsigned int ia_bits = VTCR_EL2_IPA(pgt->mmu->vtcr); + + stage2_destroy_range(pgt, 0, BIT(ia_bits)); + KVM_PGT_FN(kvm_pgtable_stage2_destroy_pgd)(pgt); +} + +/** + * kvm_init_stage2_mmu - Initialise a S2 MMU structure + * @kvm: The pointer to the KVM structure + * @mmu: The pointer to the s2 MMU structure + * @type: The machine type of the virtual machine + * + * Allocates only the stage-2 HW PGD level table(s). + * Note we don't need locking here as this is only called in two cases: + * + * - when the VM is created, which can't race against anything + * + * - when secondary kvm_s2_mmu structures are initialised for NV + * guests, and the caller must hold kvm->lock as this is called on a + * per-vcpu basis. + */ +int kvm_init_stage2_mmu(struct kvm *kvm, struct kvm_s2_mmu *mmu, unsigned long type) +{ + int cpu, err; + struct kvm_pgtable *pgt; + + /* + * If we already have our page tables in place, and that the + * MMU context is the canonical one, we have a bug somewhere, + * as this is only supposed to ever happen once per VM. + * + * Otherwise, we're building nested page tables, and that's + * probably because userspace called KVM_ARM_VCPU_INIT more + * than once on the same vcpu. Since that's actually legal, + * don't kick a fuss and leave gracefully. + */ + if (mmu->pgt != NULL) { + if (kvm_is_nested_s2_mmu(kvm, mmu)) + return 0; + + kvm_err("kvm_arch already initialized?\n"); + return -EINVAL; + } + + err = kvm_init_ipa_range(mmu, type); + if (err) + return err; + + pgt = kzalloc_obj(*pgt, GFP_KERNEL_ACCOUNT); + if (!pgt) + return -ENOMEM; + + mmu->arch = &kvm->arch; + err = KVM_PGT_FN(kvm_pgtable_stage2_init)(pgt, mmu, &kvm_s2_mm_ops); + if (err) + goto out_free_pgtable; + + mmu->pgt = pgt; + if (is_protected_kvm_enabled()) + return 0; + + mmu->last_vcpu_ran = alloc_percpu(typeof(*mmu->last_vcpu_ran)); + if (!mmu->last_vcpu_ran) { + err = -ENOMEM; + goto out_destroy_pgtable; + } + + for_each_possible_cpu(cpu) + *per_cpu_ptr(mmu->last_vcpu_ran, cpu) = -1; + + /* The eager page splitting is disabled by default */ + mmu->split_page_chunk_size = KVM_ARM_EAGER_SPLIT_CHUNK_SIZE_DEFAULT; + mmu->split_page_cache.gfp_zero = __GFP_ZERO; + + mmu->pgd_phys = __pa(pgt->pgd); + + if (kvm_is_nested_s2_mmu(kvm, mmu)) + kvm_init_nested_s2_mmu(mmu); + + return 0; + +out_destroy_pgtable: + kvm_stage2_destroy(pgt); + mmu->pgt = NULL; +out_free_pgtable: + kfree(pgt); + return err; +} + +void kvm_uninit_stage2_mmu(struct kvm *kvm) +{ + kvm_free_stage2_pgd(&kvm->arch.mmu); + kvm_mmu_free_memory_cache(&kvm->arch.mmu.split_page_cache); +} + +static void stage2_unmap_memslot(struct kvm *kvm, + struct kvm_memory_slot *memslot) +{ + hva_t hva = memslot->userspace_addr; + phys_addr_t addr = memslot->base_gfn << PAGE_SHIFT; + phys_addr_t size = PAGE_SIZE * memslot->npages; + hva_t reg_end = hva + size; + + /* + * A memory region could potentially cover multiple VMAs, and any holes + * between them, so iterate over all of them to find out if we should + * unmap any of them. + * + * +--------------------------------------------+ + * +---------------+----------------+ +----------------+ + * | : VMA 1 | VMA 2 | | VMA 3 : | + * +---------------+----------------+ +----------------+ + * | memory region | + * +--------------------------------------------+ + */ + do { + struct vm_area_struct *vma; + hva_t vm_start, vm_end; + + vma = find_vma_intersection(current->mm, hva, reg_end); + if (!vma) + 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 = addr + (vm_start - memslot->userspace_addr); + kvm_stage2_unmap_range(&kvm->arch.mmu, gpa, vm_end - vm_start, true); + } + hva = vm_end; + } while (hva < reg_end); +} + +/** + * stage2_unmap_vm - Unmap Stage-2 RAM mappings + * @kvm: The struct kvm pointer + * + * Go through the memregions and unmap any regular RAM + * backing memory already mapped to the VM. + */ +void stage2_unmap_vm(struct kvm *kvm) +{ + struct kvm_memslots *slots; + struct kvm_memory_slot *memslot; + int idx, bkt; + + idx = srcu_read_lock(&kvm->srcu); + mmap_read_lock(current->mm); + write_lock(&kvm->mmu_lock); + + slots = kvm_memslots(kvm); + kvm_for_each_memslot(memslot, bkt, slots) + stage2_unmap_memslot(kvm, memslot); + + kvm_nested_s2_unmap(kvm, true); + + write_unlock(&kvm->mmu_lock); + mmap_read_unlock(current->mm); + srcu_read_unlock(&kvm->srcu, idx); +} + +void kvm_free_stage2_pgd(struct kvm_s2_mmu *mmu) +{ + struct kvm *kvm = kvm_s2_mmu_to_kvm(mmu); + struct kvm_pgtable *pgt = NULL; + + write_lock(&kvm->mmu_lock); + pgt = mmu->pgt; + if (pgt) { + mmu->pgd_phys = 0; + mmu->pgt = NULL; + free_percpu(mmu->last_vcpu_ran); + } + + if (kvm_is_nested_s2_mmu(kvm, mmu)) + kvm_init_nested_s2_mmu(mmu); + + write_unlock(&kvm->mmu_lock); + + if (pgt) { + kvm_stage2_destroy(pgt); + kfree(pgt); + } +} + +static void hyp_mc_free_fn(void *addr, void *mc) +{ + struct kvm_hyp_memcache *memcache = mc; + + if (memcache->flags & HYP_MEMCACHE_ACCOUNT_STAGE2) + kvm_account_pgtable_pages(addr, -1); + + free_page((unsigned long)addr); +} + +static void *hyp_mc_alloc_fn(void *mc) +{ + struct kvm_hyp_memcache *memcache = mc; + void *addr; + + addr = (void *)__get_free_page(GFP_KERNEL_ACCOUNT); + if (addr && memcache->flags & HYP_MEMCACHE_ACCOUNT_STAGE2) + kvm_account_pgtable_pages(addr, 1); + + return addr; +} + +void free_hyp_memcache(struct kvm_hyp_memcache *mc) +{ + if (!is_protected_kvm_enabled()) + return; + + kfree(mc->mapping); + __free_hyp_memcache(mc, hyp_mc_free_fn, kvm_host_va, mc); +} + +int topup_hyp_memcache(struct kvm_hyp_memcache *mc, unsigned long min_pages) +{ + if (!is_protected_kvm_enabled()) + return 0; + + if (!mc->mapping) { + mc->mapping = kzalloc_obj(struct pkvm_mapping, + GFP_KERNEL_ACCOUNT); + if (!mc->mapping) + return -ENOMEM; + } + + return __topup_hyp_memcache(mc, min_pages, hyp_mc_alloc_fn, + kvm_host_pa, mc); +} + +/** + * kvm_phys_addr_ioremap - map a device range to guest IPA + * + * @kvm: The KVM pointer + * @guest_ipa: The IPA at which to insert the mapping + * @pa: The physical address of the device + * @size: The size of the mapping + * @writable: Whether or not to create a writable mapping + */ +int kvm_phys_addr_ioremap(struct kvm *kvm, phys_addr_t guest_ipa, + phys_addr_t pa, unsigned long size, bool writable) +{ + phys_addr_t addr; + int ret = 0; + struct kvm_mmu_memory_cache cache = { .gfp_zero = __GFP_ZERO }; + struct kvm_s2_mmu *mmu = &kvm->arch.mmu; + struct kvm_pgtable *pgt = mmu->pgt; + enum kvm_pgtable_prot prot = KVM_PGTABLE_PROT_DEVICE | + KVM_PGTABLE_PROT_R | + (writable ? KVM_PGTABLE_PROT_W : 0); + + if (is_protected_kvm_enabled()) + return -EPERM; + + size += offset_in_page(guest_ipa); + guest_ipa &= PAGE_MASK; + + for (addr = guest_ipa; addr < guest_ipa + size; addr += PAGE_SIZE) { + ret = kvm_mmu_topup_memory_cache(&cache, + kvm_mmu_cache_min_pages(mmu)); + if (ret) + break; + + write_lock(&kvm->mmu_lock); + ret = KVM_PGT_FN(kvm_pgtable_stage2_map)(pgt, addr, PAGE_SIZE, + pa, prot, &cache, 0); + write_unlock(&kvm->mmu_lock); + if (ret) + break; + + pa += PAGE_SIZE; + } + + kvm_mmu_free_memory_cache(&cache); + return ret; +} + +/** + * kvm_stage2_wp_range() - write protect stage2 memory region range + * @mmu: The KVM stage-2 MMU pointer + * @addr: Start address of range + * @end: End address of range + */ +void kvm_stage2_wp_range(struct kvm_s2_mmu *mmu, phys_addr_t addr, phys_addr_t end) +{ + stage2_apply_range_resched(mmu, addr, end, KVM_PGT_FN(kvm_pgtable_stage2_wrprotect)); +} + +/** + * kvm_mmu_wp_memory_region() - write protect stage 2 entries for memory slot + * @kvm: The KVM pointer + * @slot: The memory slot to write protect + * + * Called to start logging dirty pages after memory region + * KVM_MEM_LOG_DIRTY_PAGES operation is called. After this function returns + * all present PUD, PMD and PTEs are write protected in the memory region. + * Afterwards read of dirty page log can be called. + * + * Acquires kvm_mmu_lock. Called with kvm->slots_lock mutex acquired, + * serializing operations for VM memory regions. + */ +static void kvm_mmu_wp_memory_region(struct kvm *kvm, int slot) +{ + struct kvm_memslots *slots = kvm_memslots(kvm); + struct kvm_memory_slot *memslot = id_to_memslot(slots, slot); + phys_addr_t start, end; + + if (WARN_ON_ONCE(!memslot)) + return; + + start = memslot->base_gfn << PAGE_SHIFT; + end = (memslot->base_gfn + memslot->npages) << PAGE_SHIFT; + + write_lock(&kvm->mmu_lock); + kvm_stage2_wp_range(&kvm->arch.mmu, start, end); + kvm_nested_s2_wp(kvm); + write_unlock(&kvm->mmu_lock); + kvm_flush_remote_tlbs_memslot(kvm, memslot); +} + +/** + * kvm_mmu_split_memory_region() - split the stage 2 blocks into PAGE_SIZE + * pages for memory slot + * @kvm: The KVM pointer + * @slot: The memory slot to split + * + * Acquires kvm->mmu_lock. Called with kvm->slots_lock mutex acquired, + * serializing operations for VM memory regions. + */ +static void kvm_mmu_split_memory_region(struct kvm *kvm, int slot) +{ + struct kvm_memslots *slots; + struct kvm_memory_slot *memslot; + phys_addr_t start, end; + + lockdep_assert_held(&kvm->slots_lock); + + slots = kvm_memslots(kvm); + memslot = id_to_memslot(slots, slot); + + start = memslot->base_gfn << PAGE_SHIFT; + end = (memslot->base_gfn + memslot->npages) << PAGE_SHIFT; + + write_lock(&kvm->mmu_lock); + kvm_mmu_split_huge_pages(kvm, start, end); + write_unlock(&kvm->mmu_lock); +} + +/* + * kvm_arch_mmu_enable_log_dirty_pt_masked() - enable dirty logging for selected pages. + * @kvm: The KVM pointer + * @slot: The memory slot associated with mask + * @gfn_offset: The gfn offset in memory slot + * @mask: The mask of pages at offset 'gfn_offset' in this memory + * slot to enable dirty logging on + * + * Writes protect selected pages to enable dirty logging, and then + * splits them to PAGE_SIZE. Caller must acquire kvm->mmu_lock. + */ +void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm, + struct kvm_memory_slot *slot, + gfn_t gfn_offset, unsigned long mask) +{ + phys_addr_t base_gfn = slot->base_gfn + gfn_offset; + phys_addr_t start = (base_gfn + __ffs(mask)) << PAGE_SHIFT; + phys_addr_t end = (base_gfn + __fls(mask) + 1) << PAGE_SHIFT; + + lockdep_assert_held_write(&kvm->mmu_lock); + + kvm_stage2_wp_range(&kvm->arch.mmu, start, end); + + /* + * Eager-splitting is done when manual-protect is set. We + * also check for initially-all-set because we can avoid + * eager-splitting if initially-all-set is false. + * Initially-all-set equal false implies that huge-pages were + * already split when enabling dirty logging: no need to do it + * again. + */ + if (kvm_dirty_log_manual_protect_and_init_set(kvm)) + kvm_mmu_split_huge_pages(kvm, start, end); + + kvm_nested_s2_wp(kvm); +} + +static void kvm_send_hwpoison_signal(unsigned long address, short lsb) +{ + send_sig_mceerr(BUS_MCEERR_AR, (void __user *)address, lsb, current); +} + +static bool fault_supports_stage2_huge_mapping(struct kvm_memory_slot *memslot, + unsigned long hva, + unsigned long map_size) +{ + gpa_t gpa_start; + hva_t uaddr_start, uaddr_end; + size_t size; + + /* The memslot and the VMA are guaranteed to be aligned to PAGE_SIZE */ + if (map_size == PAGE_SIZE) + return true; + + /* pKVM only supports PMD_SIZE huge-mappings */ + if (is_protected_kvm_enabled() && map_size != PMD_SIZE) + return false; + + size = memslot->npages * PAGE_SIZE; + + gpa_start = memslot->base_gfn << PAGE_SHIFT; + + uaddr_start = memslot->userspace_addr; + uaddr_end = uaddr_start + size; + + /* + * Pages belonging to memslots that don't have the same alignment + * within a PMD/PUD for userspace and IPA cannot be mapped with stage-2 + * PMD/PUD entries, because we'll end up mapping the wrong pages. + * + * Consider a layout like the following: + * + * memslot->userspace_addr: + * +-----+--------------------+--------------------+---+ + * |abcde|fgh Stage-1 block | Stage-1 block tv|xyz| + * +-----+--------------------+--------------------+---+ + * + * memslot->base_gfn << PAGE_SHIFT: + * +---+--------------------+--------------------+-----+ + * |abc|def Stage-2 block | Stage-2 block |tvxyz| + * +---+--------------------+--------------------+-----+ + * + * If we create those stage-2 blocks, we'll end up with this incorrect + * mapping: + * d -> f + * e -> g + * f -> h + */ + if ((gpa_start & (map_size - 1)) != (uaddr_start & (map_size - 1))) + return false; + + /* + * Next, let's make sure we're not trying to map anything not covered + * by the memslot. This means we have to prohibit block size mappings + * for the beginning and end of a non-block aligned and non-block sized + * memory slot (illustrated by the head and tail parts of the + * userspace view above containing pages 'abcde' and 'xyz', + * respectively). + * + * Note that it doesn't matter if we do the check using the + * userspace_addr or the base_gfn, as both are equally aligned (per + * the check above) and equally sized. + */ + return (hva & ~(map_size - 1)) >= uaddr_start && + (hva & ~(map_size - 1)) + map_size <= uaddr_end; +} + +/* + * Check if the given hva is backed by a transparent huge page (THP) and + * whether it can be mapped using block mapping in stage2. If so, adjust + * the stage2 PFN and IPA accordingly. Only PMD_SIZE THPs are currently + * supported. This will need to be updated to support other THP sizes. + * + * Returns the size of the mapping. + */ +static long +transparent_hugepage_adjust(struct kvm *kvm, struct kvm_memory_slot *memslot, + unsigned long hva, kvm_pfn_t *pfnp, gfn_t *gfnp) +{ + kvm_pfn_t pfn = *pfnp; + gfn_t gfn = *gfnp; + + /* + * Make sure the adjustment is done only for THP pages. Also make + * sure that the HVA and IPA are sufficiently aligned and that the + * block map is contained within the memslot. + */ + if (fault_supports_stage2_huge_mapping(memslot, hva, PMD_SIZE)) { + int sz = get_user_mapping_size(kvm, hva); + + if (sz < 0) + return sz; + + if (sz < PMD_SIZE) + return PAGE_SIZE; + + gfn &= ~(PTRS_PER_PMD - 1); + *gfnp = gfn; + pfn &= ~(PTRS_PER_PMD - 1); + *pfnp = pfn; + + return PMD_SIZE; + } + + /* Use page mapping if we cannot use block mapping. */ + return PAGE_SIZE; +} + +static int get_vma_page_shift(struct vm_area_struct *vma, unsigned long hva) +{ + unsigned long pa; + + if (is_vm_hugetlb_page(vma) && !(vma->vm_flags & VM_PFNMAP)) + return huge_page_shift(hstate_vma(vma)); + + if (!(vma->vm_flags & VM_PFNMAP)) + return PAGE_SHIFT; + + VM_BUG_ON(is_vm_hugetlb_page(vma)); + + pa = (vma->vm_pgoff << PAGE_SHIFT) + (hva - vma->vm_start); + +#ifndef __PAGETABLE_PMD_FOLDED + if ((hva & (PUD_SIZE - 1)) == (pa & (PUD_SIZE - 1)) && + ALIGN_DOWN(hva, PUD_SIZE) >= vma->vm_start && + ALIGN(hva, PUD_SIZE) <= vma->vm_end) + return PUD_SHIFT; +#endif + + if ((hva & (PMD_SIZE - 1)) == (pa & (PMD_SIZE - 1)) && + ALIGN_DOWN(hva, PMD_SIZE) >= vma->vm_start && + ALIGN(hva, PMD_SIZE) <= vma->vm_end) + return PMD_SHIFT; + + return PAGE_SHIFT; +} + +/* + * The page will be mapped in stage 2 as Normal Cacheable, so the VM will be + * able to see the page's tags and therefore they must be initialised first. If + * PG_mte_tagged is set, tags have already been initialised. + * + * Must be called with kvm->mmu_lock held to ensure the memory remains mapped + * while the tags are zeroed. + */ +static void sanitise_mte_tags(struct kvm *kvm, kvm_pfn_t pfn, + unsigned long size) +{ + unsigned long i, nr_pages = size >> PAGE_SHIFT; + struct page *page = pfn_to_page(pfn); + struct folio *folio = page_folio(page); + + if (!kvm_has_mte(kvm)) + return; + + if (is_zero_pfn(pfn)) { + WARN_ON_ONCE(nr_pages != 1); + return; + } + + if (folio_test_hugetlb(folio)) { + /* Hugetlb has MTE flags set on head page only */ + if (folio_try_hugetlb_mte_tagging(folio)) { + for (i = 0; i < nr_pages; i++, page++) + mte_clear_page_tags(page_address(page)); + folio_set_hugetlb_mte_tagged(folio); + } + return; + } + + for (i = 0; i < nr_pages; i++, page++) { + if (try_page_mte_tagging(page)) { + mte_clear_page_tags(page_address(page)); + set_page_mte_tagged(page); + } + } +} + +static bool kvm_vma_mte_allowed(struct vm_area_struct *vma) +{ + return vma->vm_flags & VM_MTE_ALLOWED; +} + +static bool kvm_vma_is_cacheable(struct vm_area_struct *vma) +{ + switch (FIELD_GET(PTE_ATTRINDX_MASK, pgprot_val(vma->vm_page_prot))) { + case MT_NORMAL_NC: + case MT_DEVICE_nGnRnE: + case MT_DEVICE_nGnRE: + return false; + default: + return true; + } +} + +static void *get_mmu_memcache(struct kvm_vcpu *vcpu) +{ + if (!is_protected_kvm_enabled()) + return &vcpu->arch.mmu_page_cache; + else + return &vcpu->arch.pkvm_memcache; +} + +static int topup_mmu_memcache(struct kvm_vcpu *vcpu, void *memcache) +{ + int min_pages = kvm_mmu_cache_min_pages(vcpu->arch.hw_mmu); + + if (!is_protected_kvm_enabled()) + return kvm_mmu_topup_memory_cache(memcache, min_pages); + + return topup_hyp_memcache(memcache, min_pages); +} + +/* + * Potentially reduce shadow S2 permissions to match the guest's own S2. For + * exec faults, we'd only reach this point if the guest actually allowed it (see + * kvm_s2_handle_perm_fault). + * + * Also encode the level of the original translation in the SW bits of the leaf + * entry as a proxy for the span of that translation. This will be retrieved on + * TLB invalidation from the guest and used to limit the invalidation scope if a + * TTL hint or a range isn't provided. + */ +static enum kvm_pgtable_prot adjust_nested_fault_perms(struct kvm_s2_trans *nested, + enum kvm_pgtable_prot prot) +{ + if (!kvm_s2_trans_writable(nested)) + prot &= ~KVM_PGTABLE_PROT_W; + if (!kvm_s2_trans_readable(nested)) + prot &= ~KVM_PGTABLE_PROT_R; + + return prot | kvm_encode_nested_level(nested); +} + +static enum kvm_pgtable_prot adjust_nested_exec_perms(struct kvm *kvm, + struct kvm_s2_trans *nested, + enum kvm_pgtable_prot prot) +{ + if (!kvm_s2_trans_exec_el0(kvm, nested)) + prot &= ~KVM_PGTABLE_PROT_UX; + if (!kvm_s2_trans_exec_el1(kvm, nested)) + prot &= ~KVM_PGTABLE_PROT_PX; + + return prot; +} + +struct kvm_s2_fault_desc { + struct kvm_vcpu *vcpu; + phys_addr_t fault_ipa; + struct kvm_s2_trans *nested; + struct kvm_memory_slot *memslot; + unsigned long hva; +}; + +static int gmem_abort(const struct kvm_s2_fault_desc *s2fd) +{ + bool write_fault, exec_fault; + bool perm_fault = kvm_vcpu_trap_is_permission_fault(s2fd->vcpu); + enum kvm_pgtable_walk_flags flags = KVM_PGTABLE_WALK_SHARED; + enum kvm_pgtable_prot prot = KVM_PGTABLE_PROT_R; + struct kvm_pgtable *pgt = s2fd->vcpu->arch.hw_mmu->pgt; + unsigned long mmu_seq; + struct page *page; + struct kvm *kvm = s2fd->vcpu->kvm; + void *memcache = NULL; + kvm_pfn_t pfn; + gfn_t gfn; + int ret; + + if (!perm_fault) { + memcache = get_mmu_memcache(s2fd->vcpu); + ret = topup_mmu_memcache(s2fd->vcpu, memcache); + if (ret) + return ret; + } + + if (s2fd->nested) + gfn = kvm_s2_trans_output(s2fd->nested) >> PAGE_SHIFT; + else + gfn = s2fd->fault_ipa >> PAGE_SHIFT; + + write_fault = kvm_is_write_fault(s2fd->vcpu); + exec_fault = kvm_vcpu_trap_is_exec_fault(s2fd->vcpu); + + VM_WARN_ON_ONCE(write_fault && exec_fault); + + mmu_seq = kvm->mmu_invalidate_seq; + /* Pairs with the smp_wmb() in kvm_mmu_invalidate_end(). */ + smp_rmb(); + + ret = kvm_gmem_get_pfn(kvm, s2fd->memslot, gfn, &pfn, &page, NULL); + if (ret) { + kvm_prepare_memory_fault_exit(s2fd->vcpu, s2fd->fault_ipa, PAGE_SIZE, + write_fault, exec_fault, false); + return ret; + } + + if (!(s2fd->memslot->flags & KVM_MEM_READONLY)) + prot |= KVM_PGTABLE_PROT_W; + + if (s2fd->nested) + prot = adjust_nested_fault_perms(s2fd->nested, prot); + + if (exec_fault || cpus_have_final_cap(ARM64_HAS_CACHE_DIC)) + prot |= KVM_PGTABLE_PROT_X; + + if (s2fd->nested) + prot = adjust_nested_exec_perms(kvm, s2fd->nested, prot); + + kvm_fault_lock(kvm); + if (mmu_invalidate_retry(kvm, mmu_seq)) { + ret = -EAGAIN; + goto out_unlock; + } + + if (perm_fault) { + /* + * Drop the SW bits in favour of those stored in the + * PTE, which will be preserved. + */ + prot &= ~KVM_NV_GUEST_MAP_SZ; + ret = KVM_PGT_FN(kvm_pgtable_stage2_relax_perms)(pgt, s2fd->fault_ipa, + prot, flags); + } else { + ret = KVM_PGT_FN(kvm_pgtable_stage2_map)(pgt, s2fd->fault_ipa, PAGE_SIZE, + __pfn_to_phys(pfn), prot, + memcache, flags); + } + +out_unlock: + kvm_release_faultin_page(kvm, page, !!ret, prot & KVM_PGTABLE_PROT_W); + kvm_fault_unlock(kvm); + + if ((prot & KVM_PGTABLE_PROT_W) && !ret) + mark_page_dirty_in_slot(kvm, s2fd->memslot, gfn); + + return ret != -EAGAIN ? ret : 0; +} + +struct kvm_s2_fault_vma_info { + unsigned long mmu_seq; + long vma_pagesize; + vm_flags_t vm_flags; + unsigned long max_map_size; + struct page *page; + kvm_pfn_t pfn; + gfn_t gfn; + bool device; + bool mte_allowed; + bool is_vma_cacheable; + bool map_writable; + bool map_non_cacheable; +}; + +static int pkvm_mem_abort(const struct kvm_s2_fault_desc *s2fd) +{ + unsigned int flags = FOLL_HWPOISON | FOLL_LONGTERM | FOLL_WRITE; + struct kvm_vcpu *vcpu = s2fd->vcpu; + struct kvm_pgtable *pgt = vcpu->arch.hw_mmu->pgt; + struct mm_struct *mm = current->mm; + struct kvm *kvm = vcpu->kvm; + void *hyp_memcache; + struct page *page; + int ret; + + hyp_memcache = get_mmu_memcache(vcpu); + ret = topup_mmu_memcache(vcpu, hyp_memcache); + if (ret) + return -ENOMEM; + + ret = account_locked_vm(mm, 1, true); + if (ret) + return ret; + + mmap_read_lock(mm); + ret = pin_user_pages(s2fd->hva, 1, flags, &page); + mmap_read_unlock(mm); + + if (ret == -EHWPOISON) { + kvm_send_hwpoison_signal(s2fd->hva, PAGE_SHIFT); + ret = 0; + goto dec_account; + } else if (ret != 1) { + ret = -EFAULT; + goto dec_account; + } else if (!folio_test_swapbacked(page_folio(page))) { + /* + * We really can't deal with page-cache pages returned by GUP + * because (a) we may trigger writeback of a page for which we + * no longer have access and (b) page_mkclean() won't find the + * stage-2 mapping in the rmap so we can get out-of-whack with + * the filesystem when marking the page dirty during unpinning + * (see cc5095747edf ("ext4: don't BUG if someone dirty pages + * without asking ext4 first")). + * + * Ideally we'd just restrict ourselves to anonymous pages, but + * we also want to allow memfd (i.e. shmem) pages, so check for + * pages backed by swap in the knowledge that the GUP pin will + * prevent try_to_unmap() from succeeding. + */ + ret = -EIO; + goto unpin; + } + + write_lock(&kvm->mmu_lock); + ret = pkvm_pgtable_stage2_map(pgt, s2fd->fault_ipa, PAGE_SIZE, + page_to_phys(page), KVM_PGTABLE_PROT_RWX, + hyp_memcache, 0); + write_unlock(&kvm->mmu_lock); + if (ret) { + if (ret == -EAGAIN) + ret = 0; + goto unpin; + } + + return 0; +unpin: + unpin_user_pages(&page, 1); +dec_account: + account_locked_vm(mm, 1, false); + return ret; +} + +static short kvm_s2_resolve_vma_size(const struct kvm_s2_fault_desc *s2fd, + struct kvm_s2_fault_vma_info *s2vi, + struct vm_area_struct *vma) +{ + short vma_shift; + + if (memslot_is_logging(s2fd->memslot)) { + s2vi->max_map_size = PAGE_SIZE; + vma_shift = PAGE_SHIFT; + } else { + s2vi->max_map_size = PUD_SIZE; + vma_shift = get_vma_page_shift(vma, s2fd->hva); + } + + switch (vma_shift) { +#ifndef __PAGETABLE_PMD_FOLDED + case PUD_SHIFT: + if (fault_supports_stage2_huge_mapping(s2fd->memslot, s2fd->hva, PUD_SIZE)) + break; + fallthrough; +#endif + case CONT_PMD_SHIFT: + vma_shift = PMD_SHIFT; + fallthrough; + case PMD_SHIFT: + if (fault_supports_stage2_huge_mapping(s2fd->memslot, s2fd->hva, PMD_SIZE)) + break; + fallthrough; + case CONT_PTE_SHIFT: + vma_shift = PAGE_SHIFT; + s2vi->max_map_size = PAGE_SIZE; + fallthrough; + case PAGE_SHIFT: + break; + default: + WARN_ONCE(1, "Unknown vma_shift %d", vma_shift); + } + + if (s2fd->nested) { + unsigned long max_map_size; + + max_map_size = min(s2vi->max_map_size, PUD_SIZE); + + /* + * If we're about to create a shadow stage 2 entry, then we + * can only create a block mapping if the guest stage 2 page + * table uses at least as big a mapping. + */ + max_map_size = min(kvm_s2_trans_size(s2fd->nested), max_map_size); + + /* + * Be careful that if the mapping size falls between + * two host sizes, take the smallest of the two. + */ + if (max_map_size >= PMD_SIZE && max_map_size < PUD_SIZE) + max_map_size = PMD_SIZE; + else if (max_map_size >= PAGE_SIZE && max_map_size < PMD_SIZE) + max_map_size = PAGE_SIZE; + + s2vi->max_map_size = max_map_size; + vma_shift = min_t(short, vma_shift, __ffs(max_map_size)); + } + + return vma_shift; +} + +static bool kvm_s2_fault_is_perm(const struct kvm_s2_fault_desc *s2fd) +{ + return kvm_vcpu_trap_is_permission_fault(s2fd->vcpu); +} + +static int kvm_s2_fault_get_vma_info(const struct kvm_s2_fault_desc *s2fd, + struct kvm_s2_fault_vma_info *s2vi) +{ + struct vm_area_struct *vma; + struct kvm *kvm = s2fd->vcpu->kvm; + + mmap_read_lock(current->mm); + vma = vma_lookup(current->mm, s2fd->hva); + if (unlikely(!vma)) { + kvm_err("Failed to find VMA for hva 0x%lx\n", s2fd->hva); + mmap_read_unlock(current->mm); + return -EFAULT; + } + + s2vi->vma_pagesize = BIT(kvm_s2_resolve_vma_size(s2fd, s2vi, vma)); + + /* + * Both the canonical IPA and fault IPA must be aligned to the + * mapping size to ensure we find the right PFN and lay down the + * mapping in the right place. + */ + s2vi->gfn = ALIGN_DOWN(s2fd->fault_ipa, s2vi->vma_pagesize) >> PAGE_SHIFT; + + s2vi->mte_allowed = kvm_vma_mte_allowed(vma); + + s2vi->vm_flags = vma->vm_flags; + + s2vi->is_vma_cacheable = kvm_vma_is_cacheable(vma); + + /* + * Read mmu_invalidate_seq so that KVM can detect if the results of + * vma_lookup() or __kvm_faultin_pfn() become stale prior to + * acquiring kvm->mmu_lock. + * + * Rely on mmap_read_unlock() for an implicit smp_rmb(), which pairs + * with the smp_wmb() in kvm_mmu_invalidate_end(). + */ + s2vi->mmu_seq = kvm->mmu_invalidate_seq; + mmap_read_unlock(current->mm); + + return 0; +} + +static gfn_t get_canonical_gfn(const struct kvm_s2_fault_desc *s2fd, + const struct kvm_s2_fault_vma_info *s2vi) +{ + phys_addr_t ipa; + + if (!s2fd->nested) + return s2vi->gfn; + + ipa = kvm_s2_trans_output(s2fd->nested); + return ALIGN_DOWN(ipa, s2vi->vma_pagesize) >> PAGE_SHIFT; +} + +static int kvm_s2_fault_pin_pfn(const struct kvm_s2_fault_desc *s2fd, + struct kvm_s2_fault_vma_info *s2vi) +{ + int ret; + + ret = kvm_s2_fault_get_vma_info(s2fd, s2vi); + if (ret) + return ret; + + s2vi->pfn = __kvm_faultin_pfn(s2fd->memslot, get_canonical_gfn(s2fd, s2vi), + kvm_is_write_fault(s2fd->vcpu) ? FOLL_WRITE : 0, + &s2vi->map_writable, &s2vi->page); + if (unlikely(is_error_noslot_pfn(s2vi->pfn))) { + if (s2vi->pfn == KVM_PFN_ERR_HWPOISON) { + kvm_send_hwpoison_signal(s2fd->hva, __ffs(s2vi->vma_pagesize)); + return 0; + } + return -EFAULT; + } + + /* + * Check if this is non-struct page memory PFN, and cannot support + * CMOs. It could potentially be unsafe to access as cacheable. + */ + if (s2vi->vm_flags & (VM_PFNMAP | VM_MIXEDMAP) && !pfn_is_map_memory(s2vi->pfn)) { + if (s2vi->is_vma_cacheable) { + /* + * Whilst the VMA owner expects cacheable mapping to this + * PFN, hardware also has to support the FWB and CACHE DIC + * features. + * + * ARM64 KVM relies on kernel VA mapping to the PFN to + * perform cache maintenance as the CMO instructions work on + * virtual addresses. VM_PFNMAP region are not necessarily + * mapped to a KVA and hence the presence of hardware features + * S2FWB and CACHE DIC are mandatory to avoid the need for + * cache maintenance. + */ + if (!kvm_supports_cacheable_pfnmap()) { + kvm_release_faultin_page(s2fd->vcpu->kvm, s2vi->page, true, false); + return -EFAULT; + } + } else { + /* + * If the page was identified as device early by looking at + * the VMA flags, vma_pagesize is already representing the + * largest quantity we can map. If instead it was mapped + * via __kvm_faultin_pfn(), vma_pagesize is set to PAGE_SIZE + * and must not be upgraded. + * + * In both cases, we don't let transparent_hugepage_adjust() + * change things at the last minute. + */ + s2vi->map_non_cacheable = true; + } + + s2vi->device = true; + } + + return 1; +} + +static int kvm_s2_fault_compute_prot(const struct kvm_s2_fault_desc *s2fd, + const struct kvm_s2_fault_vma_info *s2vi, + enum kvm_pgtable_prot *prot) +{ + struct kvm *kvm = s2fd->vcpu->kvm; + + if (kvm_vcpu_trap_is_exec_fault(s2fd->vcpu) && s2vi->map_non_cacheable) + return -ENOEXEC; + + /* + * Guest performs atomic/exclusive operations on memory with unsupported + * attributes (e.g. ld64b/st64b on normal memory when no FEAT_LS64WB) + * and trigger the exception here. Since the memslot is valid, inject + * the fault back to the guest. + */ + if (esr_fsc_is_excl_atomic_fault(kvm_vcpu_get_esr(s2fd->vcpu))) { + kvm_inject_dabt_excl_atomic(s2fd->vcpu, kvm_vcpu_get_hfar(s2fd->vcpu)); + return 1; + } + + *prot = KVM_PGTABLE_PROT_R; + + if (s2vi->map_writable && (s2vi->device || + !memslot_is_logging(s2fd->memslot) || + kvm_is_write_fault(s2fd->vcpu))) + *prot |= KVM_PGTABLE_PROT_W; + + if (s2fd->nested) + *prot = adjust_nested_fault_perms(s2fd->nested, *prot); + + if (kvm_vcpu_trap_is_exec_fault(s2fd->vcpu)) + *prot |= KVM_PGTABLE_PROT_X; + + if (s2vi->map_non_cacheable) + *prot |= (s2vi->vm_flags & VM_ALLOW_ANY_UNCACHED) ? + KVM_PGTABLE_PROT_NORMAL_NC : KVM_PGTABLE_PROT_DEVICE; + else if (cpus_have_final_cap(ARM64_HAS_CACHE_DIC)) + *prot |= KVM_PGTABLE_PROT_X; + + if (s2fd->nested) + *prot = adjust_nested_exec_perms(kvm, s2fd->nested, *prot); + + if (!kvm_s2_fault_is_perm(s2fd) && !s2vi->map_non_cacheable && kvm_has_mte(kvm)) { + /* Check the VMM hasn't introduced a new disallowed VMA */ + if (!s2vi->mte_allowed) + return -EFAULT; + } + + return 0; +} + +static int kvm_s2_fault_map(const struct kvm_s2_fault_desc *s2fd, + const struct kvm_s2_fault_vma_info *s2vi, + enum kvm_pgtable_prot prot, + void *memcache) +{ + enum kvm_pgtable_walk_flags flags = KVM_PGTABLE_WALK_SHARED; + bool writable = prot & KVM_PGTABLE_PROT_W; + struct kvm *kvm = s2fd->vcpu->kvm; + struct kvm_pgtable *pgt; + long perm_fault_granule; + long mapping_size; + kvm_pfn_t pfn; + gfn_t gfn; + int ret; + + kvm_fault_lock(kvm); + pgt = s2fd->vcpu->arch.hw_mmu->pgt; + ret = -EAGAIN; + if (mmu_invalidate_retry(kvm, s2vi->mmu_seq)) + goto out_unlock; + + perm_fault_granule = (kvm_s2_fault_is_perm(s2fd) ? + kvm_vcpu_trap_get_perm_fault_granule(s2fd->vcpu) : 0); + mapping_size = s2vi->vma_pagesize; + pfn = s2vi->pfn; + gfn = s2vi->gfn; + + /* + * If we are not forced to use page mapping, check if we are + * backed by a THP and thus use block mapping if possible. + */ + if (mapping_size == PAGE_SIZE && + !(s2vi->max_map_size == PAGE_SIZE || s2vi->map_non_cacheable)) { + if (perm_fault_granule > PAGE_SIZE) { + mapping_size = perm_fault_granule; + } else { + mapping_size = transparent_hugepage_adjust(kvm, s2fd->memslot, + s2fd->hva, &pfn, + &gfn); + if (mapping_size < 0) { + ret = mapping_size; + goto out_unlock; + } + } + } + + if (!perm_fault_granule && !s2vi->map_non_cacheable && kvm_has_mte(kvm)) + sanitise_mte_tags(kvm, pfn, mapping_size); + + /* + * Under the premise of getting a FSC_PERM fault, we just need to relax + * permissions only if mapping_size equals perm_fault_granule. Otherwise, + * kvm_pgtable_stage2_map() should be called to change block size. + */ + if (mapping_size == perm_fault_granule) { + /* + * Drop the SW bits in favour of those stored in the + * PTE, which will be preserved. + */ + prot &= ~KVM_NV_GUEST_MAP_SZ; + ret = KVM_PGT_FN(kvm_pgtable_stage2_relax_perms)(pgt, gfn_to_gpa(gfn), + prot, flags); + } else { + ret = KVM_PGT_FN(kvm_pgtable_stage2_map)(pgt, gfn_to_gpa(gfn), mapping_size, + __pfn_to_phys(pfn), prot, + memcache, flags); + } + +out_unlock: + kvm_release_faultin_page(kvm, s2vi->page, !!ret, writable); + kvm_fault_unlock(kvm); + + /* + * Mark the page dirty only if the fault is handled successfully, + * making sure we adjust the canonical IPA if the mapping size has + * been updated (via a THP upgrade, for example). + */ + if (writable && !ret) { + phys_addr_t ipa = gfn_to_gpa(get_canonical_gfn(s2fd, s2vi)); + ipa &= ~(mapping_size - 1); + mark_page_dirty_in_slot(kvm, s2fd->memslot, gpa_to_gfn(ipa)); + } + + if (ret != -EAGAIN) + return ret; + return 0; +} + +static int user_mem_abort(const struct kvm_s2_fault_desc *s2fd) +{ + bool perm_fault = kvm_vcpu_trap_is_permission_fault(s2fd->vcpu); + struct kvm_s2_fault_vma_info s2vi = {}; + enum kvm_pgtable_prot prot; + void *memcache; + int ret; + + /* + * Permission faults just need to update the existing leaf entry, + * and so normally don't require allocations from the memcache. The + * only exception to this is when dirty logging is enabled at runtime + * and a fault needs to collapse a block entry into a table. + * Under pKVM a permission fault can also collapse pages into a block, + * which needs a fresh mapping object, and the hypervisor requires the + * min-pages memcache even when the install allocates nothing. + */ + memcache = get_mmu_memcache(s2fd->vcpu); + if (!perm_fault || memslot_is_logging(s2fd->memslot) || + is_protected_kvm_enabled()) { + ret = topup_mmu_memcache(s2fd->vcpu, memcache); + if (ret) + return ret; + } + + /* + * Let's check if we will get back a huge page backed by hugetlbfs, or + * get block mapping for device MMIO region. + */ + ret = kvm_s2_fault_pin_pfn(s2fd, &s2vi); + if (ret != 1) + return ret; + + ret = kvm_s2_fault_compute_prot(s2fd, &s2vi, &prot); + if (ret) { + kvm_release_page_unused(s2vi.page); + return ret; + } + + return kvm_s2_fault_map(s2fd, &s2vi, prot, memcache); +} + +/* Resolve the access fault by making the page young again. */ +static void handle_access_fault(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa) +{ + enum kvm_pgtable_walk_flags flags = KVM_PGTABLE_WALK_SHARED; + struct kvm_s2_mmu *mmu; + + trace_kvm_access_fault(fault_ipa); + + read_lock(&vcpu->kvm->mmu_lock); + mmu = vcpu->arch.hw_mmu; + KVM_PGT_FN(kvm_pgtable_stage2_mkyoung)(mmu->pgt, fault_ipa, flags); + read_unlock(&vcpu->kvm->mmu_lock); +} + +/* + * Returns true if the SEA should be handled locally within KVM if the abort + * is caused by a kernel memory allocation (e.g. stage-2 table memory). + */ +static bool host_owns_sea(struct kvm_vcpu *vcpu, u64 esr) +{ + /* + * Without FEAT_RAS HCR_EL2.TEA is RES0, meaning any external abort + * taken from a guest EL to EL2 is due to a host-imposed access (e.g. + * stage-2 PTW). + */ + if (!cpus_have_final_cap(ARM64_HAS_RAS_EXTN)) + return true; + + /* KVM owns the VNCR when the vCPU isn't in a nested context. */ + if (is_hyp_ctxt(vcpu) && !kvm_vcpu_trap_is_iabt(vcpu) && (esr & ESR_ELx_VNCR)) + return true; + + /* + * Determining if an external abort during a table walk happened at + * stage-2 is only possible with S1PTW is set. Otherwise, since KVM + * sets HCR_EL2.TEA, SEAs due to a stage-1 walk (i.e. accessing the + * PA of the stage-1 descriptor) can reach here and are reported + * with a TTW ESR value. + */ + return (esr_fsc_is_sea_ttw(esr) && (esr & ESR_ELx_S1PTW)); +} + +int kvm_handle_guest_sea(struct kvm_vcpu *vcpu) +{ + struct kvm *kvm = vcpu->kvm; + struct kvm_run *run = vcpu->run; + u64 esr = kvm_vcpu_get_esr(vcpu); + u64 esr_mask = ESR_ELx_EC_MASK | + ESR_ELx_IL | + ESR_ELx_FnV | + ESR_ELx_EA | + ESR_ELx_CM | + ESR_ELx_WNR | + ESR_ELx_FSC; + u64 ipa; + + /* + * Give APEI the opportunity to claim the abort before handling it + * within KVM. apei_claim_sea() expects to be called with IRQs enabled. + */ + lockdep_assert_irqs_enabled(); + if (apei_claim_sea(NULL) == 0) + return 1; + + if (host_owns_sea(vcpu, esr) || + !test_bit(KVM_ARCH_FLAG_EXIT_SEA, &vcpu->kvm->arch.flags)) + return kvm_inject_serror(vcpu); + + /* ESR_ELx.SET is RES0 when FEAT_RAS isn't implemented. */ + if (kvm_has_ras(kvm)) + esr_mask |= ESR_ELx_SET_MASK; + + /* + * Exit to userspace, and provide faulting guest virtual and physical + * addresses in case userspace wants to emulate SEA to guest by + * writing to FAR_ELx and HPFAR_ELx registers. + */ + memset(&run->arm_sea, 0, sizeof(run->arm_sea)); + run->exit_reason = KVM_EXIT_ARM_SEA; + run->arm_sea.esr = esr & esr_mask; + + if (!(esr & ESR_ELx_FnV)) + run->arm_sea.gva = kvm_vcpu_get_hfar(vcpu); + + ipa = kvm_vcpu_get_fault_ipa(vcpu); + if (ipa != INVALID_GPA) { + run->arm_sea.flags |= KVM_EXIT_ARM_SEA_FLAG_GPA_VALID; + run->arm_sea.gpa = ipa; + } + + return 0; +} + +/** + * kvm_handle_guest_abort - handles all 2nd stage aborts + * @vcpu: the VCPU pointer + * + * Any abort that gets to the host is almost guaranteed to be caused by a + * missing second stage translation table entry, which can mean that either the + * guest simply needs more memory and we must allocate an appropriate page or it + * can mean that the guest tried to access I/O memory, which is emulated by user + * space. The distinction is based on the IPA causing the fault and whether this + * memory region has been registered as standard RAM by user space. + */ +int kvm_handle_guest_abort(struct kvm_vcpu *vcpu) +{ + struct kvm_s2_trans nested_trans, *nested = NULL; + unsigned long esr; + phys_addr_t fault_ipa; /* The address we faulted on */ + phys_addr_t ipa; /* Always the IPA in the L1 guest phys space */ + struct kvm_memory_slot *memslot; + unsigned long hva; + bool is_iabt, write_fault, writable; + gfn_t gfn; + int ret, idx; + + if (kvm_vcpu_abt_issea(vcpu)) + return kvm_handle_guest_sea(vcpu); + + esr = kvm_vcpu_get_esr(vcpu); + + /* + * The fault IPA should be reliable at this point as we're not dealing + * with an SEA. + */ + ipa = fault_ipa = kvm_vcpu_get_fault_ipa(vcpu); + if (KVM_BUG_ON(ipa == INVALID_GPA, vcpu->kvm)) + return -EFAULT; + + is_iabt = kvm_vcpu_trap_is_iabt(vcpu); + + if (esr_fsc_is_translation_fault(esr)) { + /* Beyond sanitised PARange (which is the IPA limit) */ + if (fault_ipa >= BIT_ULL(get_kvm_ipa_limit())) { + kvm_inject_size_fault(vcpu); + return 1; + } + + /* Falls between the IPA range and the PARange? */ + if (fault_ipa >= BIT_ULL(VTCR_EL2_IPA(vcpu->arch.hw_mmu->vtcr))) { + fault_ipa |= FAR_TO_FIPA_OFFSET(kvm_vcpu_get_hfar(vcpu)); + + return kvm_inject_sea(vcpu, is_iabt, fault_ipa); + } + } + + trace_kvm_guest_fault(*vcpu_pc(vcpu), kvm_vcpu_get_esr(vcpu), + kvm_vcpu_get_hfar(vcpu), fault_ipa); + + /* Check the stage-2 fault is trans. fault or write fault */ + if (!esr_fsc_is_translation_fault(esr) && + !esr_fsc_is_permission_fault(esr) && + !esr_fsc_is_access_flag_fault(esr) && + !esr_fsc_is_excl_atomic_fault(esr)) { + kvm_err("Unsupported FSC: EC=%#x xFSC=%#lx ESR_EL2=%#lx\n", + kvm_vcpu_trap_get_class(vcpu), + (unsigned long)kvm_vcpu_trap_get_fault(vcpu), + (unsigned long)kvm_vcpu_get_esr(vcpu)); + return -EFAULT; + } + + idx = srcu_read_lock(&vcpu->kvm->srcu); + + /* + * We may have faulted on a shadow stage 2 page table if we are + * running a nested guest. In this case, we have to resolve the L2 + * IPA to the L1 IPA first, before knowing what kind of memory should + * back the L1 IPA. + * + * If the shadow stage 2 page table walk faults, then we simply inject + * this to the guest and carry on. + * + * If there are no shadow S2 PTs because S2 is disabled, there is + * nothing to walk and we treat it as a 1:1 before going through the + * canonical translation. + */ + if (kvm_is_nested_s2_mmu(vcpu->kvm,vcpu->arch.hw_mmu) && + vcpu->arch.hw_mmu->nested_stage2_enabled) { + u32 esr; + + ret = kvm_walk_nested_s2(vcpu, fault_ipa, &nested_trans); + if (ret == -EAGAIN) { + ret = 1; + goto out_unlock; + } + + if (ret) { + esr = kvm_s2_trans_esr(&nested_trans); + kvm_inject_s2_fault(vcpu, esr); + goto out_unlock; + } + + ret = kvm_s2_handle_perm_fault(vcpu, &nested_trans); + if (ret) { + esr = kvm_s2_trans_esr(&nested_trans); + kvm_inject_s2_fault(vcpu, esr); + goto out_unlock; + } + + ipa = kvm_s2_trans_output(&nested_trans); + nested = &nested_trans; + } + + gfn = ipa >> PAGE_SHIFT; + memslot = gfn_to_memslot(vcpu->kvm, gfn); + hva = gfn_to_hva_memslot_prot(memslot, gfn, &writable); + write_fault = kvm_is_write_fault(vcpu); + if (kvm_is_error_hva(hva) || (write_fault && !writable)) { + /* + * The guest has put either its instructions or its page-tables + * somewhere it shouldn't have. Userspace won't be able to do + * anything about this (there's no syndrome for a start), so + * re-inject the abort back into the guest. + */ + if (is_iabt) { + ret = -ENOEXEC; + goto out; + } + + if (kvm_vcpu_abt_iss1tw(vcpu)) { + ret = kvm_inject_sea_dabt(vcpu, kvm_vcpu_get_hfar(vcpu)); + goto out_unlock; + } + + /* + * Check for a cache maintenance operation. Since we + * ended-up here, we know it is outside of any memory + * slot. But we can't find out if that is for a device, + * or if the guest is just being stupid. The only thing + * we know for sure is that this range cannot be cached. + * + * So let's assume that the guest is just being + * cautious, and skip the instruction. + */ + if (kvm_is_error_hva(hva) && kvm_vcpu_dabt_is_cm(vcpu)) { + kvm_incr_pc(vcpu); + ret = 1; + goto out_unlock; + } + + /* + * The IPA is reported as [MAX:12], so we need to + * complement it with the bottom 12 bits from the + * faulting VA. This is always 12 bits, irrespective + * of the page size. + */ + ipa |= FAR_TO_FIPA_OFFSET(kvm_vcpu_get_hfar(vcpu)); + ret = io_mem_abort(vcpu, ipa); + goto out_unlock; + } + + /* Userspace should not be able to register out-of-bounds IPAs */ + VM_BUG_ON(ipa >= kvm_phys_size(vcpu->arch.hw_mmu)); + + if (esr_fsc_is_access_flag_fault(esr)) { + handle_access_fault(vcpu, fault_ipa); + ret = 1; + goto out_unlock; + } + + const struct kvm_s2_fault_desc s2fd = { + .vcpu = vcpu, + .fault_ipa = fault_ipa, + .nested = nested, + .memslot = memslot, + .hva = hva, + }; + + if (kvm_vm_is_protected(vcpu->kvm)) { + ret = pkvm_mem_abort(&s2fd); + } else { + VM_WARN_ON_ONCE(kvm_vcpu_trap_is_permission_fault(vcpu) && + !write_fault && + !kvm_vcpu_trap_is_exec_fault(vcpu)); + + if (kvm_slot_has_gmem(memslot)) + ret = gmem_abort(&s2fd); + else + ret = user_mem_abort(&s2fd); + } + + if (ret == 0) + ret = 1; +out: + if (ret == -ENOEXEC) + ret = kvm_inject_sea_iabt(vcpu, kvm_vcpu_get_hfar(vcpu)); +out_unlock: + srcu_read_unlock(&vcpu->kvm->srcu, idx); + return ret; +} + +bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range) +{ + if (!kvm->arch.mmu.pgt || kvm_vm_is_protected(kvm)) + return false; + + __unmap_stage2_range(&kvm->arch.mmu, range->start << PAGE_SHIFT, + (range->end - range->start) << PAGE_SHIFT, + range->may_block); + + kvm_nested_s2_unmap(kvm, range->may_block); + return false; +} + +bool kvm_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range) +{ + u64 size = (range->end - range->start) << PAGE_SHIFT; + + if (!kvm->arch.mmu.pgt || kvm_vm_is_protected(kvm)) + return false; + + return KVM_PGT_FN(kvm_pgtable_stage2_test_clear_young)(kvm->arch.mmu.pgt, + range->start << PAGE_SHIFT, + size, true); + /* + * TODO: Handle nested_mmu structures here using the reverse mapping in + * a later version of patch series. + */ +} + +bool kvm_test_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range) +{ + u64 size = (range->end - range->start) << PAGE_SHIFT; + + if (!kvm->arch.mmu.pgt || kvm_vm_is_protected(kvm)) + return false; + + return KVM_PGT_FN(kvm_pgtable_stage2_test_clear_young)(kvm->arch.mmu.pgt, + range->start << PAGE_SHIFT, + size, false); +} + +phys_addr_t kvm_mmu_get_httbr(void) +{ + return __pa(hyp_pgtable->pgd); +} + +phys_addr_t kvm_get_idmap_vector(void) +{ + return hyp_idmap_vector; +} + +static int kvm_map_idmap_text(void) +{ + unsigned long size = hyp_idmap_end - hyp_idmap_start; + int err = __create_hyp_mappings(hyp_idmap_start, size, hyp_idmap_start, + PAGE_HYP_EXEC); + if (err) + kvm_err("Failed to idmap %lx-%lx\n", + hyp_idmap_start, hyp_idmap_end); + + return err; +} + +static void *kvm_hyp_zalloc_page(void *arg) +{ + return (void *)get_zeroed_page(GFP_KERNEL); +} + +static struct kvm_pgtable_mm_ops kvm_hyp_mm_ops = { + .zalloc_page = kvm_hyp_zalloc_page, + .get_page = kvm_host_get_page, + .put_page = kvm_host_put_page, + .phys_to_virt = kvm_host_va, + .virt_to_phys = kvm_host_pa, +}; + +int __init kvm_mmu_init(u32 hyp_va_bits) +{ + int err; + + hyp_idmap_start = __pa_symbol(__hyp_idmap_text_start); + hyp_idmap_start = ALIGN_DOWN(hyp_idmap_start, PAGE_SIZE); + hyp_idmap_end = __pa_symbol(__hyp_idmap_text_end); + hyp_idmap_end = ALIGN(hyp_idmap_end, PAGE_SIZE); + hyp_idmap_vector = __pa_symbol(__kvm_hyp_init); + + /* + * We rely on the linker script to ensure at build time that the HYP + * init code does not cross a page boundary. + */ + BUG_ON((hyp_idmap_start ^ (hyp_idmap_end - 1)) & PAGE_MASK); + + kvm_debug("Using %u-bit virtual addresses at EL2\n", hyp_va_bits); + kvm_debug("IDMAP page: %lx\n", hyp_idmap_start); + kvm_debug("HYP VA range: %lx:%lx\n", + kern_hyp_va(PAGE_OFFSET), + kern_hyp_va((unsigned long)high_memory - 1)); + + if (hyp_idmap_start >= kern_hyp_va(PAGE_OFFSET) && + hyp_idmap_start < kern_hyp_va((unsigned long)high_memory - 1) && + hyp_idmap_start != (unsigned long)__hyp_idmap_text_start) { + /* + * The idmap page is intersecting with the VA space, + * it is not safe to continue further. + */ + kvm_err("IDMAP intersecting with HYP VA, unable to continue\n"); + err = -EINVAL; + goto out; + } + + hyp_pgtable = kzalloc_obj(*hyp_pgtable); + if (!hyp_pgtable) { + kvm_err("Hyp mode page-table not allocated\n"); + err = -ENOMEM; + goto out; + } + + err = kvm_pgtable_hyp_init(hyp_pgtable, hyp_va_bits, &kvm_hyp_mm_ops); + if (err) + goto out_free_pgtable; + + err = kvm_map_idmap_text(); + if (err) + goto out_destroy_pgtable; + + io_map_base = hyp_idmap_start; + __hyp_va_bits = hyp_va_bits; + return 0; + +out_destroy_pgtable: + kvm_pgtable_hyp_destroy(hyp_pgtable); +out_free_pgtable: + kfree(hyp_pgtable); + hyp_pgtable = NULL; +out: + return err; +} + +void kvm_arch_commit_memory_region(struct kvm *kvm, + struct kvm_memory_slot *old, + const struct kvm_memory_slot *new, + enum kvm_mr_change change) +{ + bool log_dirty_pages = new && new->flags & KVM_MEM_LOG_DIRTY_PAGES; + + /* + * At this point memslot has been committed and there is an + * allocated dirty_bitmap[], dirty pages will be tracked while the + * memory slot is write protected. + */ + if (log_dirty_pages) { + + if (change == KVM_MR_DELETE) + return; + + /* + * Huge and normal pages are write-protected and split + * on either of these two cases: + * + * 1. with initial-all-set: gradually with CLEAR ioctls, + */ + if (kvm_dirty_log_manual_protect_and_init_set(kvm)) + return; + /* + * or + * 2. without initial-all-set: all in one shot when + * enabling dirty logging. + */ + kvm_mmu_wp_memory_region(kvm, new->id); + kvm_mmu_split_memory_region(kvm, new->id); + } else { + /* + * Free any leftovers from the eager page splitting cache. Do + * this when deleting, moving, disabling dirty logging, or + * creating the memslot (a nop). Doing it for deletes makes + * sure we don't leak memory, and there's no need to keep the + * cache around for any of the other cases. + */ + kvm_mmu_free_memory_cache(&kvm->arch.mmu.split_page_cache); + } +} + +int kvm_arch_prepare_memory_region(struct kvm *kvm, + const struct kvm_memory_slot *old, + struct kvm_memory_slot *new, + enum kvm_mr_change change) +{ + hva_t hva, reg_end; + int ret = 0; + + if (kvm_vm_is_protected(kvm)) { + /* Cannot modify memslots once a pVM has run. */ + if (pkvm_hyp_vm_is_created(kvm) && + (change == KVM_MR_DELETE || change == KVM_MR_MOVE)) { + return -EPERM; + } + + if (new && + new->flags & (KVM_MEM_LOG_DIRTY_PAGES | KVM_MEM_READONLY)) { + return -EPERM; + } + } + + if (change != KVM_MR_CREATE && change != KVM_MR_MOVE && + change != KVM_MR_FLAGS_ONLY) + return 0; + + /* + * Prevent userspace from creating a memory region outside of the IPA + * space addressable by the KVM guest IPA space. + */ + if ((new->base_gfn + new->npages) > (kvm_phys_size(&kvm->arch.mmu) >> PAGE_SHIFT)) + return -EFAULT; + + /* + * Only support guest_memfd backed memslots with mappable memory, since + * there aren't any CoCo VMs that support only private memory on arm64. + */ + if (kvm_slot_has_gmem(new) && !kvm_memslot_is_gmem_only(new)) + return -EINVAL; + + /* guest_memfd is incompatible with MTE. */ + if (kvm_slot_has_gmem(new) && kvm_has_mte(kvm)) + return -EINVAL; + + hva = new->userspace_addr; + reg_end = hva + (new->npages << PAGE_SHIFT); + + mmap_read_lock(current->mm); + /* + * A memory region could potentially cover multiple VMAs, and any holes + * between them, so iterate over all of them. + * + * +--------------------------------------------+ + * +---------------+----------------+ +----------------+ + * | : VMA 1 | VMA 2 | | VMA 3 : | + * +---------------+----------------+ +----------------+ + * | memory region | + * +--------------------------------------------+ + */ + do { + struct vm_area_struct *vma; + + vma = find_vma_intersection(current->mm, hva, reg_end); + if (!vma) + break; + + if (kvm_has_mte(kvm) && !kvm_vma_mte_allowed(vma)) { + ret = -EINVAL; + break; + } + + if (vma->vm_flags & VM_PFNMAP) { + /* IO region dirty page logging not allowed */ + if (new->flags & KVM_MEM_LOG_DIRTY_PAGES) { + ret = -EINVAL; + break; + } + + /* + * Cacheable PFNMAP is allowed only if the hardware + * supports it. + */ + if (kvm_vma_is_cacheable(vma) && !kvm_supports_cacheable_pfnmap()) { + ret = -EINVAL; + break; + } + } + hva = min(reg_end, vma->vm_end); + } while (hva < reg_end); + + mmap_read_unlock(current->mm); + return ret; +} + +void kvm_arch_free_memslot(struct kvm *kvm, struct kvm_memory_slot *slot) +{ +} + +void kvm_arch_memslots_updated(struct kvm *kvm, u64 gen) +{ +} + +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; + + write_lock(&kvm->mmu_lock); + kvm_stage2_unmap_range(&kvm->arch.mmu, gpa, size, true); + kvm_nested_s2_unmap(kvm, true); + write_unlock(&kvm->mmu_lock); +} + +/* + * See note at ARMv7 ARM B1.14.4 (TL;DR: S/W ops are not easily virtualized). + * + * Main problems: + * - S/W ops are local to a CPU (not broadcast) + * - We have line migration behind our back (speculation) + * - System caches don't support S/W at all (damn!) + * + * In the face of the above, the best we can do is to try and convert + * S/W ops to VA ops. Because the guest is not allowed to infer the + * S/W to PA mapping, it can only use S/W to nuke the whole cache, + * which is a rather good thing for us. + * + * Also, it is only used when turning caches on/off ("The expected + * usage of the cache maintenance instructions that operate by set/way + * is associated with the cache maintenance instructions associated + * with the powerdown and powerup of caches, if this is required by + * the implementation."). + * + * We use the following policy: + * + * - If we trap a S/W operation, we enable VM trapping to detect + * caches being turned on/off, and do a full clean. + * + * - We flush the caches on both caches being turned on and off. + * + * - Once the caches are enabled, we stop trapping VM ops. + */ +void kvm_set_way_flush(struct kvm_vcpu *vcpu) +{ + unsigned long hcr = *vcpu_hcr(vcpu); + + /* + * If this is the first time we do a S/W operation + * (i.e. HCR_TVM not set) flush the whole memory, and set the + * VM trapping. + * + * Otherwise, rely on the VM trapping to wait for the MMU + + * Caches to be turned off. At that point, we'll be able to + * clean the caches again. + */ + if (!(hcr & HCR_TVM)) { + trace_kvm_set_way_flush(*vcpu_pc(vcpu), + vcpu_has_cache_enabled(vcpu)); + stage2_flush_vm(vcpu->kvm); + *vcpu_hcr(vcpu) = hcr | HCR_TVM; + } +} + +void kvm_toggle_cache(struct kvm_vcpu *vcpu, bool was_enabled) +{ + bool now_enabled = vcpu_has_cache_enabled(vcpu); + + /* + * If switching the MMU+caches on, need to invalidate the caches. + * If switching it off, need to clean the caches. + * Clean + invalidate does the trick always. + */ + if (now_enabled != was_enabled) + stage2_flush_vm(vcpu->kvm); + + /* Caches are now on, stop trapping VM ops (until a S/W op) */ + if (now_enabled) + *vcpu_hcr(vcpu) &= ~HCR_TVM; + + trace_kvm_toggle_cache(*vcpu_pc(vcpu), was_enabled, now_enabled); +} |