diff options
Diffstat (limited to 'arch/arm64/kvm/mmu.c')
| -rw-r--r-- | arch/arm64/kvm/mmu.c | 2467 |
1 files changed, 2467 insertions, 0 deletions
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c new file mode 100644 index 000000000000..a1f6bc70c4e4 --- /dev/null +++ b/arch/arm64/kvm/mmu.c @@ -0,0 +1,2467 @@ +// 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/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/pgalloc.h> +#include <asm/cacheflush.h> +#include <asm/kvm_arm.h> +#include <asm/kvm_mmu.h> +#include <asm/kvm_ras.h> +#include <asm/kvm_asm.h> +#include <asm/kvm_emulate.h> +#include <asm/virt.h> + +#include "trace.h" + +static pgd_t *boot_hyp_pgd; +static pgd_t *hyp_pgd; +static pgd_t *merged_hyp_pgd; +static DEFINE_MUTEX(kvm_hyp_pgd_mutex); + +static unsigned long hyp_idmap_start; +static unsigned long hyp_idmap_end; +static phys_addr_t hyp_idmap_vector; + +static unsigned long io_map_base; + +#define hyp_pgd_order get_order(PTRS_PER_PGD * sizeof(pgd_t)) + +#define KVM_S2PTE_FLAG_IS_IOMAP (1UL << 0) +#define KVM_S2_FLAG_LOGGING_ACTIVE (1UL << 1) + +static bool is_iomap(unsigned long flags) +{ + return flags & KVM_S2PTE_FLAG_IS_IOMAP; +} + +static bool memslot_is_logging(struct kvm_memory_slot *memslot) +{ + return memslot->dirty_bitmap && !(memslot->flags & KVM_MEM_READONLY); +} + +/** + * kvm_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 + */ +void kvm_flush_remote_tlbs(struct kvm *kvm) +{ + kvm_call_hyp(__kvm_tlb_flush_vmid, kvm); +} + +static void kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa) +{ + kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, kvm, ipa); +} + +/* + * D-Cache management functions. They take the page table entries by + * value, as they are flushing the cache using the kernel mapping (or + * kmap on 32bit). + */ +static void kvm_flush_dcache_pte(pte_t pte) +{ + __kvm_flush_dcache_pte(pte); +} + +static void kvm_flush_dcache_pmd(pmd_t pmd) +{ + __kvm_flush_dcache_pmd(pmd); +} + +static void kvm_flush_dcache_pud(pud_t pud) +{ + __kvm_flush_dcache_pud(pud); +} + +static bool kvm_is_device_pfn(unsigned long pfn) +{ + return !pfn_valid(pfn); +} + +/** + * stage2_dissolve_pmd() - clear and flush huge PMD entry + * @kvm: pointer to kvm structure. + * @addr: IPA + * @pmd: pmd pointer for IPA + * + * Function clears a PMD entry, flushes addr 1st and 2nd stage TLBs. + */ +static void stage2_dissolve_pmd(struct kvm *kvm, phys_addr_t addr, pmd_t *pmd) +{ + if (!pmd_thp_or_huge(*pmd)) + return; + + pmd_clear(pmd); + kvm_tlb_flush_vmid_ipa(kvm, addr); + put_page(virt_to_page(pmd)); +} + +/** + * stage2_dissolve_pud() - clear and flush huge PUD entry + * @kvm: pointer to kvm structure. + * @addr: IPA + * @pud: pud pointer for IPA + * + * Function clears a PUD entry, flushes addr 1st and 2nd stage TLBs. + */ +static void stage2_dissolve_pud(struct kvm *kvm, phys_addr_t addr, pud_t *pudp) +{ + if (!stage2_pud_huge(kvm, *pudp)) + return; + + stage2_pud_clear(kvm, pudp); + kvm_tlb_flush_vmid_ipa(kvm, addr); + put_page(virt_to_page(pudp)); +} + +static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache *cache, + int min, int max) +{ + void *page; + + BUG_ON(max > KVM_NR_MEM_OBJS); + if (cache->nobjs >= min) + return 0; + while (cache->nobjs < max) { + page = (void *)__get_free_page(GFP_PGTABLE_USER); + if (!page) + return -ENOMEM; + cache->objects[cache->nobjs++] = page; + } + return 0; +} + +static void mmu_free_memory_cache(struct kvm_mmu_memory_cache *mc) +{ + while (mc->nobjs) + free_page((unsigned long)mc->objects[--mc->nobjs]); +} + +static void *mmu_memory_cache_alloc(struct kvm_mmu_memory_cache *mc) +{ + void *p; + + BUG_ON(!mc || !mc->nobjs); + p = mc->objects[--mc->nobjs]; + return p; +} + +static void clear_stage2_pgd_entry(struct kvm *kvm, pgd_t *pgd, phys_addr_t addr) +{ + pud_t *pud_table __maybe_unused = stage2_pud_offset(kvm, pgd, 0UL); + stage2_pgd_clear(kvm, pgd); + kvm_tlb_flush_vmid_ipa(kvm, addr); + stage2_pud_free(kvm, pud_table); + put_page(virt_to_page(pgd)); +} + +static void clear_stage2_pud_entry(struct kvm *kvm, pud_t *pud, phys_addr_t addr) +{ + pmd_t *pmd_table __maybe_unused = stage2_pmd_offset(kvm, pud, 0); + VM_BUG_ON(stage2_pud_huge(kvm, *pud)); + stage2_pud_clear(kvm, pud); + kvm_tlb_flush_vmid_ipa(kvm, addr); + stage2_pmd_free(kvm, pmd_table); + put_page(virt_to_page(pud)); +} + +static void clear_stage2_pmd_entry(struct kvm *kvm, pmd_t *pmd, phys_addr_t addr) +{ + pte_t *pte_table = pte_offset_kernel(pmd, 0); + VM_BUG_ON(pmd_thp_or_huge(*pmd)); + pmd_clear(pmd); + kvm_tlb_flush_vmid_ipa(kvm, addr); + free_page((unsigned long)pte_table); + put_page(virt_to_page(pmd)); +} + +static inline void kvm_set_pte(pte_t *ptep, pte_t new_pte) +{ + WRITE_ONCE(*ptep, new_pte); + dsb(ishst); +} + +static inline void kvm_set_pmd(pmd_t *pmdp, pmd_t new_pmd) +{ + WRITE_ONCE(*pmdp, new_pmd); + dsb(ishst); +} + +static inline void kvm_pmd_populate(pmd_t *pmdp, pte_t *ptep) +{ + kvm_set_pmd(pmdp, kvm_mk_pmd(ptep)); +} + +static inline void kvm_pud_populate(pud_t *pudp, pmd_t *pmdp) +{ + WRITE_ONCE(*pudp, kvm_mk_pud(pmdp)); + dsb(ishst); +} + +static inline void kvm_pgd_populate(pgd_t *pgdp, pud_t *pudp) +{ + WRITE_ONCE(*pgdp, kvm_mk_pgd(pudp)); + dsb(ishst); +} + +/* + * 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 call kvm_flush_dcache_p*() 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. + */ +static void unmap_stage2_ptes(struct kvm *kvm, pmd_t *pmd, + phys_addr_t addr, phys_addr_t end) +{ + phys_addr_t start_addr = addr; + pte_t *pte, *start_pte; + + start_pte = pte = pte_offset_kernel(pmd, addr); + do { + if (!pte_none(*pte)) { + pte_t old_pte = *pte; + + kvm_set_pte(pte, __pte(0)); + kvm_tlb_flush_vmid_ipa(kvm, addr); + + /* No need to invalidate the cache for device mappings */ + if (!kvm_is_device_pfn(pte_pfn(old_pte))) + kvm_flush_dcache_pte(old_pte); + + put_page(virt_to_page(pte)); + } + } while (pte++, addr += PAGE_SIZE, addr != end); + + if (stage2_pte_table_empty(kvm, start_pte)) + clear_stage2_pmd_entry(kvm, pmd, start_addr); +} + +static void unmap_stage2_pmds(struct kvm *kvm, pud_t *pud, + phys_addr_t addr, phys_addr_t end) +{ + phys_addr_t next, start_addr = addr; + pmd_t *pmd, *start_pmd; + + start_pmd = pmd = stage2_pmd_offset(kvm, pud, addr); + do { + next = stage2_pmd_addr_end(kvm, addr, end); + if (!pmd_none(*pmd)) { + if (pmd_thp_or_huge(*pmd)) { + pmd_t old_pmd = *pmd; + + pmd_clear(pmd); + kvm_tlb_flush_vmid_ipa(kvm, addr); + + kvm_flush_dcache_pmd(old_pmd); + + put_page(virt_to_page(pmd)); + } else { + unmap_stage2_ptes(kvm, pmd, addr, next); + } + } + } while (pmd++, addr = next, addr != end); + + if (stage2_pmd_table_empty(kvm, start_pmd)) + clear_stage2_pud_entry(kvm, pud, start_addr); +} + +static void unmap_stage2_puds(struct kvm *kvm, pgd_t *pgd, + phys_addr_t addr, phys_addr_t end) +{ + phys_addr_t next, start_addr = addr; + pud_t *pud, *start_pud; + + start_pud = pud = stage2_pud_offset(kvm, pgd, addr); + do { + next = stage2_pud_addr_end(kvm, addr, end); + if (!stage2_pud_none(kvm, *pud)) { + if (stage2_pud_huge(kvm, *pud)) { + pud_t old_pud = *pud; + + stage2_pud_clear(kvm, pud); + kvm_tlb_flush_vmid_ipa(kvm, addr); + kvm_flush_dcache_pud(old_pud); + put_page(virt_to_page(pud)); + } else { + unmap_stage2_pmds(kvm, pud, addr, next); + } + } + } while (pud++, addr = next, addr != end); + + if (stage2_pud_table_empty(kvm, start_pud)) + clear_stage2_pgd_entry(kvm, pgd, start_addr); +} + +/** + * unmap_stage2_range -- Clear stage2 page table entries to unmap a range + * @kvm: The VM pointer + * @start: The intermediate physical base address of the range to unmap + * @size: The size of the area to unmap + * + * 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 *kvm, phys_addr_t start, u64 size) +{ + pgd_t *pgd; + phys_addr_t addr = start, end = start + size; + phys_addr_t next; + + assert_spin_locked(&kvm->mmu_lock); + WARN_ON(size & ~PAGE_MASK); + + pgd = kvm->arch.pgd + stage2_pgd_index(kvm, addr); + do { + /* + * Make sure the page table is still active, as another thread + * could have possibly freed the page table, while we released + * the lock. + */ + if (!READ_ONCE(kvm->arch.pgd)) + break; + next = stage2_pgd_addr_end(kvm, addr, end); + if (!stage2_pgd_none(kvm, *pgd)) + unmap_stage2_puds(kvm, pgd, addr, next); + /* + * If the range is too large, release the kvm->mmu_lock + * to prevent starvation and lockup detector warnings. + */ + if (next != end) + cond_resched_lock(&kvm->mmu_lock); + } while (pgd++, addr = next, addr != end); +} + +static void stage2_flush_ptes(struct kvm *kvm, pmd_t *pmd, + phys_addr_t addr, phys_addr_t end) +{ + pte_t *pte; + + pte = pte_offset_kernel(pmd, addr); + do { + if (!pte_none(*pte) && !kvm_is_device_pfn(pte_pfn(*pte))) + kvm_flush_dcache_pte(*pte); + } while (pte++, addr += PAGE_SIZE, addr != end); +} + +static void stage2_flush_pmds(struct kvm *kvm, pud_t *pud, + phys_addr_t addr, phys_addr_t end) +{ + pmd_t *pmd; + phys_addr_t next; + + pmd = stage2_pmd_offset(kvm, pud, addr); + do { + next = stage2_pmd_addr_end(kvm, addr, end); + if (!pmd_none(*pmd)) { + if (pmd_thp_or_huge(*pmd)) + kvm_flush_dcache_pmd(*pmd); + else + stage2_flush_ptes(kvm, pmd, addr, next); + } + } while (pmd++, addr = next, addr != end); +} + +static void stage2_flush_puds(struct kvm *kvm, pgd_t *pgd, + phys_addr_t addr, phys_addr_t end) +{ + pud_t *pud; + phys_addr_t next; + + pud = stage2_pud_offset(kvm, pgd, addr); + do { + next = stage2_pud_addr_end(kvm, addr, end); + if (!stage2_pud_none(kvm, *pud)) { + if (stage2_pud_huge(kvm, *pud)) + kvm_flush_dcache_pud(*pud); + else + stage2_flush_pmds(kvm, pud, addr, next); + } + } while (pud++, addr = next, addr != end); +} + +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; + phys_addr_t next; + pgd_t *pgd; + + pgd = kvm->arch.pgd + stage2_pgd_index(kvm, addr); + do { + next = stage2_pgd_addr_end(kvm, addr, end); + if (!stage2_pgd_none(kvm, *pgd)) + stage2_flush_puds(kvm, pgd, addr, next); + + if (next != end) + cond_resched_lock(&kvm->mmu_lock); + } while (pgd++, addr = next, 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; + + idx = srcu_read_lock(&kvm->srcu); + spin_lock(&kvm->mmu_lock); + + slots = kvm_memslots(kvm); + kvm_for_each_memslot(memslot, slots) + stage2_flush_memslot(kvm, memslot); + + spin_unlock(&kvm->mmu_lock); + srcu_read_unlock(&kvm->srcu, idx); +} + +static void clear_hyp_pgd_entry(pgd_t *pgd) +{ + pud_t *pud_table __maybe_unused = pud_offset(pgd, 0UL); + pgd_clear(pgd); + pud_free(NULL, pud_table); + put_page(virt_to_page(pgd)); +} + +static void clear_hyp_pud_entry(pud_t *pud) +{ + pmd_t *pmd_table __maybe_unused = pmd_offset(pud, 0); + VM_BUG_ON(pud_huge(*pud)); + pud_clear(pud); + pmd_free(NULL, pmd_table); + put_page(virt_to_page(pud)); +} + +static void clear_hyp_pmd_entry(pmd_t *pmd) +{ + pte_t *pte_table = pte_offset_kernel(pmd, 0); + VM_BUG_ON(pmd_thp_or_huge(*pmd)); + pmd_clear(pmd); + pte_free_kernel(NULL, pte_table); + put_page(virt_to_page(pmd)); +} + +static void unmap_hyp_ptes(pmd_t *pmd, phys_addr_t addr, phys_addr_t end) +{ + pte_t *pte, *start_pte; + + start_pte = pte = pte_offset_kernel(pmd, addr); + do { + if (!pte_none(*pte)) { + kvm_set_pte(pte, __pte(0)); + put_page(virt_to_page(pte)); + } + } while (pte++, addr += PAGE_SIZE, addr != end); + + if (hyp_pte_table_empty(start_pte)) + clear_hyp_pmd_entry(pmd); +} + +static void unmap_hyp_pmds(pud_t *pud, phys_addr_t addr, phys_addr_t end) +{ + phys_addr_t next; + pmd_t *pmd, *start_pmd; + + start_pmd = pmd = pmd_offset(pud, addr); + do { + next = pmd_addr_end(addr, end); + /* Hyp doesn't use huge pmds */ + if (!pmd_none(*pmd)) + unmap_hyp_ptes(pmd, addr, next); + } while (pmd++, addr = next, addr != end); + + if (hyp_pmd_table_empty(start_pmd)) + clear_hyp_pud_entry(pud); +} + +static void unmap_hyp_puds(pgd_t *pgd, phys_addr_t addr, phys_addr_t end) +{ + phys_addr_t next; + pud_t *pud, *start_pud; + + start_pud = pud = pud_offset(pgd, addr); + do { + next = pud_addr_end(addr, end); + /* Hyp doesn't use huge puds */ + if (!pud_none(*pud)) + unmap_hyp_pmds(pud, addr, next); + } while (pud++, addr = next, addr != end); + + if (hyp_pud_table_empty(start_pud)) + clear_hyp_pgd_entry(pgd); +} + +static unsigned int kvm_pgd_index(unsigned long addr, unsigned int ptrs_per_pgd) +{ + return (addr >> PGDIR_SHIFT) & (ptrs_per_pgd - 1); +} + +static void __unmap_hyp_range(pgd_t *pgdp, unsigned long ptrs_per_pgd, + phys_addr_t start, u64 size) +{ + pgd_t *pgd; + phys_addr_t addr = start, end = start + size; + phys_addr_t next; + + /* + * We don't unmap anything from HYP, except at the hyp tear down. + * Hence, we don't have to invalidate the TLBs here. + */ + pgd = pgdp + kvm_pgd_index(addr, ptrs_per_pgd); + do { + next = pgd_addr_end(addr, end); + if (!pgd_none(*pgd)) + unmap_hyp_puds(pgd, addr, next); + } while (pgd++, addr = next, addr != end); +} + +static void unmap_hyp_range(pgd_t *pgdp, phys_addr_t start, u64 size) +{ + __unmap_hyp_range(pgdp, PTRS_PER_PGD, start, size); +} + +static void unmap_hyp_idmap_range(pgd_t *pgdp, phys_addr_t start, u64 size) +{ + __unmap_hyp_range(pgdp, __kvm_idmap_ptrs_per_pgd(), start, size); +} + +/** + * free_hyp_pgds - free Hyp-mode page tables + * + * Assumes hyp_pgd is a page table used strictly in Hyp-mode and + * therefore contains either mappings in the kernel memory area (above + * PAGE_OFFSET), or device mappings in the idmap range. + * + * boot_hyp_pgd should only map the idmap range, and is only used in + * the extended idmap case. + */ +void free_hyp_pgds(void) +{ + pgd_t *id_pgd; + + mutex_lock(&kvm_hyp_pgd_mutex); + + id_pgd = boot_hyp_pgd ? boot_hyp_pgd : hyp_pgd; + + if (id_pgd) { + /* In case we never called hyp_mmu_init() */ + if (!io_map_base) + io_map_base = hyp_idmap_start; + unmap_hyp_idmap_range(id_pgd, io_map_base, + hyp_idmap_start + PAGE_SIZE - io_map_base); + } + + if (boot_hyp_pgd) { + free_pages((unsigned long)boot_hyp_pgd, hyp_pgd_order); + boot_hyp_pgd = NULL; + } + + if (hyp_pgd) { + unmap_hyp_range(hyp_pgd, kern_hyp_va(PAGE_OFFSET), + (uintptr_t)high_memory - PAGE_OFFSET); + + free_pages((unsigned long)hyp_pgd, hyp_pgd_order); + hyp_pgd = NULL; + } + if (merged_hyp_pgd) { + clear_page(merged_hyp_pgd); + free_page((unsigned long)merged_hyp_pgd); + merged_hyp_pgd = NULL; + } + + mutex_unlock(&kvm_hyp_pgd_mutex); +} + +static void create_hyp_pte_mappings(pmd_t *pmd, unsigned long start, + unsigned long end, unsigned long pfn, + pgprot_t prot) +{ + pte_t *pte; + unsigned long addr; + + addr = start; + do { + pte = pte_offset_kernel(pmd, addr); + kvm_set_pte(pte, kvm_pfn_pte(pfn, prot)); + get_page(virt_to_page(pte)); + pfn++; + } while (addr += PAGE_SIZE, addr != end); +} + +static int create_hyp_pmd_mappings(pud_t *pud, unsigned long start, + unsigned long end, unsigned long pfn, + pgprot_t prot) +{ + pmd_t *pmd; + pte_t *pte; + unsigned long addr, next; + + addr = start; + do { + pmd = pmd_offset(pud, addr); + + BUG_ON(pmd_sect(*pmd)); + + if (pmd_none(*pmd)) { + pte = pte_alloc_one_kernel(NULL); + if (!pte) { + kvm_err("Cannot allocate Hyp pte\n"); + return -ENOMEM; + } + kvm_pmd_populate(pmd, pte); + get_page(virt_to_page(pmd)); + } + + next = pmd_addr_end(addr, end); + + create_hyp_pte_mappings(pmd, addr, next, pfn, prot); + pfn += (next - addr) >> PAGE_SHIFT; + } while (addr = next, addr != end); + + 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; + } + kvm_pud_populate(pud, pmd); + get_page(virt_to_page(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 ptrs_per_pgd, + unsigned long start, unsigned long end, + unsigned long pfn, pgprot_t prot) +{ + pgd_t *pgd; + pud_t *pud; + unsigned long addr, next; + int err = 0; + + mutex_lock(&kvm_hyp_pgd_mutex); + addr = start & PAGE_MASK; + end = PAGE_ALIGN(end); + do { + pgd = pgdp + kvm_pgd_index(addr, ptrs_per_pgd); + + if (pgd_none(*pgd)) { + pud = pud_alloc_one(NULL, addr); + if (!pud) { + kvm_err("Cannot allocate Hyp pud\n"); + err = -ENOMEM; + goto out; + } + kvm_pgd_populate(pgd, pud); + get_page(virt_to_page(pgd)); + } + + next = pgd_addr_end(addr, end); + err = create_hyp_pud_mappings(pgd, addr, next, pfn, prot); + if (err) + goto out; + pfn += (next - addr) >> PAGE_SHIFT; + } while (addr = next, addr != end); +out: + 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); + } +} + +/** + * 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, pgprot_t 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; + + 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(hyp_pgd, PTRS_PER_PGD, + virt_addr, virt_addr + PAGE_SIZE, + __phys_to_pfn(phys_addr), + prot); + if (err) + return err; + } + + return 0; +} + +static int __create_hyp_private_mapping(phys_addr_t phys_addr, size_t size, + unsigned long *haddr, pgprot_t prot) +{ + pgd_t *pgd = hyp_pgd; + 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 below 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 + offset_in_page(phys_addr)); + base = io_map_base - size; + + /* + * 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)) + ret = -ENOMEM; + else + io_map_base = base; + + mutex_unlock(&kvm_hyp_pgd_mutex); + + if (ret) + goto out; + + if (__kvm_cpu_uses_extended_idmap()) + pgd = boot_hyp_pgd; + + ret = __create_hyp_mappings(pgd, __kvm_idmap_ptrs_per_pgd(), + base, base + size, + __phys_to_pfn(phys_addr), prot); + if (ret) + goto out; + + *haddr = base + offset_in_page(phys_addr); + +out: + 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; + + *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; +} + +/** + * kvm_alloc_stage2_pgd - allocate level-1 table for stage-2 translation. + * @kvm: The KVM struct pointer for the VM. + * + * Allocates only the stage-2 HW PGD level table(s) of size defined by + * stage2_pgd_size(kvm). + * + * Note we don't need locking here as this is only called when the VM is + * created, which can only be done once. + */ +int kvm_alloc_stage2_pgd(struct kvm *kvm) +{ + phys_addr_t pgd_phys; + pgd_t *pgd; + + if (kvm->arch.pgd != NULL) { + kvm_err("kvm_arch already initialized?\n"); + return -EINVAL; + } + + /* Allocate the HW PGD, making sure that each page gets its own refcount */ + pgd = alloc_pages_exact(stage2_pgd_size(kvm), GFP_KERNEL | __GFP_ZERO); + if (!pgd) + return -ENOMEM; + + pgd_phys = virt_to_phys(pgd); + if (WARN_ON(pgd_phys & ~kvm_vttbr_baddr_mask(kvm))) + return -EINVAL; + + kvm->arch.pgd = pgd; + kvm->arch.pgd_phys = pgd_phys; + return 0; +} + +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 = find_vma(current->mm, hva); + hva_t vm_start, vm_end; + + if (!vma || vma->vm_start >= reg_end) + 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); + unmap_stage2_range(kvm, gpa, vm_end - vm_start); + } + 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; + + idx = srcu_read_lock(&kvm->srcu); + down_read(¤t->mm->mmap_sem); + spin_lock(&kvm->mmu_lock); + + slots = kvm_memslots(kvm); + kvm_for_each_memslot(memslot, slots) + stage2_unmap_memslot(kvm, memslot); + + spin_unlock(&kvm->mmu_lock); + up_read(¤t->mm->mmap_sem); + srcu_read_unlock(&kvm->srcu, idx); +} + +/** + * kvm_free_stage2_pgd - free all stage-2 tables + * @kvm: The KVM struct pointer for the VM. + * + * Walks the level-1 page table pointed to by kvm->arch.pgd and frees all + * underlying level-2 and level-3 tables before freeing the actual level-1 table + * and setting the struct pointer to NULL. + */ +void kvm_free_stage2_pgd(struct kvm *kvm) +{ + void *pgd = NULL; + + spin_lock(&kvm->mmu_lock); + if (kvm->arch.pgd) { + unmap_stage2_range(kvm, 0, kvm_phys_size(kvm)); + pgd = READ_ONCE(kvm->arch.pgd); + kvm->arch.pgd = NULL; + kvm->arch.pgd_phys = 0; + } + spin_unlock(&kvm->mmu_lock); + + /* Free the HW pgd, one page at a time */ + if (pgd) + free_pages_exact(pgd, stage2_pgd_size(kvm)); +} + +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; + + pgd = kvm->arch.pgd + stage2_pgd_index(kvm, addr); + if (stage2_pgd_none(kvm, *pgd)) { + if (!cache) + return NULL; + pud = mmu_memory_cache_alloc(cache); + stage2_pgd_populate(kvm, pgd, pud); + get_page(virt_to_page(pgd)); + } + + return stage2_pud_offset(kvm, 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 || stage2_pud_huge(kvm, *pud)) + return NULL; + + if (stage2_pud_none(kvm, *pud)) { + if (!cache) + return NULL; + pmd = mmu_memory_cache_alloc(cache); + stage2_pud_populate(kvm, pud, pmd); + get_page(virt_to_page(pud)); + } + + return stage2_pmd_offset(kvm, pud, addr); +} + +static int stage2_set_pmd_huge(struct kvm *kvm, struct kvm_mmu_memory_cache + *cache, phys_addr_t addr, const pmd_t *new_pmd) +{ + pmd_t *pmd, old_pmd; + +retry: + pmd = stage2_get_pmd(kvm, cache, addr); + VM_BUG_ON(!pmd); + + old_pmd = *pmd; + /* + * Multiple vcpus faulting on the same PMD entry, can + * lead to them sequentially updating the PMD with the + * same value. Following the break-before-make + * (pmd_clear() followed by tlb_flush()) process can + * hinder forward progress due to refaults generated + * on missing translations. + * + * Skip updating the page table if the entry is + * unchanged. + */ + if (pmd_val(old_pmd) == pmd_val(*new_pmd)) + return 0; + + if (pmd_present(old_pmd)) { + /* + * If we already have PTE level mapping for this block, + * we must unmap it to avoid inconsistent TLB state and + * leaking the table page. We could end up in this situation + * if the memory slot was marked for dirty logging and was + * reverted, leaving PTE level mappings for the pages accessed + * during the period. So, unmap the PTE level mapping for this + * block and retry, as we could have released the upper level + * table in the process. + * + * Normal THP split/merge follows mmu_notifier callbacks and do + * get handled accordingly. + */ + if (!pmd_thp_or_huge(old_pmd)) { + unmap_stage2_range(kvm, addr & S2_PMD_MASK, S2_PMD_SIZE); + goto retry; + } + /* + * Mapping in huge pages should only happen through a + * fault. If a page is merged into a transparent huge + * page, the individual subpages of that huge page + * should be unmapped through MMU notifiers before we + * get here. + * + * Merging of CompoundPages is not supported; they + * should become splitting first, unmapped, merged, + * and mapped back in on-demand. + */ + WARN_ON_ONCE(pmd_pfn(old_pmd) != pmd_pfn(*new_pmd)); + pmd_clear(pmd); + kvm_tlb_flush_vmid_ipa(kvm, addr); + } else { + get_page(virt_to_page(pmd)); + } + + kvm_set_pmd(pmd, *new_pmd); + return 0; +} + +static int stage2_set_pud_huge(struct kvm *kvm, struct kvm_mmu_memory_cache *cache, + phys_addr_t addr, const pud_t *new_pudp) +{ + pud_t *pudp, old_pud; + +retry: + pudp = stage2_get_pud(kvm, cache, addr); + VM_BUG_ON(!pudp); + + old_pud = *pudp; + + /* + * A large number of vcpus faulting on the same stage 2 entry, + * can lead to a refault due to the stage2_pud_clear()/tlb_flush(). + * Skip updating the page tables if there is no change. + */ + if (pud_val(old_pud) == pud_val(*new_pudp)) + return 0; + + if (stage2_pud_present(kvm, old_pud)) { + /* + * If we already have table level mapping for this block, unmap + * the range for this block and retry. + */ + if (!stage2_pud_huge(kvm, old_pud)) { + unmap_stage2_range(kvm, addr & S2_PUD_MASK, S2_PUD_SIZE); + goto retry; + } + + WARN_ON_ONCE(kvm_pud_pfn(old_pud) != kvm_pud_pfn(*new_pudp)); + stage2_pud_clear(kvm, pudp); + kvm_tlb_flush_vmid_ipa(kvm, addr); + } else { + get_page(virt_to_page(pudp)); + } + + kvm_set_pud(pudp, *new_pudp); + return 0; +} + +/* + * stage2_get_leaf_entry - walk the stage2 VM page tables and return + * true if a valid and present leaf-entry is found. A pointer to the + * leaf-entry is returned in the appropriate level variable - pudpp, + * pmdpp, ptepp. + */ +static bool stage2_get_leaf_entry(struct kvm *kvm, phys_addr_t addr, + pud_t **pudpp, pmd_t **pmdpp, pte_t **ptepp) +{ + pud_t *pudp; + pmd_t *pmdp; + pte_t *ptep; + + *pudpp = NULL; + *pmdpp = NULL; + *ptepp = NULL; + + pudp = stage2_get_pud(kvm, NULL, addr); + if (!pudp || stage2_pud_none(kvm, *pudp) || !stage2_pud_present(kvm, *pudp)) + return false; + + if (stage2_pud_huge(kvm, *pudp)) { + *pudpp = pudp; + return true; + } + + pmdp = stage2_pmd_offset(kvm, pudp, addr); + if (!pmdp || pmd_none(*pmdp) || !pmd_present(*pmdp)) + return false; + + if (pmd_thp_or_huge(*pmdp)) { + *pmdpp = pmdp; + return true; + } + + ptep = pte_offset_kernel(pmdp, addr); + if (!ptep || pte_none(*ptep) || !pte_present(*ptep)) + return false; + + *ptepp = ptep; + return true; +} + +static bool stage2_is_exec(struct kvm *kvm, phys_addr_t addr) +{ + pud_t *pudp; + pmd_t *pmdp; + pte_t *ptep; + bool found; + + found = stage2_get_leaf_entry(kvm, addr, &pudp, &pmdp, &ptep); + if (!found) + return false; + + if (pudp) + return kvm_s2pud_exec(pudp); + else if (pmdp) + return kvm_s2pmd_exec(pmdp); + else + return kvm_s2pte_exec(ptep); +} + +static int stage2_set_pte(struct kvm *kvm, struct kvm_mmu_memory_cache *cache, + phys_addr_t addr, const pte_t *new_pte, + unsigned long flags) +{ + pud_t *pud; + pmd_t *pmd; + pte_t *pte, old_pte; + bool iomap = flags & KVM_S2PTE_FLAG_IS_IOMAP; + bool logging_active = flags & KVM_S2_FLAG_LOGGING_ACTIVE; + + VM_BUG_ON(logging_active && !cache); + + /* Create stage-2 page table mapping - Levels 0 and 1 */ + pud = stage2_get_pud(kvm, cache, addr); + if (!pud) { + /* + * Ignore calls from kvm_set_spte_hva for unallocated + * address ranges. + */ + return 0; + } + + /* + * While dirty page logging - dissolve huge PUD, then continue + * on to allocate page. + */ + if (logging_active) + stage2_dissolve_pud(kvm, addr, pud); + + if (stage2_pud_none(kvm, *pud)) { + if (!cache) + return 0; /* ignore calls from kvm_set_spte_hva */ + pmd = mmu_memory_cache_alloc(cache); + stage2_pud_populate(kvm, pud, pmd); + get_page(virt_to_page(pud)); + } + + pmd = stage2_pmd_offset(kvm, pud, addr); + if (!pmd) { + /* + * Ignore calls from kvm_set_spte_hva for unallocated + * address ranges. + */ + return 0; + } + + /* + * While dirty page logging - dissolve huge PMD, then continue on to + * allocate page. + */ + if (logging_active) + stage2_dissolve_pmd(kvm, addr, pmd); + + /* Create stage-2 page mappings - Level 2 */ + if (pmd_none(*pmd)) { + if (!cache) + return 0; /* ignore calls from kvm_set_spte_hva */ + pte = mmu_memory_cache_alloc(cache); + kvm_pmd_populate(pmd, pte); + get_page(virt_to_page(pmd)); + } + + pte = pte_offset_kernel(pmd, addr); + + if (iomap && pte_present(*pte)) + return -EFAULT; + + /* Create 2nd stage page table mapping - Level 3 */ + old_pte = *pte; + if (pte_present(old_pte)) { + /* Skip page table update if there is no change */ + if (pte_val(old_pte) == pte_val(*new_pte)) + return 0; + + kvm_set_pte(pte, __pte(0)); + kvm_tlb_flush_vmid_ipa(kvm, addr); + } else { + get_page(virt_to_page(pte)); + } + + kvm_set_pte(pte, *new_pte); + return 0; +} + +#ifndef __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG +static int stage2_ptep_test_and_clear_young(pte_t *pte) +{ + if (pte_young(*pte)) { + *pte = pte_mkold(*pte); + return 1; + } + return 0; +} +#else +static int stage2_ptep_test_and_clear_young(pte_t *pte) +{ + return __ptep_test_and_clear_young(pte); +} +#endif + +static int stage2_pmdp_test_and_clear_young(pmd_t *pmd) +{ + return stage2_ptep_test_and_clear_young((pte_t *)pmd); +} + +static int stage2_pudp_test_and_clear_young(pud_t *pud) +{ + return stage2_ptep_test_and_clear_young((pte_t *)pud); +} + +/** + * 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 + */ +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, end; + int ret = 0; + unsigned long pfn; + struct kvm_mmu_memory_cache cache = { 0, }; + + end = (guest_ipa + size + PAGE_SIZE - 1) & PAGE_MASK; + pfn = __phys_to_pfn(pa); + + for (addr = guest_ipa; addr < end; addr += PAGE_SIZE) { + pte_t pte = kvm_pfn_pte(pfn, PAGE_S2_DEVICE); + + if (writable) + pte = kvm_s2pte_mkwrite(pte); + + ret = mmu_topup_memory_cache(&cache, + kvm_mmu_cache_min_pages(kvm), + KVM_NR_MEM_OBJS); + if (ret) + goto out; + spin_lock(&kvm->mmu_lock); + ret = stage2_set_pte(kvm, &cache, addr, &pte, + KVM_S2PTE_FLAG_IS_IOMAP); + spin_unlock(&kvm->mmu_lock); + if (ret) + goto out; + + pfn++; + } + +out: + mmu_free_memory_cache(&cache); + return ret; +} + +/** + * stage2_wp_ptes - write protect PMD range + * @pmd: pointer to pmd entry + * @addr: range start address + * @end: range end address + */ +static void stage2_wp_ptes(pmd_t *pmd, phys_addr_t addr, phys_addr_t end) +{ + pte_t *pte; + + pte = pte_offset_kernel(pmd, addr); + do { + if (!pte_none(*pte)) { + if (!kvm_s2pte_readonly(pte)) + kvm_set_s2pte_readonly(pte); + } + } while (pte++, addr += PAGE_SIZE, addr != end); +} + +/** + * stage2_wp_pmds - write protect PUD range + * kvm: kvm instance for the VM + * @pud: pointer to pud entry + * @addr: range start address + * @end: range end address + */ +static void stage2_wp_pmds(struct kvm *kvm, pud_t *pud, + phys_addr_t addr, phys_addr_t end) +{ + pmd_t *pmd; + phys_addr_t next; + + pmd = stage2_pmd_offset(kvm, pud, addr); + + do { + next = stage2_pmd_addr_end(kvm, addr, end); + if (!pmd_none(*pmd)) { + if (pmd_thp_or_huge(*pmd)) { + if (!kvm_s2pmd_readonly(pmd)) + kvm_set_s2pmd_readonly(pmd); + } else { + stage2_wp_ptes(pmd, addr, next); + } + } + } while (pmd++, addr = next, addr != end); +} + +/** + * stage2_wp_puds - write protect PGD range + * @pgd: pointer to pgd entry + * @addr: range start address + * @end: range end address + */ +static void stage2_wp_puds(struct kvm *kvm, pgd_t *pgd, + phys_addr_t addr, phys_addr_t end) +{ + pud_t *pud; + phys_addr_t next; + + pud = stage2_pud_offset(kvm, pgd, addr); + do { + next = stage2_pud_addr_end(kvm, addr, end); + if (!stage2_pud_none(kvm, *pud)) { + if (stage2_pud_huge(kvm, *pud)) { + if (!kvm_s2pud_readonly(pud)) + kvm_set_s2pud_readonly(pud); + } else { + stage2_wp_pmds(kvm, pud, addr, next); + } + } + } while (pud++, addr = next, addr != end); +} + +/** + * stage2_wp_range() - write protect stage2 memory region range + * @kvm: The KVM pointer + * @addr: Start address of range + * @end: End address of range + */ +static void stage2_wp_range(struct kvm *kvm, phys_addr_t addr, phys_addr_t end) +{ + pgd_t *pgd; + phys_addr_t next; + + pgd = kvm->arch.pgd + stage2_pgd_index(kvm, addr); + do { + /* + * 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. + */ + cond_resched_lock(&kvm->mmu_lock); + if (!READ_ONCE(kvm->arch.pgd)) + break; + next = stage2_pgd_addr_end(kvm, addr, end); + if (stage2_pgd_present(kvm, *pgd)) + stage2_wp_puds(kvm, pgd, addr, next); + } while (pgd++, addr = next, addr != end); +} + +/** + * 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. + */ +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; + + spin_lock(&kvm->mmu_lock); + stage2_wp_range(kvm, start, end); + spin_unlock(&kvm->mmu_lock); + kvm_flush_remote_tlbs(kvm); +} + +/** + * kvm_mmu_write_protect_pt_masked() - write protect dirty pages + * @kvm: The KVM pointer + * @slot: The memory slot associated with mask + * @gfn_offset: The gfn offset in memory slot + * @mask: The mask of dirty pages at offset 'gfn_offset' in this memory + * slot to be write protected + * + * Walks bits set in mask write protects the associated pte's. Caller must + * acquire kvm_mmu_lock. + */ +static void kvm_mmu_write_protect_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; + + stage2_wp_range(kvm, start, end); +} + +/* + * kvm_arch_mmu_enable_log_dirty_pt_masked - enable dirty logging for selected + * dirty pages. + * + * It calls kvm_mmu_write_protect_pt_masked to write protect selected pages to + * enable dirty logging for them. + */ +void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm, + struct kvm_memory_slot *slot, + gfn_t gfn_offset, unsigned long mask) +{ + kvm_mmu_write_protect_pt_masked(kvm, slot, gfn_offset, mask); +} + +static void clean_dcache_guest_page(kvm_pfn_t pfn, unsigned long size) +{ + __clean_dcache_guest_page(pfn, size); +} + +static void invalidate_icache_guest_page(kvm_pfn_t pfn, unsigned long size) +{ + __invalidate_icache_guest_page(pfn, size); +} + +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; + + 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 unsigned long +transparent_hugepage_adjust(struct kvm_memory_slot *memslot, + unsigned long hva, kvm_pfn_t *pfnp, + phys_addr_t *ipap) +{ + kvm_pfn_t pfn = *pfnp; + + /* + * 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 (kvm_is_transparent_hugepage(pfn) && + fault_supports_stage2_huge_mapping(memslot, hva, PMD_SIZE)) { + /* + * The address we faulted on is backed by a transparent huge + * page. However, because we map the compound huge page and + * not the individual tail page, we need to transfer the + * refcount to the head page. We have to be careful that the + * THP doesn't start to split while we are adjusting the + * refcounts. + * + * We are sure this doesn't happen, because mmu_notifier_retry + * was successful and we are holding the mmu_lock, so if this + * THP is trying to split, it will be blocked in the mmu + * notifier before touching any of the pages, specifically + * before being able to call __split_huge_page_refcount(). + * + * We can therefore safely transfer the refcount from PG_tail + * to PG_head and switch the pfn from a tail page to the head + * page accordingly. + */ + *ipap &= PMD_MASK; + kvm_release_pfn_clean(pfn); + pfn &= ~(PTRS_PER_PMD - 1); + kvm_get_pfn(pfn); + *pfnp = pfn; + + return PMD_SIZE; + } + + /* Use page mapping if we cannot use block mapping. */ + return PAGE_SIZE; +} + +static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, + struct kvm_memory_slot *memslot, unsigned long hva, + unsigned long fault_status) +{ + int ret; + bool write_fault, writable, force_pte = false; + bool exec_fault, needs_exec; + unsigned long mmu_seq; + gfn_t gfn = fault_ipa >> PAGE_SHIFT; + struct kvm *kvm = vcpu->kvm; + struct kvm_mmu_memory_cache *memcache = &vcpu->arch.mmu_page_cache; + struct vm_area_struct *vma; + short vma_shift; + kvm_pfn_t pfn; + pgprot_t mem_type = PAGE_S2; + bool logging_active = memslot_is_logging(memslot); + unsigned long vma_pagesize, flags = 0; + + write_fault = kvm_is_write_fault(vcpu); + exec_fault = kvm_vcpu_trap_is_iabt(vcpu); + VM_BUG_ON(write_fault && exec_fault); + + if (fault_status == FSC_PERM && !write_fault && !exec_fault) { + kvm_err("Unexpected L2 read permission error\n"); + return -EFAULT; + } + + /* Let's check if we will get back a huge page backed by hugetlbfs */ + down_read(¤t->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(¤t->mm->mmap_sem); + return -EFAULT; + } + + if (is_vm_hugetlb_page(vma)) + vma_shift = huge_page_shift(hstate_vma(vma)); + else + vma_shift = PAGE_SHIFT; + + vma_pagesize = 1ULL << vma_shift; + if (logging_active || + (vma->vm_flags & VM_PFNMAP) || + !fault_supports_stage2_huge_mapping(memslot, hva, vma_pagesize)) { + force_pte = true; + vma_pagesize = PAGE_SIZE; + } + + /* + * The stage2 has a minimum of 2 level table (For arm64 see + * kvm_arm_setup_stage2()). Hence, we are guaranteed that we can + * use PMD_SIZE huge mappings (even when the PMD is folded into PGD). + * As for PUD huge maps, we must make sure that we have at least + * 3 levels, i.e, PMD is not folded. + */ + if (vma_pagesize == PMD_SIZE || + (vma_pagesize == PUD_SIZE && kvm_stage2_has_pmd(kvm))) + gfn = (fault_ipa & huge_page_mask(hstate_vma(vma))) >> PAGE_SHIFT; + up_read(¤t->mm->mmap_sem); + + /* We need minimum second+third level pages */ + ret = mmu_topup_memory_cache(memcache, kvm_mmu_cache_min_pages(kvm), + KVM_NR_MEM_OBJS); + if (ret) + return ret; + + mmu_seq = vcpu->kvm->mmu_notifier_seq; + /* + * Ensure the read of mmu_notifier_seq happens before we call + * gfn_to_pfn_prot (which calls get_user_pages), so that we don't risk + * the page we just got a reference to gets unmapped before we have a + * chance to grab the mmu_lock, which ensure that if the page gets + * unmapped afterwards, the call to kvm_unmap_hva will take it away + * from us again properly. This smp_rmb() interacts with the smp_wmb() + * in kvm_mmu_notifier_invalidate_<page|range_end>. + */ + smp_rmb(); + + pfn = gfn_to_pfn_prot(kvm, gfn, write_fault, &writable); + if (pfn == KVM_PFN_ERR_HWPOISON) { + kvm_send_hwpoison_signal(hva, vma_shift); + return 0; + } + if (is_error_noslot_pfn(pfn)) + return -EFAULT; + + if (kvm_is_device_pfn(pfn)) { + mem_type = PAGE_S2_DEVICE; + flags |= KVM_S2PTE_FLAG_IS_IOMAP; + } else if (logging_active) { + /* + * Faults on pages in a memslot with logging enabled + * should not be mapped with huge pages (it introduces churn + * and performance degradation), so force a pte mapping. + */ + flags |= KVM_S2_FLAG_LOGGING_ACTIVE; + + /* + * Only actually map the page as writable if this was a write + * fault. + */ + if (!write_fault) + writable = false; + } + + if (exec_fault && is_iomap(flags)) + return -ENOEXEC; + + spin_lock(&kvm->mmu_lock); + if (mmu_notifier_retry(kvm, mmu_seq)) + goto out_unlock; + + /* + * 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 (vma_pagesize == PAGE_SIZE && !force_pte) + vma_pagesize = transparent_hugepage_adjust(memslot, hva, + &pfn, &fault_ipa); + if (writable) + kvm_set_pfn_dirty(pfn); + + if (fault_status != FSC_PERM && !is_iomap(flags)) + clean_dcache_guest_page(pfn, vma_pagesize); + + if (exec_fault) + invalidate_icache_guest_page(pfn, vma_pagesize); + + /* + * If we took an execution fault we have made the + * icache/dcache coherent above and should now let the s2 + * mapping be executable. + * + * Write faults (!exec_fault && FSC_PERM) are orthogonal to + * execute permissions, and we preserve whatever we have. + */ + needs_exec = exec_fault || + (fault_status == FSC_PERM && stage2_is_exec(kvm, fault_ipa)); + + if (vma_pagesize == PUD_SIZE) { + pud_t new_pud = kvm_pfn_pud(pfn, mem_type); + + new_pud = kvm_pud_mkhuge(new_pud); + if (writable) + new_pud = kvm_s2pud_mkwrite(new_pud); + + if (needs_exec) + new_pud = kvm_s2pud_mkexec(new_pud); + + ret = stage2_set_pud_huge(kvm, memcache, fault_ipa, &new_pud); + } else if (vma_pagesize == PMD_SIZE) { + pmd_t new_pmd = kvm_pfn_pmd(pfn, mem_type); + + new_pmd = kvm_pmd_mkhuge(new_pmd); + + if (writable) + new_pmd = kvm_s2pmd_mkwrite(new_pmd); + + if (needs_exec) + new_pmd = kvm_s2pmd_mkexec(new_pmd); + + ret = stage2_set_pmd_huge(kvm, memcache, fault_ipa, &new_pmd); + } else { + pte_t new_pte = kvm_pfn_pte(pfn, mem_type); + + if (writable) { + new_pte = kvm_s2pte_mkwrite(new_pte); + mark_page_dirty(kvm, gfn); + } + + if (needs_exec) + new_pte = kvm_s2pte_mkexec(new_pte); + + ret = stage2_set_pte(kvm, memcache, fault_ipa, &new_pte, flags); + } + +out_unlock: + spin_unlock(&kvm->mmu_lock); + kvm_set_pfn_accessed(pfn); + kvm_release_pfn_clean(pfn); + return ret; +} + +/* + * Resolve the access fault by making the page young again. + * Note that because the faulting entry is guaranteed not to be + * cached in the TLB, we don't need to invalidate anything. + * Only the HW Access Flag updates are supported for Stage 2 (no DBM), + * so there is no need for atomic (pte|pmd)_mkyoung operations. + */ +static void handle_access_fault(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa) +{ + pud_t *pud; + pmd_t *pmd; + pte_t *pte; + kvm_pfn_t pfn; + bool pfn_valid = false; + + trace_kvm_access_fault(fault_ipa); + + spin_lock(&vcpu->kvm->mmu_lock); + + if (!stage2_get_leaf_entry(vcpu->kvm, fault_ipa, &pud, &pmd, &pte)) + goto out; + + if (pud) { /* HugeTLB */ + *pud = kvm_s2pud_mkyoung(*pud); + pfn = kvm_pud_pfn(*pud); + pfn_valid = true; + } else if (pmd) { /* THP, HugeTLB */ + *pmd = pmd_mkyoung(*pmd); + pfn = pmd_pfn(*pmd); + pfn_valid = true; + } else { + *pte = pte_mkyoung(*pte); /* Just a page... */ + pfn = pte_pfn(*pte); + pfn_valid = true; + } + +out: + spin_unlock(&vcpu->kvm->mmu_lock); + if (pfn_valid) + kvm_set_pfn_accessed(pfn); +} + +/** + * kvm_handle_guest_abort - handles all 2nd stage aborts + * @vcpu: the VCPU pointer + * @run: the kvm_run structure + * + * 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_run *run) +{ + unsigned long fault_status; + phys_addr_t fault_ipa; + struct kvm_memory_slot *memslot; + unsigned long hva; + bool is_iabt, write_fault, writable; + gfn_t gfn; + int ret, idx; + + fault_status = kvm_vcpu_trap_get_fault_type(vcpu); + + fault_ipa = kvm_vcpu_get_fault_ipa(vcpu); + is_iabt = kvm_vcpu_trap_is_iabt(vcpu); + + /* Synchronous External Abort? */ + if (kvm_vcpu_dabt_isextabt(vcpu)) { + /* + * For RAS the host kernel may handle this abort. + * There is no need to pass the error into the guest. + */ + if (!kvm_handle_guest_sea(fault_ipa, kvm_vcpu_get_hsr(vcpu))) + return 1; + + if (unlikely(!is_iabt)) { + kvm_inject_vabt(vcpu); + return 1; + } + } + + trace_kvm_guest_fault(*vcpu_pc(vcpu), kvm_vcpu_get_hsr(vcpu), + kvm_vcpu_get_hfar(vcpu), fault_ipa); + + /* Check the stage-2 fault is trans. fault or write fault */ + if (fault_status != FSC_FAULT && fault_status != FSC_PERM && + fault_status != FSC_ACCESS) { + 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_hsr(vcpu)); + return -EFAULT; + } + + idx = srcu_read_lock(&vcpu->kvm->srcu); + + gfn = fault_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)) { + if (is_iabt) { + /* Prefetch Abort on I/O address */ + ret = -ENOEXEC; + goto out; + } + + /* + * 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_vcpu_dabt_is_cm(vcpu)) { + kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(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. + */ + fault_ipa |= kvm_vcpu_get_hfar(vcpu) & ((1 << 12) - 1); + ret = io_mem_abort(vcpu, run, fault_ipa); + goto out_unlock; + } + + /* Userspace should not be able to register out-of-bounds IPAs */ + VM_BUG_ON(fault_ipa >= kvm_phys_size(vcpu->kvm)); + + if (fault_status == FSC_ACCESS) { + handle_access_fault(vcpu, fault_ipa); + ret = 1; + goto out_unlock; + } + + ret = user_mem_abort(vcpu, fault_ipa, memslot, hva, fault_status); + if (ret == 0) + ret = 1; +out: + if (ret == -ENOEXEC) { + kvm_inject_pabt(vcpu, kvm_vcpu_get_hfar(vcpu)); + ret = 1; + } +out_unlock: + srcu_read_unlock(&vcpu->kvm->srcu, idx); + return ret; +} + +static int handle_hva_to_gpa(struct kvm *kvm, + unsigned long start, + unsigned long end, + int (*handler)(struct kvm *kvm, + gpa_t gpa, u64 size, + void *data), + void *data) +{ + struct kvm_memslots *slots; + struct kvm_memory_slot *memslot; + int ret = 0; + + slots = kvm_memslots(kvm); + + /* we only care about the pages that the guest sees */ + kvm_for_each_memslot(memslot, slots) { + unsigned long hva_start, hva_end; + gfn_t gpa; + + hva_start = max(start, memslot->userspace_addr); + hva_end = min(end, memslot->userspace_addr + + (memslot->npages << PAGE_SHIFT)); + if (hva_start >= hva_end) + continue; + + gpa = hva_to_gfn_memslot(hva_start, memslot) << PAGE_SHIFT; + ret |= handler(kvm, gpa, (u64)(hva_end - hva_start), data); + } + + return ret; +} + +static int kvm_unmap_hva_handler(struct kvm *kvm, gpa_t gpa, u64 size, void *data) +{ + unmap_stage2_range(kvm, gpa, size); + return 0; +} + +int kvm_unmap_hva_range(struct kvm *kvm, + unsigned long start, unsigned long end) +{ + if (!kvm->arch.pgd) + return 0; + + trace_kvm_unmap_hva_range(start, end); + handle_hva_to_gpa(kvm, start, end, &kvm_unmap_hva_handler, NULL); + return 0; +} + +static int kvm_set_spte_handler(struct kvm *kvm, gpa_t gpa, u64 size, void *data) +{ + pte_t *pte = (pte_t *)data; + + WARN_ON(size != PAGE_SIZE); + /* + * We can always call stage2_set_pte with KVM_S2PTE_FLAG_LOGGING_ACTIVE + * flag clear because MMU notifiers will have unmapped a huge PMD before + * calling ->change_pte() (which in turn calls kvm_set_spte_hva()) and + * therefore stage2_set_pte() never needs to clear out a huge PMD + * through this calling path. + */ + stage2_set_pte(kvm, NULL, gpa, pte, 0); + return 0; +} + + +int kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte) +{ + unsigned long end = hva + PAGE_SIZE; + kvm_pfn_t pfn = pte_pfn(pte); + pte_t stage2_pte; + + if (!kvm->arch.pgd) + return 0; + + trace_kvm_set_spte_hva(hva); + + /* + * We've moved a page around, probably through CoW, so let's treat it + * just like a translation fault and clean the cache to the PoC. + */ + clean_dcache_guest_page(pfn, PAGE_SIZE); + stage2_pte = kvm_pfn_pte(pfn, PAGE_S2); + handle_hva_to_gpa(kvm, hva, end, &kvm_set_spte_handler, &stage2_pte); + + return 0; +} + +static int kvm_age_hva_handler(struct kvm *kvm, gpa_t gpa, u64 size, void *data) +{ + pud_t *pud; + pmd_t *pmd; + pte_t *pte; + + WARN_ON(size != PAGE_SIZE && size != PMD_SIZE && size != PUD_SIZE); + if (!stage2_get_leaf_entry(kvm, gpa, &pud, &pmd, &pte)) + return 0; + + if (pud) + return stage2_pudp_test_and_clear_young(pud); + else if (pmd) + return stage2_pmdp_test_and_clear_young(pmd); + else + return stage2_ptep_test_and_clear_young(pte); +} + +static int kvm_test_age_hva_handler(struct kvm *kvm, gpa_t gpa, u64 size, void *data) +{ + pud_t *pud; + pmd_t *pmd; + pte_t *pte; + + WARN_ON(size != PAGE_SIZE && size != PMD_SIZE && size != PUD_SIZE); + if (!stage2_get_leaf_entry(kvm, gpa, &pud, &pmd, &pte)) + return 0; + + if (pud) + return kvm_s2pud_young(*pud); + else if (pmd) + return pmd_young(*pmd); + else + return pte_young(*pte); +} + +int kvm_age_hva(struct kvm *kvm, unsigned long start, unsigned long end) +{ + if (!kvm->arch.pgd) + return 0; + trace_kvm_age_hva(start, end); + return handle_hva_to_gpa(kvm, start, end, kvm_age_hva_handler, NULL); +} + +int kvm_test_age_hva(struct kvm *kvm, unsigned long hva) +{ + if (!kvm->arch.pgd) + return 0; + trace_kvm_test_age_hva(hva); + return handle_hva_to_gpa(kvm, hva, hva + PAGE_SIZE, + kvm_test_age_hva_handler, NULL); +} + +void kvm_mmu_free_memory_caches(struct kvm_vcpu *vcpu) +{ + mmu_free_memory_cache(&vcpu->arch.mmu_page_cache); +} + +phys_addr_t kvm_mmu_get_httbr(void) +{ + if (__kvm_cpu_uses_extended_idmap()) + return virt_to_phys(merged_hyp_pgd); + else + return virt_to_phys(hyp_pgd); +} + +phys_addr_t kvm_get_idmap_vector(void) +{ + return hyp_idmap_vector; +} + +static int kvm_map_idmap_text(pgd_t *pgd) +{ + int err; + + /* Create the idmap in the boot page tables */ + err = __create_hyp_mappings(pgd, __kvm_idmap_ptrs_per_pgd(), + hyp_idmap_start, hyp_idmap_end, + __phys_to_pfn(hyp_idmap_start), + PAGE_HYP_EXEC); + if (err) + kvm_err("Failed to idmap %lx-%lx\n", + hyp_idmap_start, hyp_idmap_end); + + return err; +} + +int kvm_mmu_init(void) +{ + 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("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_pgd = (pgd_t *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, hyp_pgd_order); + if (!hyp_pgd) { + kvm_err("Hyp mode PGD not allocated\n"); + err = -ENOMEM; + goto out; + } + + if (__kvm_cpu_uses_extended_idmap()) { + boot_hyp_pgd = (pgd_t *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, + hyp_pgd_order); + if (!boot_hyp_pgd) { + kvm_err("Hyp boot PGD not allocated\n"); + err = -ENOMEM; + goto out; + } + + err = kvm_map_idmap_text(boot_hyp_pgd); + if (err) + goto out; + + merged_hyp_pgd = (pgd_t *)__get_free_page(GFP_KERNEL | __GFP_ZERO); + if (!merged_hyp_pgd) { + kvm_err("Failed to allocate extra HYP pgd\n"); + goto out; + } + __kvm_extend_hypmap(boot_hyp_pgd, hyp_pgd, merged_hyp_pgd, + hyp_idmap_start); + } else { + err = kvm_map_idmap_text(hyp_pgd); + if (err) + goto out; + } + + io_map_base = hyp_idmap_start; + return 0; +out: + free_hyp_pgds(); + return err; +} + +void kvm_arch_commit_memory_region(struct kvm *kvm, + const struct kvm_userspace_memory_region *mem, + struct kvm_memory_slot *old, + const struct kvm_memory_slot *new, + enum kvm_mr_change change) +{ + /* + * 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 (change != KVM_MR_DELETE && mem->flags & KVM_MEM_LOG_DIRTY_PAGES) { + /* + * If we're with initial-all-set, we don't need to write + * protect any pages because they're all reported as dirty. + * Huge pages and normal pages will be write protect gradually. + */ + if (!kvm_dirty_log_manual_protect_and_init_set(kvm)) { + kvm_mmu_wp_memory_region(kvm, mem->slot); + } + } +} + +int kvm_arch_prepare_memory_region(struct kvm *kvm, + struct kvm_memory_slot *memslot, + const struct kvm_userspace_memory_region *mem, + enum kvm_mr_change change) +{ + 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 && + 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 (memslot->base_gfn + memslot->npages >= + (kvm_phys_size(kvm) >> PAGE_SHIFT)) + return -EFAULT; + + down_read(¤t->mm->mmap_sem); + /* + * 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; + + /* + * 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; + + pa = (phys_addr_t)vma->vm_pgoff << PAGE_SHIFT; + pa += vm_start - vma->vm_start; + + /* IO region dirty page logging not allowed */ + if (memslot->flags & KVM_MEM_LOG_DIRTY_PAGES) { + ret = -EINVAL; + goto out; + } + + ret = kvm_phys_addr_ioremap(kvm, gpa, pa, + vm_end - vm_start, + writable); + if (ret) + break; + } + hva = vm_end; + } while (hva < reg_end); + + if (change == KVM_MR_FLAGS_ONLY) + goto out; + + spin_lock(&kvm->mmu_lock); + if (ret) + unmap_stage2_range(kvm, mem->guest_phys_addr, mem->memory_size); + else + stage2_flush_memslot(kvm, memslot); + spin_unlock(&kvm->mmu_lock); +out: + up_read(¤t->mm->mmap_sem); + 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_all(struct kvm *kvm) +{ + kvm_free_stage2_pgd(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); +} + +/* + * 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); +} |