| /* |
| * Copyright (C) 2012 - Virtual Open Systems and Columbia University |
| * Author: Christoffer Dall <c.dall@virtualopensystems.com> |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License, version 2, as |
| * published by the Free Software Foundation. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, write to the Free Software |
| * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. |
| */ |
| |
| #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_mmio.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 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. Marks all |
| * pages in the range dirty. |
| */ |
| 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. Marks all |
| * pages in the range dirty. |
| */ |
| 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(PGALLOC_GFP); |
| 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); |
| pte_free_kernel(NULL, 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); |
| } 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 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) (can support either full |
| * 40-bit input addresses or limited to 32-bit input addresses). Clears the |
| * allocated pages. |
| * |
| * 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 reguler 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; |
| |
| pmd = stage2_get_pmd(kvm, cache, addr); |
| VM_BUG_ON(!pmd); |
| |
| old_pmd = *pmd; |
| if (pmd_present(old_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; |
| |
| /* |
| * 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. |
| */ |
| VM_BUG_ON(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; |
| |
| 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)) { |
| 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; |
| } |
| |
| static bool transparent_hugepage_adjust(kvm_pfn_t *pfnp, phys_addr_t *ipap) |
| { |
| kvm_pfn_t pfn = *pfnp; |
| gfn_t gfn = *ipap >> PAGE_SHIFT; |
| struct page *page = pfn_to_page(pfn); |
| |
| /* |
| * PageTransCompoundMap() returns true for THP and |
| * hugetlbfs. Make sure the adjustment is done only for THP |
| * pages. |
| */ |
| if (!PageHuge(page) && PageTransCompoundMap(page)) { |
| unsigned long mask; |
| /* |
| * 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. |
| */ |
| mask = PTRS_PER_PMD - 1; |
| VM_BUG_ON((gfn & mask) != (pfn & mask)); |
| if (pfn & mask) { |
| *ipap &= PMD_MASK; |
| kvm_release_pfn_clean(pfn); |
| pfn &= ~mask; |
| kvm_get_pfn(pfn); |
| *pfnp = pfn; |
| } |
| |
| return true; |
| } |
| |
| return false; |
| } |
| |
| /** |
| * 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 |
| * |
| * Process PUD entries, for a huge PUD we cause a panic. |
| */ |
| 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 = memslot->base_gfn << PAGE_SHIFT; |
| phys_addr_t 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, |
| struct vm_area_struct *vma) |
| { |
| short lsb; |
| |
| if (is_vm_hugetlb_page(vma)) |
| lsb = huge_page_shift(hstate_vma(vma)); |
| else |
| lsb = PAGE_SHIFT; |
| |
| send_sig_mceerr(BUS_MCEERR_AR, (void __user *)address, lsb, current); |
| } |
| |
| static bool fault_supports_stage2_pmd_mappings(struct kvm_memory_slot *memslot, |
| unsigned long hva) |
| { |
| gpa_t gpa_start; |
| hva_t uaddr_start, uaddr_end; |
| size_t size; |
| |
| 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 for userspace and IPA cannot be mapped with stage-2 |
| * PMD entries, because we'll end up mapping the wrong pages. |
| * |
| * Consider a layout like the following: |
| * |
| * memslot->userspace_addr: |
| * +-----+--------------------+--------------------+---+ |
| * |abcde|fgh Stage-1 PMD | Stage-1 PMD tv|xyz| |
| * +-----+--------------------+--------------------+---+ |
| * |
| * memslot->base_gfn << PAGE_SIZE: |
| * +---+--------------------+--------------------+-----+ |
| * |abc|def Stage-2 PMD | Stage-2 PMD |tvxyz| |
| * +---+--------------------+--------------------+-----+ |
| * |
| * If we create those stage-2 PMDs, we'll end up with this incorrect |
| * mapping: |
| * d -> f |
| * e -> g |
| * f -> h |
| */ |
| if ((gpa_start & ~S2_PMD_MASK) != (uaddr_start & ~S2_PMD_MASK)) |
| 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 PMD size mappings |
| * for the beginning and end of a non-PMD aligned and non-PMD 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 & S2_PMD_MASK) >= uaddr_start && |
| (hva & S2_PMD_MASK) + S2_PMD_SIZE <= uaddr_end; |
| } |
| |
| 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; |
| 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; |
| } |
| |
| if (!fault_supports_stage2_pmd_mappings(memslot, hva)) |
| force_pte = true; |
| |
| if (logging_active) |
| force_pte = true; |
| |
| /* 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; |
| } |
| |
| vma_pagesize = vma_kernel_pagesize(vma); |
| /* |
| * 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))) && |
| !force_pte) { |
| 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); |
| 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; |
| } |
| |
| spin_lock(&kvm->mmu_lock); |
| if (mmu_notifier_retry(kvm, mmu_seq)) |
| goto out_unlock; |
| |
| if (vma_pagesize == PAGE_SIZE && !force_pte) { |
| /* |
| * Only PMD_SIZE transparent hugepages(THP) are |
| * currently supported. This code will need to be |
| * updated to support other THP sizes. |
| */ |
| if (transparent_hugepage_adjust(&pfn, &fault_ipa)) |
| vma_pagesize = PMD_SIZE; |
| } |
| |
| if (writable) |
| kvm_set_pfn_dirty(pfn); |
| |
| if (fault_status != FSC_PERM) |
| 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 */ |
| kvm_inject_pabt(vcpu, kvm_vcpu_get_hfar(vcpu)); |
| ret = 1; |
| 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_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_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, 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 = kvm_virt_to_phys(__hyp_idmap_text_start); |
| hyp_idmap_start = ALIGN_DOWN(hyp_idmap_start, PAGE_SIZE); |
| hyp_idmap_end = kvm_virt_to_phys(__hyp_idmap_text_end); |
| hyp_idmap_end = ALIGN(hyp_idmap_end, PAGE_SIZE); |
| hyp_idmap_vector = kvm_virt_to_phys(__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, |
| const 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 be tracked while the |
| * memory slot is write protected. |
| */ |
| if (change != KVM_MR_DELETE && mem->flags & KVM_MEM_LOG_DIRTY_PAGES) |
| 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; |
| |
| /* |
| * Mapping a read-only VMA is only allowed if the |
| * memory region is configured as read-only. |
| */ |
| if (writable && !(vma->vm_flags & VM_WRITE)) { |
| ret = -EPERM; |
| break; |
| } |
| |
| /* |
| * Take the intersection of this VMA with the memory region |
| */ |
| vm_start = max(hva, vma->vm_start); |
| vm_end = min(reg_end, vma->vm_end); |
| |
| if (vma->vm_flags & VM_PFNMAP) { |
| gpa_t gpa = mem->guest_phys_addr + |
| (vm_start - mem->userspace_addr); |
| phys_addr_t pa; |
| |
| 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 *free, |
| struct kvm_memory_slot *dont) |
| { |
| } |
| |
| int kvm_arch_create_memslot(struct kvm *kvm, struct kvm_memory_slot *slot, |
| unsigned long npages) |
| { |
| return 0; |
| } |
| |
| 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); |
| } |