diff options
Diffstat (limited to 'virt/kvm/arm/mmu.c')
| -rw-r--r-- | virt/kvm/arm/mmu.c | 2447 |
1 files changed, 0 insertions, 2447 deletions
diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c deleted file mode 100644 index e3b9ee268823..000000000000 --- a/virt/kvm/arm/mmu.c +++ /dev/null @@ -1,2447 +0,0 @@ -// 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); - } 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) 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 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; - -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. - */ |