diff options
Diffstat (limited to 'arch/arm/kvm/mmu.c')
| -rw-r--r-- | arch/arm/kvm/mmu.c | 1968 |
1 files changed, 0 insertions, 1968 deletions
diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c deleted file mode 100644 index 962616fd4ddd..000000000000 --- a/arch/arm/kvm/mmu.c +++ /dev/null @@ -1,1968 +0,0 @@ -/* - * 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 <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_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; - -#define S2_PGD_SIZE (PTRS_PER_S2_PGD * sizeof(pgd_t)) -#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)); -} - -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(pgd, 0UL); - stage2_pgd_clear(pgd); - kvm_tlb_flush_vmid_ipa(kvm, addr); - stage2_pud_free(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(pud, 0); - VM_BUG_ON(stage2_pud_huge(*pud)); - stage2_pud_clear(pud); - kvm_tlb_flush_vmid_ipa(kvm, addr); - stage2_pmd_free(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)); -} - -/* - * 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. - */ -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(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(pud, addr); - do { - next = stage2_pmd_addr_end(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(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(pgd, addr); - do { - next = stage2_pud_addr_end(addr, end); - if (!stage2_pud_none(*pud)) { - if (stage2_pud_huge(*pud)) { - pud_t old_pud = *pud; - - stage2_pud_clear(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(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; - - pgd = kvm->arch.pgd + stage2_pgd_index(addr); - do { - next = stage2_pgd_addr_end(addr, end); - if (!stage2_pgd_none(*pgd)) - unmap_stage2_puds(kvm, pgd, addr, next); - } 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(pud, addr); - do { - next = stage2_pmd_addr_end(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(pgd, addr); - do { - next = stage2_pud_addr_end(addr, end); - if (!stage2_pud_none(*pud)) { - if (stage2_pud_huge(*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(addr); - do { - next = stage2_pgd_addr_end(addr, end); - 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 void unmap_hyp_range(pgd_t *pgdp, 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 + pgd_index(addr); - do { - next = pgd_addr_end(addr, end); - if (!pgd_none(*pgd)) - unmap_hyp_puds(pgd, addr, next); - } while (pgd++, addr = next, addr != end); -} - -/** - * 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 vmalloc range (from - * VMALLOC_START to VMALLOC_END). - * - * boot_hyp_pgd should only map two pages for the init code. - */ -void free_hyp_pgds(void) -{ - unsigned long addr; - - mutex_lock(&kvm_hyp_pgd_mutex); - - if (boot_hyp_pgd) { - unmap_hyp_range(boot_hyp_pgd, hyp_idmap_start, PAGE_SIZE); - free_pages((unsigned long)boot_hyp_pgd, hyp_pgd_order); - boot_hyp_pgd = NULL; - } - - if (hyp_pgd) { - unmap_hyp_range(hyp_pgd, hyp_idmap_start, PAGE_SIZE); - for (addr = PAGE_OFFSET; virt_addr_valid(addr); addr += PGDIR_SIZE) - unmap_hyp_range(hyp_pgd, kern_hyp_va(addr), PGDIR_SIZE); - for (addr = VMALLOC_START; is_vmalloc_addr((void*)addr); addr += PGDIR_SIZE) - unmap_hyp_range(hyp_pgd, kern_hyp_va(addr), PGDIR_SIZE); - - 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, pfn_pte(pfn, prot)); - get_page(virt_to_page(pte)); - kvm_flush_dcache_to_poc(pte, sizeof(*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, addr); - if (!pte) { - kvm_err("Cannot allocate Hyp pte\n"); - return -ENOMEM; - } - pmd_populate_kernel(NULL, pmd, pte); - get_page(virt_to_page(pmd)); - kvm_flush_dcache_to_poc(pmd, sizeof(*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; - } - pud_populate(NULL, pud, pmd); - get_page(virt_to_page(pud)); - kvm_flush_dcache_to_poc(pud, sizeof(*pud)); - } - - next = pud_addr_end(addr, end); - ret = create_hyp_pmd_mappings(pud, addr, next, pfn, prot); - if (ret) - return ret; - pfn += (next - addr) >> PAGE_SHIFT; - } while (addr = next, addr != end); - - return 0; -} - -static int __create_hyp_mappings(pgd_t *pgdp, - unsigned long start, unsigned long end, - unsigned long pfn, pgprot_t prot) -{ - pgd_t *pgd; - pud_t *pud; - unsigned long addr, next; - int err = 0; - - mutex_lock(&kvm_hyp_pgd_mutex); - addr = start & PAGE_MASK; - end = PAGE_ALIGN(end); - do { - pgd = pgdp + pgd_index(addr); - - if (pgd_none(*pgd)) { - pud = pud_alloc_one(NULL, addr); - if (!pud) { - kvm_err("Cannot allocate Hyp pud\n"); - err = -ENOMEM; - goto out; - } - pgd_populate(NULL, pgd, pud); - get_page(virt_to_page(pgd)); - kvm_flush_dcache_to_poc(pgd, sizeof(*pgd)); - } - - next = pgd_addr_end(addr, end); - err = create_hyp_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, virt_addr, - virt_addr + PAGE_SIZE, - __phys_to_pfn(phys_addr), - prot); - if (err) - return err; - } - - return 0; -} - -/** - * create_hyp_io_mappings - duplicate a kernel IO mapping into Hyp mode - * @from: The kernel start VA of the range - * @to: The kernel end VA of the range (exclusive) - * @phys_addr: The physical start address which gets mapped - * - * The resulting HYP VA is the same as the kernel VA, modulo - * HYP_PAGE_OFFSET. - */ -int create_hyp_io_mappings(void *from, void *to, phys_addr_t phys_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; - - /* Check for a valid kernel IO mapping */ - if (!is_vmalloc_addr(from) || !is_vmalloc_addr(to - 1)) - return -EINVAL; - - return __create_hyp_mappings(hyp_pgd, start, end, - __phys_to_pfn(phys_addr), PAGE_HYP_DEVICE); -} - -/** - * 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) -{ - 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(S2_PGD_SIZE, GFP_KERNEL | __GFP_ZERO); - if (!pgd) - return -ENOMEM; - - kvm->arch.pgd = pgd; - 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); - 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); - 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. - * - * Note we don't need locking here as this is only called when the VM is - * destroyed, which can only be done once. - */ -void kvm_free_stage2_pgd(struct kvm *kvm) -{ - if (kvm->arch.pgd == NULL) - return; - - unmap_stage2_range(kvm, 0, KVM_PHYS_SIZE); - /* Free the HW pgd, one page at a time */ - free_pages_exact(kvm->arch.pgd, S2_PGD_SIZE); - kvm->arch.pgd = NULL; -} - -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(addr); - if (WARN_ON(stage2_pgd_none(*pgd))) { - if (!cache) - return NULL; - pud = mmu_memory_cache_alloc(cache); - stage2_pgd_populate(pgd, pud); - get_page(virt_to_page(pgd)); - } - - return stage2_pud_offset(pgd, addr); -} - -static pmd_t *stage2_get_pmd(struct kvm *kvm, struct kvm_mmu_memory_cache *cache, - phys_addr_t addr) -{ - pud_t *pud; - pmd_t *pmd; - - pud = stage2_get_pud(kvm, cache, addr); - if (stage2_pud_none(*pud)) { - if (!cache) - return NULL; - pmd = mmu_memory_cache_alloc(cache); - stage2_pud_populate(pud, pmd); - get_page(virt_to_page(pud)); - } - - return stage2_pmd_offset(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); - - /* - * 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_present(*pmd) && pmd_pfn(*pmd) != pmd_pfn(*new_pmd)); - - old_pmd = *pmd; - if (pmd_present(old_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_pte(struct kvm *kvm, struct kvm_mmu_memory_cache *cache, - phys_addr_t addr, const pte_t *new_pte, - unsigned long flags) -{ - 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 */ - pmd = stage2_get_pmd(kvm, cache, 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); - pmd_populate_kernel(NULL, 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)) { - 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); -} - -/** - * 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 = 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_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; - - if (PageTransCompoundMap(pfn_to_page(pfn))) { - 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; -} - -static bool kvm_is_write_fault(struct kvm_vcpu *vcpu) -{ - if (kvm_vcpu_trap_is_iabt(vcpu)) - return false; - - return kvm_vcpu_dabt_iswrite(vcpu); -} - -/** - * 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 - * @pud: pointer to pud entry - * @addr: range start address - * @end: range end address - */ -static void stage2_wp_pmds(pud_t *pud, phys_addr_t addr, phys_addr_t end) -{ - pmd_t *pmd; - phys_addr_t next; - - pmd = stage2_pmd_offset(pud, addr); - - do { - next = stage2_pmd_addr_end(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(pgd_t *pgd, phys_addr_t addr, phys_addr_t end) -{ - pud_t *pud; - phys_addr_t next; - - pud = stage2_pud_offset(pgd, addr); - do { - next = stage2_pud_addr_end(addr, end); - if (!stage2_pud_none(*pud)) { - /* TODO:PUD not supported, revisit later if supported */ - BUG_ON(stage2_pud_huge(*pud)); - stage2_wp_pmds(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(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. - */ - if (need_resched() || spin_needbreak(&kvm->mmu_lock)) - cond_resched_lock(&kvm->mmu_lock); - - next = stage2_pgd_addr_end(addr, end); - if (stage2_pgd_present(*pgd)) - stage2_wp_puds(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 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 coherent_cache_guest_page(struct kvm_vcpu *vcpu, kvm_pfn_t pfn, - unsigned long size) -{ - __coherent_cache_guest_page(vcpu, pfn, size); -} - -static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, - struct kvm_memory_slot *memslot, unsigned long hva, - unsigned long fault_status) -{ - int ret; - bool write_fault, writable, hugetlb = false, force_pte = false; - 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 flags = 0; - - write_fault = kvm_is_write_fault(vcpu); - if (fault_status == FSC_PERM && !write_fault) { - kvm_err("Unexpected L2 read permission error\n"); - return -EFAULT; - } - - /* Let's check if we will get back a huge page backed by hugetlbfs */ - down_read(¤t->mm->mmap_sem); - vma = find_vma_intersection(current->mm, hva, hva + 1); - if (unlikely(!vma)) { - kvm_err("Failed to find VMA for hva 0x%lx\n", hva); - up_read(¤t->mm->mmap_sem); - return -EFAULT; - } - - if (is_vm_hugetlb_page(vma) && !logging_active) { - hugetlb = true; - gfn = (fault_ipa & PMD_MASK) >> PAGE_SHIFT; - } else { - /* - * Pages belonging to memslots that don't have the same - * alignment for userspace and IPA cannot be mapped using - * block descriptors even if the pages belong to a THP for - * the process, because the stage-2 block descriptor will - * cover more than a single THP and we loose atomicity for - * unmapping, updates, and splits of the THP or other pages - * in the stage-2 block range. - */ - if ((memslot->userspace_addr & ~PMD_MASK) != - ((memslot->base_gfn << PAGE_SHIFT) & ~PMD_MASK)) - force_pte = true; - } - 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_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 (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. - */ - force_pte = true; - 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 (!hugetlb && !force_pte) - hugetlb = transparent_hugepage_adjust(&pfn, &fault_ipa); - - if (hugetlb) { - pmd_t new_pmd = pfn_pmd(pfn, mem_type); - new_pmd = pmd_mkhuge(new_pmd); - if (writable) { - new_pmd = kvm_s2pmd_mkwrite(new_pmd); - kvm_set_pfn_dirty(pfn); - } - coherent_cache_guest_page(vcpu, pfn, PMD_SIZE); - ret = stage2_set_pmd_huge(kvm, memcache, fault_ipa, &new_pmd); - } else { - pte_t new_pte = pfn_pte(pfn, mem_type); - - if (writable) { - new_pte = kvm_s2pte_mkwrite(new_pte); - kvm_set_pfn_dirty(pfn); - mark_page_dirty(kvm, gfn); - } - coherent_cache_guest_page(vcpu, pfn, PAGE_SIZE); - 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) -{ - 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); - - pmd = stage2_get_pmd(vcpu->kvm, NULL, fault_ipa); - if (!pmd || pmd_none(*pmd)) /* Nothing there */ - goto out; - - if (pmd_thp_or_huge(*pmd)) { /* THP, HugeTLB */ - *pmd = pmd_mkyoung(*pmd); - pfn = pmd_pfn(*pmd); - pfn_valid = true; - goto out; - } - - pte = pte_offset_kernel(pmd, fault_ipa); - if (pte_none(*pte)) /* Nothing there either */ - goto out; - - *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; - - is_iabt = kvm_vcpu_trap_is_iabt(vcpu); - if (unlikely(!is_iabt && kvm_vcpu_dabt_isextabt(vcpu))) { - kvm_inject_vabt(vcpu); - return 1; - } - - fault_ipa = kvm_vcpu_get_fault_ipa(vcpu); - - 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 */ - fault_status = kvm_vcpu_trap_get_fault_type(vcpu); - 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); - - 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, 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 gfn, gfn_end; - - hva_start = max(start, memslot->userspace_addr); - hva_end = min(end, memslot->userspace_addr + - (memslot->npages << PAGE_SHIFT)); - if (hva_start >= hva_end) - continue; - - /* - * {gfn(page) | page intersects with [hva_start, hva_end)} = - * {gfn_start, gfn_start+1, ..., gfn_end-1}. - */ - gfn = hva_to_gfn_memslot(hva_start, memslot); - gfn_end = hva_to_gfn_memslot(hva_end + PAGE_SIZE - 1, memslot); - - for (; gfn < gfn_end; ++gfn) { - gpa_t gpa = gfn << PAGE_SHIFT; - ret |= handler(kvm, gpa, data); - } - } - - return ret; -} - -static int kvm_unmap_hva_handler(struct kvm *kvm, gpa_t gpa, void *data) -{ - unmap_stage2_range(kvm, gpa, PAGE_SIZE); - return 0; -} - -int kvm_unmap_hva(struct kvm *kvm, unsigned long hva) -{ - unsigned long end = hva + PAGE_SIZE; - - if (!kvm->arch.pgd) - return 0; - - trace_kvm_unmap_hva(hva); - handle_hva_to_gpa(kvm, hva, end, &kvm_unmap_hva_handler, NULL); - 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, void *data) -{ - pte_t *pte = (pte_t *)data; - - /* - * 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; -} - - -void kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte) -{ - unsigned long end = hva + PAGE_SIZE; - pte_t stage2_pte; - - if (!kvm->arch.pgd) - return; - - trace_kvm_set_spte_hva(hva); - stage2_pte = pfn_pte(pte_pfn(pte), PAGE_S2); - handle_hva_to_gpa(kvm, hva, end, &kvm_set_spte_handler, &stage2_pte); -} - -static int kvm_age_hva_handler(struct kvm *kvm, gpa_t gpa, void *data) -{ - pmd_t *pmd; - pte_t *pte; - - pmd = stage2_get_pmd(kvm, NULL, gpa); - if (!pmd || pmd_none(*pmd)) /* Nothing there */ - return 0; - - if (pmd_thp_or_huge(*pmd)) /* THP, HugeTLB */ - return stage2_pmdp_test_and_clear_young(pmd); - - pte = pte_offset_kernel(pmd, gpa); - if (pte_none(*pte)) - return 0; - - return stage2_ptep_test_and_clear_young(pte); -} - -static int kvm_test_age_hva_handler(struct kvm *kvm, gpa_t gpa, void *data) -{ - pmd_t *pmd; - pte_t *pte; - - pmd = stage2_get_pmd(kvm, NULL, gpa); - if (!pmd || pmd_none(*pmd)) /* Nothing there */ - return 0; - - if (pmd_thp_or_huge(*pmd)) /* THP, HugeTLB */ - return pmd_young(*pmd); - - pte = pte_offset_kernel(pmd, gpa); - if (!pte_none(*pte)) /* Just a page... */ - return pte_young(*pte); - - return 0; -} - -int kvm_age_hva(struct kvm *kvm, unsigned long start, unsigned long end) -{ - 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) -{ - 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; -} - -phys_addr_t kvm_get_idmap_start(void) -{ - return hyp_idmap_start; -} - -static int kvm_map_idmap_text(pgd_t *pgd) -{ - int err; - - /* Create the idmap in the boot page tables */ - err = __create_hyp_mappings(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_end = kvm_virt_to_phys(__hyp_idmap_text_end); - 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_info("IDMAP page: %lx\n", hyp_idmap_start); - kvm_info("HYP VA range: %lx:%lx\n", - kern_hyp_va(PAGE_OFFSET), kern_hyp_va(~0UL)); - - if (hyp_idmap_start >= kern_hyp_va(PAGE_OFFSET) && - hyp_idmap_start < kern_hyp_va(~0UL) && - 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; - } - - 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 >> PAGE_SHIFT)) - return -EFAULT; - - /* - * A memory region could potentially cover multiple VMAs, and any holes - * between them, so iterate over all of them to find out if we can map - * any of them right now. - * - * +--------------------------------------------+ - * +---------------+----------------+ +----------------+ - * | : VMA 1 | VMA 2 | | VMA 3 : | - * +---------------+----------------+ +----------------+ - * | memory region | - * +--------------------------------------------+ - */ - do { - struct vm_area_struct *vma = find_vma(current->mm, hva); - hva_t vm_start, vm_end; - - if (!vma || vma->vm_start >= reg_end) - break; - - /* - * Mapping a read-only VMA is only allowed if the - * memory region is configured as read-only. - */ - if (writable && !(vma->vm_flags & VM_WRITE)) { - ret = -EPERM; - break; - } - - /* - * Take the intersection of this VMA with the memory region - */ - vm_start = max(hva, vma->vm_start); - vm_end = min(reg_end, vma->vm_end); - - if (vma->vm_flags & VM_PFNMAP) { - gpa_t gpa = mem->guest_phys_addr + - (vm_start - mem->userspace_addr); - phys_addr_t pa; - - 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) - return -EINVAL; - - 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) - return ret; - - 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); - 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, struct kvm_memslots *slots) -{ -} - -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_get_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_set_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_set_hcr(vcpu, vcpu_get_hcr(vcpu) & ~HCR_TVM); - - trace_kvm_toggle_cache(*vcpu_pc(vcpu), was_enabled, now_enabled); -} |