| /* |
| * 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" |
| |
| extern char __hyp_idmap_text_start[], __hyp_idmap_text_end[]; |
| |
| 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 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) |
| { |
| /* |
| * This function also gets called when dealing with HYP page |
| * tables. As HYP doesn't have an associated struct kvm (and |
| * the HYP page tables are fairly static), we don't do |
| * anything there. |
| */ |
| if (kvm) |
| 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_pgd_entry(struct kvm *kvm, pgd_t *pgd, phys_addr_t addr) |
| { |
| pud_t *pud_table __maybe_unused = pud_offset(pgd, 0); |
| pgd_clear(pgd); |
| kvm_tlb_flush_vmid_ipa(kvm, addr); |
| pud_free(NULL, pud_table); |
| put_page(virt_to_page(pgd)); |
| } |
| |
| static void clear_pud_entry(struct kvm *kvm, pud_t *pud, phys_addr_t addr) |
| { |
| pmd_t *pmd_table = pmd_offset(pud, 0); |
| VM_BUG_ON(pud_huge(*pud)); |
| pud_clear(pud); |
| kvm_tlb_flush_vmid_ipa(kvm, addr); |
| pmd_free(NULL, pmd_table); |
| put_page(virt_to_page(pud)); |
| } |
| |
| static void clear_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_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 (kvm_pte_table_empty(kvm, start_pte)) |
| clear_pmd_entry(kvm, pmd, start_addr); |
| } |
| |
| static void unmap_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 = pmd_offset(pud, addr); |
| do { |
| next = kvm_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_ptes(kvm, pmd, addr, next); |
| } |
| } |
| } while (pmd++, addr = next, addr != end); |
| |
| if (kvm_pmd_table_empty(kvm, start_pmd)) |
| clear_pud_entry(kvm, pud, start_addr); |
| } |
| |
| static void unmap_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 = pud_offset(pgd, addr); |
| do { |
| next = kvm_pud_addr_end(addr, end); |
| if (!pud_none(*pud)) { |
| if (pud_huge(*pud)) { |
| pud_t old_pud = *pud; |
| |
| pud_clear(pud); |
| kvm_tlb_flush_vmid_ipa(kvm, addr); |
| |
| kvm_flush_dcache_pud(old_pud); |
| |
| put_page(virt_to_page(pud)); |
| } else { |
| unmap_pmds(kvm, pud, addr, next); |
| } |
| } |
| } while (pud++, addr = next, addr != end); |
| |
| if (kvm_pud_table_empty(kvm, start_pud)) |
| clear_pgd_entry(kvm, pgd, start_addr); |
| } |
| |
| |
| static void unmap_range(struct kvm *kvm, pgd_t *pgdp, |
| phys_addr_t start, u64 size) |
| { |
| pgd_t *pgd; |
| phys_addr_t addr = start, end = start + size; |
| phys_addr_t next; |
| |
| pgd = pgdp + kvm_pgd_index(addr); |
| do { |
| next = kvm_pgd_addr_end(addr, end); |
| if (!pgd_none(*pgd)) |
| unmap_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_boot_hyp_pgd - free HYP boot page tables |
| * |
| * Free the HYP boot page tables. The bounce page is also freed. |
| */ |
| void free_boot_hyp_pgd(void) |
| { |
| mutex_lock(&kvm_hyp_pgd_mutex); |
| |
| if (boot_hyp_pgd) { |
| unmap_hyp_range(boot_hyp_pgd, hyp_idmap_start, PAGE_SIZE); |
| unmap_hyp_range(boot_hyp_pgd, TRAMPOLINE_VA, PAGE_SIZE); |
| free_pages((unsigned long)boot_hyp_pgd, hyp_pgd_order); |
| boot_hyp_pgd = NULL; |
| } |
| |
| if (hyp_pgd) |
| unmap_hyp_range(hyp_pgd, TRAMPOLINE_VA, PAGE_SIZE); |
| |
| mutex_unlock(&kvm_hyp_pgd_mutex); |
| } |
| |
| /** |
| * 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; |
| |
| free_boot_hyp_pgd(); |
| |
| mutex_lock(&kvm_hyp_pgd_mutex); |
| |
| if (hyp_pgd) { |
| for (addr = PAGE_OFFSET; virt_addr_valid(addr); addr += PGDIR_SIZE) |
| unmap_hyp_range(hyp_pgd, KERN_TO_HYP(addr), PGDIR_SIZE); |
| for (addr = VMALLOC_START; is_vmalloc_addr((void*)addr); addr += PGDIR_SIZE) |
| unmap_hyp_range(hyp_pgd, KERN_TO_HYP(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) |
| * |
| * 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) |
| { |
| phys_addr_t phys_addr; |
| unsigned long virt_addr; |
| unsigned long start = KERN_TO_HYP((unsigned long)from); |
| unsigned long end = KERN_TO_HYP((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), |
| PAGE_HYP); |
| 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_TO_HYP((unsigned long)from); |
| unsigned long end = KERN_TO_HYP((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); |
| } |
| |
| /* Free the HW pgd, one page at a time */ |
| static void kvm_free_hwpgd(void *hwpgd) |
| { |
| free_pages_exact(hwpgd, kvm_get_hwpgd_size()); |
| } |
| |
| /* Allocate the HW PGD, making sure that each page gets its own refcount */ |
| static void *kvm_alloc_hwpgd(void) |
| { |
| unsigned int size = kvm_get_hwpgd_size(); |
| |
| return alloc_pages_exact(size, GFP_KERNEL | __GFP_ZERO); |
| } |
| |
| /** |
| * 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; |
| void *hwpgd; |
| |
| if (kvm->arch.pgd != NULL) { |
| kvm_err("kvm_arch already initialized?\n"); |
| return -EINVAL; |
| } |
| |
| hwpgd = kvm_alloc_hwpgd(); |
| if (!hwpgd) |
| return -ENOMEM; |
| |
| /* |
| * When the kernel uses more levels of page tables than the |
| * guest, we allocate a fake PGD and pre-populate it to point |
| * to the next-level page table, which will be the real |
| * initial page table pointed to by the VTTBR. |
| */ |
| pgd = kvm_setup_fake_pgd(hwpgd); |
| if (IS_ERR(pgd)) { |
| kvm_free_hwpgd(hwpgd); |
| return PTR_ERR(pgd); |
| } |
| |
| kvm_clean_pgd(pgd); |
| kvm->arch.pgd = pgd; |
| return 0; |
| } |
| |
| /** |
| * 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) |
| { |
| unmap_range(kvm, kvm->arch.pgd, start, size); |
| } |
| |
| 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); |
| kvm_free_hwpgd(kvm_get_hwpgd(kvm)); |
| kvm_free_fake_pgd(kvm->arch.pgd); |
| 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; |
| kvm_set_pmd(pmd, *new_pmd); |
| if (pmd_present(old_pmd)) |
| kvm_tlb_flush_vmid_ipa(kvm, addr); |
| else |
| get_page(virt_to_page(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); |
| kvm_clean_pte(pte); |
| 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; |
| kvm_set_pte(pte, *new_pte); |
| if (pte_present(old_pte)) |
| kvm_tlb_flush_vmid_ipa(kvm, addr); |
| else |
| get_page(virt_to_page(pte)); |
| |
| return 0; |
| } |
| |
| /** |
| * 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) |
| kvm_set_s2pte_writable(&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 (PageTransCompound(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, bool uncached) |
| { |
| __coherent_cache_guest_page(vcpu, pfn, size, uncached); |
| } |
| |
| 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 fault_ipa_uncached; |
| 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_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); |
| |
| fault_ipa_uncached = memslot->flags & KVM_MEMSLOT_INCOHERENT; |
| |
| if (hugetlb) { |
| pmd_t new_pmd = pfn_pmd(pfn, mem_type); |
| new_pmd = pmd_mkhuge(new_pmd); |
| if (writable) { |
| kvm_set_s2pmd_writable(&new_pmd); |
| kvm_set_pfn_dirty(pfn); |
| } |
| coherent_cache_guest_page(vcpu, pfn, PMD_SIZE, fault_ipa_uncached); |
| ret = stage2_set_pmd_huge(kvm, memcache, fault_ipa, &new_pmd); |
| } else { |
| pte_t new_pte = pfn_pte(pfn, mem_type); |
| |
| if (writable) { |
| kvm_set_s2pte_writable(&new_pte); |
| kvm_set_pfn_dirty(pfn); |
| mark_page_dirty(kvm, gfn); |
| } |
| coherent_cache_guest_page(vcpu, pfn, PAGE_SIZE, fault_ipa_uncached); |
| 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. |
| */ |
| 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); |
| 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 */ |
| if (pmd_young(*pmd)) { |
| *pmd = pmd_mkold(*pmd); |
| return 1; |
| } |
| |
| return 0; |
| } |
| |
| pte = pte_offset_kernel(pmd, gpa); |
| if (pte_none(*pte)) |
| return 0; |
| |
| if (pte_young(*pte)) { |
| *pte = pte_mkold(*pte); /* Just a page... */ |
| return 1; |
| } |
| |
| return 0; |
| } |
| |
| 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_mmu_get_boot_httbr(void) |
| { |
| if (__kvm_cpu_uses_extended_idmap()) |
| return virt_to_phys(merged_hyp_pgd); |
| else |
| return virt_to_phys(boot_hyp_pgd); |
| } |
| |
| phys_addr_t kvm_get_idmap_vector(void) |
| { |
| return hyp_idmap_vector; |
| } |
| |
| 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); |
| |
| hyp_pgd = (pgd_t *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, hyp_pgd_order); |
| boot_hyp_pgd = (pgd_t *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, hyp_pgd_order); |
| |
| if (!hyp_pgd || !boot_hyp_pgd) { |
| kvm_err("Hyp mode PGD not allocated\n"); |
| err = -ENOMEM; |
| goto out; |
| } |
| |
| /* Create the idmap in the boot page tables */ |
| err = __create_hyp_mappings(boot_hyp_pgd, |
| hyp_idmap_start, hyp_idmap_end, |
| __phys_to_pfn(hyp_idmap_start), |
| PAGE_HYP); |
| |
| if (err) { |
| kvm_err("Failed to idmap %lx-%lx\n", |
| hyp_idmap_start, hyp_idmap_end); |
| goto out; |
| } |
| |
| if (__kvm_cpu_uses_extended_idmap()) { |
| 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); |
| return 0; |
| } |
| |
| /* Map the very same page at the trampoline VA */ |
| err = __create_hyp_mappings(boot_hyp_pgd, |
| TRAMPOLINE_VA, TRAMPOLINE_VA + PAGE_SIZE, |
| __phys_to_pfn(hyp_idmap_start), |
| PAGE_HYP); |
| if (err) { |
| kvm_err("Failed to map trampoline @%lx into boot HYP pgd\n", |
| TRAMPOLINE_VA); |
| goto out; |
| } |
| |
| /* Map the same page again into the runtime page tables */ |
| err = __create_hyp_mappings(hyp_pgd, |
| TRAMPOLINE_VA, TRAMPOLINE_VA + PAGE_SIZE, |
| __phys_to_pfn(hyp_idmap_start), |
| PAGE_HYP); |
| if (err) { |
| kvm_err("Failed to map trampoline @%lx into runtime HYP pgd\n", |
| TRAMPOLINE_VA); |
| 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) |
| { |
| /* |
| * Readonly memslots are not incoherent with the caches by definition, |
| * but in practice, they are used mostly to emulate ROMs or NOR flashes |
| * that the guest may consider devices and hence map as uncached. |
| * To prevent incoherency issues in these cases, tag all readonly |
| * regions as incoherent. |
| */ |
| if (slot->flags & KVM_MEM_READONLY) |
| slot->flags |= KVM_MEMSLOT_INCOHERENT; |
| return 0; |
| } |
| |
| void kvm_arch_memslots_updated(struct kvm *kvm, struct kvm_memslots *slots) |
| { |
| } |
| |
| void kvm_arch_flush_shadow_all(struct kvm *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); |
| } |