| /* |
| * This file is subject to the terms and conditions of the GNU General Public |
| * License. See the file "COPYING" in the main directory of this archive |
| * for more details. |
| * |
| * KVM/MIPS MMU handling in the KVM module. |
| * |
| * Copyright (C) 2012 MIPS Technologies, Inc. All rights reserved. |
| * Authors: Sanjay Lal <sanjayl@kymasys.com> |
| */ |
| |
| #include <linux/highmem.h> |
| #include <linux/kvm_host.h> |
| #include <linux/uaccess.h> |
| #include <asm/mmu_context.h> |
| #include <asm/pgalloc.h> |
| |
| /* |
| * KVM_MMU_CACHE_MIN_PAGES is the number of GPA page table translation levels |
| * for which pages need to be cached. |
| */ |
| #if defined(__PAGETABLE_PMD_FOLDED) |
| #define KVM_MMU_CACHE_MIN_PAGES 1 |
| #else |
| #define KVM_MMU_CACHE_MIN_PAGES 2 |
| #endif |
| |
| void kvm_mmu_free_memory_caches(struct kvm_vcpu *vcpu) |
| { |
| kvm_mmu_free_memory_cache(&vcpu->arch.mmu_page_cache); |
| } |
| |
| /** |
| * kvm_pgd_init() - Initialise KVM GPA page directory. |
| * @page: Pointer to page directory (PGD) for KVM GPA. |
| * |
| * Initialise a KVM GPA page directory with pointers to the invalid table, i.e. |
| * representing no mappings. This is similar to pgd_init(), however it |
| * initialises all the page directory pointers, not just the ones corresponding |
| * to the userland address space (since it is for the guest physical address |
| * space rather than a virtual address space). |
| */ |
| static void kvm_pgd_init(void *page) |
| { |
| unsigned long *p, *end; |
| unsigned long entry; |
| |
| #ifdef __PAGETABLE_PMD_FOLDED |
| entry = (unsigned long)invalid_pte_table; |
| #else |
| entry = (unsigned long)invalid_pmd_table; |
| #endif |
| |
| p = (unsigned long *)page; |
| end = p + PTRS_PER_PGD; |
| |
| do { |
| p[0] = entry; |
| p[1] = entry; |
| p[2] = entry; |
| p[3] = entry; |
| p[4] = entry; |
| p += 8; |
| p[-3] = entry; |
| p[-2] = entry; |
| p[-1] = entry; |
| } while (p != end); |
| } |
| |
| /** |
| * kvm_pgd_alloc() - Allocate and initialise a KVM GPA page directory. |
| * |
| * Allocate a blank KVM GPA page directory (PGD) for representing guest physical |
| * to host physical page mappings. |
| * |
| * Returns: Pointer to new KVM GPA page directory. |
| * NULL on allocation failure. |
| */ |
| pgd_t *kvm_pgd_alloc(void) |
| { |
| pgd_t *ret; |
| |
| ret = (pgd_t *)__get_free_pages(GFP_KERNEL, PGD_TABLE_ORDER); |
| if (ret) |
| kvm_pgd_init(ret); |
| |
| return ret; |
| } |
| |
| /** |
| * kvm_mips_walk_pgd() - Walk page table with optional allocation. |
| * @pgd: Page directory pointer. |
| * @addr: Address to index page table using. |
| * @cache: MMU page cache to allocate new page tables from, or NULL. |
| * |
| * Walk the page tables pointed to by @pgd to find the PTE corresponding to the |
| * address @addr. If page tables don't exist for @addr, they will be created |
| * from the MMU cache if @cache is not NULL. |
| * |
| * Returns: Pointer to pte_t corresponding to @addr. |
| * NULL if a page table doesn't exist for @addr and !@cache. |
| * NULL if a page table allocation failed. |
| */ |
| static pte_t *kvm_mips_walk_pgd(pgd_t *pgd, struct kvm_mmu_memory_cache *cache, |
| unsigned long addr) |
| { |
| p4d_t *p4d; |
| pud_t *pud; |
| pmd_t *pmd; |
| |
| pgd += pgd_index(addr); |
| if (pgd_none(*pgd)) { |
| /* Not used on MIPS yet */ |
| BUG(); |
| return NULL; |
| } |
| p4d = p4d_offset(pgd, addr); |
| pud = pud_offset(p4d, addr); |
| if (pud_none(*pud)) { |
| pmd_t *new_pmd; |
| |
| if (!cache) |
| return NULL; |
| new_pmd = kvm_mmu_memory_cache_alloc(cache); |
| pmd_init((unsigned long)new_pmd, |
| (unsigned long)invalid_pte_table); |
| pud_populate(NULL, pud, new_pmd); |
| } |
| pmd = pmd_offset(pud, addr); |
| if (pmd_none(*pmd)) { |
| pte_t *new_pte; |
| |
| if (!cache) |
| return NULL; |
| new_pte = kvm_mmu_memory_cache_alloc(cache); |
| clear_page(new_pte); |
| pmd_populate_kernel(NULL, pmd, new_pte); |
| } |
| return pte_offset_kernel(pmd, addr); |
| } |
| |
| /* Caller must hold kvm->mm_lock */ |
| static pte_t *kvm_mips_pte_for_gpa(struct kvm *kvm, |
| struct kvm_mmu_memory_cache *cache, |
| unsigned long addr) |
| { |
| return kvm_mips_walk_pgd(kvm->arch.gpa_mm.pgd, cache, addr); |
| } |
| |
| /* |
| * kvm_mips_flush_gpa_{pte,pmd,pud,pgd,pt}. |
| * Flush a range of guest physical address space from the VM's GPA page tables. |
| */ |
| |
| static bool kvm_mips_flush_gpa_pte(pte_t *pte, unsigned long start_gpa, |
| unsigned long end_gpa) |
| { |
| int i_min = pte_index(start_gpa); |
| int i_max = pte_index(end_gpa); |
| bool safe_to_remove = (i_min == 0 && i_max == PTRS_PER_PTE - 1); |
| int i; |
| |
| for (i = i_min; i <= i_max; ++i) { |
| if (!pte_present(pte[i])) |
| continue; |
| |
| set_pte(pte + i, __pte(0)); |
| } |
| return safe_to_remove; |
| } |
| |
| static bool kvm_mips_flush_gpa_pmd(pmd_t *pmd, unsigned long start_gpa, |
| unsigned long end_gpa) |
| { |
| pte_t *pte; |
| unsigned long end = ~0ul; |
| int i_min = pmd_index(start_gpa); |
| int i_max = pmd_index(end_gpa); |
| bool safe_to_remove = (i_min == 0 && i_max == PTRS_PER_PMD - 1); |
| int i; |
| |
| for (i = i_min; i <= i_max; ++i, start_gpa = 0) { |
| if (!pmd_present(pmd[i])) |
| continue; |
| |
| pte = pte_offset_kernel(pmd + i, 0); |
| if (i == i_max) |
| end = end_gpa; |
| |
| if (kvm_mips_flush_gpa_pte(pte, start_gpa, end)) { |
| pmd_clear(pmd + i); |
| pte_free_kernel(NULL, pte); |
| } else { |
| safe_to_remove = false; |
| } |
| } |
| return safe_to_remove; |
| } |
| |
| static bool kvm_mips_flush_gpa_pud(pud_t *pud, unsigned long start_gpa, |
| unsigned long end_gpa) |
| { |
| pmd_t *pmd; |
| unsigned long end = ~0ul; |
| int i_min = pud_index(start_gpa); |
| int i_max = pud_index(end_gpa); |
| bool safe_to_remove = (i_min == 0 && i_max == PTRS_PER_PUD - 1); |
| int i; |
| |
| for (i = i_min; i <= i_max; ++i, start_gpa = 0) { |
| if (!pud_present(pud[i])) |
| continue; |
| |
| pmd = pmd_offset(pud + i, 0); |
| if (i == i_max) |
| end = end_gpa; |
| |
| if (kvm_mips_flush_gpa_pmd(pmd, start_gpa, end)) { |
| pud_clear(pud + i); |
| pmd_free(NULL, pmd); |
| } else { |
| safe_to_remove = false; |
| } |
| } |
| return safe_to_remove; |
| } |
| |
| static bool kvm_mips_flush_gpa_pgd(pgd_t *pgd, unsigned long start_gpa, |
| unsigned long end_gpa) |
| { |
| p4d_t *p4d; |
| pud_t *pud; |
| unsigned long end = ~0ul; |
| int i_min = pgd_index(start_gpa); |
| int i_max = pgd_index(end_gpa); |
| bool safe_to_remove = (i_min == 0 && i_max == PTRS_PER_PGD - 1); |
| int i; |
| |
| for (i = i_min; i <= i_max; ++i, start_gpa = 0) { |
| if (!pgd_present(pgd[i])) |
| continue; |
| |
| p4d = p4d_offset(pgd, 0); |
| pud = pud_offset(p4d + i, 0); |
| if (i == i_max) |
| end = end_gpa; |
| |
| if (kvm_mips_flush_gpa_pud(pud, start_gpa, end)) { |
| pgd_clear(pgd + i); |
| pud_free(NULL, pud); |
| } else { |
| safe_to_remove = false; |
| } |
| } |
| return safe_to_remove; |
| } |
| |
| /** |
| * kvm_mips_flush_gpa_pt() - Flush a range of guest physical addresses. |
| * @kvm: KVM pointer. |
| * @start_gfn: Guest frame number of first page in GPA range to flush. |
| * @end_gfn: Guest frame number of last page in GPA range to flush. |
| * |
| * Flushes a range of GPA mappings from the GPA page tables. |
| * |
| * The caller must hold the @kvm->mmu_lock spinlock. |
| * |
| * Returns: Whether its safe to remove the top level page directory because |
| * all lower levels have been removed. |
| */ |
| bool kvm_mips_flush_gpa_pt(struct kvm *kvm, gfn_t start_gfn, gfn_t end_gfn) |
| { |
| return kvm_mips_flush_gpa_pgd(kvm->arch.gpa_mm.pgd, |
| start_gfn << PAGE_SHIFT, |
| end_gfn << PAGE_SHIFT); |
| } |
| |
| #define BUILD_PTE_RANGE_OP(name, op) \ |
| static int kvm_mips_##name##_pte(pte_t *pte, unsigned long start, \ |
| unsigned long end) \ |
| { \ |
| int ret = 0; \ |
| int i_min = pte_index(start); \ |
| int i_max = pte_index(end); \ |
| int i; \ |
| pte_t old, new; \ |
| \ |
| for (i = i_min; i <= i_max; ++i) { \ |
| if (!pte_present(pte[i])) \ |
| continue; \ |
| \ |
| old = pte[i]; \ |
| new = op(old); \ |
| if (pte_val(new) == pte_val(old)) \ |
| continue; \ |
| set_pte(pte + i, new); \ |
| ret = 1; \ |
| } \ |
| return ret; \ |
| } \ |
| \ |
| /* returns true if anything was done */ \ |
| static int kvm_mips_##name##_pmd(pmd_t *pmd, unsigned long start, \ |
| unsigned long end) \ |
| { \ |
| int ret = 0; \ |
| pte_t *pte; \ |
| unsigned long cur_end = ~0ul; \ |
| int i_min = pmd_index(start); \ |
| int i_max = pmd_index(end); \ |
| int i; \ |
| \ |
| for (i = i_min; i <= i_max; ++i, start = 0) { \ |
| if (!pmd_present(pmd[i])) \ |
| continue; \ |
| \ |
| pte = pte_offset_kernel(pmd + i, 0); \ |
| if (i == i_max) \ |
| cur_end = end; \ |
| \ |
| ret |= kvm_mips_##name##_pte(pte, start, cur_end); \ |
| } \ |
| return ret; \ |
| } \ |
| \ |
| static int kvm_mips_##name##_pud(pud_t *pud, unsigned long start, \ |
| unsigned long end) \ |
| { \ |
| int ret = 0; \ |
| pmd_t *pmd; \ |
| unsigned long cur_end = ~0ul; \ |
| int i_min = pud_index(start); \ |
| int i_max = pud_index(end); \ |
| int i; \ |
| \ |
| for (i = i_min; i <= i_max; ++i, start = 0) { \ |
| if (!pud_present(pud[i])) \ |
| continue; \ |
| \ |
| pmd = pmd_offset(pud + i, 0); \ |
| if (i == i_max) \ |
| cur_end = end; \ |
| \ |
| ret |= kvm_mips_##name##_pmd(pmd, start, cur_end); \ |
| } \ |
| return ret; \ |
| } \ |
| \ |
| static int kvm_mips_##name##_pgd(pgd_t *pgd, unsigned long start, \ |
| unsigned long end) \ |
| { \ |
| int ret = 0; \ |
| p4d_t *p4d; \ |
| pud_t *pud; \ |
| unsigned long cur_end = ~0ul; \ |
| int i_min = pgd_index(start); \ |
| int i_max = pgd_index(end); \ |
| int i; \ |
| \ |
| for (i = i_min; i <= i_max; ++i, start = 0) { \ |
| if (!pgd_present(pgd[i])) \ |
| continue; \ |
| \ |
| p4d = p4d_offset(pgd, 0); \ |
| pud = pud_offset(p4d + i, 0); \ |
| if (i == i_max) \ |
| cur_end = end; \ |
| \ |
| ret |= kvm_mips_##name##_pud(pud, start, cur_end); \ |
| } \ |
| return ret; \ |
| } |
| |
| /* |
| * kvm_mips_mkclean_gpa_pt. |
| * Mark a range of guest physical address space clean (writes fault) in the VM's |
| * GPA page table to allow dirty page tracking. |
| */ |
| |
| BUILD_PTE_RANGE_OP(mkclean, pte_mkclean) |
| |
| /** |
| * kvm_mips_mkclean_gpa_pt() - Make a range of guest physical addresses clean. |
| * @kvm: KVM pointer. |
| * @start_gfn: Guest frame number of first page in GPA range to flush. |
| * @end_gfn: Guest frame number of last page in GPA range to flush. |
| * |
| * Make a range of GPA mappings clean so that guest writes will fault and |
| * trigger dirty page logging. |
| * |
| * The caller must hold the @kvm->mmu_lock spinlock. |
| * |
| * Returns: Whether any GPA mappings were modified, which would require |
| * derived mappings (GVA page tables & TLB enties) to be |
| * invalidated. |
| */ |
| int kvm_mips_mkclean_gpa_pt(struct kvm *kvm, gfn_t start_gfn, gfn_t end_gfn) |
| { |
| return kvm_mips_mkclean_pgd(kvm->arch.gpa_mm.pgd, |
| start_gfn << PAGE_SHIFT, |
| end_gfn << PAGE_SHIFT); |
| } |
| |
| /** |
| * kvm_arch_mmu_enable_log_dirty_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. |
| */ |
| void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm, |
| struct kvm_memory_slot *slot, |
| gfn_t gfn_offset, unsigned long mask) |
| { |
| gfn_t base_gfn = slot->base_gfn + gfn_offset; |
| gfn_t start = base_gfn + __ffs(mask); |
| gfn_t end = base_gfn + __fls(mask); |
| |
| kvm_mips_mkclean_gpa_pt(kvm, start, end); |
| } |
| |
| /* |
| * kvm_mips_mkold_gpa_pt. |
| * Mark a range of guest physical address space old (all accesses fault) in the |
| * VM's GPA page table to allow detection of commonly used pages. |
| */ |
| |
| BUILD_PTE_RANGE_OP(mkold, pte_mkold) |
| |
| static int kvm_mips_mkold_gpa_pt(struct kvm *kvm, gfn_t start_gfn, |
| gfn_t end_gfn) |
| { |
| return kvm_mips_mkold_pgd(kvm->arch.gpa_mm.pgd, |
| start_gfn << PAGE_SHIFT, |
| end_gfn << PAGE_SHIFT); |
| } |
| |
| bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range) |
| { |
| kvm_mips_flush_gpa_pt(kvm, range->start, range->end); |
| return true; |
| } |
| |
| bool kvm_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range) |
| { |
| gpa_t gpa = range->start << PAGE_SHIFT; |
| pte_t hva_pte = range->pte; |
| pte_t *gpa_pte = kvm_mips_pte_for_gpa(kvm, NULL, gpa); |
| pte_t old_pte; |
| |
| if (!gpa_pte) |
| return false; |
| |
| /* Mapping may need adjusting depending on memslot flags */ |
| old_pte = *gpa_pte; |
| if (range->slot->flags & KVM_MEM_LOG_DIRTY_PAGES && !pte_dirty(old_pte)) |
| hva_pte = pte_mkclean(hva_pte); |
| else if (range->slot->flags & KVM_MEM_READONLY) |
| hva_pte = pte_wrprotect(hva_pte); |
| |
| set_pte(gpa_pte, hva_pte); |
| |
| /* Replacing an absent or old page doesn't need flushes */ |
| if (!pte_present(old_pte) || !pte_young(old_pte)) |
| return false; |
| |
| /* Pages swapped, aged, moved, or cleaned require flushes */ |
| return !pte_present(hva_pte) || |
| !pte_young(hva_pte) || |
| pte_pfn(old_pte) != pte_pfn(hva_pte) || |
| (pte_dirty(old_pte) && !pte_dirty(hva_pte)); |
| } |
| |
| bool kvm_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range) |
| { |
| return kvm_mips_mkold_gpa_pt(kvm, range->start, range->end); |
| } |
| |
| bool kvm_test_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range) |
| { |
| gpa_t gpa = range->start << PAGE_SHIFT; |
| pte_t *gpa_pte = kvm_mips_pte_for_gpa(kvm, NULL, gpa); |
| |
| if (!gpa_pte) |
| return false; |
| return pte_young(*gpa_pte); |
| } |
| |
| /** |
| * _kvm_mips_map_page_fast() - Fast path GPA fault handler. |
| * @vcpu: VCPU pointer. |
| * @gpa: Guest physical address of fault. |
| * @write_fault: Whether the fault was due to a write. |
| * @out_entry: New PTE for @gpa (written on success unless NULL). |
| * @out_buddy: New PTE for @gpa's buddy (written on success unless |
| * NULL). |
| * |
| * Perform fast path GPA fault handling, doing all that can be done without |
| * calling into KVM. This handles marking old pages young (for idle page |
| * tracking), and dirtying of clean pages (for dirty page logging). |
| * |
| * Returns: 0 on success, in which case we can update derived mappings and |
| * resume guest execution. |
| * -EFAULT on failure due to absent GPA mapping or write to |
| * read-only page, in which case KVM must be consulted. |
| */ |
| static int _kvm_mips_map_page_fast(struct kvm_vcpu *vcpu, unsigned long gpa, |
| bool write_fault, |
| pte_t *out_entry, pte_t *out_buddy) |
| { |
| struct kvm *kvm = vcpu->kvm; |
| gfn_t gfn = gpa >> PAGE_SHIFT; |
| pte_t *ptep; |
| kvm_pfn_t pfn = 0; /* silence bogus GCC warning */ |
| bool pfn_valid = false; |
| int ret = 0; |
| |
| spin_lock(&kvm->mmu_lock); |
| |
| /* Fast path - just check GPA page table for an existing entry */ |
| ptep = kvm_mips_pte_for_gpa(kvm, NULL, gpa); |
| if (!ptep || !pte_present(*ptep)) { |
| ret = -EFAULT; |
| goto out; |
| } |
| |
| /* Track access to pages marked old */ |
| if (!pte_young(*ptep)) { |
| set_pte(ptep, pte_mkyoung(*ptep)); |
| pfn = pte_pfn(*ptep); |
| pfn_valid = true; |
| /* call kvm_set_pfn_accessed() after unlock */ |
| } |
| if (write_fault && !pte_dirty(*ptep)) { |
| if (!pte_write(*ptep)) { |
| ret = -EFAULT; |
| goto out; |
| } |
| |
| /* Track dirtying of writeable pages */ |
| set_pte(ptep, pte_mkdirty(*ptep)); |
| pfn = pte_pfn(*ptep); |
| mark_page_dirty(kvm, gfn); |
| kvm_set_pfn_dirty(pfn); |
| } |
| |
| if (out_entry) |
| *out_entry = *ptep; |
| if (out_buddy) |
| *out_buddy = *ptep_buddy(ptep); |
| |
| out: |
| spin_unlock(&kvm->mmu_lock); |
| if (pfn_valid) |
| kvm_set_pfn_accessed(pfn); |
| return ret; |
| } |
| |
| /** |
| * kvm_mips_map_page() - Map a guest physical page. |
| * @vcpu: VCPU pointer. |
| * @gpa: Guest physical address of fault. |
| * @write_fault: Whether the fault was due to a write. |
| * @out_entry: New PTE for @gpa (written on success unless NULL). |
| * @out_buddy: New PTE for @gpa's buddy (written on success unless |
| * NULL). |
| * |
| * Handle GPA faults by creating a new GPA mapping (or updating an existing |
| * one). |
| * |
| * This takes care of marking pages young or dirty (idle/dirty page tracking), |
| * asking KVM for the corresponding PFN, and creating a mapping in the GPA page |
| * tables. Derived mappings (GVA page tables and TLBs) must be handled by the |
| * caller. |
| * |
| * Returns: 0 on success, in which case the caller may use the @out_entry |
| * and @out_buddy PTEs to update derived mappings and resume guest |
| * execution. |
| * -EFAULT if there is no memory region at @gpa or a write was |
| * attempted to a read-only memory region. This is usually handled |
| * as an MMIO access. |
| */ |
| static int kvm_mips_map_page(struct kvm_vcpu *vcpu, unsigned long gpa, |
| bool write_fault, |
| pte_t *out_entry, pte_t *out_buddy) |
| { |
| struct kvm *kvm = vcpu->kvm; |
| struct kvm_mmu_memory_cache *memcache = &vcpu->arch.mmu_page_cache; |
| gfn_t gfn = gpa >> PAGE_SHIFT; |
| int srcu_idx, err; |
| kvm_pfn_t pfn; |
| pte_t *ptep, entry, old_pte; |
| bool writeable; |
| unsigned long prot_bits; |
| unsigned long mmu_seq; |
| |
| /* Try the fast path to handle old / clean pages */ |
| srcu_idx = srcu_read_lock(&kvm->srcu); |
| err = _kvm_mips_map_page_fast(vcpu, gpa, write_fault, out_entry, |
| out_buddy); |
| if (!err) |
| goto out; |
| |
| /* We need a minimum of cached pages ready for page table creation */ |
| err = kvm_mmu_topup_memory_cache(memcache, KVM_MMU_CACHE_MIN_PAGES); |
| if (err) |
| goto out; |
| |
| retry: |
| /* |
| * Used to check for invalidations in progress, of the pfn that is |
| * returned by pfn_to_pfn_prot below. |
| */ |
| mmu_seq = kvm->mmu_notifier_seq; |
| /* |
| * Ensure the read of mmu_notifier_seq isn't reordered with PTE reads in |
| * gfn_to_pfn_prot() (which calls get_user_pages()), so that we don't |
| * risk the page we get a reference to getting unmapped before we have a |
| * chance to grab the mmu_lock without mmu_notifier_retry() noticing. |
| * |
| * This smp_rmb() pairs with the effective smp_wmb() of the combination |
| * of the pte_unmap_unlock() after the PTE is zapped, and the |
| * spin_lock() in kvm_mmu_notifier_invalidate_<page|range_end>() before |
| * mmu_notifier_seq is incremented. |
| */ |
| smp_rmb(); |
| |
| /* Slow path - ask KVM core whether we can access this GPA */ |
| pfn = gfn_to_pfn_prot(kvm, gfn, write_fault, &writeable); |
| if (is_error_noslot_pfn(pfn)) { |
| err = -EFAULT; |
| goto out; |
| } |
| |
| spin_lock(&kvm->mmu_lock); |
| /* Check if an invalidation has taken place since we got pfn */ |
| if (mmu_notifier_retry(kvm, mmu_seq)) { |
| /* |
| * This can happen when mappings are changed asynchronously, but |
| * also synchronously if a COW is triggered by |
| * gfn_to_pfn_prot(). |
| */ |
| spin_unlock(&kvm->mmu_lock); |
| kvm_release_pfn_clean(pfn); |
| goto retry; |
| } |
| |
| /* Ensure page tables are allocated */ |
| ptep = kvm_mips_pte_for_gpa(kvm, memcache, gpa); |
| |
| /* Set up the PTE */ |
| prot_bits = _PAGE_PRESENT | __READABLE | _page_cachable_default; |
| if (writeable) { |
| prot_bits |= _PAGE_WRITE; |
| if (write_fault) { |
| prot_bits |= __WRITEABLE; |
| mark_page_dirty(kvm, gfn); |
| kvm_set_pfn_dirty(pfn); |
| } |
| } |
| entry = pfn_pte(pfn, __pgprot(prot_bits)); |
| |
| /* Write the PTE */ |
| old_pte = *ptep; |
| set_pte(ptep, entry); |
| |
| err = 0; |
| if (out_entry) |
| *out_entry = *ptep; |
| if (out_buddy) |
| *out_buddy = *ptep_buddy(ptep); |
| |
| spin_unlock(&kvm->mmu_lock); |
| kvm_release_pfn_clean(pfn); |
| kvm_set_pfn_accessed(pfn); |
| out: |
| srcu_read_unlock(&kvm->srcu, srcu_idx); |
| return err; |
| } |
| |
| int kvm_mips_handle_vz_root_tlb_fault(unsigned long badvaddr, |
| struct kvm_vcpu *vcpu, |
| bool write_fault) |
| { |
| int ret; |
| |
| ret = kvm_mips_map_page(vcpu, badvaddr, write_fault, NULL, NULL); |
| if (ret) |
| return ret; |
| |
| /* Invalidate this entry in the TLB */ |
| return kvm_vz_host_tlb_inv(vcpu, badvaddr); |
| } |
| |
| /** |
| * kvm_mips_migrate_count() - Migrate timer. |
| * @vcpu: Virtual CPU. |
| * |
| * Migrate CP0_Count hrtimer to the current CPU by cancelling and restarting it |
| * if it was running prior to being cancelled. |
| * |
| * Must be called when the VCPU is migrated to a different CPU to ensure that |
| * timer expiry during guest execution interrupts the guest and causes the |
| * interrupt to be delivered in a timely manner. |
| */ |
| static void kvm_mips_migrate_count(struct kvm_vcpu *vcpu) |
| { |
| if (hrtimer_cancel(&vcpu->arch.comparecount_timer)) |
| hrtimer_restart(&vcpu->arch.comparecount_timer); |
| } |
| |
| /* Restore ASID once we are scheduled back after preemption */ |
| void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu) |
| { |
| unsigned long flags; |
| |
| kvm_debug("%s: vcpu %p, cpu: %d\n", __func__, vcpu, cpu); |
| |
| local_irq_save(flags); |
| |
| vcpu->cpu = cpu; |
| if (vcpu->arch.last_sched_cpu != cpu) { |
| kvm_debug("[%d->%d]KVM VCPU[%d] switch\n", |
| vcpu->arch.last_sched_cpu, cpu, vcpu->vcpu_id); |
| /* |
| * Migrate the timer interrupt to the current CPU so that it |
| * always interrupts the guest and synchronously triggers a |
| * guest timer interrupt. |
| */ |
| kvm_mips_migrate_count(vcpu); |
| } |
| |
| /* restore guest state to registers */ |
| kvm_mips_callbacks->vcpu_load(vcpu, cpu); |
| |
| local_irq_restore(flags); |
| } |
| |
| /* ASID can change if another task is scheduled during preemption */ |
| void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu) |
| { |
| unsigned long flags; |
| int cpu; |
| |
| local_irq_save(flags); |
| |
| cpu = smp_processor_id(); |
| vcpu->arch.last_sched_cpu = cpu; |
| vcpu->cpu = -1; |
| |
| /* save guest state in registers */ |
| kvm_mips_callbacks->vcpu_put(vcpu, cpu); |
| |
| local_irq_restore(flags); |
| } |