/* * Kernel-based Virtual Machine driver for Linux * * This module enables machines with Intel VT-x extensions to run virtual * machines without emulation or binary translation. * * Copyright (C) 2006 Qumranet, Inc. * Copyright 2010 Red Hat, Inc. and/or its affiliates. * * Authors: * Avi Kivity * Yaniv Kamay * * This work is licensed under the terms of the GNU GPL, version 2. See * the COPYING file in the top-level directory. * */ #include "iodev.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "coalesced_mmio.h" #include "async_pf.h" #define CREATE_TRACE_POINTS #include MODULE_AUTHOR("Qumranet"); MODULE_LICENSE("GPL"); /* * Ordering of locks: * * kvm->lock --> kvm->slots_lock --> kvm->irq_lock */ DEFINE_SPINLOCK(kvm_lock); static DEFINE_RAW_SPINLOCK(kvm_count_lock); LIST_HEAD(vm_list); static cpumask_var_t cpus_hardware_enabled; static int kvm_usage_count = 0; static atomic_t hardware_enable_failed; struct kmem_cache *kvm_vcpu_cache; EXPORT_SYMBOL_GPL(kvm_vcpu_cache); static __read_mostly struct preempt_ops kvm_preempt_ops; struct dentry *kvm_debugfs_dir; static long kvm_vcpu_ioctl(struct file *file, unsigned int ioctl, unsigned long arg); #ifdef CONFIG_COMPAT static long kvm_vcpu_compat_ioctl(struct file *file, unsigned int ioctl, unsigned long arg); #endif static int hardware_enable_all(void); static void hardware_disable_all(void); static void kvm_io_bus_destroy(struct kvm_io_bus *bus); static void update_memslots(struct kvm_memslots *slots, struct kvm_memory_slot *new, u64 last_generation); static void kvm_release_pfn_dirty(pfn_t pfn); static void mark_page_dirty_in_slot(struct kvm *kvm, struct kvm_memory_slot *memslot, gfn_t gfn); __visible bool kvm_rebooting; EXPORT_SYMBOL_GPL(kvm_rebooting); static bool largepages_enabled = true; bool kvm_is_mmio_pfn(pfn_t pfn) { if (pfn_valid(pfn)) return PageReserved(pfn_to_page(pfn)); return true; } /* * Switches to specified vcpu, until a matching vcpu_put() */ int vcpu_load(struct kvm_vcpu *vcpu) { int cpu; if (mutex_lock_killable(&vcpu->mutex)) return -EINTR; if (unlikely(vcpu->pid != current->pids[PIDTYPE_PID].pid)) { /* The thread running this VCPU changed. */ struct pid *oldpid = vcpu->pid; struct pid *newpid = get_task_pid(current, PIDTYPE_PID); rcu_assign_pointer(vcpu->pid, newpid); synchronize_rcu(); put_pid(oldpid); } cpu = get_cpu(); preempt_notifier_register(&vcpu->preempt_notifier); kvm_arch_vcpu_load(vcpu, cpu); put_cpu(); return 0; } void vcpu_put(struct kvm_vcpu *vcpu) { preempt_disable(); kvm_arch_vcpu_put(vcpu); preempt_notifier_unregister(&vcpu->preempt_notifier); preempt_enable(); mutex_unlock(&vcpu->mutex); } static void ack_flush(void *_completed) { } static bool make_all_cpus_request(struct kvm *kvm, unsigned int req) { int i, cpu, me; cpumask_var_t cpus; bool called = true; struct kvm_vcpu *vcpu; zalloc_cpumask_var(&cpus, GFP_ATOMIC); me = get_cpu(); kvm_for_each_vcpu(i, vcpu, kvm) { kvm_make_request(req, vcpu); cpu = vcpu->cpu; /* Set ->requests bit before we read ->mode */ smp_mb(); if (cpus != NULL && cpu != -1 && cpu != me && kvm_vcpu_exiting_guest_mode(vcpu) != OUTSIDE_GUEST_MODE) cpumask_set_cpu(cpu, cpus); } if (unlikely(cpus == NULL)) smp_call_function_many(cpu_online_mask, ack_flush, NULL, 1); else if (!cpumask_empty(cpus)) smp_call_function_many(cpus, ack_flush, NULL, 1); else called = false; put_cpu(); free_cpumask_var(cpus); return called; } void kvm_flush_remote_tlbs(struct kvm *kvm) { long dirty_count = kvm->tlbs_dirty; smp_mb(); if (make_all_cpus_request(kvm, KVM_REQ_TLB_FLUSH)) ++kvm->stat.remote_tlb_flush; cmpxchg(&kvm->tlbs_dirty, dirty_count, 0); } EXPORT_SYMBOL_GPL(kvm_flush_remote_tlbs); void kvm_reload_remote_mmus(struct kvm *kvm) { make_all_cpus_request(kvm, KVM_REQ_MMU_RELOAD); } void kvm_make_mclock_inprogress_request(struct kvm *kvm) { make_all_cpus_request(kvm, KVM_REQ_MCLOCK_INPROGRESS); } void kvm_make_scan_ioapic_request(struct kvm *kvm) { make_all_cpus_request(kvm, KVM_REQ_SCAN_IOAPIC); } int kvm_vcpu_init(struct kvm_vcpu *vcpu, struct kvm *kvm, unsigned id) { struct page *page; int r; mutex_init(&vcpu->mutex); vcpu->cpu = -1; vcpu->kvm = kvm; vcpu->vcpu_id = id; vcpu->pid = NULL; init_waitqueue_head(&vcpu->wq); kvm_async_pf_vcpu_init(vcpu); page = alloc_page(GFP_KERNEL | __GFP_ZERO); if (!page) { r = -ENOMEM; goto fail; } vcpu->run = page_address(page); kvm_vcpu_set_in_spin_loop(vcpu, false); kvm_vcpu_set_dy_eligible(vcpu, false); vcpu->preempted = false; r = kvm_arch_vcpu_init(vcpu); if (r < 0) goto fail_free_run; return 0; fail_free_run: free_page((unsigned long)vcpu->run); fail: return r; } EXPORT_SYMBOL_GPL(kvm_vcpu_init); void kvm_vcpu_uninit(struct kvm_vcpu *vcpu) { put_pid(vcpu->pid); kvm_arch_vcpu_uninit(vcpu); free_page((unsigned long)vcpu->run); } EXPORT_SYMBOL_GPL(kvm_vcpu_uninit); #if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER) static inline struct kvm *mmu_notifier_to_kvm(struct mmu_notifier *mn) { return container_of(mn, struct kvm, mmu_notifier); } static void kvm_mmu_notifier_invalidate_page(struct mmu_notifier *mn, struct mm_struct *mm, unsigned long address) { struct kvm *kvm = mmu_notifier_to_kvm(mn); int need_tlb_flush, idx; /* * When ->invalidate_page runs, the linux pte has been zapped * already but the page is still allocated until * ->invalidate_page returns. So if we increase the sequence * here the kvm page fault will notice if the spte can't be * established because the page is going to be freed. If * instead the kvm page fault establishes the spte before * ->invalidate_page runs, kvm_unmap_hva will release it * before returning. * * The sequence increase only need to be seen at spin_unlock * time, and not at spin_lock time. * * Increasing the sequence after the spin_unlock would be * unsafe because the kvm page fault could then establish the * pte after kvm_unmap_hva returned, without noticing the page * is going to be freed. */ idx = srcu_read_lock(&kvm->srcu); spin_lock(&kvm->mmu_lock); kvm->mmu_notifier_seq++; need_tlb_flush = kvm_unmap_hva(kvm, address) | kvm->tlbs_dirty; /* we've to flush the tlb before the pages can be freed */ if (need_tlb_flush) kvm_flush_remote_tlbs(kvm); spin_unlock(&kvm->mmu_lock); srcu_read_unlock(&kvm->srcu, idx); } static void kvm_mmu_notifier_change_pte(struct mmu_notifier *mn, struct mm_struct *mm, unsigned long address, pte_t pte) { struct kvm *kvm = mmu_notifier_to_kvm(mn); int idx; idx = srcu_read_lock(&kvm->srcu); spin_lock(&kvm->mmu_lock); kvm->mmu_notifier_seq++; kvm_set_spte_hva(kvm, address, pte); spin_unlock(&kvm->mmu_lock); srcu_read_unlock(&kvm->srcu, idx); } static void kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn, struct mm_struct *mm, unsigned long start, unsigned long end) { struct kvm *kvm = mmu_notifier_to_kvm(mn); int need_tlb_flush = 0, idx; idx = srcu_read_lock(&kvm->srcu); spin_lock(&kvm->mmu_lock); /* * The count increase must become visible at unlock time as no * spte can be established without taking the mmu_lock and * count is also read inside the mmu_lock critical section. */ kvm->mmu_notifier_count++; need_tlb_flush = kvm_unmap_hva_range(kvm, start, end); need_tlb_flush |= kvm->tlbs_dirty; /* we've to flush the tlb before the pages can be freed */ if (need_tlb_flush) kvm_flush_remote_tlbs(kvm); spin_unlock(&kvm->mmu_lock); srcu_read_unlock(&kvm->srcu, idx); } static void kvm_mmu_notifier_invalidate_range_end(struct mmu_notifier *mn, struct mm_struct *mm, unsigned long start, unsigned long end) { struct kvm *kvm = mmu_notifier_to_kvm(mn); spin_lock(&kvm->mmu_lock); /* * This sequence increase will notify the kvm page fault that * the page that is going to be mapped in the spte could have * been freed. */ kvm->mmu_notifier_seq++; smp_wmb(); /* * The above sequence increase must be visible before the * below count decrease, which is ensured by the smp_wmb above * in conjunction with the smp_rmb in mmu_notifier_retry(). */ kvm->mmu_notifier_count--; spin_unlock(&kvm->mmu_lock); BUG_ON(kvm->mmu_notifier_count < 0); } static int kvm_mmu_notifier_clear_flush_young(struct mmu_notifier *mn, struct mm_struct *mm, unsigned long address) { struct kvm *kvm = mmu_notifier_to_kvm(mn); int young, idx; idx = srcu_read_lock(&kvm->srcu); spin_lock(&kvm->mmu_lock); young = kvm_age_hva(kvm, address); if (young) kvm_flush_remote_tlbs(kvm); spin_unlock(&kvm->mmu_lock); srcu_read_unlock(&kvm->srcu, idx); return young; } static int kvm_mmu_notifier_test_young(struct mmu_notifier *mn, struct mm_struct *mm, unsigned long address) { struct kvm *kvm = mmu_notifier_to_kvm(mn); int young, idx; idx = srcu_read_lock(&kvm->srcu); spin_lock(&kvm->mmu_lock); young = kvm_test_age_hva(kvm, address); spin_unlock(&kvm->mmu_lock); srcu_read_unlock(&kvm->srcu, idx); return young; } static void kvm_mmu_notifier_release(struct mmu_notifier *mn, struct mm_struct *mm) { struct kvm *kvm = mmu_notifier_to_kvm(mn); int idx; idx = srcu_read_lock(&kvm->srcu); kvm_arch_flush_shadow_all(kvm); srcu_read_unlock(&kvm->srcu, idx); } static const struct mmu_notifier_ops kvm_mmu_notifier_ops = { .invalidate_page = kvm_mmu_notifier_invalidate_page, .invalidate_range_start = kvm_mmu_notifier_invalidate_range_start, .invalidate_range_end = kvm_mmu_notifier_invalidate_range_end, .clear_flush_young = kvm_mmu_notifier_clear_flush_young, .test_young = kvm_mmu_notifier_test_young, .change_pte = kvm_mmu_notifier_change_pte, .release = kvm_mmu_notifier_release, }; static int kvm_init_mmu_notifier(struct kvm *kvm) { kvm->mmu_notifier.ops = &kvm_mmu_notifier_ops; return mmu_notifier_register(&kvm->mmu_notifier, current->mm); } #else /* !(CONFIG_MMU_NOTIFIER && KVM_ARCH_WANT_MMU_NOTIFIER) */ static int kvm_init_mmu_notifier(struct kvm *kvm) { return 0; } #endif /* CONFIG_MMU_NOTIFIER && KVM_ARCH_WANT_MMU_NOTIFIER */ static void kvm_init_memslots_id(struct kvm *kvm) { int i; struct kvm_memslots *slots = kvm->memslots; for (i = 0; i < KVM_MEM_SLOTS_NUM; i++) slots->id_to_index[i] = slots->memslots[i].id = i; } static struct kvm *kvm_create_vm(unsigned long type) { int r, i; struct kvm *kvm = kvm_arch_alloc_vm(); if (!kvm) return ERR_PTR(-ENOMEM); r = kvm_arch_init_vm(kvm, type); if (r) goto out_err_no_disable; r = hardware_enable_all(); if (r) goto out_err_no_disable; #ifdef CONFIG_HAVE_KVM_IRQCHIP INIT_HLIST_HEAD(&kvm->mask_notifier_list); INIT_HLIST_HEAD(&kvm->irq_ack_notifier_list); #endif BUILD_BUG_ON(KVM_MEM_SLOTS_NUM > SHRT_MAX); r = -ENOMEM; kvm->memslots = kzalloc(sizeof(struct kvm_memslots), GFP_KERNEL); if (!kvm->memslots) goto out_err_no_srcu; kvm_init_memslots_id(kvm); if (init_srcu_struct(&kvm->srcu)) goto out_err_no_srcu; if (init_srcu_struct(&kvm->irq_srcu)) goto out_err_no_irq_srcu; for (i = 0; i < KVM_NR_BUSES; i++) { kvm->buses[i] = kzalloc(sizeof(struct kvm_io_bus), GFP_KERNEL); if (!kvm->buses[i]) goto out_err; } spin_lock_init(&kvm->mmu_lock); kvm->mm = current->mm; atomic_inc(&kvm->mm->mm_count); kvm_eventfd_init(kvm); mutex_init(&kvm->lock); mutex_init(&kvm->irq_lock); mutex_init(&kvm->slots_lock); atomic_set(&kvm->users_count, 1); INIT_LIST_HEAD(&kvm->devices); r = kvm_init_mmu_notifier(kvm); if (r) goto out_err; spin_lock(&kvm_lock); list_add(&kvm->vm_list, &vm_list); spin_unlock(&kvm_lock); return kvm; out_err: cleanup_srcu_struct(&kvm->irq_srcu); out_err_no_irq_srcu: cleanup_srcu_struct(&kvm->srcu); out_err_no_srcu: hardware_disable_all(); out_err_no_disable: for (i = 0; i < KVM_NR_BUSES; i++) kfree(kvm->buses[i]); kfree(kvm->memslots); kvm_arch_free_vm(kvm); return ERR_PTR(r); } /* * Avoid using vmalloc for a small buffer. * Should not be used when the size is statically known. */ void *kvm_kvzalloc(unsigned long size) { if (size > PAGE_SIZE) return vzalloc(size); else return kzalloc(size, GFP_KERNEL); } void kvm_kvfree(const void *addr) { if (is_vmalloc_addr(addr)) vfree(addr); else kfree(addr); } static void kvm_destroy_dirty_bitmap(struct kvm_memory_slot *memslot) { if (!memslot->dirty_bitmap) return; kvm_kvfree(memslot->dirty_bitmap); memslot->dirty_bitmap = NULL; } /* * Free any memory in @free but not in @dont. */ static void kvm_free_physmem_slot(struct kvm *kvm, struct kvm_memory_slot *free, struct kvm_memory_slot *dont) { if (!dont || free->dirty_bitmap != dont->dirty_bitmap) kvm_destroy_dirty_bitmap(free); kvm_arch_free_memslot(kvm, free, dont); free->npages = 0; } static void kvm_free_physmem(struct kvm *kvm) { struct kvm_memslots *slots = kvm->memslots; struct kvm_memory_slot *memslot; kvm_for_each_memslot(memslot, slots) kvm_free_physmem_slot(kvm, memslot, NULL); kfree(kvm->memslots); } static void kvm_destroy_devices(struct kvm *kvm) { struct list_head *node, *tmp; list_for_each_safe(node, tmp, &kvm->devices) { struct kvm_device *dev = list_entry(node, struct kvm_device, vm_node); list_del(node); dev->ops->destroy(dev); } } static void kvm_destroy_vm(struct kvm *kvm) { int i; struct mm_struct *mm = kvm->mm; kvm_arch_sync_events(kvm); spin_lock(&kvm_lock); list_del(&kvm->vm_list); spin_unlock(&kvm_lock); kvm_free_irq_routing(kvm); for (i = 0; i < KVM_NR_BUSES; i++) kvm_io_bus_destroy(kvm->buses[i]); kvm_coalesced_mmio_free(kvm); #if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER) mmu_notifier_unregister(&kvm->mmu_notifier, kvm->mm); #else kvm_arch_flush_shadow_all(kvm); #endif kvm_arch_destroy_vm(kvm); kvm_destroy_devices(kvm); kvm_free_physmem(kvm); cleanup_srcu_struct(&kvm->irq_srcu); cleanup_srcu_struct(&kvm->srcu); kvm_arch_free_vm(kvm); hardware_disable_all(); mmdrop(mm); } void kvm_get_kvm(struct kvm *kvm) { atomic_inc(&kvm->users_count); } EXPORT_SYMBOL_GPL(kvm_get_kvm); void kvm_put_kvm(struct kvm *kvm) { if (atomic_dec_and_test(&kvm->users_count)) kvm_destroy_vm(kvm); } EXPORT_SYMBOL_GPL(kvm_put_kvm); static int kvm_vm_release(struct inode *inode, struct file *filp) { struct kvm *kvm = filp->private_data; kvm_irqfd_release(kvm); kvm_put_kvm(kvm); return 0; } /* * Allocation size is twice as large as the actual dirty bitmap size. * See x86's kvm_vm_ioctl_get_dirty_log() why this is needed. */ static int kvm_create_dirty_bitmap(struct kvm_memory_slot *memslot) { unsigned long dirty_bytes = 2 * kvm_dirty_bitmap_bytes(memslot); memslot->dirty_bitmap = kvm_kvzalloc(dirty_bytes); if (!memslot->dirty_bitmap) return -ENOMEM; return 0; } static int cmp_memslot(const void *slot1, const void *slot2) { struct kvm_memory_slot *s1, *s2; s1 = (struct kvm_memory_slot *)slot1; s2 = (struct kvm_memory_slot *)slot2; if (s1->npages < s2->npages) return 1; if (s1->npages > s2->npages) return -1; return 0; } /* * Sort the memslots base on its size, so the larger slots * will get better fit. */ static void sort_memslots(struct kvm_memslots *slots) { int i; sort(slots->memslots, KVM_MEM_SLOTS_NUM, sizeof(struct kvm_memory_slot), cmp_memslot, NULL); for (i = 0; i < KVM_MEM_SLOTS_NUM; i++) slots->id_to_index[slots->memslots[i].id] = i; } static void update_memslots(struct kvm_memslots *slots, struct kvm_memory_slot *new, u64 last_generation) { if (new) { int id = new->id; struct kvm_memory_slot *old = id_to_memslot(slots, id); unsigned long npages = old->npages; *old = *new; if (new->npages != npages) sort_memslots(slots); } slots->generation = last_generation + 1; } static int check_memory_region_flags(struct kvm_userspace_memory_region *mem) { u32 valid_flags = KVM_MEM_LOG_DIRTY_PAGES; #ifdef KVM_CAP_READONLY_MEM valid_flags |= KVM_MEM_READONLY; #endif if (mem->flags & ~valid_flags) return -EINVAL; return 0; } static struct kvm_memslots *install_new_memslots(struct kvm *kvm, struct kvm_memslots *slots, struct kvm_memory_slot *new) { struct kvm_memslots *old_memslots = kvm->memslots; update_memslots(slots, new, kvm->memslots->generation); rcu_assign_pointer(kvm->memslots, slots); synchronize_srcu_expedited(&kvm->srcu); kvm_arch_memslots_updated(kvm); return old_memslots; } /* * Allocate some memory and give it an address in the guest physical address * space. * * Discontiguous memory is allowed, mostly for framebuffers. * * Must be called holding mmap_sem for write. */ int __kvm_set_memory_region(struct kvm *kvm, struct kvm_userspace_memory_region *mem) { int r; gfn_t base_gfn; unsigned long npages; struct kvm_memory_slot *slot; struct kvm_memory_slot old, new; struct kvm_memslots *slots = NULL, *old_memslots; enum kvm_mr_change change; r = check_memory_region_flags(mem); if (r) goto out; r = -EINVAL; /* General sanity checks */ if (mem->memory_size & (PAGE_SIZE - 1)) goto out; if (mem->guest_phys_addr & (PAGE_SIZE - 1)) goto out; /* We can read the guest memory with __xxx_user() later on. */ if ((mem->slot < KVM_USER_MEM_SLOTS) && ((mem->userspace_addr & (PAGE_SIZE - 1)) || !access_ok(VERIFY_WRITE, (void __user *)(unsigned long)mem->userspace_addr, mem->memory_size))) goto out; if (mem->slot >= KVM_MEM_SLOTS_NUM) goto out; if (mem->guest_phys_addr + mem->memory_size < mem->guest_phys_addr) goto out; slot = id_to_memslot(kvm->memslots, mem->slot); base_gfn = mem->guest_phys_addr >> PAGE_SHIFT; npages = mem->memory_size >> PAGE_SHIFT; r = -EINVAL; if (npages > KVM_MEM_MAX_NR_PAGES) goto out; if (!npages) mem->flags &= ~KVM_MEM_LOG_DIRTY_PAGES; new = old = *slot; new.id = mem->slot; new.base_gfn = base_gfn; new.npages = npages; new.flags = mem->flags; r = -EINVAL; if (npages) { if (!old.npages) change = KVM_MR_CREATE; else { /* Modify an existing slot. */ if ((mem->userspace_addr != old.userspace_addr) || (npages != old.npages) || ((new.flags ^ old.flags) & KVM_MEM_READONLY)) goto out; if (base_gfn != old.base_gfn) change = KVM_MR_MOVE; else if (new.flags != old.flags) change = KVM_MR_FLAGS_ONLY; else { /* Nothing to change. */ r = 0; goto out; } } } else if (old.npages) { change = KVM_MR_DELETE; } else /* Modify a non-existent slot: disallowed. */ goto out; if ((change == KVM_MR_CREATE) || (change == KVM_MR_MOVE)) { /* Check for overlaps */ r = -EEXIST; kvm_for_each_memslot(slot, kvm->memslots) { if ((slot->id >= KVM_USER_MEM_SLOTS) || (slot->id == mem->slot)) continue; if (!((base_gfn + npages <= slot->base_gfn) || (base_gfn >= slot->base_gfn + slot->npages))) goto out; } } /* Free page dirty bitmap if unneeded */ if (!(new.flags & KVM_MEM_LOG_DIRTY_PAGES)) new.dirty_bitmap = NULL; r = -ENOMEM; if (change == KVM_MR_CREATE) { new.userspace_addr = mem->userspace_addr; if (kvm_arch_create_memslot(kvm, &new, npages)) goto out_free; } /* Allocate page dirty bitmap if needed */ if ((new.flags & KVM_MEM_LOG_DIRTY_PAGES) && !new.dirty_bitmap) { if (kvm_create_dirty_bitmap(&new) < 0) goto out_free; } if ((change == KVM_MR_DELETE) || (change == KVM_MR_MOVE)) { r = -ENOMEM; slots = kmemdup(kvm->memslots, sizeof(struct kvm_memslots), GFP_KERNEL); if (!slots) goto out_free; slot = id_to_memslot(slots, mem->slot); slot->flags |= KVM_MEMSLOT_INVALID; old_memslots = install_new_memslots(kvm, slots, NULL); /* slot was deleted or moved, clear iommu mapping */ kvm_iommu_unmap_pages(kvm, &old); /* From this point no new shadow pages pointing to a deleted, * or moved, memslot will be created. * * validation of sp->gfn happens in: * - gfn_to_hva (kvm_read_guest, gfn_to_pfn) * - kvm_is_visible_gfn (mmu_check_roots) */ kvm_arch_flush_shadow_memslot(kvm, slot); slots = old_memslots; } r = kvm_arch_prepare_memory_region(kvm, &new, mem, change); if (r) goto out_slots; r = -ENOMEM; /* * We can re-use the old_memslots from above, the only difference * from the currently installed memslots is the invalid flag. This * will get overwritten by update_memslots anyway. */ if (!slots) { slots = kmemdup(kvm->memslots, sizeof(struct kvm_memslots), GFP_KERNEL); if (!slots) goto out_free; } /* actual memory is freed via old in kvm_free_physmem_slot below */ if (change == KVM_MR_DELETE) { new.dirty_bitmap = NULL; memset(&new.arch, 0, sizeof(new.arch)); } old_memslots = install_new_memslots(kvm, slots, &new); kvm_arch_commit_memory_region(kvm, mem, &old, change); kvm_free_physmem_slot(kvm, &old, &new); kfree(old_memslots); /* * IOMMU mapping: New slots need to be mapped. Old slots need to be * un-mapped and re-mapped if their base changes. Since base change * unmapping is handled above with slot deletion, mapping alone is * needed here. Anything else the iommu might care about for existing * slots (size changes, userspace addr changes and read-only flag * changes) is disallowed above, so any other attribute changes getting * here can be skipped. */ if ((change == KVM_MR_CREATE) || (change == KVM_MR_MOVE)) { r = kvm_iommu_map_pages(kvm, &new); return r; } return 0; out_slots: kfree(slots); out_free: kvm_free_physmem_slot(kvm, &new, &old); out: return r; } EXPORT_SYMBOL_GPL(__kvm_set_memory_region); int kvm_set_memory_region(struct kvm *kvm, struct kvm_userspace_memory_region *mem) { int r; mutex_lock(&kvm->slots_lock); r = __kvm_set_memory_region(kvm, mem); mutex_unlock(&kvm->slots_lock); return r; } EXPORT_SYMBOL_GPL(kvm_set_memory_region); static int kvm_vm_ioctl_set_memory_region(struct kvm *kvm, struct kvm_userspace_memory_region *mem) { if (mem->slot >= KVM_USER_MEM_SLOTS) return -EINVAL; return kvm_set_memory_region(kvm, mem); } int kvm_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log, int *is_dirty) { struct kvm_memory_slot *memslot; int r, i; unsigned long n; unsigned long any = 0; r = -EINVAL; if (log->slot >= KVM_USER_MEM_SLOTS) goto out; memslot = id_to_memslot(kvm->memslots, log->slot); r = -ENOENT; if (!memslot->dirty_bitmap) goto out; n = kvm_dirty_bitmap_bytes(memslot); for (i = 0; !any && i < n/sizeof(long); ++i) any = memslot->dirty_bitmap[i]; r = -EFAULT; if (copy_to_user(log->dirty_bitmap, memslot->dirty_bitmap, n)) goto out; if (any) *is_dirty = 1; r = 0; out: return r; } EXPORT_SYMBOL_GPL(kvm_get_dirty_log); bool kvm_largepages_enabled(void) { return largepages_enabled; } void kvm_disable_largepages(void) { largepages_enabled = false; } EXPORT_SYMBOL_GPL(kvm_disable_largepages); struct kvm_memory_slot *gfn_to_memslot(struct kvm *kvm, gfn_t gfn) { return __gfn_to_memslot(kvm_memslots(kvm), gfn); } EXPORT_SYMBOL_GPL(gfn_to_memslot); int kvm_is_visible_gfn(struct kvm *kvm, gfn_t gfn) { struct kvm_memory_slot *memslot = gfn_to_memslot(kvm, gfn); if (!memslot || memslot->id >= KVM_USER_MEM_SLOTS || memslot->flags & KVM_MEMSLOT_INVALID) return 0; return 1; } EXPORT_SYMBOL_GPL(kvm_is_visible_gfn); unsigned long kvm_host_page_size(struct kvm *kvm, gfn_t gfn) { struct vm_area_struct *vma; unsigned long addr, size; size = PAGE_SIZE; addr = gfn_to_hva(kvm, gfn); if (kvm_is_error_hva(addr)) return PAGE_SIZE; down_read(¤t->mm->mmap_sem); vma = find_vma(current->mm, addr); if (!vma) goto out; size = vma_kernel_pagesize(vma); out: up_read(¤t->mm->mmap_sem); return size; } static bool memslot_is_readonly(struct kvm_memory_slot *slot) { return slot->flags & KVM_MEM_READONLY; } static unsigned long __gfn_to_hva_many(struct kvm_memory_slot *slot, gfn_t gfn, gfn_t *nr_pages, bool write) { if (!slot || slot->flags & KVM_MEMSLOT_INVALID) return KVM_HVA_ERR_BAD; if (memslot_is_readonly(slot) && write) return KVM_HVA_ERR_RO_BAD; if (nr_pages) *nr_pages = slot->npages - (gfn - slot->base_gfn); return __gfn_to_hva_memslot(slot, gfn); } static unsigned long gfn_to_hva_many(struct kvm_memory_slot *slot, gfn_t gfn, gfn_t *nr_pages) { return __gfn_to_hva_many(slot, gfn, nr_pages, true); } unsigned long gfn_to_hva_memslot(struct kvm_memory_slot *slot, gfn_t gfn) { return gfn_to_hva_many(slot, gfn, NULL); } EXPORT_SYMBOL_GPL(gfn_to_hva_memslot); unsigned long gfn_to_hva(struct kvm *kvm, gfn_t gfn) { return gfn_to_hva_many(gfn_to_memslot(kvm, gfn), gfn, NULL); } EXPORT_SYMBOL_GPL(gfn_to_hva); /* * If writable is set to false, the hva returned by this function is only * allowed to be read. */ unsigned long gfn_to_hva_prot(struct kvm *kvm, gfn_t gfn, bool *writable) { struct kvm_memory_slot *slot = gfn_to_memslot(kvm, gfn); unsigned long hva = __gfn_to_hva_many(slot, gfn, NULL, false); if (!kvm_is_error_hva(hva) && writable) *writable = !memslot_is_readonly(slot); return hva; } static int kvm_read_hva(void *data, void __user *hva, int len) { return __copy_from_user(data, hva, len); } static int kvm_read_hva_atomic(void *data, void __user *hva, int len) { return __copy_from_user_inatomic(data, hva, len); } static int get_user_page_nowait(struct task_struct *tsk, struct mm_struct *mm, unsigned long start, int write, struct page **page) { int flags = FOLL_TOUCH | FOLL_NOWAIT | FOLL_HWPOISON | FOLL_GET; if (write) flags |= FOLL_WRITE; return __get_user_pages(tsk, mm, start, 1, flags, page, NULL, NULL); } static inline int check_user_page_hwpoison(unsigned long addr) { int rc, flags = FOLL_TOUCH | FOLL_HWPOISON | FOLL_WRITE; rc = __get_user_pages(current, current->mm, addr, 1, flags, NULL, NULL, NULL); return rc == -EHWPOISON; } /* * The atomic path to get the writable pfn which will be stored in @pfn, * true indicates success, otherwise false is returned. */ static bool hva_to_pfn_fast(unsigned long addr, bool atomic, bool *async, bool write_fault, bool *writable, pfn_t *pfn) { struct page *page[1]; int npages; if (!(async || atomic)) return false; /* * Fast pin a writable pfn only if it is a write fault request * or the caller allows to map a writable pfn for a read fault * request. */ if (!(write_fault || writable)) return false; npages = __get_user_pages_fast(addr, 1, 1, page); if (npages == 1) { *pfn = page_to_pfn(page[0]); if (writable) *writable = true; return true; } return false; } /* * The slow path to get the pfn of the specified host virtual address, * 1 indicates success, -errno is returned if error is detected. */ static int hva_to_pfn_slow(unsigned long addr, bool *async, bool write_fault, bool *writable, pfn_t *pfn) { struct page *page[1]; int npages = 0; might_sleep(); if (writable) *writable = write_fault; if (async) { down_read(¤t->mm->mmap_sem); npages = get_user_page_nowait(current, current->mm, addr, write_fault, page); up_read(¤t->mm->mmap_sem); } else npages = get_user_pages_fast(addr, 1, write_fault, page); if (npages != 1) return npages; /* map read fault as writable if possible */ if (unlikely(!write_fault) && writable) { struct page *wpage[1]; npages = __get_user_pages_fast(addr, 1, 1, wpage); if (npages == 1) { *writable = true; put_page(page[0]); page[0] = wpage[0]; } npages = 1; } *pfn = page_to_pfn(page[0]); return npages; } static bool vma_is_valid(struct vm_area_struct *vma, bool write_fault) { if (unlikely(!(vma->vm_flags & VM_READ))) return false; if (write_fault && (unlikely(!(vma->vm_flags & VM_WRITE)))) return false; return true; } /* * Pin guest page in memory and return its pfn. * @addr: host virtual address which maps memory to the guest * @atomic: whether this function can sleep * @async: whether this function need to wait IO complete if the * host page is not in the memory * @write_fault: whether we should get a writable host page * @writable: whether it allows to map a writable host page for !@write_fault * * The function will map a writable host page for these two cases: * 1): @write_fault = true * 2): @write_fault = false && @writable, @writable will tell the caller * whether the mapping is writable. */ static pfn_t hva_to_pfn(unsigned long addr, bool atomic, bool *async, bool write_fault, bool *writable) { struct vm_area_struct *vma; pfn_t pfn = 0; int npages; /* we can do it either atomically or asynchronously, not both */ BUG_ON(atomic && async); if (hva_to_pfn_fast(addr, atomic, async, write_fault, writable, &pfn)) return pfn; if (atomic) return KVM_PFN_ERR_FAULT; npages = hva_to_pfn_slow(addr, async, write_fault, writable, &pfn); if (npages == 1) return pfn; down_read(¤t->mm->mmap_sem); if (npages == -EHWPOISON || (!async && check_user_page_hwpoison(addr))) { pfn = KVM_PFN_ERR_HWPOISON; goto exit; } vma = find_vma_intersection(current->mm, addr, addr + 1); if (vma == NULL) pfn = KVM_PFN_ERR_FAULT; else if ((vma->vm_flags & VM_PFNMAP)) { pfn = ((addr - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff; BUG_ON(!kvm_is_mmio_pfn(pfn)); } else { if (async && vma_is_valid(vma, write_fault)) *async = true; pfn = KVM_PFN_ERR_FAULT; } exit: up_read(¤t->mm->mmap_sem); return pfn; } static pfn_t __gfn_to_pfn_memslot(struct kvm_memory_slot *slot, gfn_t gfn, bool atomic, bool *async, bool write_fault, bool *writable) { unsigned long addr = __gfn_to_hva_many(slot, gfn, NULL, write_fault); if (addr == KVM_HVA_ERR_RO_BAD) return KVM_PFN_ERR_RO_FAULT; if (kvm_is_error_hva(addr)) return KVM_PFN_NOSLOT; /* Do not map writable pfn in the readonly memslot. */ if (writable && memslot_is_readonly(slot)) { *writable = false; writable = NULL; } return hva_to_pfn(addr, atomic, async, write_fault, writable); } static pfn_t __gfn_to_pfn(struct kvm *kvm, gfn_t gfn, bool atomic, bool *async, bool write_fault, bool *writable) { struct kvm_memory_slot *slot; if (async) *async = false; slot = gfn_to_memslot(kvm, gfn); return __gfn_to_pfn_memslot(slot, gfn, atomic, async, write_fault, writable); } pfn_t gfn_to_pfn_atomic(struct kvm *kvm, gfn_t gfn) { return __gfn_to_pfn(kvm, gfn, true, NULL, true, NULL); } EXPORT_SYMBOL_GPL(gfn_to_pfn_atomic); pfn_t gfn_to_pfn_async(struct kvm *kvm, gfn_t gfn, bool *async, bool write_fault, bool *writable) { return __gfn_to_pfn(kvm, gfn, false, async, write_fault, writable); } EXPORT_SYMBOL_GPL(gfn_to_pfn_async); pfn_t gfn_to_pfn(struct kvm *kvm, gfn_t gfn) { return __gfn_to_pfn(kvm, gfn, false, NULL, true, NULL); } EXPORT_SYMBOL_GPL(gfn_to_pfn); pfn_t gfn_to_pfn_prot(struct kvm *kvm, gfn_t gfn, bool write_fault, bool *writable) { return __gfn_to_pfn(kvm, gfn, false, NULL, write_fault, writable); } EXPORT_SYMBOL_GPL(gfn_to_pfn_prot); pfn_t gfn_to_pfn_memslot(struct kvm_memory_slot *slot, gfn_t gfn) { return __gfn_to_pfn_memslot(slot, gfn, false, NULL, true, NULL); } pfn_t gfn_to_pfn_memslot_atomic(struct kvm_memory_slot *slot, gfn_t gfn) { return __gfn_to_pfn_memslot(slot, gfn, true, NULL, true, NULL); } EXPORT_SYMBOL_GPL(gfn_to_pfn_memslot_atomic); int gfn_to_page_many_atomic(struct kvm *kvm, gfn_t gfn, struct page **pages, int nr_pages) { unsigned long addr; gfn_t entry; addr = gfn_to_hva_many(gfn_to_memslot(kvm, gfn), gfn, &entry); if (kvm_is_error_hva(addr)) return -1; if (entry < nr_pages) return 0; return __get_user_pages_fast(addr, nr_pages, 1, pages); } EXPORT_SYMBOL_GPL(gfn_to_page_many_atomic); static struct page *kvm_pfn_to_page(pfn_t pfn) { if (is_error_noslot_pfn(pfn)) return KVM_ERR_PTR_BAD_PAGE; if (kvm_is_mmio_pfn(pfn)) { WARN_ON(1); return KVM_ERR_PTR_BAD_PAGE; } return pfn_to_page(pfn); } struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn) { pfn_t pfn; pfn = gfn_to_pfn(kvm, gfn); return kvm_pfn_to_page(pfn); } EXPORT_SYMBOL_GPL(gfn_to_page); void kvm_release_page_clean(struct page *page) { WARN_ON(is_error_page(page)); kvm_release_pfn_clean(page_to_pfn(page)); } EXPORT_SYMBOL_GPL(kvm_release_page_clean); void kvm_release_pfn_clean(pfn_t pfn) { if (!is_error_noslot_pfn(pfn) && !kvm_is_mmio_pfn(pfn)) put_page(pfn_to_page(pfn)); } EXPORT_SYMBOL_GPL(kvm_release_pfn_clean); void kvm_release_page_dirty(struct page *page) { WARN_ON(is_error_page(page)); kvm_release_pfn_dirty(page_to_pfn(page)); } EXPORT_SYMBOL_GPL(kvm_release_page_dirty); static void kvm_release_pfn_dirty(pfn_t pfn) { kvm_set_pfn_dirty(pfn); kvm_release_pfn_clean(pfn); } void kvm_set_pfn_dirty(pfn_t pfn) { if (!kvm_is_mmio_pfn(pfn)) { struct page *page = pfn_to_page(pfn); if (!PageReserved(page)) SetPageDirty(page); } } EXPORT_SYMBOL_GPL(kvm_set_pfn_dirty); void kvm_set_pfn_accessed(pfn_t pfn) { if (!kvm_is_mmio_pfn(pfn)) mark_page_accessed(pfn_to_page(pfn)); } EXPORT_SYMBOL_GPL(kvm_set_pfn_accessed); void kvm_get_pfn(pfn_t pfn) { if (!kvm_is_mmio_pfn(pfn)) get_page(pfn_to_page(pfn)); } EXPORT_SYMBOL_GPL(kvm_get_pfn); static int next_segment(unsigned long len, int offset) { if (len > PAGE_SIZE - offset) return PAGE_SIZE - offset; else return len; } int kvm_read_guest_page(struct kvm *kvm, gfn_t gfn, void *data, int offset, int len) { int r; unsigned long addr; addr = gfn_to_hva_prot(kvm, gfn, NULL); if (kvm_is_error_hva(addr)) return -EFAULT; r = kvm_read_hva(data, (void __user *)addr + offset, len); if (r) return -EFAULT; return 0; } EXPORT_SYMBOL_GPL(kvm_read_guest_page); int kvm_read_guest(struct kvm *kvm, gpa_t gpa, void *data, unsigned long len) { gfn_t gfn = gpa >> PAGE_SHIFT; int seg; int offset = offset_in_page(gpa); int ret; while ((seg = next_segment(len, offset)) != 0) { ret = kvm_read_guest_page(kvm, gfn, data, offset, seg); if (ret < 0) return ret; offset = 0; len -= seg; data += seg; ++gfn; } return 0; } EXPORT_SYMBOL_GPL(kvm_read_guest); int kvm_read_guest_atomic(struct kvm *kvm, gpa_t gpa, void *data, unsigned long len) { int r; unsigned long addr; gfn_t gfn = gpa >> PAGE_SHIFT; int offset = offset_in_page(gpa); addr = gfn_to_hva_prot(kvm, gfn, NULL); if (kvm_is_error_hva(addr)) return -EFAULT; pagefault_disable(); r = kvm_read_hva_atomic(data, (void __user *)addr + offset, len); pagefault_enable(); if (r) return -EFAULT; return 0; } EXPORT_SYMBOL(kvm_read_guest_atomic); int kvm_write_guest_page(struct kvm *kvm, gfn_t gfn, const void *data, int offset, int len) { int r; unsigned long addr; addr = gfn_to_hva(kvm, gfn); if (kvm_is_error_hva(addr)) return -EFAULT; r = __copy_to_user((void __user *)addr + offset, data, len); if (r) return -EFAULT; mark_page_dirty(kvm, gfn); return 0; } EXPORT_SYMBOL_GPL(kvm_write_guest_page); int kvm_write_guest(struct kvm *kvm, gpa_t gpa, const void *data, unsigned long len) { gfn_t gfn = gpa >> PAGE_SHIFT; int seg; int offset = offset_in_page(gpa); int ret; while ((seg = next_segment(len, offset)) != 0) { ret = kvm_write_guest_page(kvm, gfn, data, offset, seg); if (ret < 0) return ret; offset = 0; len -= seg; data += seg; ++gfn; } return 0; } int kvm_gfn_to_hva_cache_init(struct kvm *kvm, struct gfn_to_hva_cache *ghc, gpa_t gpa, unsigned long len) { struct kvm_memslots *slots = kvm_memslots(kvm); int offset = offset_in_page(gpa); gfn_t start_gfn = gpa >> PAGE_SHIFT; gfn_t end_gfn = (gpa + len - 1) >> PAGE_SHIFT; gfn_t nr_pages_needed = end_gfn - start_gfn + 1; gfn_t nr_pages_avail; ghc->gpa = gpa; ghc->generation = slots->generation; ghc->len = len; ghc->memslot = gfn_to_memslot(kvm, start_gfn); ghc->hva = gfn_to_hva_many(ghc->memslot, start_gfn, &nr_pages_avail); if (!kvm_is_error_hva(ghc->hva) && nr_pages_avail >= nr_pages_needed) { ghc->hva += offset; } else { /* * If the requested region crosses two memslots, we still * verify that the entire region is valid here. */ while (start_gfn <= end_gfn) { ghc->memslot = gfn_to_memslot(kvm, start_gfn); ghc->hva = gfn_to_hva_many(ghc->memslot, start_gfn, &nr_pages_avail); if (kvm_is_error_hva(ghc->hva)) return -EFAULT; start_gfn += nr_pages_avail; } /* Use the slow path for cross page reads and writes. */ ghc->memslot = NULL; } return 0; } EXPORT_SYMBOL_GPL(kvm_gfn_to_hva_cache_init); int kvm_write_guest_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc, void *data, unsigned long len) { struct kvm_memslots *slots = kvm_memslots(kvm); int r; BUG_ON(len > ghc->len); if (slots->generation != ghc->generation) kvm_gfn_to_hva_cache_init(kvm, ghc, ghc->gpa, ghc->len); if (unlikely(!ghc->memslot)) return kvm_write_guest(kvm, ghc->gpa, data, len); if (kvm_is_error_hva(ghc->hva)) return -EFAULT; r = __copy_to_user((void __user *)ghc->hva, data, len); if (r) return -EFAULT; mark_page_dirty_in_slot(kvm, ghc->memslot, ghc->gpa >> PAGE_SHIFT); return 0; } EXPORT_SYMBOL_GPL(kvm_write_guest_cached); int kvm_read_guest_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc, void *data, unsigned long len) { struct kvm_memslots *slots = kvm_memslots(kvm); int r; BUG_ON(len > ghc->len); if (slots->generation != ghc->generation) kvm_gfn_to_hva_cache_init(kvm, ghc, ghc->gpa, ghc->len); if (unlikely(!ghc->memslot)) return kvm_read_guest(kvm, ghc->gpa, data, len); if (kvm_is_error_hva(ghc->hva)) return -EFAULT; r = __copy_from_user(data, (void __user *)ghc->hva, len); if (r) return -EFAULT; return 0; } EXPORT_SYMBOL_GPL(kvm_read_guest_cached); int kvm_clear_guest_page(struct kvm *kvm, gfn_t gfn, int offset, int len) { const void *zero_page = (const void *) __va(page_to_phys(ZERO_PAGE(0))); return kvm_write_guest_page(kvm, gfn, zero_page, offset, len); } EXPORT_SYMBOL_GPL(kvm_clear_guest_page); int kvm_clear_guest(struct kvm *kvm, gpa_t gpa, unsigned long len) { gfn_t gfn = gpa >> PAGE_SHIFT; int seg; int offset = offset_in_page(gpa); int ret; while ((seg = next_segment(len, offset)) != 0) { ret = kvm_clear_guest_page(kvm, gfn, offset, seg); if (ret < 0) return ret; offset = 0; len -= seg; ++gfn; } return 0; } EXPORT_SYMBOL_GPL(kvm_clear_guest); static void mark_page_dirty_in_slot(struct kvm *kvm, struct kvm_memory_slot *memslot, gfn_t gfn) { if (memslot && memslot->dirty_bitmap) { unsigned long rel_gfn = gfn - memslot->base_gfn; set_bit_le(rel_gfn, memslot->dirty_bitmap); } } void mark_page_dirty(struct kvm *kvm, gfn_t gfn) { struct kvm_memory_slot *memslot; memslot = gfn_to_memslot(kvm, gfn); mark_page_dirty_in_slot(kvm, memslot, gfn); } EXPORT_SYMBOL_GPL(mark_page_dirty); /* * The vCPU has executed a HLT instruction with in-kernel mode enabled. */ void kvm_vcpu_block(struct kvm_vcpu *vcpu) { DEFINE_WAIT(wait); for (;;) { prepare_to_wait(&vcpu->wq, &wait, TASK_INTERRUPTIBLE); if (kvm_arch_vcpu_runnable(vcpu)) { kvm_make_request(KVM_REQ_UNHALT, vcpu); break; } if (kvm_cpu_has_pending_timer(vcpu)) break; if (signal_pending(current)) break; schedule(); } finish_wait(&vcpu->wq, &wait); } EXPORT_SYMBOL_GPL(kvm_vcpu_block); #ifndef CONFIG_S390 /* * Kick a sleeping VCPU, or a guest VCPU in guest mode, into host kernel mode. */ void kvm_vcpu_kick(struct kvm_vcpu *vcpu) { int me; int cpu = vcpu->cpu; wait_queue_head_t *wqp; wqp = kvm_arch_vcpu_wq(vcpu); if (waitqueue_active(wqp)) { wake_up_interruptible(wqp); ++vcpu->stat.halt_wakeup; } me = get_cpu(); if (cpu != me && (unsigned)cpu < nr_cpu_ids && cpu_online(cpu)) if (kvm_arch_vcpu_should_kick(vcpu)) smp_send_reschedule(cpu); put_cpu(); } EXPORT_SYMBOL_GPL(kvm_vcpu_kick); #endif /* !CONFIG_S390 */ int kvm_vcpu_yield_to(struct kvm_vcpu *target) { struct pid *pid; struct task_struct *task = NULL; int ret = 0; rcu_read_lock(); pid = rcu_dereference(target->pid); if (pid) task = get_pid_task(target->pid, PIDTYPE_PID); rcu_read_unlock(); if (!task) return ret; if (task->flags & PF_VCPU) { put_task_struct(task); return ret; } ret = yield_to(task, 1); put_task_struct(task); return ret; } EXPORT_SYMBOL_GPL(kvm_vcpu_yield_to); /* * Helper that checks whether a VCPU is eligible for directed yield. * Most eligible candidate to yield is decided by following heuristics: * * (a) VCPU which has not done pl-exit or cpu relax intercepted recently * (preempted lock holder), indicated by @in_spin_loop. * Set at the beiginning and cleared at the end of interception/PLE handler. * * (b) VCPU which has done pl-exit/ cpu relax intercepted but did not get * chance last time (mostly it has become eligible now since we have probably * yielded to lockholder in last iteration. This is done by toggling * @dy_eligible each time a VCPU checked for eligibility.) * * Yielding to a recently pl-exited/cpu relax intercepted VCPU before yielding * to preempted lock-holder could result in wrong VCPU selection and CPU * burning. Giving priority for a potential lock-holder increases lock * progress. * * Since algorithm is based on heuristics, accessing another VCPU data without * locking does not harm. It may result in trying to yield to same VCPU, fail * and continue with next VCPU and so on. */ static bool kvm_vcpu_eligible_for_directed_yield(struct kvm_vcpu *vcpu) { #ifdef CONFIG_HAVE_KVM_CPU_RELAX_INTERCEPT bool eligible; eligible = !vcpu->spin_loop.in_spin_loop || (vcpu->spin_loop.in_spin_loop && vcpu->spin_loop.dy_eligible); if (vcpu->spin_loop.in_spin_loop) kvm_vcpu_set_dy_eligible(vcpu, !vcpu->spin_loop.dy_eligible); return eligible; #else return true; #endif } void kvm_vcpu_on_spin(struct kvm_vcpu *me) { struct kvm *kvm = me->kvm; struct kvm_vcpu *vcpu; int last_boosted_vcpu = me->kvm->last_boosted_vcpu; int yielded = 0; int try = 3; int pass; int i; kvm_vcpu_set_in_spin_loop(me, true); /* * We boost the priority of a VCPU that is runnable but not * currently running, because it got preempted by something * else and called schedule in __vcpu_run. Hopefully that * VCPU is holding the lock that we need and will release it. * We approximate round-robin by starting at the last boosted VCPU. */ for (pass = 0; pass < 2 && !yielded && try; pass++) { kvm_for_each_vcpu(i, vcpu, kvm) { if (!pass && i <= last_boosted_vcpu) { i = last_boosted_vcpu; continue; } else if (pass && i > last_boosted_vcpu) break; if (!ACCESS_ONCE(vcpu->preempted)) continue; if (vcpu == me) continue; if (waitqueue_active(&vcpu->wq) && !kvm_arch_vcpu_runnable(vcpu)) continue; if (!kvm_vcpu_eligible_for_directed_yield(vcpu)) continue; yielded = kvm_vcpu_yield_to(vcpu); if (yielded > 0) { kvm->last_boosted_vcpu = i; break; } else if (yielded < 0) { try--; if (!try) break; } } } kvm_vcpu_set_in_spin_loop(me, false); /* Ensure vcpu is not eligible during next spinloop */ kvm_vcpu_set_dy_eligible(me, false); } EXPORT_SYMBOL_GPL(kvm_vcpu_on_spin); static int kvm_vcpu_fault(struct vm_area_struct *vma, struct vm_fault *vmf) { struct kvm_vcpu *vcpu = vma->vm_file->private_data; struct page *page; if (vmf->pgoff == 0) page = virt_to_page(vcpu->run); #ifdef CONFIG_X86 else if (vmf->pgoff == KVM_PIO_PAGE_OFFSET) page = virt_to_page(vcpu->arch.pio_data); #endif #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET else if (vmf->pgoff == KVM_COALESCED_MMIO_PAGE_OFFSET) page = virt_to_page(vcpu->kvm->coalesced_mmio_ring); #endif else return kvm_arch_vcpu_fault(vcpu, vmf); get_page(page); vmf->page = page; return 0; } static const struct vm_operations_struct kvm_vcpu_vm_ops = { .fault = kvm_vcpu_fault, }; static int kvm_vcpu_mmap(struct file *file, struct vm_area_struct *vma) { vma->vm_ops = &kvm_vcpu_vm_ops; return 0; } static int kvm_vcpu_release(struct inode *inode, struct file *filp) { struct kvm_vcpu *vcpu = filp->private_data; kvm_put_kvm(vcpu->kvm); return 0; } static struct file_operations kvm_vcpu_fops = { .release = kvm_vcpu_release, .unlocked_ioctl = kvm_vcpu_ioctl, #ifdef CONFIG_COMPAT .compat_ioctl = kvm_vcpu_compat_ioctl, #endif .mmap = kvm_vcpu_mmap, .llseek = noop_llseek, }; /* * Allocates an inode for the vcpu. */ static int create_vcpu_fd(struct kvm_vcpu *vcpu) { return anon_inode_getfd("kvm-vcpu", &kvm_vcpu_fops, vcpu, O_RDWR | O_CLOEXEC); } /* * Creates some virtual cpus. Good luck creating more than one. */ static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, u32 id) { int r; struct kvm_vcpu *vcpu, *v; if (id >= KVM_MAX_VCPUS) return -EINVAL; vcpu = kvm_arch_vcpu_create(kvm, id); if (IS_ERR(vcpu)) return PTR_ERR(vcpu); preempt_notifier_init(&vcpu->preempt_notifier, &kvm_preempt_ops); r = kvm_arch_vcpu_setup(vcpu); if (r) goto vcpu_destroy; mutex_lock(&kvm->lock); if (!kvm_vcpu_compatible(vcpu)) { r = -EINVAL; goto unlock_vcpu_destroy; } if (atomic_read(&kvm->online_vcpus) == KVM_MAX_VCPUS) { r = -EINVAL; goto unlock_vcpu_destroy; } kvm_for_each_vcpu(r, v, kvm) if (v->vcpu_id == id) { r = -EEXIST; goto unlock_vcpu_destroy; } BUG_ON(kvm->vcpus[atomic_read(&kvm->online_vcpus)]); /* Now it's all set up, let userspace reach it */ kvm_get_kvm(kvm); r = create_vcpu_fd(vcpu); if (r < 0) { kvm_put_kvm(kvm); goto unlock_vcpu_destroy; } kvm->vcpus[atomic_read(&kvm->online_vcpus)] = vcpu; smp_wmb(); atomic_inc(&kvm->online_vcpus); mutex_unlock(&kvm->lock); kvm_arch_vcpu_postcreate(vcpu); return r; unlock_vcpu_destroy: mutex_unlock(&kvm->lock); vcpu_destroy: kvm_arch_vcpu_destroy(vcpu); return r; } static int kvm_vcpu_ioctl_set_sigmask(struct kvm_vcpu *vcpu, sigset_t *sigset) { if (sigset) { sigdelsetmask(sigset, sigmask(SIGKILL)|sigmask(SIGSTOP)); vcpu->sigset_active = 1; vcpu->sigset = *sigset; } else vcpu->sigset_active = 0; return 0; } static long kvm_vcpu_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg) { struct kvm_vcpu *vcpu = filp->private_data; void __user *argp = (void __user *)arg; int r; struct kvm_fpu *fpu = NULL; struct kvm_sregs *kvm_sregs = NULL; if (vcpu->kvm->mm != current->mm) return -EIO; #if defined(CONFIG_S390) || defined(CONFIG_PPC) || defined(CONFIG_MIPS) /* * Special cases: vcpu ioctls that are asynchronous to vcpu execution, * so vcpu_load() would break it. */ if (ioctl == KVM_S390_INTERRUPT || ioctl == KVM_INTERRUPT) return kvm_arch_vcpu_ioctl(filp, ioctl, arg); #endif r = vcpu_load(vcpu); if (r) return r; switch (ioctl) { case KVM_RUN: r = -EINVAL; if (arg) goto out; r = kvm_arch_vcpu_ioctl_run(vcpu, vcpu->run); trace_kvm_userspace_exit(vcpu->run->exit_reason, r); break; case KVM_GET_REGS: { struct kvm_regs *kvm_regs; r = -ENOMEM; kvm_regs = kzalloc(sizeof(struct kvm_regs), GFP_KERNEL); if (!kvm_regs) goto out; r = kvm_arch_vcpu_ioctl_get_regs(vcpu, kvm_regs); if (r) goto out_free1; r = -EFAULT; if (copy_to_user(argp, kvm_regs, sizeof(struct kvm_regs))) goto out_free1; r = 0; out_free1: kfree(kvm_regs); break; } case KVM_SET_REGS: { struct kvm_regs *kvm_regs; r = -ENOMEM; kvm_regs = memdup_user(argp, sizeof(*kvm_regs)); if (IS_ERR(kvm_regs)) { r = PTR_ERR(kvm_regs); goto out; } r = kvm_arch_vcpu_ioctl_set_regs(vcpu, kvm_regs); kfree(kvm_regs); break; } case KVM_GET_SREGS: { kvm_sregs = kzalloc(sizeof(struct kvm_sregs), GFP_KERNEL); r = -ENOMEM; if (!kvm_sregs) goto out; r = kvm_arch_vcpu_ioctl_get_sregs(vcpu, kvm_sregs); if (r) goto out; r = -EFAULT; if (copy_to_user(argp, kvm_sregs, sizeof(struct kvm_sregs))) goto out; r = 0; break; } case KVM_SET_SREGS: { kvm_sregs = memdup_user(argp, sizeof(*kvm_sregs)); if (IS_ERR(kvm_sregs)) { r = PTR_ERR(kvm_sregs); kvm_sregs = NULL; goto out; } r = kvm_arch_vcpu_ioctl_set_sregs(vcpu, kvm_sregs); break; } case KVM_GET_MP_STATE: { struct kvm_mp_state mp_state; r = kvm_arch_vcpu_ioctl_get_mpstate(vcpu, &mp_state); if (r) goto out; r = -EFAULT; if (copy_to_user(argp, &mp_state, sizeof mp_state)) goto out; r = 0; break; } case KVM_SET_MP_STATE: { struct kvm_mp_state mp_state; r = -EFAULT; if (copy_from_user(&mp_state, argp, sizeof mp_state)) goto out; r = kvm_arch_vcpu_ioctl_set_mpstate(vcpu, &mp_state); break; } case KVM_TRANSLATE: { struct kvm_translation tr; r = -EFAULT; if (copy_from_user(&tr, argp, sizeof tr)) goto out; r = kvm_arch_vcpu_ioctl_translate(vcpu, &tr); if (r) goto out; r = -EFAULT; if (copy_to_user(argp, &tr, sizeof tr)) goto out; r = 0; break; } case KVM_SET_GUEST_DEBUG: { struct kvm_guest_debug dbg; r = -EFAULT; if (copy_from_user(&dbg, argp, sizeof dbg)) goto out; r = kvm_arch_vcpu_ioctl_set_guest_debug(vcpu, &dbg); break; } case KVM_SET_SIGNAL_MASK: { struct kvm_signal_mask __user *sigmask_arg = argp; struct kvm_signal_mask kvm_sigmask; sigset_t sigset, *p; p = NULL; if (argp) { r = -EFAULT; if (copy_from_user(&kvm_sigmask, argp, sizeof kvm_sigmask)) goto out; r = -EINVAL; if (kvm_sigmask.len != sizeof sigset) goto out; r = -EFAULT; if (copy_from_user(&sigset, sigmask_arg->sigset, sizeof sigset)) goto out; p = &sigset; } r = kvm_vcpu_ioctl_set_sigmask(vcpu, p); break; } case KVM_GET_FPU: { fpu = kzalloc(sizeof(struct kvm_fpu), GFP_KERNEL); r = -ENOMEM; if (!fpu) goto out; r = kvm_arch_vcpu_ioctl_get_fpu(vcpu, fpu); if (r) goto out; r = -EFAULT; if (copy_to_user(argp, fpu, sizeof(struct kvm_fpu))) goto out; r = 0; break; } case KVM_SET_FPU: { fpu = memdup_user(argp, sizeof(*fpu)); if (IS_ERR(fpu)) { r = PTR_ERR(fpu); fpu = NULL; goto out; } r = kvm_arch_vcpu_ioctl_set_fpu(vcpu, fpu); break; } default: r = kvm_arch_vcpu_ioctl(filp, ioctl, arg); } out: vcpu_put(vcpu); kfree(fpu); kfree(kvm_sregs); return r; } #ifdef CONFIG_COMPAT static long kvm_vcpu_compat_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg) { struct kvm_vcpu *vcpu = filp->private_data; void __user *argp = compat_ptr(arg); int r; if (vcpu->kvm->mm != current->mm) return -EIO; switch (ioctl) { case KVM_SET_SIGNAL_MASK: { struct kvm_signal_mask __user *sigmask_arg = argp; struct kvm_signal_mask kvm_sigmask; compat_sigset_t csigset; sigset_t sigset; if (argp) { r = -EFAULT; if (copy_from_user(&kvm_sigmask, argp, sizeof kvm_sigmask)) goto out; r = -EINVAL; if (kvm_sigmask.len != sizeof csigset) goto out; r = -EFAULT; if (copy_from_user(&csigset, sigmask_arg->sigset, sizeof csigset)) goto out; sigset_from_compat(&sigset, &csigset); r = kvm_vcpu_ioctl_set_sigmask(vcpu, &sigset); } else r = kvm_vcpu_ioctl_set_sigmask(vcpu, NULL); break; } default: r = kvm_vcpu_ioctl(filp, ioctl, arg); } out: return r; } #endif static int kvm_device_ioctl_attr(struct kvm_device *dev, int (*accessor)(struct kvm_device *dev, struct kvm_device_attr *attr), unsigned long arg) { struct kvm_device_attr attr; if (!accessor) return -EPERM; if (copy_from_user(&attr, (void __user *)arg, sizeof(attr))) return -EFAULT; return accessor(dev, &attr); } static long kvm_device_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg) { struct kvm_device *dev = filp->private_data; switch (ioctl) { case KVM_SET_DEVICE_ATTR: return kvm_device_ioctl_attr(dev, dev->ops->set_attr, arg); case KVM_GET_DEVICE_ATTR: return kvm_device_ioctl_attr(dev, dev->ops->get_attr, arg); case KVM_HAS_DEVICE_ATTR: return kvm_device_ioctl_attr(dev, dev->ops->has_attr, arg); default: if (dev->ops->ioctl) return dev->ops->ioctl(dev, ioctl, arg); return -ENOTTY; } } static int kvm_device_release(struct inode *inode, struct file *filp) { struct kvm_device *dev = filp->private_data; struct kvm *kvm = dev->kvm; kvm_put_kvm(kvm); return 0; } static const struct file_operations kvm_device_fops = { .unlocked_ioctl = kvm_device_ioctl, #ifdef CONFIG_COMPAT .compat_ioctl = kvm_device_ioctl, #endif .release = kvm_device_release, }; struct kvm_device *kvm_device_from_filp(struct file *filp) { if (filp->f_op != &kvm_device_fops) return NULL; return filp->private_data; } static int kvm_ioctl_create_device(struct kvm *kvm, struct kvm_create_device *cd) { struct kvm_device_ops *ops = NULL; struct kvm_device *dev; bool test = cd->flags & KVM_CREATE_DEVICE_TEST; int ret; switch (cd->type) { #ifdef CONFIG_KVM_MPIC case KVM_DEV_TYPE_FSL_MPIC_20: case KVM_DEV_TYPE_FSL_MPIC_42: ops = &kvm_mpic_ops; break; #endif #ifdef CONFIG_KVM_XICS case KVM_DEV_TYPE_XICS: ops = &kvm_xics_ops; break; #endif #ifdef CONFIG_KVM_VFIO case KVM_DEV_TYPE_VFIO: ops = &kvm_vfio_ops; break; #endif #ifdef CONFIG_KVM_ARM_VGIC case KVM_DEV_TYPE_ARM_VGIC_V2: ops = &kvm_arm_vgic_v2_ops; break; #endif #ifdef CONFIG_S390 case KVM_DEV_TYPE_FLIC: ops = &kvm_flic_ops; break; #endif default: return -ENODEV; } if (test) return 0; dev = kzalloc(sizeof(*dev), GFP_KERNEL); if (!dev) return -ENOMEM; dev->ops = ops; dev->kvm = kvm; ret = ops->create(dev, cd->type); if (ret < 0) { kfree(dev); return ret; } ret = anon_inode_getfd(ops->name, &kvm_device_fops, dev, O_RDWR | O_CLOEXEC); if (ret < 0) { ops->destroy(dev); return ret; } list_add(&dev->vm_node, &kvm->devices); kvm_get_kvm(kvm); cd->fd = ret; return 0; } static long kvm_vm_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg) { struct kvm *kvm = filp->private_data; void __user *argp = (void __user *)arg; int r; if (kvm->mm != current->mm) return -EIO; switch (ioctl) { case KVM_CREATE_VCPU: r = kvm_vm_ioctl_create_vcpu(kvm, arg); break; case KVM_SET_USER_MEMORY_REGION: { struct kvm_userspace_memory_region kvm_userspace_mem; r = -EFAULT; if (copy_from_user(&kvm_userspace_mem, argp, sizeof kvm_userspace_mem)) goto out; r = kvm_vm_ioctl_set_memory_region(kvm, &kvm_userspace_mem); break; } case KVM_GET_DIRTY_LOG: { struct kvm_dirty_log log; r = -EFAULT; if (copy_from_user(&log, argp, sizeof log)) goto out; r = kvm_vm_ioctl_get_dirty_log(kvm, &log); break; } #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET case KVM_REGISTER_COALESCED_MMIO: { struct kvm_coalesced_mmio_zone zone; r = -EFAULT; if (copy_from_user(&zone, argp, sizeof zone)) goto out; r = kvm_vm_ioctl_register_coalesced_mmio(kvm, &zone); break; } case KVM_UNREGISTER_COALESCED_MMIO: { struct kvm_coalesced_mmio_zone zone; r = -EFAULT; if (copy_from_user(&zone, argp, sizeof zone)) goto out; r = kvm_vm_ioctl_unregister_coalesced_mmio(kvm, &zone); break; } #endif case KVM_IRQFD: { struct kvm_irqfd data; r = -EFAULT; if (copy_from_user(&data, argp, sizeof data)) goto out; r = kvm_irqfd(kvm, &data); break; } case KVM_IOEVENTFD: { struct kvm_ioeventfd data; r = -EFAULT; if (copy_from_user(&data, argp, sizeof data)) goto out; r = kvm_ioeventfd(kvm, &data); break; } #ifdef CONFIG_KVM_APIC_ARCHITECTURE case KVM_SET_BOOT_CPU_ID: r = 0; mutex_lock(&kvm->lock); if (atomic_read(&kvm->online_vcpus) != 0) r = -EBUSY; else kvm->bsp_vcpu_id = arg; mutex_unlock(&kvm->lock); break; #endif #ifdef CONFIG_HAVE_KVM_MSI case KVM_SIGNAL_MSI: { struct kvm_msi msi; r = -EFAULT; if (copy_from_user(&msi, argp, sizeof msi)) goto out; r = kvm_send_userspace_msi(kvm, &msi); break; } #endif #ifdef __KVM_HAVE_IRQ_LINE case KVM_IRQ_LINE_STATUS: case KVM_IRQ_LINE: { struct kvm_irq_level irq_event; r = -EFAULT; if (copy_from_user(&irq_event, argp, sizeof irq_event)) goto out; r = kvm_vm_ioctl_irq_line(kvm, &irq_event, ioctl == KVM_IRQ_LINE_STATUS); if (r) goto out; r = -EFAULT; if (ioctl == KVM_IRQ_LINE_STATUS) { if (copy_to_user(argp, &irq_event, sizeof irq_event)) goto out; } r = 0; break; } #endif #ifdef CONFIG_HAVE_KVM_IRQ_ROUTING case KVM_SET_GSI_ROUTING: { struct kvm_irq_routing routing; struct kvm_irq_routing __user *urouting; struct kvm_irq_routing_entry *entries; r = -EFAULT; if (copy_from_user(&routing, argp, sizeof(routing))) goto out; r = -EINVAL; if (routing.nr >= KVM_MAX_IRQ_ROUTES) goto out; if (routing.flags) goto out; r = -ENOMEM; entries = vmalloc(routing.nr * sizeof(*entries)); if (!entries) goto out; r = -EFAULT; urouting = argp; if (copy_from_user(entries, urouting->entries, routing.nr * sizeof(*entries))) goto out_free_irq_routing; r = kvm_set_irq_routing(kvm, entries, routing.nr, routing.flags); out_free_irq_routing: vfree(entries); break; } #endif /* CONFIG_HAVE_KVM_IRQ_ROUTING */ case KVM_CREATE_DEVICE: { struct kvm_create_device cd; r = -EFAULT; if (copy_from_user(&cd, argp, sizeof(cd))) goto out; r = kvm_ioctl_create_device(kvm, &cd); if (r) goto out; r = -EFAULT; if (copy_to_user(argp, &cd, sizeof(cd))) goto out; r = 0; break; } default: r = kvm_arch_vm_ioctl(filp, ioctl, arg); if (r == -ENOTTY) r = kvm_vm_ioctl_assigned_device(kvm, ioctl, arg); } out: return r; } #ifdef CONFIG_COMPAT struct compat_kvm_dirty_log { __u32 slot; __u32 padding1; union { compat_uptr_t dirty_bitmap; /* one bit per page */ __u64 padding2; }; }; static long kvm_vm_compat_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg) { struct kvm *kvm = filp->private_data; int r; if (kvm->mm != current->mm) return -EIO; switch (ioctl) { case KVM_GET_DIRTY_LOG: { struct compat_kvm_dirty_log compat_log; struct kvm_dirty_log log; r = -EFAULT; if (copy_from_user(&compat_log, (void __user *)arg, sizeof(compat_log))) goto out; log.slot = compat_log.slot; log.padding1 = compat_log.padding1; log.padding2 = compat_log.padding2; log.dirty_bitmap = compat_ptr(compat_log.dirty_bitmap); r = kvm_vm_ioctl_get_dirty_log(kvm, &log); break; } default: r = kvm_vm_ioctl(filp, ioctl, arg); } out: return r; } #endif static struct file_operations kvm_vm_fops = { .release = kvm_vm_release, .unlocked_ioctl = kvm_vm_ioctl, #ifdef CONFIG_COMPAT .compat_ioctl = kvm_vm_compat_ioctl, #endif .llseek = noop_llseek, }; static int kvm_dev_ioctl_create_vm(unsigned long type) { int r; struct kvm *kvm; kvm = kvm_create_vm(type); if (IS_ERR(kvm)) return PTR_ERR(kvm); #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET r = kvm_coalesced_mmio_init(kvm); if (r < 0) { kvm_put_kvm(kvm); return r; } #endif r = anon_inode_getfd("kvm-vm", &kvm_vm_fops, kvm, O_RDWR | O_CLOEXEC); if (r < 0) kvm_put_kvm(kvm); return r; } static long kvm_vm_ioctl_check_extension_generic(struct kvm *kvm, long arg) { switch (arg) { case KVM_CAP_USER_MEMORY: case KVM_CAP_DESTROY_MEMORY_REGION_WORKS: case KVM_CAP_JOIN_MEMORY_REGIONS_WORKS: #ifdef CONFIG_KVM_APIC_ARCHITECTURE case KVM_CAP_SET_BOOT_CPU_ID: #endif case KVM_CAP_INTERNAL_ERROR_DATA: #ifdef CONFIG_HAVE_KVM_MSI case KVM_CAP_SIGNAL_MSI: #endif #ifdef CONFIG_HAVE_KVM_IRQ_ROUTING case KVM_CAP_IRQFD_RESAMPLE: #endif return 1; #ifdef CONFIG_HAVE_KVM_IRQ_ROUTING case KVM_CAP_IRQ_ROUTING: return KVM_MAX_IRQ_ROUTES; #endif default: break; } return kvm_vm_ioctl_check_extension(kvm, arg); } static long kvm_dev_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg) { long r = -EINVAL; switch (ioctl) { case KVM_GET_API_VERSION: r = -EINVAL; if (arg) goto out; r = KVM_API_VERSION; break; case KVM_CREATE_VM: r = kvm_dev_ioctl_create_vm(arg); break; case KVM_CHECK_EXTENSION: r = kvm_vm_ioctl_check_extension_generic(NULL, arg); break; case KVM_GET_VCPU_MMAP_SIZE: r = -EINVAL; if (arg) goto out; r = PAGE_SIZE; /* struct kvm_run */ #ifdef CONFIG_X86 r += PAGE_SIZE; /* pio data page */ #endif #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET r += PAGE_SIZE; /* coalesced mmio ring page */ #endif break; case KVM_TRACE_ENABLE: case KVM_TRACE_PAUSE: case KVM_TRACE_DISABLE: r = -EOPNOTSUPP; break; default: return kvm_arch_dev_ioctl(filp, ioctl, arg); } out: return r; } static struct file_operations kvm_chardev_ops = { .unlocked_ioctl = kvm_dev_ioctl, .compat_ioctl = kvm_dev_ioctl, .llseek = noop_llseek, }; static struct miscdevice kvm_dev = { KVM_MINOR, "kvm", &kvm_chardev_ops, }; static void hardware_enable_nolock(void *junk) { int cpu = raw_smp_processor_id(); int r; if (cpumask_test_cpu(cpu, cpus_hardware_enabled)) return; cpumask_set_cpu(cpu, cpus_hardware_enabled); r = kvm_arch_hardware_enable(NULL); if (r) { cpumask_clear_cpu(cpu, cpus_hardware_enabled); atomic_inc(&hardware_enable_failed); printk(KERN_INFO "kvm: enabling virtualization on " "CPU%d failed\n", cpu); } } static void hardware_enable(void) { raw_spin_lock(&kvm_count_lock); if (kvm_usage_count) hardware_enable_nolock(NULL); raw_spin_unlock(&kvm_count_lock); } static void hardware_disable_nolock(void *junk) { int cpu = raw_smp_processor_id(); if (!cpumask_test_cpu(cpu, cpus_hardware_enabled)) return; cpumask_clear_cpu(cpu, cpus_hardware_enabled); kvm_arch_hardware_disable(NULL); } static void hardware_disable(void) { raw_spin_lock(&kvm_count_lock); if (kvm_usage_count) hardware_disable_nolock(NULL); raw_spin_unlock(&kvm_count_lock); } static void hardware_disable_all_nolock(void) { BUG_ON(!kvm_usage_count); kvm_usage_count--; if (!kvm_usage_count) on_each_cpu(hardware_disable_nolock, NULL, 1); } static void hardware_disable_all(void) { raw_spin_lock(&kvm_count_lock); hardware_disable_all_nolock(); raw_spin_unlock(&kvm_count_lock); } static int hardware_enable_all(void) { int r = 0; raw_spin_lock(&kvm_count_lock); kvm_usage_count++; if (kvm_usage_count == 1) { atomic_set(&hardware_enable_failed, 0); on_each_cpu(hardware_enable_nolock, NULL, 1); if (atomic_read(&hardware_enable_failed)) { hardware_disable_all_nolock(); r = -EBUSY; } } raw_spin_unlock(&kvm_count_lock); return r; } static int kvm_cpu_hotplug(struct notifier_block *notifier, unsigned long val, void *v) { int cpu = (long)v; val &= ~CPU_TASKS_FROZEN; switch (val) { case CPU_DYING: printk(KERN_INFO "kvm: disabling virtualization on CPU%d\n", cpu); hardware_disable(); break; case CPU_STARTING: printk(KERN_INFO "kvm: enabling virtualization on CPU%d\n", cpu); hardware_enable(); break; } return NOTIFY_OK; } static int kvm_reboot(struct notifier_block *notifier, unsigned long val, void *v) { /* * Some (well, at least mine) BIOSes hang on reboot if * in vmx root mode. * * And Intel TXT required VMX off for all cpu when system shutdown. */ printk(KERN_INFO "kvm: exiting hardware virtualization\n"); kvm_rebooting = true; on_each_cpu(hardware_disable_nolock, NULL, 1); return NOTIFY_OK; } static struct notifier_block kvm_reboot_notifier = { .notifier_call = kvm_reboot, .priority = 0, }; static void kvm_io_bus_destroy(struct kvm_io_bus *bus) { int i; for (i = 0; i < bus->dev_count; i++) { struct kvm_io_device *pos = bus->range[i].dev; kvm_iodevice_destructor(pos); } kfree(bus); } static inline int kvm_io_bus_cmp(const struct kvm_io_range *r1, const struct kvm_io_range *r2) { if (r1->addr < r2->addr) return -1; if (r1->addr + r1->len > r2->addr + r2->len) return 1; return 0; } static int kvm_io_bus_sort_cmp(const void *p1, const void *p2) { return kvm_io_bus_cmp(p1, p2); } static int kvm_io_bus_insert_dev(struct kvm_io_bus *bus, struct kvm_io_device *dev, gpa_t addr, int len) { bus->range[bus->dev_count++] = (struct kvm_io_range) { .addr = addr, .len = len, .dev = dev, }; sort(bus->range, bus->dev_count, sizeof(struct kvm_io_range), kvm_io_bus_sort_cmp, NULL); return 0; } static int kvm_io_bus_get_first_dev(struct kvm_io_bus *bus, gpa_t addr, int len) { struct kvm_io_range *range, key; int off; key = (struct kvm_io_range) { .addr = addr, .len = len, }; range = bsearch(&key, bus->range, bus->dev_count, sizeof(struct kvm_io_range), kvm_io_bus_sort_cmp); if (range == NULL) return -ENOENT; off = range - bus->range; while (off > 0 && kvm_io_bus_cmp(&key, &bus->range[off-1]) == 0) off--; return off; } static int __kvm_io_bus_write(struct kvm_io_bus *bus, struct kvm_io_range *range, const void *val) { int idx; idx = kvm_io_bus_get_first_dev(bus, range->addr, range->len); if (idx < 0) return -EOPNOTSUPP; while (idx < bus->dev_count && kvm_io_bus_cmp(range, &bus->range[idx]) == 0) { if (!kvm_iodevice_write(bus->range[idx].dev, range->addr, range->len, val)) return idx; idx++; } return -EOPNOTSUPP; } /* kvm_io_bus_write - called under kvm->slots_lock */ int kvm_io_bus_write(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr, int len, const void *val) { struct kvm_io_bus *bus; struct kvm_io_range range; int r; range = (struct kvm_io_range) { .addr = addr, .len = len, }; bus = srcu_dereference(kvm->buses[bus_idx], &kvm->srcu); r = __kvm_io_bus_write(bus, &range, val); return r < 0 ? r : 0; } /* kvm_io_bus_write_cookie - called under kvm->slots_lock */ int kvm_io_bus_write_cookie(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr, int len, const void *val, long cookie) { struct kvm_io_bus *bus; struct kvm_io_range range; range = (struct kvm_io_range) { .addr = addr, .len = len, }; bus = srcu_dereference(kvm->buses[bus_idx], &kvm->srcu); /* First try the device referenced by cookie. */ if ((cookie >= 0) && (cookie < bus->dev_count) && (kvm_io_bus_cmp(&range, &bus->range[cookie]) == 0)) if (!kvm_iodevice_write(bus->range[cookie].dev, addr, len, val)) return cookie; /* * cookie contained garbage; fall back to search and return the * correct cookie value. */ return __kvm_io_bus_write(bus, &range, val); } static int __kvm_io_bus_read(struct kvm_io_bus *bus, struct kvm_io_range *range, void *val) { int idx; idx = kvm_io_bus_get_first_dev(bus, range->addr, range->len); if (idx < 0) return -EOPNOTSUPP; while (idx < bus->dev_count && kvm_io_bus_cmp(range, &bus->range[idx]) == 0) { if (!kvm_iodevice_read(bus->range[idx].dev, range->addr, range->len, val)) return idx; idx++; } return -EOPNOTSUPP; } EXPORT_SYMBOL_GPL(kvm_io_bus_write); /* kvm_io_bus_read - called under kvm->slots_lock */ int kvm_io_bus_read(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr, int len, void *val) { struct kvm_io_bus *bus; struct kvm_io_range range; int r; range = (struct kvm_io_range) { .addr = addr, .len = len, }; bus = srcu_dereference(kvm->buses[bus_idx], &kvm->srcu); r = __kvm_io_bus_read(bus, &range, val); return r < 0 ? r : 0; } /* Caller must hold slots_lock. */ int kvm_io_bus_register_dev(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr, int len, struct kvm_io_device *dev) { struct kvm_io_bus *new_bus, *bus; bus = kvm->buses[bus_idx]; /* exclude ioeventfd which is limited by maximum fd */ if (bus->dev_count - bus->ioeventfd_count > NR_IOBUS_DEVS - 1) return -ENOSPC; new_bus = kzalloc(sizeof(*bus) + ((bus->dev_count + 1) * sizeof(struct kvm_io_range)), GFP_KERNEL); if (!new_bus) return -ENOMEM; memcpy(new_bus, bus, sizeof(*bus) + (bus->dev_count * sizeof(struct kvm_io_range))); kvm_io_bus_insert_dev(new_bus, dev, addr, len); rcu_assign_pointer(kvm->buses[bus_idx], new_bus); synchronize_srcu_expedited(&kvm->srcu); kfree(bus); return 0; } /* Caller must hold slots_lock. */ int kvm_io_bus_unregister_dev(struct kvm *kvm, enum kvm_bus bus_idx, struct kvm_io_device *dev) { int i, r; struct kvm_io_bus *new_bus, *bus; bus = kvm->buses[bus_idx]; r = -ENOENT; for (i = 0; i < bus->dev_count; i++) if (bus->range[i].dev == dev) { r = 0; break; } if (r) return r; new_bus = kzalloc(sizeof(*bus) + ((bus->dev_count - 1) * sizeof(struct kvm_io_range)), GFP_KERNEL); if (!new_bus) return -ENOMEM; memcpy(new_bus, bus, sizeof(*bus) + i * sizeof(struct kvm_io_range)); new_bus->dev_count--; memcpy(new_bus->range + i, bus->range + i + 1, (new_bus->dev_count - i) * sizeof(struct kvm_io_range)); rcu_assign_pointer(kvm->buses[bus_idx], new_bus); synchronize_srcu_expedited(&kvm->srcu); kfree(bus); return r; } static struct notifier_block kvm_cpu_notifier = { .notifier_call = kvm_cpu_hotplug, }; static int vm_stat_get(void *_offset, u64 *val) { unsigned offset = (long)_offset; struct kvm *kvm; *val = 0; spin_lock(&kvm_lock); list_for_each_entry(kvm, &vm_list, vm_list) *val += *(u32 *)((void *)kvm + offset); spin_unlock(&kvm_lock); return 0; } DEFINE_SIMPLE_ATTRIBUTE(vm_stat_fops, vm_stat_get, NULL, "%llu\n"); static int vcpu_stat_get(void *_offset, u64 *val) { unsigned offset = (long)_offset; struct kvm *kvm; struct kvm_vcpu *vcpu; int i; *val = 0; spin_lock(&kvm_lock); list_for_each_entry(kvm, &vm_list, vm_list) kvm_for_each_vcpu(i, vcpu, kvm) *val += *(u32 *)((void *)vcpu + offset); spin_unlock(&kvm_lock); return 0; } DEFINE_SIMPLE_ATTRIBUTE(vcpu_stat_fops, vcpu_stat_get, NULL, "%llu\n"); static const struct file_operations *stat_fops[] = { [KVM_STAT_VCPU] = &vcpu_stat_fops, [KVM_STAT_VM] = &vm_stat_fops, }; static int kvm_init_debug(void) { int r = -EEXIST; struct kvm_stats_debugfs_item *p; kvm_debugfs_dir = debugfs_create_dir("kvm", NULL); if (kvm_debugfs_dir == NULL) goto out; for (p = debugfs_entries; p->name; ++p) { p->dentry = debugfs_create_file(p->name, 0444, kvm_debugfs_dir, (void *)(long)p->offset, stat_fops[p->kind]); if (p->dentry == NULL) goto out_dir; } return 0; out_dir: debugfs_remove_recursive(kvm_debugfs_dir); out: return r; } static void kvm_exit_debug(void) { struct kvm_stats_debugfs_item *p; for (p = debugfs_entries; p->name; ++p) debugfs_remove(p->dentry); debugfs_remove(kvm_debugfs_dir); } static int kvm_suspend(void) { if (kvm_usage_count) hardware_disable_nolock(NULL); return 0; } static void kvm_resume(void) { if (kvm_usage_count) { WARN_ON(raw_spin_is_locked(&kvm_count_lock)); hardware_enable_nolock(NULL); } } static struct syscore_ops kvm_syscore_ops = { .suspend = kvm_suspend, .resume = kvm_resume, }; static inline struct kvm_vcpu *preempt_notifier_to_vcpu(struct preempt_notifier *pn) { return container_of(pn, struct kvm_vcpu, preempt_notifier); } static void kvm_sched_in(struct preempt_notifier *pn, int cpu) { struct kvm_vcpu *vcpu = preempt_notifier_to_vcpu(pn); if (vcpu->preempted) vcpu->preempted = false; kvm_arch_vcpu_load(vcpu, cpu); } static void kvm_sched_out(struct preempt_notifier *pn, struct task_struct *next) { struct kvm_vcpu *vcpu = preempt_notifier_to_vcpu(pn); if (current->state == TASK_RUNNING) vcpu->preempted = true; kvm_arch_vcpu_put(vcpu); } int kvm_init(void *opaque, unsigned vcpu_size, unsigned vcpu_align, struct module *module) { int r; int cpu; r = kvm_arch_init(opaque); if (r) goto out_fail; /* * kvm_arch_init makes sure there's at most one caller * for architectures that support multiple implementations, * like intel and amd on x86. * kvm_arch_init must be called before kvm_irqfd_init to avoid creating * conflicts in case kvm is already setup for another implementation. */ r = kvm_irqfd_init(); if (r) goto out_irqfd; if (!zalloc_cpumask_var(&cpus_hardware_enabled, GFP_KERNEL)) { r = -ENOMEM; goto out_free_0; } r = kvm_arch_hardware_setup(); if (r < 0) goto out_free_0a; for_each_online_cpu(cpu) { smp_call_function_single(cpu, kvm_arch_check_processor_compat, &r, 1); if (r < 0) goto out_free_1; } r = register_cpu_notifier(&kvm_cpu_notifier); if (r) goto out_free_2; register_reboot_notifier(&kvm_reboot_notifier); /* A kmem cache lets us meet the alignment requirements of fx_save. */ if (!vcpu_align) vcpu_align = __alignof__(struct kvm_vcpu); kvm_vcpu_cache = kmem_cache_create("kvm_vcpu", vcpu_size, vcpu_align, 0, NULL); if (!kvm_vcpu_cache) { r = -ENOMEM; goto out_free_3; } r = kvm_async_pf_init(); if (r) goto out_free; kvm_chardev_ops.owner = module; kvm_vm_fops.owner = module; kvm_vcpu_fops.owner = module; r = misc_register(&kvm_dev); if (r) { printk(KERN_ERR "kvm: misc device register failed\n"); goto out_unreg; } register_syscore_ops(&kvm_syscore_ops); kvm_preempt_ops.sched_in = kvm_sched_in; kvm_preempt_ops.sched_out = kvm_sched_out; r = kvm_init_debug(); if (r) { printk(KERN_ERR "kvm: create debugfs files failed\n"); goto out_undebugfs; } return 0; out_undebugfs: unregister_syscore_ops(&kvm_syscore_ops); misc_deregister(&kvm_dev); out_unreg: kvm_async_pf_deinit(); out_free: kmem_cache_destroy(kvm_vcpu_cache); out_free_3: unregister_reboot_notifier(&kvm_reboot_notifier); unregister_cpu_notifier(&kvm_cpu_notifier); out_free_2: out_free_1: kvm_arch_hardware_unsetup(); out_free_0a: free_cpumask_var(cpus_hardware_enabled); out_free_0: kvm_irqfd_exit(); out_irqfd: kvm_arch_exit(); out_fail: return r; } EXPORT_SYMBOL_GPL(kvm_init); void kvm_exit(void) { kvm_exit_debug(); misc_deregister(&kvm_dev); kmem_cache_destroy(kvm_vcpu_cache); kvm_async_pf_deinit(); unregister_syscore_ops(&kvm_syscore_ops); unregister_reboot_notifier(&kvm_reboot_notifier); unregister_cpu_notifier(&kvm_cpu_notifier); on_each_cpu(hardware_disable_nolock, NULL, 1); kvm_arch_hardware_unsetup(); kvm_arch_exit(); kvm_irqfd_exit(); free_cpumask_var(cpus_hardware_enabled); } EXPORT_SYMBOL_GPL(kvm_exit);