// SPDX-License-Identifier: GPL-2.0-only /* * 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 */ #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 #include #include #include #include #include "coalesced_mmio.h" #include "async_pf.h" #include "mmu_lock.h" #include "vfio.h" #define CREATE_TRACE_POINTS #include #include /* Worst case buffer size needed for holding an integer. */ #define ITOA_MAX_LEN 12 MODULE_AUTHOR("Qumranet"); MODULE_LICENSE("GPL"); /* Architectures should define their poll value according to the halt latency */ unsigned int halt_poll_ns = KVM_HALT_POLL_NS_DEFAULT; module_param(halt_poll_ns, uint, 0644); EXPORT_SYMBOL_GPL(halt_poll_ns); /* Default doubles per-vcpu halt_poll_ns. */ unsigned int halt_poll_ns_grow = 2; module_param(halt_poll_ns_grow, uint, 0644); EXPORT_SYMBOL_GPL(halt_poll_ns_grow); /* The start value to grow halt_poll_ns from */ unsigned int halt_poll_ns_grow_start = 10000; /* 10us */ module_param(halt_poll_ns_grow_start, uint, 0644); EXPORT_SYMBOL_GPL(halt_poll_ns_grow_start); /* Default resets per-vcpu halt_poll_ns . */ unsigned int halt_poll_ns_shrink; module_param(halt_poll_ns_shrink, uint, 0644); EXPORT_SYMBOL_GPL(halt_poll_ns_shrink); /* * Ordering of locks: * * kvm->lock --> kvm->slots_lock --> kvm->irq_lock */ DEFINE_MUTEX(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; static atomic_t hardware_enable_failed; static struct kmem_cache *kvm_vcpu_cache; static __read_mostly struct preempt_ops kvm_preempt_ops; static DEFINE_PER_CPU(struct kvm_vcpu *, kvm_running_vcpu); struct dentry *kvm_debugfs_dir; EXPORT_SYMBOL_GPL(kvm_debugfs_dir); static int kvm_debugfs_num_entries; static const struct file_operations stat_fops_per_vm; static long kvm_vcpu_ioctl(struct file *file, unsigned int ioctl, unsigned long arg); #ifdef CONFIG_KVM_COMPAT static long kvm_vcpu_compat_ioctl(struct file *file, unsigned int ioctl, unsigned long arg); #define KVM_COMPAT(c) .compat_ioctl = (c) #else /* * For architectures that don't implement a compat infrastructure, * adopt a double line of defense: * - Prevent a compat task from opening /dev/kvm * - If the open has been done by a 64bit task, and the KVM fd * passed to a compat task, let the ioctls fail. */ static long kvm_no_compat_ioctl(struct file *file, unsigned int ioctl, unsigned long arg) { return -EINVAL; } static int kvm_no_compat_open(struct inode *inode, struct file *file) { return is_compat_task() ? -ENODEV : 0; } #define KVM_COMPAT(c) .compat_ioctl = kvm_no_compat_ioctl, \ .open = kvm_no_compat_open #endif static int hardware_enable_all(void); static void hardware_disable_all(void); static void kvm_io_bus_destroy(struct kvm_io_bus *bus); __visible bool kvm_rebooting; EXPORT_SYMBOL_GPL(kvm_rebooting); #define KVM_EVENT_CREATE_VM 0 #define KVM_EVENT_DESTROY_VM 1 static void kvm_uevent_notify_change(unsigned int type, struct kvm *kvm); static unsigned long long kvm_createvm_count; static unsigned long long kvm_active_vms; __weak void kvm_arch_mmu_notifier_invalidate_range(struct kvm *kvm, unsigned long start, unsigned long end) { } bool kvm_is_zone_device_pfn(kvm_pfn_t pfn) { /* * The metadata used by is_zone_device_page() to determine whether or * not a page is ZONE_DEVICE is guaranteed to be valid if and only if * the device has been pinned, e.g. by get_user_pages(). WARN if the * page_count() is zero to help detect bad usage of this helper. */ if (!pfn_valid(pfn) || WARN_ON_ONCE(!page_count(pfn_to_page(pfn)))) return false; return is_zone_device_page(pfn_to_page(pfn)); } bool kvm_is_reserved_pfn(kvm_pfn_t pfn) { /* * ZONE_DEVICE pages currently set PG_reserved, but from a refcounting * perspective they are "normal" pages, albeit with slightly different * usage rules. */ if (pfn_valid(pfn)) return PageReserved(pfn_to_page(pfn)) && !is_zero_pfn(pfn) && !kvm_is_zone_device_pfn(pfn); return true; } bool kvm_is_transparent_hugepage(kvm_pfn_t pfn) { struct page *page = pfn_to_page(pfn); if (!PageTransCompoundMap(page)) return false; return is_transparent_hugepage(compound_head(page)); } /* * Switches to specified vcpu, until a matching vcpu_put() */ void vcpu_load(struct kvm_vcpu *vcpu) { int cpu = get_cpu(); __this_cpu_write(kvm_running_vcpu, vcpu); preempt_notifier_register(&vcpu->preempt_notifier); kvm_arch_vcpu_load(vcpu, cpu); put_cpu(); } EXPORT_SYMBOL_GPL(vcpu_load); void vcpu_put(struct kvm_vcpu *vcpu) { preempt_disable(); kvm_arch_vcpu_put(vcpu); preempt_notifier_unregister(&vcpu->preempt_notifier); __this_cpu_write(kvm_running_vcpu, NULL); preempt_enable(); } EXPORT_SYMBOL_GPL(vcpu_put); /* TODO: merge with kvm_arch_vcpu_should_kick */ static bool kvm_request_needs_ipi(struct kvm_vcpu *vcpu, unsigned req) { int mode = kvm_vcpu_exiting_guest_mode(vcpu); /* * We need to wait for the VCPU to reenable interrupts and get out of * READING_SHADOW_PAGE_TABLES mode. */ if (req & KVM_REQUEST_WAIT) return mode != OUTSIDE_GUEST_MODE; /* * Need to kick a running VCPU, but otherwise there is nothing to do. */ return mode == IN_GUEST_MODE; } static void ack_flush(void *_completed) { } static inline bool kvm_kick_many_cpus(const struct cpumask *cpus, bool wait) { if (unlikely(!cpus)) cpus = cpu_online_mask; if (cpumask_empty(cpus)) return false; smp_call_function_many(cpus, ack_flush, NULL, wait); return true; } bool kvm_make_vcpus_request_mask(struct kvm *kvm, unsigned int req, struct kvm_vcpu *except, unsigned long *vcpu_bitmap, cpumask_var_t tmp) { int i, cpu, me; struct kvm_vcpu *vcpu; bool called; me = get_cpu(); kvm_for_each_vcpu(i, vcpu, kvm) { if ((vcpu_bitmap && !test_bit(i, vcpu_bitmap)) || vcpu == except) continue; kvm_make_request(req, vcpu); cpu = vcpu->cpu; if (!(req & KVM_REQUEST_NO_WAKEUP) && kvm_vcpu_wake_up(vcpu)) continue; if (tmp != NULL && cpu != -1 && cpu != me && kvm_request_needs_ipi(vcpu, req)) __cpumask_set_cpu(cpu, tmp); } called = kvm_kick_many_cpus(tmp, !!(req & KVM_REQUEST_WAIT)); put_cpu(); return called; } bool kvm_make_all_cpus_request_except(struct kvm *kvm, unsigned int req, struct kvm_vcpu *except) { cpumask_var_t cpus; bool called; zalloc_cpumask_var(&cpus, GFP_ATOMIC); called = kvm_make_vcpus_request_mask(kvm, req, except, NULL, cpus); free_cpumask_var(cpus); return called; } bool kvm_make_all_cpus_request(struct kvm *kvm, unsigned int req) { return kvm_make_all_cpus_request_except(kvm, req, NULL); } #ifndef CONFIG_HAVE_KVM_ARCH_TLB_FLUSH_ALL void kvm_flush_remote_tlbs(struct kvm *kvm) { /* * Read tlbs_dirty before setting KVM_REQ_TLB_FLUSH in * kvm_make_all_cpus_request. */ long dirty_count = smp_load_acquire(&kvm->tlbs_dirty); /* * We want to publish modifications to the page tables before reading * mode. Pairs with a memory barrier in arch-specific code. * - x86: smp_mb__after_srcu_read_unlock in vcpu_enter_guest * and smp_mb in walk_shadow_page_lockless_begin/end. * - powerpc: smp_mb in kvmppc_prepare_to_enter. * * There is already an smp_mb__after_atomic() before * kvm_make_all_cpus_request() reads vcpu->mode. We reuse that * barrier here. */ if (!kvm_arch_flush_remote_tlb(kvm) || kvm_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); #endif void kvm_reload_remote_mmus(struct kvm *kvm) { kvm_make_all_cpus_request(kvm, KVM_REQ_MMU_RELOAD); } #ifdef KVM_ARCH_NR_OBJS_PER_MEMORY_CACHE static inline void *mmu_memory_cache_alloc_obj(struct kvm_mmu_memory_cache *mc, gfp_t gfp_flags) { gfp_flags |= mc->gfp_zero; if (mc->kmem_cache) return kmem_cache_alloc(mc->kmem_cache, gfp_flags); else return (void *)__get_free_page(gfp_flags); } int kvm_mmu_topup_memory_cache(struct kvm_mmu_memory_cache *mc, int min) { void *obj; if (mc->nobjs >= min) return 0; while (mc->nobjs < ARRAY_SIZE(mc->objects)) { obj = mmu_memory_cache_alloc_obj(mc, GFP_KERNEL_ACCOUNT); if (!obj) return mc->nobjs >= min ? 0 : -ENOMEM; mc->objects[mc->nobjs++] = obj; } return 0; } int kvm_mmu_memory_cache_nr_free_objects(struct kvm_mmu_memory_cache *mc) { return mc->nobjs; } void kvm_mmu_free_memory_cache(struct kvm_mmu_memory_cache *mc) { while (mc->nobjs) { if (mc->kmem_cache) kmem_cache_free(mc->kmem_cache, mc->objects[--mc->nobjs]); else free_page((unsigned long)mc->objects[--mc->nobjs]); } } void *kvm_mmu_memory_cache_alloc(struct kvm_mmu_memory_cache *mc) { void *p; if (WARN_ON(!mc->nobjs)) p = mmu_memory_cache_alloc_obj(mc, GFP_ATOMIC | __GFP_ACCOUNT); else p = mc->objects[--mc->nobjs]; BUG_ON(!p); return p; } #endif static void kvm_vcpu_init(struct kvm_vcpu *vcpu, struct kvm *kvm, unsigned id) { mutex_init(&vcpu->mutex); vcpu->cpu = -1; vcpu->kvm = kvm; vcpu->vcpu_id = id; vcpu->pid = NULL; rcuwait_init(&vcpu->wait); kvm_async_pf_vcpu_init(vcpu); vcpu->pre_pcpu = -1; INIT_LIST_HEAD(&vcpu->blocked_vcpu_list); kvm_vcpu_set_in_spin_loop(vcpu, false); kvm_vcpu_set_dy_eligible(vcpu, false); vcpu->preempted = false; vcpu->ready = false; preempt_notifier_init(&vcpu->preempt_notifier, &kvm_preempt_ops); } void kvm_vcpu_destroy(struct kvm_vcpu *vcpu) { kvm_dirty_ring_free(&vcpu->dirty_ring); kvm_arch_vcpu_destroy(vcpu); /* * No need for rcu_read_lock as VCPU_RUN is the only place that changes * the vcpu->pid pointer, and at destruction time all file descriptors * are already gone. */ put_pid(rcu_dereference_protected(vcpu->pid, 1)); free_page((unsigned long)vcpu->run); kmem_cache_free(kvm_vcpu_cache, vcpu); } EXPORT_SYMBOL_GPL(kvm_vcpu_destroy); #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_range(struct mmu_notifier *mn, struct mm_struct *mm, unsigned long start, unsigned long end) { struct kvm *kvm = mmu_notifier_to_kvm(mn); int idx; idx = srcu_read_lock(&kvm->srcu); kvm_arch_mmu_notifier_invalidate_range(kvm, start, end); 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); KVM_MMU_LOCK(kvm); kvm->mmu_notifier_seq++; if (kvm_set_spte_hva(kvm, address, pte)) kvm_flush_remote_tlbs(kvm); KVM_MMU_UNLOCK(kvm); srcu_read_unlock(&kvm->srcu, idx); } static int kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn, const struct mmu_notifier_range *range) { struct kvm *kvm = mmu_notifier_to_kvm(mn); int need_tlb_flush = 0, idx; idx = srcu_read_lock(&kvm->srcu); KVM_MMU_LOCK(kvm); /* * 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, range->start, range->end, range->flags); /* we've to flush the tlb before the pages can be freed */ if (need_tlb_flush || kvm->tlbs_dirty) kvm_flush_remote_tlbs(kvm); KVM_MMU_UNLOCK(kvm); srcu_read_unlock(&kvm->srcu, idx); return 0; } static void kvm_mmu_notifier_invalidate_range_end(struct mmu_notifier *mn, const struct mmu_notifier_range *range) { struct kvm *kvm = mmu_notifier_to_kvm(mn); KVM_MMU_LOCK(kvm); /* * 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--; KVM_MMU_UNLOCK(kvm); 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 start, unsigned long end) { struct kvm *kvm = mmu_notifier_to_kvm(mn); int young, idx; idx = srcu_read_lock(&kvm->srcu); KVM_MMU_LOCK(kvm); young = kvm_age_hva(kvm, start, end); if (young) kvm_flush_remote_tlbs(kvm); KVM_MMU_UNLOCK(kvm); srcu_read_unlock(&kvm->srcu, idx); return young; } static int kvm_mmu_notifier_clear_young(struct mmu_notifier *mn, struct mm_struct *mm, unsigned long start, unsigned long end) { struct kvm *kvm = mmu_notifier_to_kvm(mn); int young, idx; idx = srcu_read_lock(&kvm->srcu); KVM_MMU_LOCK(kvm); /* * Even though we do not flush TLB, this will still adversely * affect performance on pre-Haswell Intel EPT, where there is * no EPT Access Bit to clear so that we have to tear down EPT * tables instead. If we find this unacceptable, we can always * add a parameter to kvm_age_hva so that it effectively doesn't * do anything on clear_young. * * Also note that currently we never issue secondary TLB flushes * from clear_young, leaving this job up to the regular system * cadence. If we find this inaccurate, we might come up with a * more sophisticated heuristic later. */ young = kvm_age_hva(kvm, start, end); KVM_MMU_UNLOCK(kvm); 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); KVM_MMU_LOCK(kvm); young = kvm_test_age_hva(kvm, address); KVM_MMU_UNLOCK(kvm); 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_range = kvm_mmu_notifier_invalidate_range, .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, .clear_young = kvm_mmu_notifier_clear_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 struct kvm_memslots *kvm_alloc_memslots(void) { int i; struct kvm_memslots *slots; slots = kvzalloc(sizeof(struct kvm_memslots), GFP_KERNEL_ACCOUNT); if (!slots) return NULL; for (i = 0; i < KVM_MEM_SLOTS_NUM; i++) slots->id_to_index[i] = -1; return slots; } static void kvm_destroy_dirty_bitmap(struct kvm_memory_slot *memslot) { if (!memslot->dirty_bitmap) return; kvfree(memslot->dirty_bitmap); memslot->dirty_bitmap = NULL; } static void kvm_free_memslot(struct kvm *kvm, struct kvm_memory_slot *slot) { kvm_destroy_dirty_bitmap(slot); kvm_arch_free_memslot(kvm, slot); slot->flags = 0; slot->npages = 0; } static void kvm_free_memslots(struct kvm *kvm, struct kvm_memslots *slots) { struct kvm_memory_slot *memslot; if (!slots) return; kvm_for_each_memslot(memslot, slots) kvm_free_memslot(kvm, memslot); kvfree(slots); } static void kvm_destroy_vm_debugfs(struct kvm *kvm) { int i; if (!kvm->debugfs_dentry) return; debugfs_remove_recursive(kvm->debugfs_dentry); if (kvm->debugfs_stat_data) { for (i = 0; i < kvm_debugfs_num_entries; i++) kfree(kvm->debugfs_stat_data[i]); kfree(kvm->debugfs_stat_data); } } static int kvm_create_vm_debugfs(struct kvm *kvm, int fd) { char dir_name[ITOA_MAX_LEN * 2]; struct kvm_stat_data *stat_data; struct kvm_stats_debugfs_item *p; if (!debugfs_initialized()) return 0; snprintf(dir_name, sizeof(dir_name), "%d-%d", task_pid_nr(current), fd); kvm->debugfs_dentry = debugfs_create_dir(dir_name, kvm_debugfs_dir); kvm->debugfs_stat_data = kcalloc(kvm_debugfs_num_entries, sizeof(*kvm->debugfs_stat_data), GFP_KERNEL_ACCOUNT); if (!kvm->debugfs_stat_data) return -ENOMEM; for (p = debugfs_entries; p->name; p++) { stat_data = kzalloc(sizeof(*stat_data), GFP_KERNEL_ACCOUNT); if (!stat_data) return -ENOMEM; stat_data->kvm = kvm; stat_data->dbgfs_item = p; kvm->debugfs_stat_data[p - debugfs_entries] = stat_data; debugfs_create_file(p->name, KVM_DBGFS_GET_MODE(p), kvm->debugfs_dentry, stat_data, &stat_fops_per_vm); } return 0; } /* * Called after the VM is otherwise initialized, but just before adding it to * the vm_list. */ int __weak kvm_arch_post_init_vm(struct kvm *kvm) { return 0; } /* * Called just after removing the VM from the vm_list, but before doing any * other destruction. */ void __weak kvm_arch_pre_destroy_vm(struct kvm *kvm) { } static struct kvm *kvm_create_vm(unsigned long type) { struct kvm *kvm = kvm_arch_alloc_vm(); int r = -ENOMEM; int i; if (!kvm) return ERR_PTR(-ENOMEM); KVM_MMU_LOCK_INIT(kvm); mmgrab(current->mm); kvm->mm = current->mm; kvm_eventfd_init(kvm); mutex_init(&kvm->lock); mutex_init(&kvm->irq_lock); mutex_init(&kvm->slots_lock); INIT_LIST_HEAD(&kvm->devices); BUILD_BUG_ON(KVM_MEM_SLOTS_NUM > SHRT_MAX); if (init_srcu_struct(&kvm->srcu)) goto out_err_no_srcu; if (init_srcu_struct(&kvm->irq_srcu)) goto out_err_no_irq_srcu; refcount_set(&kvm->users_count, 1); for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) { struct kvm_memslots *slots = kvm_alloc_memslots(); if (!slots) goto out_err_no_arch_destroy_vm; /* Generations must be different for each address space. */ slots->generation = i; rcu_assign_pointer(kvm->memslots[i], slots); } for (i = 0; i < KVM_NR_BUSES; i++) { rcu_assign_pointer(kvm->buses[i], kzalloc(sizeof(struct kvm_io_bus), GFP_KERNEL_ACCOUNT)); if (!kvm->buses[i]) goto out_err_no_arch_destroy_vm; } kvm->max_halt_poll_ns = halt_poll_ns; r = kvm_arch_init_vm(kvm, type); if (r) goto out_err_no_arch_destroy_vm; r = hardware_enable_all(); if (r) goto out_err_no_disable; #ifdef CONFIG_HAVE_KVM_IRQFD INIT_HLIST_HEAD(&kvm->irq_ack_notifier_list); #endif r = kvm_init_mmu_notifier(kvm); if (r) goto out_err_no_mmu_notifier; r = kvm_arch_post_init_vm(kvm); if (r) goto out_err; mutex_lock(&kvm_lock); list_add(&kvm->vm_list, &vm_list); mutex_unlock(&kvm_lock); preempt_notifier_inc(); return kvm; out_err: #if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER) if (kvm->mmu_notifier.ops) mmu_notifier_unregister(&kvm->mmu_notifier, current->mm); #endif out_err_no_mmu_notifier: hardware_disable_all(); out_err_no_disable: kvm_arch_destroy_vm(kvm); out_err_no_arch_destroy_vm: WARN_ON_ONCE(!refcount_dec_and_test(&kvm->users_count)); for (i = 0; i < KVM_NR_BUSES; i++) kfree(kvm_get_bus(kvm, i)); for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) kvm_free_memslots(kvm, __kvm_memslots(kvm, i)); cleanup_srcu_struct(&kvm->irq_srcu); out_err_no_irq_srcu: cleanup_srcu_struct(&kvm->srcu); out_err_no_srcu: kvm_arch_free_vm(kvm); mmdrop(current->mm); return ERR_PTR(r); } static void kvm_destroy_devices(struct kvm *kvm) { struct kvm_device *dev, *tmp; /* * We do not need to take the kvm->lock here, because nobody else * has a reference to the struct kvm at this point and therefore * cannot access the devices list anyhow. */ list_for_each_entry_safe(dev, tmp, &kvm->devices, vm_node) { list_del(&dev->vm_node); dev->ops->destroy(dev); } } static void kvm_destroy_vm(struct kvm *kvm) { int i; struct mm_struct *mm = kvm->mm; kvm_uevent_notify_change(KVM_EVENT_DESTROY_VM, kvm); kvm_destroy_vm_debugfs(kvm); kvm_arch_sync_events(kvm); mutex_lock(&kvm_lock); list_del(&kvm->vm_list); mutex_unlock(&kvm_lock); kvm_arch_pre_destroy_vm(kvm); kvm_free_irq_routing(kvm); for (i = 0; i < KVM_NR_BUSES; i++) { struct kvm_io_bus *bus = kvm_get_bus(kvm, i); if (bus) kvm_io_bus_destroy(bus); kvm->buses[i] = NULL; } 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); for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) kvm_free_memslots(kvm, __kvm_memslots(kvm, i)); cleanup_srcu_struct(&kvm->irq_srcu); cleanup_srcu_struct(&kvm->srcu); kvm_arch_free_vm(kvm); preempt_notifier_dec(); hardware_disable_all(); mmdrop(mm); } void kvm_get_kvm(struct kvm *kvm) { refcount_inc(&kvm->users_count); } EXPORT_SYMBOL_GPL(kvm_get_kvm); void kvm_put_kvm(struct kvm *kvm) { if (refcount_dec_and_test(&kvm->users_count)) kvm_destroy_vm(kvm); } EXPORT_SYMBOL_GPL(kvm_put_kvm); /* * Used to put a reference that was taken on behalf of an object associated * with a user-visible file descriptor, e.g. a vcpu or device, if installation * of the new file descriptor fails and the reference cannot be transferred to * its final owner. In such cases, the caller is still actively using @kvm and * will fail miserably if the refcount unexpectedly hits zero. */ void kvm_put_kvm_no_destroy(struct kvm *kvm) { WARN_ON(refcount_dec_and_test(&kvm->users_count)); } EXPORT_SYMBOL_GPL(kvm_put_kvm_no_destroy); 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 kvm_vm_ioctl_get_dirty_log() why this is needed. */ static int kvm_alloc_dirty_bitmap(struct kvm_memory_slot *memslot) { unsigned long dirty_bytes = 2 * kvm_dirty_bitmap_bytes(memslot); memslot->dirty_bitmap = kvzalloc(dirty_bytes, GFP_KERNEL_ACCOUNT); if (!memslot->dirty_bitmap) return -ENOMEM; return 0; } /* * Delete a memslot by decrementing the number of used slots and shifting all * other entries in the array forward one spot. */ static inline void kvm_memslot_delete(struct kvm_memslots *slots, struct kvm_memory_slot *memslot) { struct kvm_memory_slot *mslots = slots->memslots; int i; if (WARN_ON(slots->id_to_index[memslot->id] == -1)) return; slots->used_slots--; if (atomic_read(&slots->lru_slot) >= slots->used_slots) atomic_set(&slots->lru_slot, 0); for (i = slots->id_to_index[memslot->id]; i < slots->used_slots; i++) { mslots[i] = mslots[i + 1]; slots->id_to_index[mslots[i].id] = i; } mslots[i] = *memslot; slots->id_to_index[memslot->id] = -1; } /* * "Insert" a new memslot by incrementing the number of used slots. Returns * the new slot's initial index into the memslots array. */ static inline int kvm_memslot_insert_back(struct kvm_memslots *slots) { return slots->used_slots++; } /* * Move a changed memslot backwards in the array by shifting existing slots * with a higher GFN toward the front of the array. Note, the changed memslot * itself is not preserved in the array, i.e. not swapped at this time, only * its new index into the array is tracked. Returns the changed memslot's * current index into the memslots array. */ static inline int kvm_memslot_move_backward(struct kvm_memslots *slots, struct kvm_memory_slot *memslot) { struct kvm_memory_slot *mslots = slots->memslots; int i; if (WARN_ON_ONCE(slots->id_to_index[memslot->id] == -1) || WARN_ON_ONCE(!slots->used_slots)) return -1; /* * Move the target memslot backward in the array by shifting existing * memslots with a higher GFN (than the target memslot) towards the * front of the array. */ for (i = slots->id_to_index[memslot->id]; i < slots->used_slots - 1; i++) { if (memslot->base_gfn > mslots[i + 1].base_gfn) break; WARN_ON_ONCE(memslot->base_gfn == mslots[i + 1].base_gfn); /* Shift the next memslot forward one and update its index. */ mslots[i] = mslots[i + 1]; slots->id_to_index[mslots[i].id] = i; } return i; } /* * Move a changed memslot forwards in the array by shifting existing slots with * a lower GFN toward the back of the array. Note, the changed memslot itself * is not preserved in the array, i.e. not swapped at this time, only its new * index into the array is tracked. Returns the changed memslot's final index * into the memslots array. */ static inline int kvm_memslot_move_forward(struct kvm_memslots *slots, struct kvm_memory_slot *memslot, int start) { struct kvm_memory_slot *mslots = slots->memslots; int i; for (i = start; i > 0; i--) { if (memslot->base_gfn < mslots[i - 1].base_gfn) break; WARN_ON_ONCE(memslot->base_gfn == mslots[i - 1].base_gfn); /* Shift the next memslot back one and update its index. */ mslots[i] = mslots[i - 1]; slots->id_to_index[mslots[i].id] = i; } return i; } /* * Re-sort memslots based on their GFN to account for an added, deleted, or * moved memslot. Sorting memslots by GFN allows using a binary search during * memslot lookup. * * IMPORTANT: Slots are sorted from highest GFN to lowest GFN! I.e. the entry * at memslots[0] has the highest GFN. * * The sorting algorithm takes advantage of having initially sorted memslots * and knowing the position of the changed memslot. Sorting is also optimized * by not swapping the updated memslot and instead only shifting other memslots * and tracking the new index for the update memslot. Only once its final * index is known is the updated memslot copied into its position in the array. * * - When deleting a memslot, the deleted memslot simply needs to be moved to * the end of the array. * * - When creating a memslot, the algorithm "inserts" the new memslot at the * end of the array and then it forward to its correct location. * * - When moving a memslot, the algorithm first moves the updated memslot * backward to handle the scenario where the memslot's GFN was changed to a * lower value. update_memslots() then falls through and runs the same flow * as creating a memslot to move the memslot forward to handle the scenario * where its GFN was changed to a higher value. * * Note, slots are sorted from highest->lowest instead of lowest->highest for * historical reasons. Originally, invalid memslots where denoted by having * GFN=0, thus sorting from highest->lowest naturally sorted invalid memslots * to the end of the array. The current algorithm uses dedicated logic to * delete a memslot and thus does not rely on invalid memslots having GFN=0. * * The other historical motiviation for highest->lowest was to improve the * performance of memslot lookup. KVM originally used a linear search starting * at memslots[0]. On x86, the largest memslot usually has one of the highest, * if not *the* highest, GFN, as the bulk of the guest's RAM is located in a * single memslot above the 4gb boundary. As the largest memslot is also the * most likely to be referenced, sorting it to the front of the array was * advantageous. The current binary search starts from the middle of the array * and uses an LRU pointer to improve performance for all memslots and GFNs. */ static void update_memslots(struct kvm_memslots *slots, struct kvm_memory_slot *memslot, enum kvm_mr_change change) { int i; if (change == KVM_MR_DELETE) { kvm_memslot_delete(slots, memslot); } else { if (change == KVM_MR_CREATE) i = kvm_memslot_insert_back(slots); else i = kvm_memslot_move_backward(slots, memslot); i = kvm_memslot_move_forward(slots, memslot, i); /* * Copy the memslot to its new position in memslots and update * its index accordingly. */ slots->memslots[i] = *memslot; slots->id_to_index[memslot->id] = i; } } static int check_memory_region_flags(const struct kvm_userspace_memory_region *mem) { u32 valid_flags = KVM_MEM_LOG_DIRTY_PAGES; #ifdef __KVM_HAVE_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, int as_id, struct kvm_memslots *slots) { struct kvm_memslots *old_memslots = __kvm_memslots(kvm, as_id); u64 gen = old_memslots->generation; WARN_ON(gen & KVM_MEMSLOT_GEN_UPDATE_IN_PROGRESS); slots->generation = gen | KVM_MEMSLOT_GEN_UPDATE_IN_PROGRESS; rcu_assign_pointer(kvm->memslots[as_id], slots); synchronize_srcu_expedited(&kvm->srcu); /* * Increment the new memslot generation a second time, dropping the * update in-progress flag and incrementing the generation based on * the number of address spaces. This provides a unique and easily * identifiable generation number while the memslots are in flux. */ gen = slots->generation & ~KVM_MEMSLOT_GEN_UPDATE_IN_PROGRESS; /* * Generations must be unique even across address spaces. We do not need * a global counter for that, instead the generation space is evenly split * across address spaces. For example, with two address spaces, address * space 0 will use generations 0, 2, 4, ... while address space 1 will * use generations 1, 3, 5, ... */ gen += KVM_ADDRESS_SPACE_NUM; kvm_arch_memslots_updated(kvm, gen); slots->generation = gen; return old_memslots; } /* * Note, at a minimum, the current number of used slots must be allocated, even * when deleting a memslot, as we need a complete duplicate of the memslots for * use when invalidating a memslot prior to deleting/moving the memslot. */ static struct kvm_memslots *kvm_dup_memslots(struct kvm_memslots *old, enum kvm_mr_change change) { struct kvm_memslots *slots; size_t old_size, new_size; old_size = sizeof(struct kvm_memslots) + (sizeof(struct kvm_memory_slot) * old->used_slots); if (change == KVM_MR_CREATE) new_size = old_size + sizeof(struct kvm_memory_slot); else new_size = old_size; slots = kvzalloc(new_size, GFP_KERNEL_ACCOUNT); if (likely(slots)) memcpy(slots, old, old_size); return slots; } static int kvm_set_memslot(struct kvm *kvm, const struct kvm_userspace_memory_region *mem, struct kvm_memory_slot *old, struct kvm_memory_slot *new, int as_id, enum kvm_mr_change change) { struct kvm_memory_slot *slot; struct kvm_memslots *slots; int r; slots = kvm_dup_memslots(__kvm_memslots(kvm, as_id), change); if (!slots) return -ENOMEM; if (change == KVM_MR_DELETE || change == KVM_MR_MOVE) { /* * Note, the INVALID flag needs to be in the appropriate entry * in the freshly allocated memslots, not in @old or @new. */ slot = id_to_memslot(slots, old->id); slot->flags |= KVM_MEMSLOT_INVALID; /* * We can re-use the old memslots, the only difference from the * newly installed memslots is the invalid flag, which will get * dropped by update_memslots anyway. We'll also revert to the * old memslots if preparing the new memory region fails. */ slots = install_new_memslots(kvm, as_id, slots); /* 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_root) */ kvm_arch_flush_shadow_memslot(kvm, slot); } r = kvm_arch_prepare_memory_region(kvm, new, mem, change); if (r) goto out_slots; update_memslots(slots, new, change); slots = install_new_memslots(kvm, as_id, slots); kvm_arch_commit_memory_region(kvm, mem, old, new, change); kvfree(slots); return 0; out_slots: if (change == KVM_MR_DELETE || change == KVM_MR_MOVE) slots = install_new_memslots(kvm, as_id, slots); kvfree(slots); return r; } static int kvm_delete_memslot(struct kvm *kvm, const struct kvm_userspace_memory_region *mem, struct kvm_memory_slot *old, int as_id) { struct kvm_memory_slot new; int r; if (!old->npages) return -EINVAL; memset(&new, 0, sizeof(new)); new.id = old->id; /* * This is only for debugging purpose; it should never be referenced * for a removed memslot. */ new.as_id = as_id; r = kvm_set_memslot(kvm, mem, old, &new, as_id, KVM_MR_DELETE); if (r) return r; kvm_free_memslot(kvm, old); return 0; } /* * 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 kvm->slots_lock for write. */ int __kvm_set_memory_region(struct kvm *kvm, const struct kvm_userspace_memory_region *mem) { struct kvm_memory_slot old, new; struct kvm_memory_slot *tmp; enum kvm_mr_change change; int as_id, id; int r; r = check_memory_region_flags(mem); if (r) return r; as_id = mem->slot >> 16; id = (u16)mem->slot; /* General sanity checks */ if (mem->memory_size & (PAGE_SIZE - 1)) return -EINVAL; if (mem->guest_phys_addr & (PAGE_SIZE - 1)) return -EINVAL; /* We can read the guest memory with __xxx_user() later on. */ if ((mem->userspace_addr & (PAGE_SIZE - 1)) || (mem->userspace_addr != untagged_addr(mem->userspace_addr)) || !access_ok((void __user *)(unsigned long)mem->userspace_addr, mem->memory_size)) return -EINVAL; if (as_id >= KVM_ADDRESS_SPACE_NUM || id >= KVM_MEM_SLOTS_NUM) return -EINVAL; if (mem->guest_phys_addr + mem->memory_size < mem->guest_phys_addr) return -EINVAL; /* * Make a full copy of the old memslot, the pointer will become stale * when the memslots are re-sorted by update_memslots(), and the old * memslot needs to be referenced after calling update_memslots(), e.g. * to free its resources and for arch specific behavior. */ tmp = id_to_memslot(__kvm_memslots(kvm, as_id), id); if (tmp) { old = *tmp; tmp = NULL; } else { memset(&old, 0, sizeof(old)); old.id = id; } if (!mem->memory_size) return kvm_delete_memslot(kvm, mem, &old, as_id); new.as_id = as_id; new.id = id; new.base_gfn = mem->guest_phys_addr >> PAGE_SHIFT; new.npages = mem->memory_size >> PAGE_SHIFT; new.flags = mem->flags; new.userspace_addr = mem->userspace_addr; if (new.npages > KVM_MEM_MAX_NR_PAGES) return -EINVAL; if (!old.npages) { change = KVM_MR_CREATE; new.dirty_bitmap = NULL; memset(&new.arch, 0, sizeof(new.arch)); } else { /* Modify an existing slot. */ if ((new.userspace_addr != old.userspace_addr) || (new.npages != old.npages) || ((new.flags ^ old.flags) & KVM_MEM_READONLY)) return -EINVAL; if (new.base_gfn != old.base_gfn) change = KVM_MR_MOVE; else if (new.flags != old.flags) change = KVM_MR_FLAGS_ONLY; else /* Nothing to change. */ return 0; /* Copy dirty_bitmap and arch from the current memslot. */ new.dirty_bitmap = old.dirty_bitmap; memcpy(&new.arch, &old.arch, sizeof(new.arch)); } if ((change == KVM_MR_CREATE) || (change == KVM_MR_MOVE)) { /* Check for overlaps */ kvm_for_each_memslot(tmp, __kvm_memslots(kvm, as_id)) { if (tmp->id == id) continue; if (!((new.base_gfn + new.npages <= tmp->base_gfn) || (new.base_gfn >= tmp->base_gfn + tmp->npages))) return -EEXIST; } } /* Allocate/free page dirty bitmap as needed */ if (!(new.flags & KVM_MEM_LOG_DIRTY_PAGES)) new.dirty_bitmap = NULL; else if (!new.dirty_bitmap && !kvm->dirty_ring_size) { r = kvm_alloc_dirty_bitmap(&new); if (r) return r; if (kvm_dirty_log_manual_protect_and_init_set(kvm)) bitmap_set(new.dirty_bitmap, 0, new.npages); } r = kvm_set_memslot(kvm, mem, &old, &new, as_id, change); if (r) goto out_bitmap; if (old.dirty_bitmap && !new.dirty_bitmap) kvm_destroy_dirty_bitmap(&old); return 0; out_bitmap: if (new.dirty_bitmap && !old.dirty_bitmap) kvm_destroy_dirty_bitmap(&new); return r; } EXPORT_SYMBOL_GPL(__kvm_set_memory_region); int kvm_set_memory_region(struct kvm *kvm, const 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 ((u16)mem->slot >= KVM_USER_MEM_SLOTS) return -EINVAL; return kvm_set_memory_region(kvm, mem); } #ifndef CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT /** * kvm_get_dirty_log - get a snapshot of dirty pages * @kvm: pointer to kvm instance * @log: slot id and address to which we copy the log * @is_dirty: set to '1' if any dirty pages were found * @memslot: set to the associated memslot, always valid on success */ int kvm_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log, int *is_dirty, struct kvm_memory_slot **memslot) { struct kvm_memslots *slots; int i, as_id, id; unsigned long n; unsigned long any = 0; /* Dirty ring tracking is exclusive to dirty log tracking */ if (kvm->dirty_ring_size) return -ENXIO; *memslot = NULL; *is_dirty = 0; as_id = log->slot >> 16; id = (u16)log->slot; if (as_id >= KVM_ADDRESS_SPACE_NUM || id >= KVM_USER_MEM_SLOTS) return -EINVAL; slots = __kvm_memslots(kvm, as_id); *memslot = id_to_memslot(slots, id); if (!(*memslot) || !(*memslot)->dirty_bitmap) return -ENOENT; kvm_arch_sync_dirty_log(kvm, *memslot); n = kvm_dirty_bitmap_bytes(*memslot); for (i = 0; !any && i < n/sizeof(long); ++i) any = (*memslot)->dirty_bitmap[i]; if (copy_to_user(log->dirty_bitmap, (*memslot)->dirty_bitmap, n)) return -EFAULT; if (any) *is_dirty = 1; return 0; } EXPORT_SYMBOL_GPL(kvm_get_dirty_log); #else /* CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT */ /** * kvm_get_dirty_log_protect - get a snapshot of dirty pages * and reenable dirty page tracking for the corresponding pages. * @kvm: pointer to kvm instance * @log: slot id and address to which we copy the log * * We need to keep it in mind that VCPU threads can write to the bitmap * concurrently. So, to avoid losing track of dirty pages we keep the * following order: * * 1. Take a snapshot of the bit and clear it if needed. * 2. Write protect the corresponding page. * 3. Copy the snapshot to the userspace. * 4. Upon return caller flushes TLB's if needed. * * Between 2 and 4, the guest may write to the page using the remaining TLB * entry. This is not a problem because the page is reported dirty using * the snapshot taken before and step 4 ensures that writes done after * exiting to userspace will be logged for the next call. * */ static int kvm_get_dirty_log_protect(struct kvm *kvm, struct kvm_dirty_log *log) { struct kvm_memslots *slots; struct kvm_memory_slot *memslot; int i, as_id, id; unsigned long n; unsigned long *dirty_bitmap; unsigned long *dirty_bitmap_buffer; bool flush; /* Dirty ring tracking is exclusive to dirty log tracking */ if (kvm->dirty_ring_size) return -ENXIO; as_id = log->slot >> 16; id = (u16)log->slot; if (as_id >= KVM_ADDRESS_SPACE_NUM || id >= KVM_USER_MEM_SLOTS) return -EINVAL; slots = __kvm_memslots(kvm, as_id); memslot = id_to_memslot(slots, id); if (!memslot || !memslot->dirty_bitmap) return -ENOENT; dirty_bitmap = memslot->dirty_bitmap; kvm_arch_sync_dirty_log(kvm, memslot); n = kvm_dirty_bitmap_bytes(memslot); flush = false; if (kvm->manual_dirty_log_protect) { /* * Unlike kvm_get_dirty_log, we always return false in *flush, * because no flush is needed until KVM_CLEAR_DIRTY_LOG. There * is some code duplication between this function and * kvm_get_dirty_log, but hopefully all architecture * transition to kvm_get_dirty_log_protect and kvm_get_dirty_log * can be eliminated. */ dirty_bitmap_buffer = dirty_bitmap; } else { dirty_bitmap_buffer = kvm_second_dirty_bitmap(memslot); memset(dirty_bitmap_buffer, 0, n); KVM_MMU_LOCK(kvm); for (i = 0; i < n / sizeof(long); i++) { unsigned long mask; gfn_t offset; if (!dirty_bitmap[i]) continue; flush = true; mask = xchg(&dirty_bitmap[i], 0); dirty_bitmap_buffer[i] = mask; offset = i * BITS_PER_LONG; kvm_arch_mmu_enable_log_dirty_pt_masked(kvm, memslot, offset, mask); } KVM_MMU_UNLOCK(kvm); } if (flush) kvm_arch_flush_remote_tlbs_memslot(kvm, memslot); if (copy_to_user(log->dirty_bitmap, dirty_bitmap_buffer, n)) return -EFAULT; return 0; } /** * kvm_vm_ioctl_get_dirty_log - get and clear the log of dirty pages in a slot * @kvm: kvm instance * @log: slot id and address to which we copy the log * * Steps 1-4 below provide general overview of dirty page logging. See * kvm_get_dirty_log_protect() function description for additional details. * * We call kvm_get_dirty_log_protect() to handle steps 1-3, upon return we * always flush the TLB (step 4) even if previous step failed and the dirty * bitmap may be corrupt. Regardless of previous outcome the KVM logging API * does not preclude user space subsequent dirty log read. Flushing TLB ensures * writes will be marked dirty for next log read. * * 1. Take a snapshot of the bit and clear it if needed. * 2. Write protect the corresponding page. * 3. Copy the snapshot to the userspace. * 4. Flush TLB's if needed. */ static int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log) { int r; mutex_lock(&kvm->slots_lock); r = kvm_get_dirty_log_protect(kvm, log); mutex_unlock(&kvm->slots_lock); return r; } /** * kvm_clear_dirty_log_protect - clear dirty bits in the bitmap * and reenable dirty page tracking for the corresponding pages. * @kvm: pointer to kvm instance * @log: slot id and address from which to fetch the bitmap of dirty pages */ static int kvm_clear_dirty_log_protect(struct kvm *kvm, struct kvm_clear_dirty_log *log) { struct kvm_memslots *slots; struct kvm_memory_slot *memslot; int as_id, id; gfn_t offset; unsigned long i, n; unsigned long *dirty_bitmap; unsigned long *dirty_bitmap_buffer; bool flush; /* Dirty ring tracking is exclusive to dirty log tracking */ if (kvm->dirty_ring_size) return -ENXIO; as_id = log->slot >> 16; id = (u16)log->slot; if (as_id >= KVM_ADDRESS_SPACE_NUM || id >= KVM_USER_MEM_SLOTS) return -EINVAL; if (log->first_page & 63) return -EINVAL; slots = __kvm_memslots(kvm, as_id); memslot = id_to_memslot(slots, id); if (!memslot || !memslot->dirty_bitmap) return -ENOENT; dirty_bitmap = memslot->dirty_bitmap; n = ALIGN(log->num_pages, BITS_PER_LONG) / 8; if (log->first_page > memslot->npages || log->num_pages > memslot->npages - log->first_page || (log->num_pages < memslot->npages - log->first_page && (log->num_pages & 63))) return -EINVAL; kvm_arch_sync_dirty_log(kvm, memslot); flush = false; dirty_bitmap_buffer = kvm_second_dirty_bitmap(memslot); if (copy_from_user(dirty_bitmap_buffer, log->dirty_bitmap, n)) return -EFAULT; KVM_MMU_LOCK(kvm); for (offset = log->first_page, i = offset / BITS_PER_LONG, n = DIV_ROUND_UP(log->num_pages, BITS_PER_LONG); n--; i++, offset += BITS_PER_LONG) { unsigned long mask = *dirty_bitmap_buffer++; atomic_long_t *p = (atomic_long_t *) &dirty_bitmap[i]; if (!mask) continue; mask &= atomic_long_fetch_andnot(mask, p); /* * mask contains the bits that really have been cleared. This * never includes any bits beyond the length of the memslot (if * the length is not aligned to 64 pages), therefore it is not * a problem if userspace sets them in log->dirty_bitmap. */ if (mask) { flush = true; kvm_arch_mmu_enable_log_dirty_pt_masked(kvm, memslot, offset, mask); } } KVM_MMU_UNLOCK(kvm); if (flush) kvm_arch_flush_remote_tlbs_memslot(kvm, memslot); return 0; } static int kvm_vm_ioctl_clear_dirty_log(struct kvm *kvm, struct kvm_clear_dirty_log *log) { int r; mutex_lock(&kvm->slots_lock); r = kvm_clear_dirty_log_protect(kvm, log); mutex_unlock(&kvm->slots_lock); return r; } #endif /* CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT */ 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); struct kvm_memory_slot *kvm_vcpu_gfn_to_memslot(struct kvm_vcpu *vcpu, gfn_t gfn) { return __gfn_to_memslot(kvm_vcpu_memslots(vcpu), gfn); } EXPORT_SYMBOL_GPL(kvm_vcpu_gfn_to_memslot); bool kvm_is_visible_gfn(struct kvm *kvm, gfn_t gfn) { struct kvm_memory_slot *memslot = gfn_to_memslot(kvm, gfn); return kvm_is_visible_memslot(memslot); } EXPORT_SYMBOL_GPL(kvm_is_visible_gfn); bool kvm_vcpu_is_visible_gfn(struct kvm_vcpu *vcpu, gfn_t gfn) { struct kvm_memory_slot *memslot = kvm_vcpu_gfn_to_memslot(vcpu, gfn); return kvm_is_visible_memslot(memslot); } EXPORT_SYMBOL_GPL(kvm_vcpu_is_visible_gfn); unsigned long kvm_host_page_size(struct kvm_vcpu *vcpu, gfn_t gfn) { struct vm_area_struct *vma; unsigned long addr, size; size = PAGE_SIZE; addr = kvm_vcpu_gfn_to_hva_prot(vcpu, gfn, NULL); if (kvm_is_error_hva(addr)) return PAGE_SIZE; mmap_read_lock(current->mm); vma = find_vma(current->mm, addr); if (!vma) goto out; size = vma_kernel_pagesize(vma); out: mmap_read_unlock(current->mm); 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); unsigned long kvm_vcpu_gfn_to_hva(struct kvm_vcpu *vcpu, gfn_t gfn) { return gfn_to_hva_many(kvm_vcpu_gfn_to_memslot(vcpu, gfn), gfn, NULL); } EXPORT_SYMBOL_GPL(kvm_vcpu_gfn_to_hva); /* * Return the hva of a @gfn and the R/W attribute if possible. * * @slot: the kvm_memory_slot which contains @gfn * @gfn: the gfn to be translated * @writable: used to return the read/write attribute of the @slot if the hva * is valid and @writable is not NULL */ unsigned long gfn_to_hva_memslot_prot(struct kvm_memory_slot *slot, gfn_t gfn, bool *writable) { 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; } unsigned long gfn_to_hva_prot(struct kvm *kvm, gfn_t gfn, bool *writable) { struct kvm_memory_slot *slot = gfn_to_memslot(kvm, gfn); return gfn_to_hva_memslot_prot(slot, gfn, writable); } unsigned long kvm_vcpu_gfn_to_hva_prot(struct kvm_vcpu *vcpu, gfn_t gfn, bool *writable) { struct kvm_memory_slot *slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn); return gfn_to_hva_memslot_prot(slot, gfn, writable); } static inline int check_user_page_hwpoison(unsigned long addr) { int rc, flags = FOLL_HWPOISON | FOLL_WRITE; rc = get_user_pages(addr, 1, flags, NULL, NULL); return rc == -EHWPOISON; } /* * The fast path to get the writable pfn which will be stored in @pfn, * true indicates success, otherwise false is returned. It's also the * only part that runs if we can in atomic context. */ static bool hva_to_pfn_fast(unsigned long addr, bool write_fault, bool *writable, kvm_pfn_t *pfn) { struct page *page[1]; /* * 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; if (get_user_page_fast_only(addr, FOLL_WRITE, page)) { *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, kvm_pfn_t *pfn) { unsigned int flags = FOLL_HWPOISON; struct page *page; int npages = 0; might_sleep(); if (writable) *writable = write_fault; if (write_fault) flags |= FOLL_WRITE; if (async) flags |= FOLL_NOWAIT; npages = get_user_pages_unlocked(addr, 1, &page, flags); if (npages != 1) return npages; /* map read fault as writable if possible */ if (unlikely(!write_fault) && writable) { struct page *wpage; if (get_user_page_fast_only(addr, FOLL_WRITE, &wpage)) { *writable = true; put_page(page); page = wpage; } } *pfn = page_to_pfn(page); 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; } static int hva_to_pfn_remapped(struct vm_area_struct *vma, unsigned long addr, bool *async, bool write_fault, bool *writable, kvm_pfn_t *p_pfn) { unsigned long pfn; pte_t *ptep; spinlock_t *ptl; int r; r = follow_pte(vma->vm_mm, addr, &ptep, &ptl); if (r) { /* * get_user_pages fails for VM_IO and VM_PFNMAP vmas and does * not call the fault handler, so do it here. */ bool unlocked = false; r = fixup_user_fault(current->mm, addr, (write_fault ? FAULT_FLAG_WRITE : 0), &unlocked); if (unlocked) return -EAGAIN; if (r) return r; r = follow_pte(vma->vm_mm, addr, &ptep, &ptl); if (r) return r; } if (write_fault && !pte_write(*ptep)) { pfn = KVM_PFN_ERR_RO_FAULT; goto out; } if (writable) *writable = pte_write(*ptep); pfn = pte_pfn(*ptep); /* * Get a reference here because callers of *hva_to_pfn* and * *gfn_to_pfn* ultimately call kvm_release_pfn_clean on the * returned pfn. This is only needed if the VMA has VM_MIXEDMAP * set, but the kvm_get_pfn/kvm_release_pfn_clean pair will * simply do nothing for reserved pfns. * * Whoever called remap_pfn_range is also going to call e.g. * unmap_mapping_range before the underlying pages are freed, * causing a call to our MMU notifier. */ kvm_get_pfn(pfn); out: pte_unmap_unlock(ptep, ptl); *p_pfn = pfn; return 0; } /* * 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 kvm_pfn_t hva_to_pfn(unsigned long addr, bool atomic, bool *async, bool write_fault, bool *writable) { struct vm_area_struct *vma; kvm_pfn_t pfn = 0; int npages, r; /* we can do it either atomically or asynchronously, not both */ BUG_ON(atomic && async); if (hva_to_pfn_fast(addr, 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; mmap_read_lock(current->mm); if (npages == -EHWPOISON || (!async && check_user_page_hwpoison(addr))) { pfn = KVM_PFN_ERR_HWPOISON; goto exit; } retry: vma = find_vma_intersection(current->mm, addr, addr + 1); if (vma == NULL) pfn = KVM_PFN_ERR_FAULT; else if (vma->vm_flags & (VM_IO | VM_PFNMAP)) { r = hva_to_pfn_remapped(vma, addr, async, write_fault, writable, &pfn); if (r == -EAGAIN) goto retry; if (r < 0) pfn = KVM_PFN_ERR_FAULT; } else { if (async && vma_is_valid(vma, write_fault)) *async = true; pfn = KVM_PFN_ERR_FAULT; } exit: mmap_read_unlock(current->mm); return pfn; } kvm_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) { if (writable) *writable = false; return KVM_PFN_ERR_RO_FAULT; } if (kvm_is_error_hva(addr)) { if (writable) *writable = false; 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); } EXPORT_SYMBOL_GPL(__gfn_to_pfn_memslot); kvm_pfn_t gfn_to_pfn_prot(struct kvm *kvm, gfn_t gfn, bool write_fault, bool *writable) { return __gfn_to_pfn_memslot(gfn_to_memslot(kvm, gfn), gfn, false, NULL, write_fault, writable); } EXPORT_SYMBOL_GPL(gfn_to_pfn_prot); kvm_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); } EXPORT_SYMBOL_GPL(gfn_to_pfn_memslot); kvm_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); kvm_pfn_t kvm_vcpu_gfn_to_pfn_atomic(struct kvm_vcpu *vcpu, gfn_t gfn) { return gfn_to_pfn_memslot_atomic(kvm_vcpu_gfn_to_memslot(vcpu, gfn), gfn); } EXPORT_SYMBOL_GPL(kvm_vcpu_gfn_to_pfn_atomic); kvm_pfn_t gfn_to_pfn(struct kvm *kvm, gfn_t gfn) { return gfn_to_pfn_memslot(gfn_to_memslot(kvm, gfn), gfn); } EXPORT_SYMBOL_GPL(gfn_to_pfn); kvm_pfn_t kvm_vcpu_gfn_to_pfn(struct kvm_vcpu *vcpu, gfn_t gfn) { return gfn_to_pfn_memslot(kvm_vcpu_gfn_to_memslot(vcpu, gfn), gfn); } EXPORT_SYMBOL_GPL(kvm_vcpu_gfn_to_pfn); int gfn_to_page_many_atomic(struct kvm_memory_slot *slot, gfn_t gfn, struct page **pages, int nr_pages) { unsigned long addr; gfn_t entry = 0; addr = gfn_to_hva_many(slot, gfn, &entry); if (kvm_is_error_hva(addr)) return -1; if (entry < nr_pages) return 0; return get_user_pages_fast_only(addr, nr_pages, FOLL_WRITE, pages); } EXPORT_SYMBOL_GPL(gfn_to_page_many_atomic); static struct page *kvm_pfn_to_page(kvm_pfn_t pfn) { if (is_error_noslot_pfn(pfn)) return KVM_ERR_PTR_BAD_PAGE; if (kvm_is_reserved_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) { kvm_pfn_t pfn; pfn = gfn_to_pfn(kvm, gfn); return kvm_pfn_to_page(pfn); } EXPORT_SYMBOL_GPL(gfn_to_page); void kvm_release_pfn(kvm_pfn_t pfn, bool dirty, struct gfn_to_pfn_cache *cache) { if (pfn == 0) return; if (cache) cache->pfn = cache->gfn = 0; if (dirty) kvm_release_pfn_dirty(pfn); else kvm_release_pfn_clean(pfn); } static void kvm_cache_gfn_to_pfn(struct kvm_memory_slot *slot, gfn_t gfn, struct gfn_to_pfn_cache *cache, u64 gen) { kvm_release_pfn(cache->pfn, cache->dirty, cache); cache->pfn = gfn_to_pfn_memslot(slot, gfn); cache->gfn = gfn; cache->dirty = false; cache->generation = gen; } static int __kvm_map_gfn(struct kvm_memslots *slots, gfn_t gfn, struct kvm_host_map *map, struct gfn_to_pfn_cache *cache, bool atomic) { kvm_pfn_t pfn; void *hva = NULL; struct page *page = KVM_UNMAPPED_PAGE; struct kvm_memory_slot *slot = __gfn_to_memslot(slots, gfn); u64 gen = slots->generation; if (!map) return -EINVAL; if (cache) { if (!cache->pfn || cache->gfn != gfn || cache->generation != gen) { if (atomic) return -EAGAIN; kvm_cache_gfn_to_pfn(slot, gfn, cache, gen); } pfn = cache->pfn; } else { if (atomic) return -EAGAIN; pfn = gfn_to_pfn_memslot(slot, gfn); } if (is_error_noslot_pfn(pfn)) return -EINVAL; if (pfn_valid(pfn)) { page = pfn_to_page(pfn); if (atomic) hva = kmap_atomic(page); else hva = kmap(page); #ifdef CONFIG_HAS_IOMEM } else if (!atomic) { hva = memremap(pfn_to_hpa(pfn), PAGE_SIZE, MEMREMAP_WB); } else { return -EINVAL; #endif } if (!hva) return -EFAULT; map->page = page; map->hva = hva; map->pfn = pfn; map->gfn = gfn; return 0; } int kvm_map_gfn(struct kvm_vcpu *vcpu, gfn_t gfn, struct kvm_host_map *map, struct gfn_to_pfn_cache *cache, bool atomic) { return __kvm_map_gfn(kvm_memslots(vcpu->kvm), gfn, map, cache, atomic); } EXPORT_SYMBOL_GPL(kvm_map_gfn); int kvm_vcpu_map(struct kvm_vcpu *vcpu, gfn_t gfn, struct kvm_host_map *map) { return __kvm_map_gfn(kvm_vcpu_memslots(vcpu), gfn, map, NULL, false); } EXPORT_SYMBOL_GPL(kvm_vcpu_map); static void __kvm_unmap_gfn(struct kvm *kvm, struct kvm_memory_slot *memslot, struct kvm_host_map *map, struct gfn_to_pfn_cache *cache, bool dirty, bool atomic) { if (!map) return; if (!map->hva) return; if (map->page != KVM_UNMAPPED_PAGE) { if (atomic) kunmap_atomic(map->hva); else kunmap(map->page); } #ifdef CONFIG_HAS_IOMEM else if (!atomic) memunmap(map->hva); else WARN_ONCE(1, "Unexpected unmapping in atomic context"); #endif if (dirty) mark_page_dirty_in_slot(kvm, memslot, map->gfn); if (cache) cache->dirty |= dirty; else kvm_release_pfn(map->pfn, dirty, NULL); map->hva = NULL; map->page = NULL; } int kvm_unmap_gfn(struct kvm_vcpu *vcpu, struct kvm_host_map *map, struct gfn_to_pfn_cache *cache, bool dirty, bool atomic) { __kvm_unmap_gfn(vcpu->kvm, gfn_to_memslot(vcpu->kvm, map->gfn), map, cache, dirty, atomic); return 0; } EXPORT_SYMBOL_GPL(kvm_unmap_gfn); void kvm_vcpu_unmap(struct kvm_vcpu *vcpu, struct kvm_host_map *map, bool dirty) { __kvm_unmap_gfn(vcpu->kvm, kvm_vcpu_gfn_to_memslot(vcpu, map->gfn), map, NULL, dirty, false); } EXPORT_SYMBOL_GPL(kvm_vcpu_unmap); struct page *kvm_vcpu_gfn_to_page(struct kvm_vcpu *vcpu, gfn_t gfn) { kvm_pfn_t pfn; pfn = kvm_vcpu_gfn_to_pfn(vcpu, gfn); return kvm_pfn_to_page(pfn); } EXPORT_SYMBOL_GPL(kvm_vcpu_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(kvm_pfn_t pfn) { if (!is_error_noslot_pfn(pfn) && !kvm_is_reserved_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); void kvm_release_pfn_dirty(kvm_pfn_t pfn) { kvm_set_pfn_dirty(pfn); kvm_release_pfn_clean(pfn); } EXPORT_SYMBOL_GPL(kvm_release_pfn_dirty); void kvm_set_pfn_dirty(kvm_pfn_t pfn) { if (!kvm_is_reserved_pfn(pfn) && !kvm_is_zone_device_pfn(pfn)) SetPageDirty(pfn_to_page(pfn)); } EXPORT_SYMBOL_GPL(kvm_set_pfn_dirty); void kvm_set_pfn_accessed(kvm_pfn_t pfn) { if (!kvm_is_reserved_pfn(pfn) && !kvm_is_zone_device_pfn(pfn)) mark_page_accessed(pfn_to_page(pfn)); } EXPORT_SYMBOL_GPL(kvm_set_pfn_accessed); void kvm_get_pfn(kvm_pfn_t pfn) { if (!kvm_is_reserved_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; } static int __kvm_read_guest_page(struct kvm_memory_slot *slot, gfn_t gfn, void *data, int offset, int len) { int r; unsigned long addr; addr = gfn_to_hva_memslot_prot(slot, gfn, NULL); if (kvm_is_error_hva(addr)) return -EFAULT; r = __copy_from_user(data, (void __user *)addr + offset, len); if (r) return -EFAULT; return 0; } int kvm_read_guest_page(struct kvm *kvm, gfn_t gfn, void *data, int offset, int len) { struct kvm_memory_slot *slot = gfn_to_memslot(kvm, gfn); return __kvm_read_guest_page(slot, gfn, data, offset, len); } EXPORT_SYMBOL_GPL(kvm_read_guest_page); int kvm_vcpu_read_guest_page(struct kvm_vcpu *vcpu, gfn_t gfn, void *data, int offset, int len) { struct kvm_memory_slot *slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn); return __kvm_read_guest_page(slot, gfn, data, offset, len); } EXPORT_SYMBOL_GPL(kvm_vcpu_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_vcpu_read_guest(struct kvm_vcpu *vcpu, 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_vcpu_read_guest_page(vcpu, gfn, data, offset, seg); if (ret < 0) return ret; offset = 0; len -= seg; data += seg; ++gfn; } return 0; } EXPORT_SYMBOL_GPL(kvm_vcpu_read_guest); static int __kvm_read_guest_atomic(struct kvm_memory_slot *slot, gfn_t gfn, void *data, int offset, unsigned long len) { int r; unsigned long addr; addr = gfn_to_hva_memslot_prot(slot, gfn, NULL); if (kvm_is_error_hva(addr)) return -EFAULT; pagefault_disable(); r = __copy_from_user_inatomic(data, (void __user *)addr + offset, len); pagefault_enable(); if (r) return -EFAULT; return 0; } int kvm_vcpu_read_guest_atomic(struct kvm_vcpu *vcpu, gpa_t gpa, void *data, unsigned long len) { gfn_t gfn = gpa >> PAGE_SHIFT; struct kvm_memory_slot *slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn); int offset = offset_in_page(gpa); return __kvm_read_guest_atomic(slot, gfn, data, offset, len); } EXPORT_SYMBOL_GPL(kvm_vcpu_read_guest_atomic); static int __kvm_write_guest_page(struct kvm *kvm, struct kvm_memory_slot *memslot, gfn_t gfn, const void *data, int offset, int len) { int r; unsigned long addr; addr = gfn_to_hva_memslot(memslot, 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_in_slot(kvm, memslot, gfn); return 0; } int kvm_write_guest_page(struct kvm *kvm, gfn_t gfn, const void *data, int offset, int len) { struct kvm_memory_slot *slot = gfn_to_memslot(kvm, gfn); return __kvm_write_guest_page(kvm, slot, gfn, data, offset, len); } EXPORT_SYMBOL_GPL(kvm_write_guest_page); int kvm_vcpu_write_guest_page(struct kvm_vcpu *vcpu, gfn_t gfn, const void *data, int offset, int len) { struct kvm_memory_slot *slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn); return __kvm_write_guest_page(vcpu->kvm, slot, gfn, data, offset, len); } EXPORT_SYMBOL_GPL(kvm_vcpu_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; } EXPORT_SYMBOL_GPL(kvm_write_guest); int kvm_vcpu_write_guest(struct kvm_vcpu *vcpu, 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_vcpu_write_guest_page(vcpu, gfn, data, offset, seg); if (ret < 0) return ret; offset = 0; len -= seg; data += seg; ++gfn; } return 0; } EXPORT_SYMBOL_GPL(kvm_vcpu_write_guest); static int __kvm_gfn_to_hva_cache_init(struct kvm_memslots *slots, struct gfn_to_hva_cache *ghc, gpa_t gpa, unsigned long len) { 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; /* Update ghc->generation before performing any error checks. */ ghc->generation = slots->generation; if (start_gfn > end_gfn) { ghc->hva = KVM_HVA_ERR_BAD; return -EINVAL; } /* * If the requested region crosses two memslots, we still * verify that the entire region is valid here. */ for ( ; start_gfn <= end_gfn; start_gfn += nr_pages_avail) { ghc->memslot = __gfn_to_memslot(slots, start_gfn); ghc->hva = gfn_to_hva_many(ghc->memslot, start_gfn, &nr_pages_avail); if (kvm_is_error_hva(ghc->hva)) return -EFAULT; } /* Use the slow path for cross page reads and writes. */ if (nr_pages_needed == 1) ghc->hva += offset; else ghc->memslot = NULL; ghc->gpa = gpa; ghc->len = len; 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); return __kvm_gfn_to_hva_cache_init(slots, ghc, gpa, len); } EXPORT_SYMBOL_GPL(kvm_gfn_to_hva_cache_init); int kvm_write_guest_offset_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc, void *data, unsigned int offset, unsigned long len) { struct kvm_memslots *slots = kvm_memslots(kvm); int r; gpa_t gpa = ghc->gpa + offset; BUG_ON(len + offset > ghc->len); if (slots->generation != ghc->generation) { if (__kvm_gfn_to_hva_cache_init(slots, ghc, ghc->gpa, ghc->len)) return -EFAULT; } if (kvm_is_error_hva(ghc->hva)) return -EFAULT; if (unlikely(!ghc->memslot)) return kvm_write_guest(kvm, gpa, data, len); r = __copy_to_user((void __user *)ghc->hva + offset, data, len); if (r) return -EFAULT; mark_page_dirty_in_slot(kvm, ghc->memslot, gpa >> PAGE_SHIFT); return 0; } EXPORT_SYMBOL_GPL(kvm_write_guest_offset_cached); int kvm_write_guest_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc, void *data, unsigned long len) { return kvm_write_guest_offset_cached(kvm, ghc, data, 0, len); } EXPORT_SYMBOL_GPL(kvm_write_guest_cached); int kvm_read_guest_offset_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc, void *data, unsigned int offset, unsigned long len) { struct kvm_memslots *slots = kvm_memslots(kvm); int r; gpa_t gpa = ghc->gpa + offset; BUG_ON(len + offset > ghc->len); if (slots->generation != ghc->generation) { if (__kvm_gfn_to_hva_cache_init(slots, ghc, ghc->gpa, ghc->len)) return -EFAULT; } if (kvm_is_error_hva(ghc->hva)) return -EFAULT; if (unlikely(!ghc->memslot)) return kvm_read_guest(kvm, gpa, data, len); r = __copy_from_user(data, (void __user *)ghc->hva + offset, len); if (r) return -EFAULT; return 0; } EXPORT_SYMBOL_GPL(kvm_read_guest_offset_cached); int kvm_read_guest_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc, void *data, unsigned long len) { return kvm_read_guest_offset_cached(kvm, ghc, data, 0, len); } EXPORT_SYMBOL_GPL(kvm_read_guest_cached); int kvm_clear_guest(struct kvm *kvm, gpa_t gpa, unsigned long len) { const void *zero_page = (const void *) __va(page_to_phys(ZERO_PAGE(0))); 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, zero_page, offset, len); if (ret < 0) return ret; offset = 0; len -= seg; ++gfn; } return 0; } EXPORT_SYMBOL_GPL(kvm_clear_guest); void mark_page_dirty_in_slot(struct kvm *kvm, struct kvm_memory_slot *memslot, gfn_t gfn) { if (memslot && kvm_slot_dirty_track_enabled(memslot)) { unsigned long rel_gfn = gfn - memslot->base_gfn; u32 slot = (memslot->as_id << 16) | memslot->id; if (kvm->dirty_ring_size) kvm_dirty_ring_push(kvm_dirty_ring_get(kvm), slot, rel_gfn); else set_bit_le(rel_gfn, memslot->dirty_bitmap); } } EXPORT_SYMBOL_GPL(mark_page_dirty_in_slot); 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); void kvm_vcpu_mark_page_dirty(struct kvm_vcpu *vcpu, gfn_t gfn) { struct kvm_memory_slot *memslot; memslot = kvm_vcpu_gfn_to_memslot(vcpu, gfn); mark_page_dirty_in_slot(vcpu->kvm, memslot, gfn); } EXPORT_SYMBOL_GPL(kvm_vcpu_mark_page_dirty); void kvm_sigset_activate(struct kvm_vcpu *vcpu) { if (!vcpu->sigset_active) return; /* * This does a lockless modification of ->real_blocked, which is fine * because, only current can change ->real_blocked and all readers of * ->real_blocked don't care as long ->real_blocked is always a subset * of ->blocked. */ sigprocmask(SIG_SETMASK, &vcpu->sigset, ¤t->real_blocked); } void kvm_sigset_deactivate(struct kvm_vcpu *vcpu) { if (!vcpu->sigset_active) return; sigprocmask(SIG_SETMASK, ¤t->real_blocked, NULL); sigemptyset(¤t->real_blocked); } static void grow_halt_poll_ns(struct kvm_vcpu *vcpu) { unsigned int old, val, grow, grow_start; old = val = vcpu->halt_poll_ns; grow_start = READ_ONCE(halt_poll_ns_grow_start); grow = READ_ONCE(halt_poll_ns_grow); if (!grow) goto out; val *= grow; if (val < grow_start) val = grow_start; if (val > halt_poll_ns) val = halt_poll_ns; vcpu->halt_poll_ns = val; out: trace_kvm_halt_poll_ns_grow(vcpu->vcpu_id, val, old); } static void shrink_halt_poll_ns(struct kvm_vcpu *vcpu) { unsigned int old, val, shrink; old = val = vcpu->halt_poll_ns; shrink = READ_ONCE(halt_poll_ns_shrink); if (shrink == 0) val = 0; else val /= shrink; vcpu->halt_poll_ns = val; trace_kvm_halt_poll_ns_shrink(vcpu->vcpu_id, val, old); } static int kvm_vcpu_check_block(struct kvm_vcpu *vcpu) { int ret = -EINTR; int idx = srcu_read_lock(&vcpu->kvm->srcu); if (kvm_arch_vcpu_runnable(vcpu)) { kvm_make_request(KVM_REQ_UNHALT, vcpu); goto out; } if (kvm_cpu_has_pending_timer(vcpu)) goto out; if (signal_pending(current)) goto out; ret = 0; out: srcu_read_unlock(&vcpu->kvm->srcu, idx); return ret; } static inline void update_halt_poll_stats(struct kvm_vcpu *vcpu, u64 poll_ns, bool waited) { if (waited) vcpu->stat.halt_poll_fail_ns += poll_ns; else vcpu->stat.halt_poll_success_ns += poll_ns; } /* * The vCPU has executed a HLT instruction with in-kernel mode enabled. */ void kvm_vcpu_block(struct kvm_vcpu *vcpu) { ktime_t start, cur, poll_end; bool waited = false; u64 block_ns; kvm_arch_vcpu_blocking(vcpu); start = cur = poll_end = ktime_get(); if (vcpu->halt_poll_ns && !kvm_arch_no_poll(vcpu)) { ktime_t stop = ktime_add_ns(ktime_get(), vcpu->halt_poll_ns); ++vcpu->stat.halt_attempted_poll; do { /* * This sets KVM_REQ_UNHALT if an interrupt * arrives. */ if (kvm_vcpu_check_block(vcpu) < 0) { ++vcpu->stat.halt_successful_poll; if (!vcpu_valid_wakeup(vcpu)) ++vcpu->stat.halt_poll_invalid; goto out; } poll_end = cur = ktime_get(); } while (single_task_running() && ktime_before(cur, stop)); } prepare_to_rcuwait(&vcpu->wait); for (;;) { set_current_state(TASK_INTERRUPTIBLE); if (kvm_vcpu_check_block(vcpu) < 0) break; waited = true; schedule(); } finish_rcuwait(&vcpu->wait); cur = ktime_get(); out: kvm_arch_vcpu_unblocking(vcpu); block_ns = ktime_to_ns(cur) - ktime_to_ns(start); update_halt_poll_stats( vcpu, ktime_to_ns(ktime_sub(poll_end, start)), waited); if (!kvm_arch_no_poll(vcpu)) { if (!vcpu_valid_wakeup(vcpu)) { shrink_halt_poll_ns(vcpu); } else if (vcpu->kvm->max_halt_poll_ns) { if (block_ns <= vcpu->halt_poll_ns) ; /* we had a long block, shrink polling */ else if (vcpu->halt_poll_ns && block_ns > vcpu->kvm->max_halt_poll_ns) shrink_halt_poll_ns(vcpu); /* we had a short halt and our poll time is too small */ else if (vcpu->halt_poll_ns < vcpu->kvm->max_halt_poll_ns && block_ns < vcpu->kvm->max_halt_poll_ns) grow_halt_poll_ns(vcpu); } else { vcpu->halt_poll_ns = 0; } } trace_kvm_vcpu_wakeup(block_ns, waited, vcpu_valid_wakeup(vcpu)); kvm_arch_vcpu_block_finish(vcpu); } EXPORT_SYMBOL_GPL(kvm_vcpu_block); bool kvm_vcpu_wake_up(struct kvm_vcpu *vcpu) { struct rcuwait *waitp; waitp = kvm_arch_vcpu_get_wait(vcpu); if (rcuwait_wake_up(waitp)) { WRITE_ONCE(vcpu->ready, true); ++vcpu->stat.halt_wakeup; return true; } return false; } EXPORT_SYMBOL_GPL(kvm_vcpu_wake_up); #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; if (kvm_vcpu_wake_up(vcpu)) return; 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(pid, PIDTYPE_PID); rcu_read_unlock(); if (!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 beginning 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.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 } /* * Unlike kvm_arch_vcpu_runnable, this function is called outside * a vcpu_load/vcpu_put pair. However, for most architectures * kvm_arch_vcpu_runnable does not require vcpu_load. */ bool __weak kvm_arch_dy_runnable(struct kvm_vcpu *vcpu) { return kvm_arch_vcpu_runnable(vcpu); } static bool vcpu_dy_runnable(struct kvm_vcpu *vcpu) { if (kvm_arch_dy_runnable(vcpu)) return true; #ifdef CONFIG_KVM_ASYNC_PF if (!list_empty_careful(&vcpu->async_pf.done)) return true; #endif return false; } void kvm_vcpu_on_spin(struct kvm_vcpu *me, bool yield_to_kernel_mode) { 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 (!READ_ONCE(vcpu->ready)) continue; if (vcpu == me) continue; if (rcuwait_active(&vcpu->wait) && !vcpu_dy_runnable(vcpu)) continue; if (READ_ONCE(vcpu->preempted) && yield_to_kernel_mode && !kvm_arch_vcpu_in_kernel(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 bool kvm_page_in_dirty_ring(struct kvm *kvm, unsigned long pgoff) { #if KVM_DIRTY_LOG_PAGE_OFFSET > 0 return (pgoff >= KVM_DIRTY_LOG_PAGE_OFFSET) && (pgoff < KVM_DIRTY_LOG_PAGE_OFFSET + kvm->dirty_ring_size / PAGE_SIZE); #else return false; #endif } static vm_fault_t kvm_vcpu_fault(struct vm_fault *vmf) { struct kvm_vcpu *vcpu = vmf->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 CONFIG_KVM_MMIO else if (vmf->pgoff == KVM_COALESCED_MMIO_PAGE_OFFSET) page = virt_to_page(vcpu->kvm->coalesced_mmio_ring); #endif else if (kvm_page_in_dirty_ring(vcpu->kvm, vmf->pgoff)) page = kvm_dirty_ring_get_page( &vcpu->dirty_ring, vmf->pgoff - KVM_DIRTY_LOG_PAGE_OFFSET); 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) { struct kvm_vcpu *vcpu = file->private_data; unsigned long pages = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT; if ((kvm_page_in_dirty_ring(vcpu->kvm, vma->vm_pgoff) || kvm_page_in_dirty_ring(vcpu->kvm, vma->vm_pgoff + pages - 1)) && ((vma->vm_flags & VM_EXEC) || !(vma->vm_flags & VM_SHARED))) return -EINVAL; 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, .mmap = kvm_vcpu_mmap, .llseek = noop_llseek, KVM_COMPAT(kvm_vcpu_compat_ioctl), }; /* * Allocates an inode for the vcpu. */ static int create_vcpu_fd(struct kvm_vcpu *vcpu) { char name[8 + 1 + ITOA_MAX_LEN + 1]; snprintf(name, sizeof(name), "kvm-vcpu:%d", vcpu->vcpu_id); return anon_inode_getfd(name, &kvm_vcpu_fops, vcpu, O_RDWR | O_CLOEXEC); } static void kvm_create_vcpu_debugfs(struct kvm_vcpu *vcpu) { #ifdef __KVM_HAVE_ARCH_VCPU_DEBUGFS struct dentry *debugfs_dentry; char dir_name[ITOA_MAX_LEN * 2]; if (!debugfs_initialized()) return; snprintf(dir_name, sizeof(dir_name), "vcpu%d", vcpu->vcpu_id); debugfs_dentry = debugfs_create_dir(dir_name, vcpu->kvm->debugfs_dentry); kvm_arch_create_vcpu_debugfs(vcpu, debugfs_dentry); #endif } /* * 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; struct page *page; if (id >= KVM_MAX_VCPU_ID) return -EINVAL; mutex_lock(&kvm->lock); if (kvm->created_vcpus == KVM_MAX_VCPUS) { mutex_unlock(&kvm->lock); return -EINVAL; } kvm->created_vcpus++; mutex_unlock(&kvm->lock); r = kvm_arch_vcpu_precreate(kvm, id); if (r) goto vcpu_decrement; vcpu = kmem_cache_zalloc(kvm_vcpu_cache, GFP_KERNEL); if (!vcpu) { r = -ENOMEM; goto vcpu_decrement; } BUILD_BUG_ON(sizeof(struct kvm_run) > PAGE_SIZE); page = alloc_page(GFP_KERNEL_ACCOUNT | __GFP_ZERO); if (!page) { r = -ENOMEM; goto vcpu_free; } vcpu->run = page_address(page); kvm_vcpu_init(vcpu, kvm, id); r = kvm_arch_vcpu_create(vcpu); if (r) goto vcpu_free_run_page; if (kvm->dirty_ring_size) { r = kvm_dirty_ring_alloc(&vcpu->dirty_ring, id, kvm->dirty_ring_size); if (r) goto arch_vcpu_destroy; } mutex_lock(&kvm->lock); if (kvm_get_vcpu_by_id(kvm, id)) { r = -EEXIST; goto unlock_vcpu_destroy; } vcpu->vcpu_idx = atomic_read(&kvm->online_vcpus); BUG_ON(kvm->vcpus[vcpu->vcpu_idx]); /* 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_no_destroy(kvm); goto unlock_vcpu_destroy; } kvm->vcpus[vcpu->vcpu_idx] = vcpu; /* * Pairs with smp_rmb() in kvm_get_vcpu. Write kvm->vcpus * before kvm->online_vcpu's incremented value. */ smp_wmb(); atomic_inc(&kvm->online_vcpus); mutex_unlock(&kvm->lock); kvm_arch_vcpu_postcreate(vcpu); kvm_create_vcpu_debugfs(vcpu); return r; unlock_vcpu_destroy: mutex_unlock(&kvm->lock); kvm_dirty_ring_free(&vcpu->dirty_ring); arch_vcpu_destroy: kvm_arch_vcpu_destroy(vcpu); vcpu_free_run_page: free_page((unsigned long)vcpu->run); vcpu_free: kmem_cache_free(kvm_vcpu_cache, vcpu); vcpu_decrement: mutex_lock(&kvm->lock); kvm->created_vcpus--; mutex_unlock(&kvm->lock); 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 (unlikely(_IOC_TYPE(ioctl) != KVMIO)) return -EINVAL; /* * Some architectures have vcpu ioctls that are asynchronous to vcpu * execution; mutex_lock() would break them. */ r = kvm_arch_vcpu_async_ioctl(filp, ioctl, arg); if (r != -ENOIOCTLCMD) return r; if (mutex_lock_killable(&vcpu->mutex)) return -EINTR; switch (ioctl) { case KVM_RUN: { struct pid *oldpid; r = -EINVAL; if (arg) goto out; oldpid = rcu_access_pointer(vcpu->pid); if (unlikely(oldpid != task_pid(current))) { /* The thread running this VCPU changed. */ struct pid *newpid; r = kvm_arch_vcpu_run_pid_change(vcpu); if (r) break; newpid = get_task_pid(current, PIDTYPE_PID); rcu_assign_pointer(vcpu->pid, newpid); if (oldpid) synchronize_rcu(); put_pid(oldpid); } r = kvm_arch_vcpu_ioctl_run(vcpu); 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_ACCOUNT); 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; 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_ACCOUNT); 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_ACCOUNT); 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: mutex_unlock(&vcpu->mutex); kfree(fpu); kfree(kvm_sregs); return r; } #ifdef CONFIG_KVM_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; 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(compat_sigset_t)) goto out; r = -EFAULT; if (get_compat_sigset(&sigset, (compat_sigset_t __user *)sigmask_arg->sigset)) goto out; 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_mmap(struct file *filp, struct vm_area_struct *vma) { struct kvm_device *dev = filp->private_data; if (dev->ops->mmap) return dev->ops->mmap(dev, vma); return -ENODEV; } 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; if (dev->kvm->mm != current->mm) return -EIO; 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; if (dev->ops->release) { mutex_lock(&kvm->lock); list_del(&dev->vm_node); dev->ops->release(dev); mutex_unlock(&kvm->lock); } kvm_put_kvm(kvm); return 0; } static const struct file_operations kvm_device_fops = { .unlocked_ioctl = kvm_device_ioctl, .release = kvm_device_release, KVM_COMPAT(kvm_device_ioctl), .mmap = kvm_device_mmap, }; struct kvm_device *kvm_device_from_filp(struct file *filp) { if (filp->f_op != &kvm_device_fops) return NULL; return filp->private_data; } static const struct kvm_device_ops *kvm_device_ops_table[KVM_DEV_TYPE_MAX] = { #ifdef CONFIG_KVM_MPIC [KVM_DEV_TYPE_FSL_MPIC_20] = &kvm_mpic_ops, [KVM_DEV_TYPE_FSL_MPIC_42] = &kvm_mpic_ops, #endif }; int kvm_register_device_ops(const struct kvm_device_ops *ops, u32 type) { if (type >= ARRAY_SIZE(kvm_device_ops_table)) return -ENOSPC; if (kvm_device_ops_table[type] != NULL) return -EEXIST; kvm_device_ops_table[type] = ops; return 0; } void kvm_unregister_device_ops(u32 type) { if (kvm_device_ops_table[type] != NULL) kvm_device_ops_table[type] = NULL; } static int kvm_ioctl_create_device(struct kvm *kvm, struct kvm_create_device *cd) { const struct kvm_device_ops *ops = NULL; struct kvm_device *dev; bool test = cd->flags & KVM_CREATE_DEVICE_TEST; int type; int ret; if (cd->type >= ARRAY_SIZE(kvm_device_ops_table)) return -ENODEV; type = array_index_nospec(cd->type, ARRAY_SIZE(kvm_device_ops_table)); ops = kvm_device_ops_table[type]; if (ops == NULL) return -ENODEV; if (test) return 0; dev = kzalloc(sizeof(*dev), GFP_KERNEL_ACCOUNT); if (!dev) return -ENOMEM; dev->ops = ops; dev->kvm = kvm; mutex_lock(&kvm->lock); ret = ops->create(dev, type); if (ret < 0) { mutex_unlock(&kvm->lock); kfree(dev); return ret; } list_add(&dev->vm_node, &kvm->devices); mutex_unlock(&kvm->lock); if (ops->init) ops->init(dev); kvm_get_kvm(kvm); ret = anon_inode_getfd(ops->name, &kvm_device_fops, dev, O_RDWR | O_CLOEXEC); if (ret < 0) { kvm_put_kvm_no_destroy(kvm); mutex_lock(&kvm->lock); list_del(&dev->vm_node); mutex_unlock(&kvm->lock); ops->destroy(dev); return ret; } cd->fd = ret; return 0; } 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: case KVM_CAP_INTERNAL_ERROR_DATA: #ifdef CONFIG_HAVE_KVM_MSI case KVM_CAP_SIGNAL_MSI: #endif #ifdef CONFIG_HAVE_KVM_IRQFD case KVM_CAP_IRQFD: case KVM_CAP_IRQFD_RESAMPLE: #endif case KVM_CAP_IOEVENTFD_ANY_LENGTH: case KVM_CAP_CHECK_EXTENSION_VM: case KVM_CAP_ENABLE_CAP_VM: case KVM_CAP_HALT_POLL: return 1; #ifdef CONFIG_KVM_MMIO case KVM_CAP_COALESCED_MMIO: return KVM_COALESCED_MMIO_PAGE_OFFSET; case KVM_CAP_COALESCED_PIO: return 1; #endif #ifdef CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT case KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2: return KVM_DIRTY_LOG_MANUAL_CAPS; #endif #ifdef CONFIG_HAVE_KVM_IRQ_ROUTING case KVM_CAP_IRQ_ROUTING: return KVM_MAX_IRQ_ROUTES; #endif #if KVM_ADDRESS_SPACE_NUM > 1 case KVM_CAP_MULTI_ADDRESS_SPACE: return KVM_ADDRESS_SPACE_NUM; #endif case KVM_CAP_NR_MEMSLOTS: return KVM_USER_MEM_SLOTS; case KVM_CAP_DIRTY_LOG_RING: #if KVM_DIRTY_LOG_PAGE_OFFSET > 0 return KVM_DIRTY_RING_MAX_ENTRIES * sizeof(struct kvm_dirty_gfn); #else return 0; #endif default: break; } return kvm_vm_ioctl_check_extension(kvm, arg); } static int kvm_vm_ioctl_enable_dirty_log_ring(struct kvm *kvm, u32 size) { int r; if (!KVM_DIRTY_LOG_PAGE_OFFSET) return -EINVAL; /* the size should be power of 2 */ if (!size || (size & (size - 1))) return -EINVAL; /* Should be bigger to keep the reserved entries, or a page */ if (size < kvm_dirty_ring_get_rsvd_entries() * sizeof(struct kvm_dirty_gfn) || size < PAGE_SIZE) return -EINVAL; if (size > KVM_DIRTY_RING_MAX_ENTRIES * sizeof(struct kvm_dirty_gfn)) return -E2BIG; /* We only allow it to set once */ if (kvm->dirty_ring_size) return -EINVAL; mutex_lock(&kvm->lock); if (kvm->created_vcpus) { /* We don't allow to change this value after vcpu created */ r = -EINVAL; } else { kvm->dirty_ring_size = size; r = 0; } mutex_unlock(&kvm->lock); return r; } static int kvm_vm_ioctl_reset_dirty_pages(struct kvm *kvm) { int i; struct kvm_vcpu *vcpu; int cleared = 0; if (!kvm->dirty_ring_size) return -EINVAL; mutex_lock(&kvm->slots_lock); kvm_for_each_vcpu(i, vcpu, kvm) cleared += kvm_dirty_ring_reset(vcpu->kvm, &vcpu->dirty_ring); mutex_unlock(&kvm->slots_lock); if (cleared) kvm_flush_remote_tlbs(kvm); return cleared; } int __attribute__((weak)) kvm_vm_ioctl_enable_cap(struct kvm *kvm, struct kvm_enable_cap *cap) { return -EINVAL; } static int kvm_vm_ioctl_enable_cap_generic(struct kvm *kvm, struct kvm_enable_cap *cap) { switch (cap->cap) { #ifdef CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT case KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2: { u64 allowed_options = KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE; if (cap->args[0] & KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE) allowed_options = KVM_DIRTY_LOG_MANUAL_CAPS; if (cap->flags || (cap->args[0] & ~allowed_options)) return -EINVAL; kvm->manual_dirty_log_protect = cap->args[0]; return 0; } #endif case KVM_CAP_HALT_POLL: { if (cap->flags || cap->args[0] != (unsigned int)cap->args[0]) return -EINVAL; kvm->max_halt_poll_ns = cap->args[0]; return 0; } case KVM_CAP_DIRTY_LOG_RING: return kvm_vm_ioctl_enable_dirty_log_ring(kvm, cap->args[0]); default: return kvm_vm_ioctl_enable_cap(kvm, cap); } } 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_ENABLE_CAP: { struct kvm_enable_cap cap; r = -EFAULT; if (copy_from_user(&cap, argp, sizeof(cap))) goto out; r = kvm_vm_ioctl_enable_cap_generic(kvm, &cap); 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 CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT case KVM_CLEAR_DIRTY_LOG: { struct kvm_clear_dirty_log log; r = -EFAULT; if (copy_from_user(&log, argp, sizeof(log))) goto out; r = kvm_vm_ioctl_clear_dirty_log(kvm, &log); break; } #endif #ifdef CONFIG_KVM_MMIO 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_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 = NULL; r = -EFAULT; if (copy_from_user(&routing, argp, sizeof(routing))) goto out; r = -EINVAL; if (!kvm_arch_can_set_irq_routing(kvm)) goto out; if (routing.nr > KVM_MAX_IRQ_ROUTES) goto out; if (routing.flags) goto out; if (routing.nr) { urouting = argp; entries = vmemdup_user(urouting->entries, array_size(sizeof(*entries), routing.nr)); if (IS_ERR(entries)) { r = PTR_ERR(entries); goto out; } } r = kvm_set_irq_routing(kvm, entries, routing.nr, routing.flags); kvfree(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; } case KVM_CHECK_EXTENSION: r = kvm_vm_ioctl_check_extension_generic(kvm, arg); break; case KVM_RESET_DIRTY_RINGS: r = kvm_vm_ioctl_reset_dirty_pages(kvm); break; default: r = kvm_arch_vm_ioctl(filp, ioctl, arg); } out: return r; } #ifdef CONFIG_KVM_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; if (copy_from_user(&compat_log, (void __user *)arg, sizeof(compat_log))) return -EFAULT; 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); } return r; } #endif static struct file_operations kvm_vm_fops = { .release = kvm_vm_release, .unlocked_ioctl = kvm_vm_ioctl, .llseek = noop_llseek, KVM_COMPAT(kvm_vm_compat_ioctl), }; static int kvm_dev_ioctl_create_vm(unsigned long type) { int r; struct kvm *kvm; struct file *file; kvm = kvm_create_vm(type); if (IS_ERR(kvm)) return PTR_ERR(kvm); #ifdef CONFIG_KVM_MMIO r = kvm_coalesced_mmio_init(kvm); if (r < 0) goto put_kvm; #endif r = get_unused_fd_flags(O_CLOEXEC); if (r < 0) goto put_kvm; file = anon_inode_getfile("kvm-vm", &kvm_vm_fops, kvm, O_RDWR); if (IS_ERR(file)) { put_unused_fd(r); r = PTR_ERR(file); goto put_kvm; } /* * Don't call kvm_put_kvm anymore at this point; file->f_op is * already set, with ->release() being kvm_vm_release(). In error * cases it will be called by the final fput(file) and will take * care of doing kvm_put_kvm(kvm). */ if (kvm_create_vm_debugfs(kvm, r) < 0) { put_unused_fd(r); fput(file); return -ENOMEM; } kvm_uevent_notify_change(KVM_EVENT_CREATE_VM, kvm); fd_install(r, file); return r; put_kvm: kvm_put_kvm(kvm); return r; } static long kvm_dev_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg) { long r = -EINVAL; switch (ioctl) { case KVM_GET_API_VERSION: 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: if (arg) goto out; r = PAGE_SIZE; /* struct kvm_run */ #ifdef CONFIG_X86 r += PAGE_SIZE; /* pio data page */ #endif #ifdef CONFIG_KVM_MMIO 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, .llseek = noop_llseek, KVM_COMPAT(kvm_dev_ioctl), }; 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(); if (r) { cpumask_clear_cpu(cpu, cpus_hardware_enabled); atomic_inc(&hardware_enable_failed); pr_info("kvm: enabling virtualization on CPU%d failed\n", cpu); } } static int kvm_starting_cpu(unsigned int cpu) { raw_spin_lock(&kvm_count_lock); if (kvm_usage_count) hardware_enable_nolock(NULL); raw_spin_unlock(&kvm_count_lock); return 0; } 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(); } static int kvm_dying_cpu(unsigned int cpu) { raw_spin_lock(&kvm_count_lock); if (kvm_usage_count) hardware_disable_nolock(NULL); raw_spin_unlock(&kvm_count_lock); return 0; } 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_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. */ pr_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) { gpa_t addr1 = r1->addr; gpa_t addr2 = r2->addr; if (addr1 < addr2) return -1; /* If r2->len == 0, match the exact address. If r2->len != 0, * accept any overlapping write. Any order is acceptable for * overlapping ranges, because kvm_io_bus_get_first_dev ensures * we process all of them. */ if (r2->len) { addr1 += r1->len; addr2 += r2->len; } if (addr1 > addr2) 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_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_vcpu *vcpu, 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(vcpu, 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_vcpu *vcpu, 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(vcpu->kvm->buses[bus_idx], &vcpu->kvm->srcu); if (!bus) return -ENOMEM; r = __kvm_io_bus_write(vcpu, bus, &range, val); return r < 0 ? r : 0; } EXPORT_SYMBOL_GPL(kvm_io_bus_write); /* kvm_io_bus_write_cookie - called under kvm->slots_lock */ int kvm_io_bus_write_cookie(struct kvm_vcpu *vcpu, 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(vcpu->kvm->buses[bus_idx], &vcpu->kvm->srcu); if (!bus) return -ENOMEM; /* 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(vcpu, 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(vcpu, bus, &range, val); } static int __kvm_io_bus_read(struct kvm_vcpu *vcpu, 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(vcpu, bus->range[idx].dev, range->addr, range->len, val)) return idx; idx++; } return -EOPNOTSUPP; } /* kvm_io_bus_read - called under kvm->slots_lock */ int kvm_io_bus_read(struct kvm_vcpu *vcpu, 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(vcpu->kvm->buses[bus_idx], &vcpu->kvm->srcu); if (!bus) return -ENOMEM; r = __kvm_io_bus_read(vcpu, 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) { int i; struct kvm_io_bus *new_bus, *bus; struct kvm_io_range range; bus = kvm_get_bus(kvm, bus_idx); if (!bus) return -ENOMEM; /* exclude ioeventfd which is limited by maximum fd */ if (bus->dev_count - bus->ioeventfd_count > NR_IOBUS_DEVS - 1) return -ENOSPC; new_bus = kmalloc(struct_size(bus, range, bus->dev_count + 1), GFP_KERNEL_ACCOUNT); if (!new_bus) return -ENOMEM; range = (struct kvm_io_range) { .addr = addr, .len = len, .dev = dev, }; for (i = 0; i < bus->dev_count; i++) if (kvm_io_bus_cmp(&bus->range[i], &range) > 0) break; memcpy(new_bus, bus, sizeof(*bus) + i * sizeof(struct kvm_io_range)); new_bus->dev_count++; new_bus->range[i] = range; memcpy(new_bus->range + i + 1, bus->range + i, (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 0; } /* Caller must hold slots_lock. */ void kvm_io_bus_unregister_dev(struct kvm *kvm, enum kvm_bus bus_idx, struct kvm_io_device *dev) { int i, j; struct kvm_io_bus *new_bus, *bus; bus = kvm_get_bus(kvm, bus_idx); if (!bus) return; for (i = 0; i < bus->dev_count; i++) if (bus->range[i].dev == dev) { break; } if (i == bus->dev_count) return; new_bus = kmalloc(struct_size(bus, range, bus->dev_count - 1), GFP_KERNEL_ACCOUNT); if (new_bus) { memcpy(new_bus, bus, struct_size(bus, range, i)); new_bus->dev_count--; memcpy(new_bus->range + i, bus->range + i + 1, flex_array_size(new_bus, range, new_bus->dev_count - i)); } else { pr_err("kvm: failed to shrink bus, removing it completely\n"); for (j = 0; j < bus->dev_count; j++) { if (j == i) continue; kvm_iodevice_destructor(bus->range[j].dev); } } rcu_assign_pointer(kvm->buses[bus_idx], new_bus); synchronize_srcu_expedited(&kvm->srcu); kfree(bus); return; } struct kvm_io_device *kvm_io_bus_get_dev(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr) { struct kvm_io_bus *bus; int dev_idx, srcu_idx; struct kvm_io_device *iodev = NULL; srcu_idx = srcu_read_lock(&kvm->srcu); bus = srcu_dereference(kvm->buses[bus_idx], &kvm->srcu); if (!bus) goto out_unlock; dev_idx = kvm_io_bus_get_first_dev(bus, addr, 1); if (dev_idx < 0) goto out_unlock; iodev = bus->range[dev_idx].dev; out_unlock: srcu_read_unlock(&kvm->srcu, srcu_idx); return iodev; } EXPORT_SYMBOL_GPL(kvm_io_bus_get_dev); static int kvm_debugfs_open(struct inode *inode, struct file *file, int (*get)(void *, u64 *), int (*set)(void *, u64), const char *fmt) { struct kvm_stat_data *stat_data = (struct kvm_stat_data *) inode->i_private; /* The debugfs files are a reference to the kvm struct which * is still valid when kvm_destroy_vm is called. * To avoid the race between open and the removal of the debugfs * directory we test against the users count. */ if (!refcount_inc_not_zero(&stat_data->kvm->users_count)) return -ENOENT; if (simple_attr_open(inode, file, get, KVM_DBGFS_GET_MODE(stat_data->dbgfs_item) & 0222 ? set : NULL, fmt)) { kvm_put_kvm(stat_data->kvm); return -ENOMEM; } return 0; } static int kvm_debugfs_release(struct inode *inode, struct file *file) { struct kvm_stat_data *stat_data = (struct kvm_stat_data *) inode->i_private; simple_attr_release(inode, file); kvm_put_kvm(stat_data->kvm); return 0; } static int kvm_get_stat_per_vm(struct kvm *kvm, size_t offset, u64 *val) { *val = *(ulong *)((void *)kvm + offset); return 0; } static int kvm_clear_stat_per_vm(struct kvm *kvm, size_t offset) { *(ulong *)((void *)kvm + offset) = 0; return 0; } static int kvm_get_stat_per_vcpu(struct kvm *kvm, size_t offset, u64 *val) { int i; struct kvm_vcpu *vcpu; *val = 0; kvm_for_each_vcpu(i, vcpu, kvm) *val += *(u64 *)((void *)vcpu + offset); return 0; } static int kvm_clear_stat_per_vcpu(struct kvm *kvm, size_t offset) { int i; struct kvm_vcpu *vcpu; kvm_for_each_vcpu(i, vcpu, kvm) *(u64 *)((void *)vcpu + offset) = 0; return 0; } static int kvm_stat_data_get(void *data, u64 *val) { int r = -EFAULT; struct kvm_stat_data *stat_data = (struct kvm_stat_data *)data; switch (stat_data->dbgfs_item->kind) { case KVM_STAT_VM: r = kvm_get_stat_per_vm(stat_data->kvm, stat_data->dbgfs_item->offset, val); break; case KVM_STAT_VCPU: r = kvm_get_stat_per_vcpu(stat_data->kvm, stat_data->dbgfs_item->offset, val); break; } return r; } static int kvm_stat_data_clear(void *data, u64 val) { int r = -EFAULT; struct kvm_stat_data *stat_data = (struct kvm_stat_data *)data; if (val) return -EINVAL; switch (stat_data->dbgfs_item->kind) { case KVM_STAT_VM: r = kvm_clear_stat_per_vm(stat_data->kvm, stat_data->dbgfs_item->offset); break; case KVM_STAT_VCPU: r = kvm_clear_stat_per_vcpu(stat_data->kvm, stat_data->dbgfs_item->offset); break; } return r; } static int kvm_stat_data_open(struct inode *inode, struct file *file) { __simple_attr_check_format("%llu\n", 0ull); return kvm_debugfs_open(inode, file, kvm_stat_data_get, kvm_stat_data_clear, "%llu\n"); } static const struct file_operations stat_fops_per_vm = { .owner = THIS_MODULE, .open = kvm_stat_data_open, .release = kvm_debugfs_release, .read = simple_attr_read, .write = simple_attr_write, .llseek = no_llseek, }; static int vm_stat_get(void *_offset, u64 *val) { unsigned offset = (long)_offset; struct kvm *kvm; u64 tmp_val; *val = 0; mutex_lock(&kvm_lock); list_for_each_entry(kvm, &vm_list, vm_list) { kvm_get_stat_per_vm(kvm, offset, &tmp_val); *val += tmp_val; } mutex_unlock(&kvm_lock); return 0; } static int vm_stat_clear(void *_offset, u64 val) { unsigned offset = (long)_offset; struct kvm *kvm; if (val) return -EINVAL; mutex_lock(&kvm_lock); list_for_each_entry(kvm, &vm_list, vm_list) { kvm_clear_stat_per_vm(kvm, offset); } mutex_unlock(&kvm_lock); return 0; } DEFINE_SIMPLE_ATTRIBUTE(vm_stat_fops, vm_stat_get, vm_stat_clear, "%llu\n"); static int vcpu_stat_get(void *_offset, u64 *val) { unsigned offset = (long)_offset; struct kvm *kvm; u64 tmp_val; *val = 0; mutex_lock(&kvm_lock); list_for_each_entry(kvm, &vm_list, vm_list) { kvm_get_stat_per_vcpu(kvm, offset, &tmp_val); *val += tmp_val; } mutex_unlock(&kvm_lock); return 0; } static int vcpu_stat_clear(void *_offset, u64 val) { unsigned offset = (long)_offset; struct kvm *kvm; if (val) return -EINVAL; mutex_lock(&kvm_lock); list_for_each_entry(kvm, &vm_list, vm_list) { kvm_clear_stat_per_vcpu(kvm, offset); } mutex_unlock(&kvm_lock); return 0; } DEFINE_SIMPLE_ATTRIBUTE(vcpu_stat_fops, vcpu_stat_get, vcpu_stat_clear, "%llu\n"); static const struct file_operations *stat_fops[] = { [KVM_STAT_VCPU] = &vcpu_stat_fops, [KVM_STAT_VM] = &vm_stat_fops, }; static void kvm_uevent_notify_change(unsigned int type, struct kvm *kvm) { struct kobj_uevent_env *env; unsigned long long created, active; if (!kvm_dev.this_device || !kvm) return; mutex_lock(&kvm_lock); if (type == KVM_EVENT_CREATE_VM) { kvm_createvm_count++; kvm_active_vms++; } else if (type == KVM_EVENT_DESTROY_VM) { kvm_active_vms--; } created = kvm_createvm_count; active = kvm_active_vms; mutex_unlock(&kvm_lock); env = kzalloc(sizeof(*env), GFP_KERNEL_ACCOUNT); if (!env) return; add_uevent_var(env, "CREATED=%llu", created); add_uevent_var(env, "COUNT=%llu", active); if (type == KVM_EVENT_CREATE_VM) { add_uevent_var(env, "EVENT=create"); kvm->userspace_pid = task_pid_nr(current); } else if (type == KVM_EVENT_DESTROY_VM) { add_uevent_var(env, "EVENT=destroy"); } add_uevent_var(env, "PID=%d", kvm->userspace_pid); if (!IS_ERR_OR_NULL(kvm->debugfs_dentry)) { char *tmp, *p = kmalloc(PATH_MAX, GFP_KERNEL_ACCOUNT); if (p) { tmp = dentry_path_raw(kvm->debugfs_dentry, p, PATH_MAX); if (!IS_ERR(tmp)) add_uevent_var(env, "STATS_PATH=%s", tmp); kfree(p); } } /* no need for checks, since we are adding at most only 5 keys */ env->envp[env->envp_idx++] = NULL; kobject_uevent_env(&kvm_dev.this_device->kobj, KOBJ_CHANGE, env->envp); kfree(env); } static void kvm_init_debug(void) { struct kvm_stats_debugfs_item *p; kvm_debugfs_dir = debugfs_create_dir("kvm", NULL); kvm_debugfs_num_entries = 0; for (p = debugfs_entries; p->name; ++p, kvm_debugfs_num_entries++) { debugfs_create_file(p->name, KVM_DBGFS_GET_MODE(p), kvm_debugfs_dir, (void *)(long)p->offset, stat_fops[p->kind]); } } static int kvm_suspend(void) { if (kvm_usage_count) hardware_disable_nolock(NULL); return 0; } static void kvm_resume(void) { if (kvm_usage_count) { #ifdef CONFIG_LOCKDEP WARN_ON(lockdep_is_held(&kvm_count_lock)); #endif 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); WRITE_ONCE(vcpu->preempted, false); WRITE_ONCE(vcpu->ready, false); __this_cpu_write(kvm_running_vcpu, vcpu); kvm_arch_sched_in(vcpu, cpu); 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) { WRITE_ONCE(vcpu->preempted, true); WRITE_ONCE(vcpu->ready, true); } kvm_arch_vcpu_put(vcpu); __this_cpu_write(kvm_running_vcpu, NULL); } /** * kvm_get_running_vcpu - get the vcpu running on the current CPU. * * We can disable preemption locally around accessing the per-CPU variable, * and use the resolved vcpu pointer after enabling preemption again, * because even if the current thread is migrated to another CPU, reading * the per-CPU value later will give us the same value as we update the * per-CPU variable in the preempt notifier handlers. */ struct kvm_vcpu *kvm_get_running_vcpu(void) { struct kvm_vcpu *vcpu; preempt_disable(); vcpu = __this_cpu_read(kvm_running_vcpu); preempt_enable(); return vcpu; } EXPORT_SYMBOL_GPL(kvm_get_running_vcpu); /** * kvm_get_running_vcpus - get the per-CPU array of currently running vcpus. */ struct kvm_vcpu * __percpu *kvm_get_running_vcpus(void) { return &kvm_running_vcpu; } struct kvm_cpu_compat_check { void *opaque; int *ret; }; static void check_processor_compat(void *data) { struct kvm_cpu_compat_check *c = data; *c->ret = kvm_arch_check_processor_compat(c->opaque); } int kvm_init(void *opaque, unsigned vcpu_size, unsigned vcpu_align, struct module *module) { struct kvm_cpu_compat_check c; 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(opaque); if (r < 0) goto out_free_1; c.ret = &r; c.opaque = opaque; for_each_online_cpu(cpu) { smp_call_function_single(cpu, check_processor_compat, &c, 1); if (r < 0) goto out_free_2; } r = cpuhp_setup_state_nocalls(CPUHP_AP_KVM_STARTING, "kvm/cpu:starting", kvm_starting_cpu, kvm_dying_cpu); 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_usercopy("kvm_vcpu", vcpu_size, vcpu_align, SLAB_ACCOUNT, offsetof(struct kvm_vcpu, arch), sizeof_field(struct kvm_vcpu, arch), 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) { pr_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; kvm_init_debug(); r = kvm_vfio_ops_init(); WARN_ON(r); return 0; out_unreg: kvm_async_pf_deinit(); out_free: kmem_cache_destroy(kvm_vcpu_cache); out_free_3: unregister_reboot_notifier(&kvm_reboot_notifier); cpuhp_remove_state_nocalls(CPUHP_AP_KVM_STARTING); out_free_2: kvm_arch_hardware_unsetup(); out_free_1: 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) { debugfs_remove_recursive(kvm_debugfs_dir); 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); cpuhp_remove_state_nocalls(CPUHP_AP_KVM_STARTING); on_each_cpu(hardware_disable_nolock, NULL, 1); kvm_arch_hardware_unsetup(); kvm_arch_exit(); kvm_irqfd_exit(); free_cpumask_var(cpus_hardware_enabled); kvm_vfio_ops_exit(); } EXPORT_SYMBOL_GPL(kvm_exit); struct kvm_vm_worker_thread_context { struct kvm *kvm; struct task_struct *parent; struct completion init_done; kvm_vm_thread_fn_t thread_fn; uintptr_t data; int err; }; static int kvm_vm_worker_thread(void *context) { /* * The init_context is allocated on the stack of the parent thread, so * we have to locally copy anything that is needed beyond initialization */ struct kvm_vm_worker_thread_context *init_context = context; struct kvm *kvm = init_context->kvm; kvm_vm_thread_fn_t thread_fn = init_context->thread_fn; uintptr_t data = init_context->data; int err; err = kthread_park(current); /* kthread_park(current) is never supposed to return an error */ WARN_ON(err != 0); if (err) goto init_complete; err = cgroup_attach_task_all(init_context->parent, current); if (err) { kvm_err("%s: cgroup_attach_task_all failed with err %d\n", __func__, err); goto init_complete; } set_user_nice(current, task_nice(init_context->parent)); init_complete: init_context->err = err; complete(&init_context->init_done); init_context = NULL; if (err) return err; /* Wait to be woken up by the spawner before proceeding. */ kthread_parkme(); if (!kthread_should_stop()) err = thread_fn(kvm, data); return err; } int kvm_vm_create_worker_thread(struct kvm *kvm, kvm_vm_thread_fn_t thread_fn, uintptr_t data, const char *name, struct task_struct **thread_ptr) { struct kvm_vm_worker_thread_context init_context = {}; struct task_struct *thread; *thread_ptr = NULL; init_context.kvm = kvm; init_context.parent = current; init_context.thread_fn = thread_fn; init_context.data = data; init_completion(&init_context.init_done); thread = kthread_run(kvm_vm_worker_thread, &init_context, "%s-%d", name, task_pid_nr(current)); if (IS_ERR(thread)) return PTR_ERR(thread); /* kthread_run is never supposed to return NULL */ WARN_ON(thread == NULL); wait_for_completion(&init_context.init_done); if (!init_context.err) *thread_ptr = thread; return init_context.err; }