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kernel_optimize_test/virt/kvm/kvm_main.c
Nicholas Piggin dd8ed6c9bc KVM: do not allow mapping valid but non-reference-counted pages 
commit f8be156be163a052a067306417cd0ff679068c97 upstream.

It's possible to create a region which maps valid but non-refcounted
pages (e.g., tail pages of non-compound higher order allocations). These
host pages can then be returned by gfn_to_page, gfn_to_pfn, etc., family
of APIs, which take a reference to the page, which takes it from 0 to 1.
When the reference is dropped, this will free the page incorrectly.

Fix this by only taking a reference on valid pages if it was non-zero,
which indicates it is participating in normal refcounting (and can be
released with put_page).

This addresses CVE-2021-22543.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Tested-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-06-30 08:47:25 -04:00

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// 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 <avi@qumranet.com>
* Yaniv Kamay <yaniv@qumranet.com>
*/
#include <kvm/iodev.h>
#include <linux/kvm_host.h>
#include <linux/kvm.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/percpu.h>
#include <linux/mm.h>
#include <linux/miscdevice.h>
#include <linux/vmalloc.h>
#include <linux/reboot.h>
#include <linux/debugfs.h>
#include <linux/highmem.h>
#include <linux/file.h>
#include <linux/syscore_ops.h>
#include <linux/cpu.h>
#include <linux/sched/signal.h>
#include <linux/sched/mm.h>
#include <linux/sched/stat.h>
#include <linux/cpumask.h>
#include <linux/smp.h>
#include <linux/anon_inodes.h>
#include <linux/profile.h>
#include <linux/kvm_para.h>
#include <linux/pagemap.h>
#include <linux/mman.h>
#include <linux/swap.h>
#include <linux/bitops.h>
#include <linux/spinlock.h>
#include <linux/compat.h>
#include <linux/srcu.h>
#include <linux/hugetlb.h>
#include <linux/slab.h>
#include <linux/sort.h>
#include <linux/bsearch.h>
#include <linux/io.h>
#include <linux/lockdep.h>
#include <linux/kthread.h>
#include <asm/processor.h>
#include <asm/ioctl.h>
#include <linux/uaccess.h>
#include "coalesced_mmio.h"
#include "async_pf.h"
#include "vfio.h"
#define CREATE_TRACE_POINTS
#include <trace/events/kvm.h>
/* 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_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);
spin_lock(&kvm->mmu_lock);
kvm->mmu_notifier_seq++;
if (kvm_set_spte_hva(kvm, address, pte))
kvm_flush_remote_tlbs(kvm);
spin_unlock(&kvm->mmu_lock);
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);
spin_lock(&kvm->mmu_lock);
/*
* The count increase must become visible at unlock time as no
* spte can be established without taking the mmu_lock and
* count is also read inside the mmu_lock critical section.
*/
kvm->mmu_notifier_count++;
need_tlb_flush = kvm_unmap_hva_range(kvm, 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);
spin_unlock(&kvm->mmu_lock);
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);
spin_lock(&kvm->mmu_lock);
/*
* This sequence increase will notify the kvm page fault that
* the page that is going to be mapped in the spte could have
* been freed.
*/
kvm->mmu_notifier_seq++;
smp_wmb();
/*
* The above sequence increase must be visible before the
* below count decrease, which is ensured by the smp_wmb above
* in conjunction with the smp_rmb in mmu_notifier_retry().
*/
kvm->mmu_notifier_count--;
spin_unlock(&kvm->mmu_lock);
BUG_ON(kvm->mmu_notifier_count < 0);
}
static int kvm_mmu_notifier_clear_flush_young(struct mmu_notifier *mn,
struct mm_struct *mm,
unsigned long start,
unsigned long end)
{
struct kvm *kvm = mmu_notifier_to_kvm(mn);
int young, idx;
idx = srcu_read_lock(&kvm->srcu);
spin_lock(&kvm->mmu_lock);
young = kvm_age_hva(kvm, start, end);
if (young)
kvm_flush_remote_tlbs(kvm);
spin_unlock(&kvm->mmu_lock);
srcu_read_unlock(&kvm->srcu, idx);
return young;
}
static int kvm_mmu_notifier_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);
spin_lock(&kvm->mmu_lock);
/*
* 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);
spin_unlock(&kvm->mmu_lock);
srcu_read_unlock(&kvm->srcu, idx);
return young;
}
static int kvm_mmu_notifier_test_young(struct mmu_notifier *mn,
struct mm_struct *mm,
unsigned long address)
{
struct kvm *kvm = mmu_notifier_to_kvm(mn);
int young, idx;
idx = srcu_read_lock(&kvm->srcu);
spin_lock(&kvm->mmu_lock);
young = kvm_test_age_hva(kvm, address);
spin_unlock(&kvm->mmu_lock);
srcu_read_unlock(&kvm->srcu, idx);
return young;
}
static void kvm_mmu_notifier_release(struct mmu_notifier *mn,
struct mm_struct *mm)
{
struct kvm *kvm = mmu_notifier_to_kvm(mn);
int idx;
idx = srcu_read_lock(&kvm->srcu);
kvm_arch_flush_shadow_all(kvm);
srcu_read_unlock(&kvm->srcu, idx);
}
static const struct mmu_notifier_ops kvm_mmu_notifier_ops = {
.invalidate_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);
spin_lock_init(&kvm->mmu_lock);
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) {
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;
*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;
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);
spin_lock(&kvm->mmu_lock);
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);
}
spin_unlock(&kvm->mmu_lock);
}
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;
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;
spin_lock(&kvm->mmu_lock);
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);
}
}
spin_unlock(&kvm->mmu_lock);
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 kvm_try_get_pfn(kvm_pfn_t pfn)
{
if (kvm_is_reserved_pfn(pfn))
return 1;
return get_page_unless_zero(pfn_to_page(pfn));
}
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)
{
kvm_pfn_t 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.
*
* Certain IO or PFNMAP mappings can be backed with valid
* struct pages, but be allocated without refcounting e.g.,
* tail pages of non-compound higher order allocations, which
* would then underflow the refcount when the caller does the
* required put_page. Don't allow those pages here.
*/
if (!kvm_try_get_pfn(pfn))
r = -EFAULT;
out:
pte_unmap_unlock(ptep, ptl);
*p_pfn = pfn;
return r;
}
/*
* 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_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(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(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(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_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(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(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(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(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_page(struct kvm *kvm, gfn_t gfn, int offset, int len)
{
const void *zero_page = (const void *) __va(page_to_phys(ZERO_PAGE(0)));
return kvm_write_guest_page(kvm, gfn, zero_page, offset, len);
}
EXPORT_SYMBOL_GPL(kvm_clear_guest_page);
int kvm_clear_guest(struct kvm *kvm, gpa_t gpa, unsigned long len)
{
gfn_t gfn = gpa >> PAGE_SHIFT;
int seg;
int offset = offset_in_page(gpa);
int ret;
while ((seg = next_segment(len, offset)) != 0) {
ret = kvm_clear_guest_page(kvm, gfn, offset, seg);
if (ret < 0)
return ret;
offset = 0;
len -= seg;
++gfn;
}
return 0;
}
EXPORT_SYMBOL_GPL(kvm_clear_guest);
void mark_page_dirty_in_slot(struct kvm_memory_slot *memslot, gfn_t gfn)
{
if (memslot && memslot->dirty_bitmap) {
unsigned long rel_gfn = gfn - memslot->base_gfn;
set_bit_le(rel_gfn, memslot->dirty_bitmap);
}
}
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(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(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, &current->real_blocked);
}
void kvm_sigset_deactivate(struct kvm_vcpu *vcpu)
{
if (!vcpu->sigset_active)
return;
sigprocmask(SIG_SETMASK, &current->real_blocked, NULL);
sigemptyset(&current->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 > vcpu->kvm->max_halt_poll_ns)
val = vcpu->kvm->max_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() && !need_resched() &&
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 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
return kvm_arch_vcpu_fault(vcpu, vmf);
get_page(page);
vmf->page = page;
return 0;
}
static const struct vm_operations_struct kvm_vcpu_vm_ops = {
.fault = kvm_vcpu_fault,
};
static int kvm_vcpu_mmap(struct file *file, struct vm_area_struct *vma)
{
vma->vm_ops = &kvm_vcpu_vm_ops;
return 0;
}
static int kvm_vcpu_release(struct inode *inode, struct file *filp)
{
struct kvm_vcpu *vcpu = filp->private_data;
kvm_put_kvm(vcpu->kvm);
return 0;
}
static struct file_operations kvm_vcpu_fops = {
.release = kvm_vcpu_release,
.unlocked_ioctl = kvm_vcpu_ioctl,
.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 | __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;
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_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;
default:
break;
}
return kvm_vm_ioctl_check_extension(kvm, arg);
}
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;
}
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;
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. */
int 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 0;
for (i = 0; i < bus->dev_count; i++)
if (bus->range[i].dev == dev) {
break;
}
if (i == bus->dev_count)
return 0;
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));
}
rcu_assign_pointer(kvm->buses[bus_idx], new_bus);
synchronize_srcu_expedited(&kvm->srcu);
/* Destroy the old bus _after_ installing the (null) bus. */
if (!new_bus) {
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);
}
}
kfree(bus);
return new_bus ? 0 : -ENOMEM;
}
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;
}
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