linux/virt/kvm/kvm_main.c
Marcelo Tosatti e5c239cfd5 KVM: Fix kvm_vcpu_block() task state race
There's still a race in kvm_vcpu_block(), if a wake_up_interruptible()
call happens before the task state is set to TASK_INTERRUPTIBLE:

CPU0                            CPU1

kvm_vcpu_block

add_wait_queue

kvm_cpu_has_interrupt = 0
                                set interrupt
                                if (waitqueue_active())
                                        wake_up_interruptible()

kvm_cpu_has_pending_timer
kvm_arch_vcpu_runnable
signal_pending

set_current_state(TASK_INTERRUPTIBLE)
schedule()

Can be fixed by using prepare_to_wait() which sets the task state before
testing for the wait condition.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-05-18 14:37:12 +03:00

1557 lines
32 KiB
C

/*
* 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.
*
* Authors:
* Avi Kivity <avi@qumranet.com>
* Yaniv Kamay <yaniv@qumranet.com>
*
* This work is licensed under the terms of the GNU GPL, version 2. See
* the COPYING file in the top-level directory.
*
*/
#include "iodev.h"
#include <linux/kvm_host.h>
#include <linux/kvm.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/percpu.h>
#include <linux/gfp.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/sysdev.h>
#include <linux/cpu.h>
#include <linux/sched.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 <asm/processor.h>
#include <asm/io.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
MODULE_AUTHOR("Qumranet");
MODULE_LICENSE("GPL");
DEFINE_SPINLOCK(kvm_lock);
LIST_HEAD(vm_list);
static cpumask_t cpus_hardware_enabled;
struct kmem_cache *kvm_vcpu_cache;
EXPORT_SYMBOL_GPL(kvm_vcpu_cache);
static __read_mostly struct preempt_ops kvm_preempt_ops;
struct dentry *kvm_debugfs_dir;
static long kvm_vcpu_ioctl(struct file *file, unsigned int ioctl,
unsigned long arg);
static inline int valid_vcpu(int n)
{
return likely(n >= 0 && n < KVM_MAX_VCPUS);
}
/*
* Switches to specified vcpu, until a matching vcpu_put()
*/
void vcpu_load(struct kvm_vcpu *vcpu)
{
int cpu;
mutex_lock(&vcpu->mutex);
cpu = get_cpu();
preempt_notifier_register(&vcpu->preempt_notifier);
kvm_arch_vcpu_load(vcpu, cpu);
put_cpu();
}
void vcpu_put(struct kvm_vcpu *vcpu)
{
preempt_disable();
kvm_arch_vcpu_put(vcpu);
preempt_notifier_unregister(&vcpu->preempt_notifier);
preempt_enable();
mutex_unlock(&vcpu->mutex);
}
static void ack_flush(void *_completed)
{
}
void kvm_flush_remote_tlbs(struct kvm *kvm)
{
int i, cpu;
cpumask_t cpus;
struct kvm_vcpu *vcpu;
cpus_clear(cpus);
for (i = 0; i < KVM_MAX_VCPUS; ++i) {
vcpu = kvm->vcpus[i];
if (!vcpu)
continue;
if (test_and_set_bit(KVM_REQ_TLB_FLUSH, &vcpu->requests))
continue;
cpu = vcpu->cpu;
if (cpu != -1 && cpu != raw_smp_processor_id())
cpu_set(cpu, cpus);
}
if (cpus_empty(cpus))
return;
++kvm->stat.remote_tlb_flush;
smp_call_function_mask(cpus, ack_flush, NULL, 1);
}
void kvm_reload_remote_mmus(struct kvm *kvm)
{
int i, cpu;
cpumask_t cpus;
struct kvm_vcpu *vcpu;
cpus_clear(cpus);
for (i = 0; i < KVM_MAX_VCPUS; ++i) {
vcpu = kvm->vcpus[i];
if (!vcpu)
continue;
if (test_and_set_bit(KVM_REQ_MMU_RELOAD, &vcpu->requests))
continue;
cpu = vcpu->cpu;
if (cpu != -1 && cpu != raw_smp_processor_id())
cpu_set(cpu, cpus);
}
if (cpus_empty(cpus))
return;
smp_call_function_mask(cpus, ack_flush, NULL, 1);
}
int kvm_vcpu_init(struct kvm_vcpu *vcpu, struct kvm *kvm, unsigned id)
{
struct page *page;
int r;
mutex_init(&vcpu->mutex);
vcpu->cpu = -1;
vcpu->kvm = kvm;
vcpu->vcpu_id = id;
init_waitqueue_head(&vcpu->wq);
page = alloc_page(GFP_KERNEL | __GFP_ZERO);
if (!page) {
r = -ENOMEM;
goto fail;
}
vcpu->run = page_address(page);
r = kvm_arch_vcpu_init(vcpu);
if (r < 0)
goto fail_free_run;
return 0;
fail_free_run:
free_page((unsigned long)vcpu->run);
fail:
return r;
}
EXPORT_SYMBOL_GPL(kvm_vcpu_init);
void kvm_vcpu_uninit(struct kvm_vcpu *vcpu)
{
kvm_arch_vcpu_uninit(vcpu);
free_page((unsigned long)vcpu->run);
}
EXPORT_SYMBOL_GPL(kvm_vcpu_uninit);
static struct kvm *kvm_create_vm(void)
{
struct kvm *kvm = kvm_arch_create_vm();
if (IS_ERR(kvm))
goto out;
kvm->mm = current->mm;
atomic_inc(&kvm->mm->mm_count);
spin_lock_init(&kvm->mmu_lock);
kvm_io_bus_init(&kvm->pio_bus);
mutex_init(&kvm->lock);
kvm_io_bus_init(&kvm->mmio_bus);
init_rwsem(&kvm->slots_lock);
atomic_set(&kvm->users_count, 1);
spin_lock(&kvm_lock);
list_add(&kvm->vm_list, &vm_list);
spin_unlock(&kvm_lock);
out:
return kvm;
}
/*
* Free any memory in @free but not in @dont.
*/
static void kvm_free_physmem_slot(struct kvm_memory_slot *free,
struct kvm_memory_slot *dont)
{
if (!dont || free->rmap != dont->rmap)
vfree(free->rmap);
if (!dont || free->dirty_bitmap != dont->dirty_bitmap)
vfree(free->dirty_bitmap);
if (!dont || free->lpage_info != dont->lpage_info)
vfree(free->lpage_info);
free->npages = 0;
free->dirty_bitmap = NULL;
free->rmap = NULL;
free->lpage_info = NULL;
}
void kvm_free_physmem(struct kvm *kvm)
{
int i;
for (i = 0; i < kvm->nmemslots; ++i)
kvm_free_physmem_slot(&kvm->memslots[i], NULL);
}
static void kvm_destroy_vm(struct kvm *kvm)
{
struct mm_struct *mm = kvm->mm;
spin_lock(&kvm_lock);
list_del(&kvm->vm_list);
spin_unlock(&kvm_lock);
kvm_io_bus_destroy(&kvm->pio_bus);
kvm_io_bus_destroy(&kvm->mmio_bus);
kvm_arch_destroy_vm(kvm);
mmdrop(mm);
}
void kvm_get_kvm(struct kvm *kvm)
{
atomic_inc(&kvm->users_count);
}
EXPORT_SYMBOL_GPL(kvm_get_kvm);
void kvm_put_kvm(struct kvm *kvm)
{
if (atomic_dec_and_test(&kvm->users_count))
kvm_destroy_vm(kvm);
}
EXPORT_SYMBOL_GPL(kvm_put_kvm);
static int kvm_vm_release(struct inode *inode, struct file *filp)
{
struct kvm *kvm = filp->private_data;
kvm_put_kvm(kvm);
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 mmap_sem for write.
*/
int __kvm_set_memory_region(struct kvm *kvm,
struct kvm_userspace_memory_region *mem,
int user_alloc)
{
int r;
gfn_t base_gfn;
unsigned long npages;
unsigned long i;
struct kvm_memory_slot *memslot;
struct kvm_memory_slot old, new;
r = -EINVAL;
/* General sanity checks */
if (mem->memory_size & (PAGE_SIZE - 1))
goto out;
if (mem->guest_phys_addr & (PAGE_SIZE - 1))
goto out;
if (mem->slot >= KVM_MEMORY_SLOTS + KVM_PRIVATE_MEM_SLOTS)
goto out;
if (mem->guest_phys_addr + mem->memory_size < mem->guest_phys_addr)
goto out;
memslot = &kvm->memslots[mem->slot];
base_gfn = mem->guest_phys_addr >> PAGE_SHIFT;
npages = mem->memory_size >> PAGE_SHIFT;
if (!npages)
mem->flags &= ~KVM_MEM_LOG_DIRTY_PAGES;
new = old = *memslot;
new.base_gfn = base_gfn;
new.npages = npages;
new.flags = mem->flags;
/* Disallow changing a memory slot's size. */
r = -EINVAL;
if (npages && old.npages && npages != old.npages)
goto out_free;
/* Check for overlaps */
r = -EEXIST;
for (i = 0; i < KVM_MEMORY_SLOTS; ++i) {
struct kvm_memory_slot *s = &kvm->memslots[i];
if (s == memslot)
continue;
if (!((base_gfn + npages <= s->base_gfn) ||
(base_gfn >= s->base_gfn + s->npages)))
goto out_free;
}
/* Free page dirty bitmap if unneeded */
if (!(new.flags & KVM_MEM_LOG_DIRTY_PAGES))
new.dirty_bitmap = NULL;
r = -ENOMEM;
/* Allocate if a slot is being created */
if (npages && !new.rmap) {
new.rmap = vmalloc(npages * sizeof(struct page *));
if (!new.rmap)
goto out_free;
memset(new.rmap, 0, npages * sizeof(*new.rmap));
new.user_alloc = user_alloc;
new.userspace_addr = mem->userspace_addr;
}
if (npages && !new.lpage_info) {
int largepages = npages / KVM_PAGES_PER_HPAGE;
if (npages % KVM_PAGES_PER_HPAGE)
largepages++;
if (base_gfn % KVM_PAGES_PER_HPAGE)
largepages++;
new.lpage_info = vmalloc(largepages * sizeof(*new.lpage_info));
if (!new.lpage_info)
goto out_free;
memset(new.lpage_info, 0, largepages * sizeof(*new.lpage_info));
if (base_gfn % KVM_PAGES_PER_HPAGE)
new.lpage_info[0].write_count = 1;
if ((base_gfn+npages) % KVM_PAGES_PER_HPAGE)
new.lpage_info[largepages-1].write_count = 1;
}
/* Allocate page dirty bitmap if needed */
if ((new.flags & KVM_MEM_LOG_DIRTY_PAGES) && !new.dirty_bitmap) {
unsigned dirty_bytes = ALIGN(npages, BITS_PER_LONG) / 8;
new.dirty_bitmap = vmalloc(dirty_bytes);
if (!new.dirty_bitmap)
goto out_free;
memset(new.dirty_bitmap, 0, dirty_bytes);
}
if (mem->slot >= kvm->nmemslots)
kvm->nmemslots = mem->slot + 1;
*memslot = new;
r = kvm_arch_set_memory_region(kvm, mem, old, user_alloc);
if (r) {
*memslot = old;
goto out_free;
}
kvm_free_physmem_slot(&old, &new);
return 0;
out_free:
kvm_free_physmem_slot(&new, &old);
out:
return r;
}
EXPORT_SYMBOL_GPL(__kvm_set_memory_region);
int kvm_set_memory_region(struct kvm *kvm,
struct kvm_userspace_memory_region *mem,
int user_alloc)
{
int r;
down_write(&kvm->slots_lock);
r = __kvm_set_memory_region(kvm, mem, user_alloc);
up_write(&kvm->slots_lock);
return r;
}
EXPORT_SYMBOL_GPL(kvm_set_memory_region);
int kvm_vm_ioctl_set_memory_region(struct kvm *kvm,
struct
kvm_userspace_memory_region *mem,
int user_alloc)
{
if (mem->slot >= KVM_MEMORY_SLOTS)
return -EINVAL;
return kvm_set_memory_region(kvm, mem, user_alloc);
}
int kvm_get_dirty_log(struct kvm *kvm,
struct kvm_dirty_log *log, int *is_dirty)
{
struct kvm_memory_slot *memslot;
int r, i;
int n;
unsigned long any = 0;
r = -EINVAL;
if (log->slot >= KVM_MEMORY_SLOTS)
goto out;
memslot = &kvm->memslots[log->slot];
r = -ENOENT;
if (!memslot->dirty_bitmap)
goto out;
n = ALIGN(memslot->npages, BITS_PER_LONG) / 8;
for (i = 0; !any && i < n/sizeof(long); ++i)
any = memslot->dirty_bitmap[i];
r = -EFAULT;
if (copy_to_user(log->dirty_bitmap, memslot->dirty_bitmap, n))
goto out;
if (any)
*is_dirty = 1;
r = 0;
out:
return r;
}
int is_error_page(struct page *page)
{
return page == bad_page;
}
EXPORT_SYMBOL_GPL(is_error_page);
int is_error_pfn(pfn_t pfn)
{
return pfn == bad_pfn;
}
EXPORT_SYMBOL_GPL(is_error_pfn);
static inline unsigned long bad_hva(void)
{
return PAGE_OFFSET;
}
int kvm_is_error_hva(unsigned long addr)
{
return addr == bad_hva();
}
EXPORT_SYMBOL_GPL(kvm_is_error_hva);
static struct kvm_memory_slot *__gfn_to_memslot(struct kvm *kvm, gfn_t gfn)
{
int i;
for (i = 0; i < kvm->nmemslots; ++i) {
struct kvm_memory_slot *memslot = &kvm->memslots[i];
if (gfn >= memslot->base_gfn
&& gfn < memslot->base_gfn + memslot->npages)
return memslot;
}
return NULL;
}
struct kvm_memory_slot *gfn_to_memslot(struct kvm *kvm, gfn_t gfn)
{
gfn = unalias_gfn(kvm, gfn);
return __gfn_to_memslot(kvm, gfn);
}
int kvm_is_visible_gfn(struct kvm *kvm, gfn_t gfn)
{
int i;
gfn = unalias_gfn(kvm, gfn);
for (i = 0; i < KVM_MEMORY_SLOTS; ++i) {
struct kvm_memory_slot *memslot = &kvm->memslots[i];
if (gfn >= memslot->base_gfn
&& gfn < memslot->base_gfn + memslot->npages)
return 1;
}
return 0;
}
EXPORT_SYMBOL_GPL(kvm_is_visible_gfn);
unsigned long gfn_to_hva(struct kvm *kvm, gfn_t gfn)
{
struct kvm_memory_slot *slot;
gfn = unalias_gfn(kvm, gfn);
slot = __gfn_to_memslot(kvm, gfn);
if (!slot)
return bad_hva();
return (slot->userspace_addr + (gfn - slot->base_gfn) * PAGE_SIZE);
}
EXPORT_SYMBOL_GPL(gfn_to_hva);
/*
* Requires current->mm->mmap_sem to be held
*/
pfn_t gfn_to_pfn(struct kvm *kvm, gfn_t gfn)
{
struct page *page[1];
unsigned long addr;
int npages;
might_sleep();
addr = gfn_to_hva(kvm, gfn);
if (kvm_is_error_hva(addr)) {
get_page(bad_page);
return page_to_pfn(bad_page);
}
npages = get_user_pages(current, current->mm, addr, 1, 1, 1, page,
NULL);
if (npages != 1) {
get_page(bad_page);
return page_to_pfn(bad_page);
}
return page_to_pfn(page[0]);
}
EXPORT_SYMBOL_GPL(gfn_to_pfn);
struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn)
{
return pfn_to_page(gfn_to_pfn(kvm, gfn));
}
EXPORT_SYMBOL_GPL(gfn_to_page);
void kvm_release_page_clean(struct page *page)
{
kvm_release_pfn_clean(page_to_pfn(page));
}
EXPORT_SYMBOL_GPL(kvm_release_page_clean);
void kvm_release_pfn_clean(pfn_t pfn)
{
put_page(pfn_to_page(pfn));
}
EXPORT_SYMBOL_GPL(kvm_release_pfn_clean);
void kvm_release_page_dirty(struct page *page)
{
kvm_release_pfn_dirty(page_to_pfn(page));
}
EXPORT_SYMBOL_GPL(kvm_release_page_dirty);
void kvm_release_pfn_dirty(pfn_t pfn)
{
kvm_set_pfn_dirty(pfn);
kvm_release_pfn_clean(pfn);
}
EXPORT_SYMBOL_GPL(kvm_release_pfn_dirty);
void kvm_set_page_dirty(struct page *page)
{
kvm_set_pfn_dirty(page_to_pfn(page));
}
EXPORT_SYMBOL_GPL(kvm_set_page_dirty);
void kvm_set_pfn_dirty(pfn_t pfn)
{
struct page *page = pfn_to_page(pfn);
if (!PageReserved(page))
SetPageDirty(page);
}
EXPORT_SYMBOL_GPL(kvm_set_pfn_dirty);
void kvm_set_pfn_accessed(pfn_t pfn)
{
mark_page_accessed(pfn_to_page(pfn));
}
EXPORT_SYMBOL_GPL(kvm_set_pfn_accessed);
void kvm_get_pfn(pfn_t pfn)
{
get_page(pfn_to_page(pfn));
}
EXPORT_SYMBOL_GPL(kvm_get_pfn);
static int next_segment(unsigned long len, int offset)
{
if (len > PAGE_SIZE - offset)
return PAGE_SIZE - offset;
else
return len;
}
int kvm_read_guest_page(struct kvm *kvm, gfn_t gfn, void *data, int offset,
int len)
{
int r;
unsigned long addr;
addr = gfn_to_hva(kvm, gfn);
if (kvm_is_error_hva(addr))
return -EFAULT;
r = copy_from_user(data, (void __user *)addr + offset, len);
if (r)
return -EFAULT;
return 0;
}
EXPORT_SYMBOL_GPL(kvm_read_guest_page);
int kvm_read_guest(struct kvm *kvm, gpa_t gpa, void *data, unsigned long len)
{
gfn_t gfn = gpa >> PAGE_SHIFT;
int seg;
int offset = offset_in_page(gpa);
int ret;
while ((seg = next_segment(len, offset)) != 0) {
ret = kvm_read_guest_page(kvm, gfn, data, offset, seg);
if (ret < 0)
return ret;
offset = 0;
len -= seg;
data += seg;
++gfn;
}
return 0;
}
EXPORT_SYMBOL_GPL(kvm_read_guest);
int kvm_read_guest_atomic(struct kvm *kvm, gpa_t gpa, void *data,
unsigned long len)
{
int r;
unsigned long addr;
gfn_t gfn = gpa >> PAGE_SHIFT;
int offset = offset_in_page(gpa);
addr = gfn_to_hva(kvm, gfn);
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;
}
EXPORT_SYMBOL(kvm_read_guest_atomic);
int kvm_write_guest_page(struct kvm *kvm, gfn_t gfn, const void *data,
int offset, int len)
{
int r;
unsigned long addr;
addr = gfn_to_hva(kvm, gfn);
if (kvm_is_error_hva(addr))
return -EFAULT;
r = copy_to_user((void __user *)addr + offset, data, len);
if (r)
return -EFAULT;
mark_page_dirty(kvm, gfn);
return 0;
}
EXPORT_SYMBOL_GPL(kvm_write_guest_page);
int kvm_write_guest(struct kvm *kvm, gpa_t gpa, const void *data,
unsigned long len)
{
gfn_t gfn = gpa >> PAGE_SHIFT;
int seg;
int offset = offset_in_page(gpa);
int ret;
while ((seg = next_segment(len, offset)) != 0) {
ret = kvm_write_guest_page(kvm, gfn, data, offset, seg);
if (ret < 0)
return ret;
offset = 0;
len -= seg;
data += seg;
++gfn;
}
return 0;
}
int kvm_clear_guest_page(struct kvm *kvm, gfn_t gfn, int offset, int len)
{
return kvm_write_guest_page(kvm, gfn, empty_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(struct kvm *kvm, gfn_t gfn)
{
struct kvm_memory_slot *memslot;
gfn = unalias_gfn(kvm, gfn);
memslot = __gfn_to_memslot(kvm, gfn);
if (memslot && memslot->dirty_bitmap) {
unsigned long rel_gfn = gfn - memslot->base_gfn;
/* avoid RMW */
if (!test_bit(rel_gfn, memslot->dirty_bitmap))
set_bit(rel_gfn, memslot->dirty_bitmap);
}
}
/*
* The vCPU has executed a HLT instruction with in-kernel mode enabled.
*/
void kvm_vcpu_block(struct kvm_vcpu *vcpu)
{
DEFINE_WAIT(wait);
for (;;) {
prepare_to_wait(&vcpu->wq, &wait, TASK_INTERRUPTIBLE);
if (kvm_cpu_has_interrupt(vcpu))
break;
if (kvm_cpu_has_pending_timer(vcpu))
break;
if (kvm_arch_vcpu_runnable(vcpu))
break;
if (signal_pending(current))
break;
vcpu_put(vcpu);
schedule();
vcpu_load(vcpu);
}
finish_wait(&vcpu->wq, &wait);
}
void kvm_resched(struct kvm_vcpu *vcpu)
{
if (!need_resched())
return;
cond_resched();
}
EXPORT_SYMBOL_GPL(kvm_resched);
static int kvm_vcpu_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
{
struct kvm_vcpu *vcpu = vma->vm_file->private_data;
struct page *page;
if (vmf->pgoff == 0)
page = virt_to_page(vcpu->run);
#ifdef CONFIG_X86
else if (vmf->pgoff == KVM_PIO_PAGE_OFFSET)
page = virt_to_page(vcpu->arch.pio_data);
#endif
else
return VM_FAULT_SIGBUS;
get_page(page);
vmf->page = page;
return 0;
}
static 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 const struct file_operations kvm_vcpu_fops = {
.release = kvm_vcpu_release,
.unlocked_ioctl = kvm_vcpu_ioctl,
.compat_ioctl = kvm_vcpu_ioctl,
.mmap = kvm_vcpu_mmap,
};
/*
* Allocates an inode for the vcpu.
*/
static int create_vcpu_fd(struct kvm_vcpu *vcpu)
{
int fd = anon_inode_getfd("kvm-vcpu", &kvm_vcpu_fops, vcpu);
if (fd < 0)
kvm_put_kvm(vcpu->kvm);
return fd;
}
/*
* Creates some virtual cpus. Good luck creating more than one.
*/
static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, int n)
{
int r;
struct kvm_vcpu *vcpu;
if (!valid_vcpu(n))
return -EINVAL;
vcpu = kvm_arch_vcpu_create(kvm, n);
if (IS_ERR(vcpu))
return PTR_ERR(vcpu);
preempt_notifier_init(&vcpu->preempt_notifier, &kvm_preempt_ops);
r = kvm_arch_vcpu_setup(vcpu);
if (r)
goto vcpu_destroy;
mutex_lock(&kvm->lock);
if (kvm->vcpus[n]) {
r = -EEXIST;
mutex_unlock(&kvm->lock);
goto vcpu_destroy;
}
kvm->vcpus[n] = vcpu;
mutex_unlock(&kvm->lock);
/* Now it's all set up, let userspace reach it */
kvm_get_kvm(kvm);
r = create_vcpu_fd(vcpu);
if (r < 0)
goto unlink;
return r;
unlink:
mutex_lock(&kvm->lock);
kvm->vcpus[n] = NULL;
mutex_unlock(&kvm->lock);
vcpu_destroy:
kvm_arch_vcpu_destroy(vcpu);
return r;
}
static int kvm_vcpu_ioctl_set_sigmask(struct kvm_vcpu *vcpu, sigset_t *sigset)
{
if (sigset) {
sigdelsetmask(sigset, sigmask(SIGKILL)|sigmask(SIGSTOP));
vcpu->sigset_active = 1;
vcpu->sigset = *sigset;
} else
vcpu->sigset_active = 0;
return 0;
}
static long kvm_vcpu_ioctl(struct file *filp,
unsigned int ioctl, unsigned long arg)
{
struct kvm_vcpu *vcpu = filp->private_data;
void __user *argp = (void __user *)arg;
int r;
if (vcpu->kvm->mm != current->mm)
return -EIO;
switch (ioctl) {
case KVM_RUN:
r = -EINVAL;
if (arg)
goto out;
r = kvm_arch_vcpu_ioctl_run(vcpu, vcpu->run);
break;
case KVM_GET_REGS: {
struct kvm_regs *kvm_regs;
r = -ENOMEM;
kvm_regs = kzalloc(sizeof(struct kvm_regs), GFP_KERNEL);
if (!kvm_regs)
goto out;
r = kvm_arch_vcpu_ioctl_get_regs(vcpu, kvm_regs);
if (r)
goto out_free1;
r = -EFAULT;
if (copy_to_user(argp, kvm_regs, sizeof(struct kvm_regs)))
goto out_free1;
r = 0;
out_free1:
kfree(kvm_regs);
break;
}
case KVM_SET_REGS: {
struct kvm_regs *kvm_regs;
r = -ENOMEM;
kvm_regs = kzalloc(sizeof(struct kvm_regs), GFP_KERNEL);
if (!kvm_regs)
goto out;
r = -EFAULT;
if (copy_from_user(kvm_regs, argp, sizeof(struct kvm_regs)))
goto out_free2;
r = kvm_arch_vcpu_ioctl_set_regs(vcpu, kvm_regs);
if (r)
goto out_free2;
r = 0;
out_free2:
kfree(kvm_regs);
break;
}
case KVM_GET_SREGS: {
struct kvm_sregs kvm_sregs;
memset(&kvm_sregs, 0, sizeof kvm_sregs);
r = kvm_arch_vcpu_ioctl_get_sregs(vcpu, &kvm_sregs);
if (r)
goto out;
r = -EFAULT;
if (copy_to_user(argp, &kvm_sregs, sizeof kvm_sregs))
goto out;
r = 0;
break;
}
case KVM_SET_SREGS: {
struct kvm_sregs kvm_sregs;
r = -EFAULT;
if (copy_from_user(&kvm_sregs, argp, sizeof kvm_sregs))
goto out;
r = kvm_arch_vcpu_ioctl_set_sregs(vcpu, &kvm_sregs);
if (r)
goto out;
r = 0;
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);
if (r)
goto out;
r = 0;
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_DEBUG_GUEST: {
struct kvm_debug_guest dbg;
r = -EFAULT;
if (copy_from_user(&dbg, argp, sizeof dbg))
goto out;
r = kvm_arch_vcpu_ioctl_debug_guest(vcpu, &dbg);
if (r)
goto out;
r = 0;
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, &sigset);
break;
}
case KVM_GET_FPU: {
struct kvm_fpu fpu;
memset(&fpu, 0, sizeof fpu);
r = kvm_arch_vcpu_ioctl_get_fpu(vcpu, &fpu);
if (r)
goto out;
r = -EFAULT;
if (copy_to_user(argp, &fpu, sizeof fpu))
goto out;
r = 0;
break;
}
case KVM_SET_FPU: {
struct kvm_fpu fpu;
r = -EFAULT;
if (copy_from_user(&fpu, argp, sizeof fpu))
goto out;
r = kvm_arch_vcpu_ioctl_set_fpu(vcpu, &fpu);
if (r)
goto out;
r = 0;
break;
}
default:
r = kvm_arch_vcpu_ioctl(filp, ioctl, arg);
}
out:
return r;
}
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);
if (r < 0)
goto out;
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, 1);
if (r)
goto out;
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);
if (r)
goto out;
break;
}
default:
r = kvm_arch_vm_ioctl(filp, ioctl, arg);
}
out:
return r;
}
static int kvm_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
{
struct kvm *kvm = vma->vm_file->private_data;
struct page *page;
if (!kvm_is_visible_gfn(kvm, vmf->pgoff))
return VM_FAULT_SIGBUS;
page = gfn_to_page(kvm, vmf->pgoff);
if (is_error_page(page)) {
kvm_release_page_clean(page);
return VM_FAULT_SIGBUS;
}
vmf->page = page;
return 0;
}
static struct vm_operations_struct kvm_vm_vm_ops = {
.fault = kvm_vm_fault,
};
static int kvm_vm_mmap(struct file *file, struct vm_area_struct *vma)
{
vma->vm_ops = &kvm_vm_vm_ops;
return 0;
}
static const struct file_operations kvm_vm_fops = {
.release = kvm_vm_release,
.unlocked_ioctl = kvm_vm_ioctl,
.compat_ioctl = kvm_vm_ioctl,
.mmap = kvm_vm_mmap,
};
static int kvm_dev_ioctl_create_vm(void)
{
int fd;
struct kvm *kvm;
kvm = kvm_create_vm();
if (IS_ERR(kvm))
return PTR_ERR(kvm);
fd = anon_inode_getfd("kvm-vm", &kvm_vm_fops, kvm);
if (fd < 0)
kvm_put_kvm(kvm);
return fd;
}
static long kvm_dev_ioctl(struct file *filp,
unsigned int ioctl, unsigned long arg)
{
void __user *argp = (void __user *)arg;
long r = -EINVAL;
switch (ioctl) {
case KVM_GET_API_VERSION:
r = -EINVAL;
if (arg)
goto out;
r = KVM_API_VERSION;
break;
case KVM_CREATE_VM:
r = -EINVAL;
if (arg)
goto out;
r = kvm_dev_ioctl_create_vm();
break;
case KVM_CHECK_EXTENSION:
r = kvm_dev_ioctl_check_extension((long)argp);
break;
case KVM_GET_VCPU_MMAP_SIZE:
r = -EINVAL;
if (arg)
goto out;
r = PAGE_SIZE; /* struct kvm_run */
#ifdef CONFIG_X86
r += PAGE_SIZE; /* pio data page */
#endif
break;
case KVM_TRACE_ENABLE:
case KVM_TRACE_PAUSE:
case KVM_TRACE_DISABLE:
r = kvm_trace_ioctl(ioctl, arg);
break;
default:
return kvm_arch_dev_ioctl(filp, ioctl, arg);
}
out:
return r;
}
static struct file_operations kvm_chardev_ops = {
.unlocked_ioctl = kvm_dev_ioctl,
.compat_ioctl = kvm_dev_ioctl,
};
static struct miscdevice kvm_dev = {
KVM_MINOR,
"kvm",
&kvm_chardev_ops,
};
static void hardware_enable(void *junk)
{
int cpu = raw_smp_processor_id();
if (cpu_isset(cpu, cpus_hardware_enabled))
return;
cpu_set(cpu, cpus_hardware_enabled);
kvm_arch_hardware_enable(NULL);
}
static void hardware_disable(void *junk)
{
int cpu = raw_smp_processor_id();
if (!cpu_isset(cpu, cpus_hardware_enabled))
return;
cpu_clear(cpu, cpus_hardware_enabled);
decache_vcpus_on_cpu(cpu);
kvm_arch_hardware_disable(NULL);
}
static int kvm_cpu_hotplug(struct notifier_block *notifier, unsigned long val,
void *v)
{
int cpu = (long)v;
val &= ~CPU_TASKS_FROZEN;
switch (val) {
case CPU_DYING:
printk(KERN_INFO "kvm: disabling virtualization on CPU%d\n",
cpu);
hardware_disable(NULL);
break;
case CPU_UP_CANCELED:
printk(KERN_INFO "kvm: disabling virtualization on CPU%d\n",
cpu);
smp_call_function_single(cpu, hardware_disable, NULL, 0, 1);
break;
case CPU_ONLINE:
printk(KERN_INFO "kvm: enabling virtualization on CPU%d\n",
cpu);
smp_call_function_single(cpu, hardware_enable, NULL, 0, 1);
break;
}
return NOTIFY_OK;
}
static int kvm_reboot(struct notifier_block *notifier, unsigned long val,
void *v)
{
if (val == SYS_RESTART) {
/*
* Some (well, at least mine) BIOSes hang on reboot if
* in vmx root mode.
*/
printk(KERN_INFO "kvm: exiting hardware virtualization\n");
on_each_cpu(hardware_disable, NULL, 0, 1);
}
return NOTIFY_OK;
}
static struct notifier_block kvm_reboot_notifier = {
.notifier_call = kvm_reboot,
.priority = 0,
};
void kvm_io_bus_init(struct kvm_io_bus *bus)
{
memset(bus, 0, sizeof(*bus));
}
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->devs[i];
kvm_iodevice_destructor(pos);
}
}
struct kvm_io_device *kvm_io_bus_find_dev(struct kvm_io_bus *bus, gpa_t addr)
{
int i;
for (i = 0; i < bus->dev_count; i++) {
struct kvm_io_device *pos = bus->devs[i];
if (pos->in_range(pos, addr))
return pos;
}
return NULL;
}
void kvm_io_bus_register_dev(struct kvm_io_bus *bus, struct kvm_io_device *dev)
{
BUG_ON(bus->dev_count > (NR_IOBUS_DEVS-1));
bus->devs[bus->dev_count++] = dev;
}
static struct notifier_block kvm_cpu_notifier = {
.notifier_call = kvm_cpu_hotplug,
.priority = 20, /* must be > scheduler priority */
};
static int vm_stat_get(void *_offset, u64 *val)
{
unsigned offset = (long)_offset;
struct kvm *kvm;
*val = 0;
spin_lock(&kvm_lock);
list_for_each_entry(kvm, &vm_list, vm_list)
*val += *(u32 *)((void *)kvm + offset);
spin_unlock(&kvm_lock);
return 0;
}
DEFINE_SIMPLE_ATTRIBUTE(vm_stat_fops, vm_stat_get, NULL, "%llu\n");
static int vcpu_stat_get(void *_offset, u64 *val)
{
unsigned offset = (long)_offset;
struct kvm *kvm;
struct kvm_vcpu *vcpu;
int i;
*val = 0;
spin_lock(&kvm_lock);
list_for_each_entry(kvm, &vm_list, vm_list)
for (i = 0; i < KVM_MAX_VCPUS; ++i) {
vcpu = kvm->vcpus[i];
if (vcpu)
*val += *(u32 *)((void *)vcpu + offset);
}
spin_unlock(&kvm_lock);
return 0;
}
DEFINE_SIMPLE_ATTRIBUTE(vcpu_stat_fops, vcpu_stat_get, NULL, "%llu\n");
static struct file_operations *stat_fops[] = {
[KVM_STAT_VCPU] = &vcpu_stat_fops,
[KVM_STAT_VM] = &vm_stat_fops,
};
static void kvm_init_debug(void)
{
struct kvm_stats_debugfs_item *p;
kvm_debugfs_dir = debugfs_create_dir("kvm", NULL);
for (p = debugfs_entries; p->name; ++p)
p->dentry = debugfs_create_file(p->name, 0444, kvm_debugfs_dir,
(void *)(long)p->offset,
stat_fops[p->kind]);
}
static void kvm_exit_debug(void)
{
struct kvm_stats_debugfs_item *p;
for (p = debugfs_entries; p->name; ++p)
debugfs_remove(p->dentry);
debugfs_remove(kvm_debugfs_dir);
}
static int kvm_suspend(struct sys_device *dev, pm_message_t state)
{
hardware_disable(NULL);
return 0;
}
static int kvm_resume(struct sys_device *dev)
{
hardware_enable(NULL);
return 0;
}
static struct sysdev_class kvm_sysdev_class = {
.name = "kvm",
.suspend = kvm_suspend,
.resume = kvm_resume,
};
static struct sys_device kvm_sysdev = {
.id = 0,
.cls = &kvm_sysdev_class,
};
struct page *bad_page;
pfn_t bad_pfn;
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);
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);
kvm_arch_vcpu_put(vcpu);
}
int kvm_init(void *opaque, unsigned int vcpu_size,
struct module *module)
{
int r;
int cpu;
kvm_init_debug();
r = kvm_arch_init(opaque);
if (r)
goto out_fail;
bad_page = alloc_page(GFP_KERNEL | __GFP_ZERO);
if (bad_page == NULL) {
r = -ENOMEM;
goto out;
}
bad_pfn = page_to_pfn(bad_page);
r = kvm_arch_hardware_setup();
if (r < 0)
goto out_free_0;
for_each_online_cpu(cpu) {
smp_call_function_single(cpu,
kvm_arch_check_processor_compat,
&r, 0, 1);
if (r < 0)
goto out_free_1;
}
on_each_cpu(hardware_enable, NULL, 0, 1);
r = register_cpu_notifier(&kvm_cpu_notifier);
if (r)
goto out_free_2;
register_reboot_notifier(&kvm_reboot_notifier);
r = sysdev_class_register(&kvm_sysdev_class);
if (r)
goto out_free_3;
r = sysdev_register(&kvm_sysdev);
if (r)
goto out_free_4;
/* A kmem cache lets us meet the alignment requirements of fx_save. */
kvm_vcpu_cache = kmem_cache_create("kvm_vcpu", vcpu_size,
__alignof__(struct kvm_vcpu),
0, NULL);
if (!kvm_vcpu_cache) {
r = -ENOMEM;
goto out_free_5;
}
kvm_chardev_ops.owner = module;
r = misc_register(&kvm_dev);
if (r) {
printk(KERN_ERR "kvm: misc device register failed\n");
goto out_free;
}
kvm_preempt_ops.sched_in = kvm_sched_in;
kvm_preempt_ops.sched_out = kvm_sched_out;
return 0;
out_free:
kmem_cache_destroy(kvm_vcpu_cache);
out_free_5:
sysdev_unregister(&kvm_sysdev);
out_free_4:
sysdev_class_unregister(&kvm_sysdev_class);
out_free_3:
unregister_reboot_notifier(&kvm_reboot_notifier);
unregister_cpu_notifier(&kvm_cpu_notifier);
out_free_2:
on_each_cpu(hardware_disable, NULL, 0, 1);
out_free_1:
kvm_arch_hardware_unsetup();
out_free_0:
__free_page(bad_page);
out:
kvm_arch_exit();
kvm_exit_debug();
out_fail:
return r;
}
EXPORT_SYMBOL_GPL(kvm_init);
void kvm_exit(void)
{
kvm_trace_cleanup();
misc_deregister(&kvm_dev);
kmem_cache_destroy(kvm_vcpu_cache);
sysdev_unregister(&kvm_sysdev);
sysdev_class_unregister(&kvm_sysdev_class);
unregister_reboot_notifier(&kvm_reboot_notifier);
unregister_cpu_notifier(&kvm_cpu_notifier);
on_each_cpu(hardware_disable, NULL, 0, 1);
kvm_arch_hardware_unsetup();
kvm_arch_exit();
kvm_exit_debug();
__free_page(bad_page);
}
EXPORT_SYMBOL_GPL(kvm_exit);