KVM: Fix possible circular locking in kvm_vm_ioctl_assign_device()
[safe/jmp/linux-2.6] / virt / kvm / kvm_main.c
index 0ed662d..7db071b 100644 (file)
 #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 <asm/processor.h>
 #include <asm/io.h>
 #include <asm/uaccess.h>
 #include <asm/pgtable.h>
+#include <asm-generic/bitops/le.h>
 
 #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
 #include "coalesced_mmio.h"
 #endif
 
-#ifdef KVM_CAP_DEVICE_ASSIGNMENT
-#include <linux/pci.h>
-#include <linux/interrupt.h>
-#include "irq.h"
-#endif
+#define CREATE_TRACE_POINTS
+#include <trace/events/kvm.h>
 
 MODULE_AUTHOR("Qumranet");
 MODULE_LICENSE("GPL");
 
-static int msi2intx = 1;
-module_param(msi2intx, bool, 0);
+/*
+ * Ordering of locks:
+ *
+ *             kvm->lock --> kvm->slots_lock --> kvm->irq_lock
+ */
 
 DEFINE_SPINLOCK(kvm_lock);
 LIST_HEAD(vm_list);
 
 static cpumask_var_t cpus_hardware_enabled;
+static int kvm_usage_count = 0;
+static atomic_t hardware_enable_failed;
 
 struct kmem_cache *kvm_vcpu_cache;
 EXPORT_SYMBOL_GPL(kvm_vcpu_cache);
@@ -77,461 +83,12 @@ struct dentry *kvm_debugfs_dir;
 
 static long kvm_vcpu_ioctl(struct file *file, unsigned int ioctl,
                           unsigned long arg);
+static int hardware_enable_all(void);
+static void hardware_disable_all(void);
 
 static bool kvm_rebooting;
 
-#ifdef KVM_CAP_DEVICE_ASSIGNMENT
-static struct kvm_assigned_dev_kernel *kvm_find_assigned_dev(struct list_head *head,
-                                                     int assigned_dev_id)
-{
-       struct list_head *ptr;
-       struct kvm_assigned_dev_kernel *match;
-
-       list_for_each(ptr, head) {
-               match = list_entry(ptr, struct kvm_assigned_dev_kernel, list);
-               if (match->assigned_dev_id == assigned_dev_id)
-                       return match;
-       }
-       return NULL;
-}
-
-static void kvm_assigned_dev_interrupt_work_handler(struct work_struct *work)
-{
-       struct kvm_assigned_dev_kernel *assigned_dev;
-
-       assigned_dev = container_of(work, struct kvm_assigned_dev_kernel,
-                                   interrupt_work);
-
-       /* This is taken to safely inject irq inside the guest. When
-        * the interrupt injection (or the ioapic code) uses a
-        * finer-grained lock, update this
-        */
-       mutex_lock(&assigned_dev->kvm->lock);
-       kvm_set_irq(assigned_dev->kvm, assigned_dev->irq_source_id,
-                   assigned_dev->guest_irq, 1);
-
-       if (assigned_dev->irq_requested_type & KVM_ASSIGNED_DEV_GUEST_MSI) {
-               enable_irq(assigned_dev->host_irq);
-               assigned_dev->host_irq_disabled = false;
-       }
-       mutex_unlock(&assigned_dev->kvm->lock);
-}
-
-static irqreturn_t kvm_assigned_dev_intr(int irq, void *dev_id)
-{
-       struct kvm_assigned_dev_kernel *assigned_dev =
-               (struct kvm_assigned_dev_kernel *) dev_id;
-
-       schedule_work(&assigned_dev->interrupt_work);
-
-       disable_irq_nosync(irq);
-       assigned_dev->host_irq_disabled = true;
-
-       return IRQ_HANDLED;
-}
-
-/* Ack the irq line for an assigned device */
-static void kvm_assigned_dev_ack_irq(struct kvm_irq_ack_notifier *kian)
-{
-       struct kvm_assigned_dev_kernel *dev;
-
-       if (kian->gsi == -1)
-               return;
-
-       dev = container_of(kian, struct kvm_assigned_dev_kernel,
-                          ack_notifier);
-
-       kvm_set_irq(dev->kvm, dev->irq_source_id, dev->guest_irq, 0);
-
-       /* The guest irq may be shared so this ack may be
-        * from another device.
-        */
-       if (dev->host_irq_disabled) {
-               enable_irq(dev->host_irq);
-               dev->host_irq_disabled = false;
-       }
-}
-
-/* The function implicit hold kvm->lock mutex due to cancel_work_sync() */
-static void kvm_free_assigned_irq(struct kvm *kvm,
-                                 struct kvm_assigned_dev_kernel *assigned_dev)
-{
-       if (!irqchip_in_kernel(kvm))
-               return;
-
-       kvm_unregister_irq_ack_notifier(&assigned_dev->ack_notifier);
-
-       if (assigned_dev->irq_source_id != -1)
-               kvm_free_irq_source_id(kvm, assigned_dev->irq_source_id);
-       assigned_dev->irq_source_id = -1;
-
-       if (!assigned_dev->irq_requested_type)
-               return;
-
-       /*
-        * In kvm_free_device_irq, cancel_work_sync return true if:
-        * 1. work is scheduled, and then cancelled.
-        * 2. work callback is executed.
-        *
-        * The first one ensured that the irq is disabled and no more events
-        * would happen. But for the second one, the irq may be enabled (e.g.
-        * for MSI). So we disable irq here to prevent further events.
-        *
-        * Notice this maybe result in nested disable if the interrupt type is
-        * INTx, but it's OK for we are going to free it.
-        *
-        * If this function is a part of VM destroy, please ensure that till
-        * now, the kvm state is still legal for probably we also have to wait
-        * interrupt_work done.
-        */
-       disable_irq_nosync(assigned_dev->host_irq);
-       cancel_work_sync(&assigned_dev->interrupt_work);
-
-       free_irq(assigned_dev->host_irq, (void *)assigned_dev);
-
-       if (assigned_dev->irq_requested_type & KVM_ASSIGNED_DEV_HOST_MSI)
-               pci_disable_msi(assigned_dev->dev);
-
-       assigned_dev->irq_requested_type = 0;
-}
-
-
-static void kvm_free_assigned_device(struct kvm *kvm,
-                                    struct kvm_assigned_dev_kernel
-                                    *assigned_dev)
-{
-       kvm_free_assigned_irq(kvm, assigned_dev);
-
-       pci_reset_function(assigned_dev->dev);
-
-       pci_release_regions(assigned_dev->dev);
-       pci_disable_device(assigned_dev->dev);
-       pci_dev_put(assigned_dev->dev);
-
-       list_del(&assigned_dev->list);
-       kfree(assigned_dev);
-}
-
-void kvm_free_all_assigned_devices(struct kvm *kvm)
-{
-       struct list_head *ptr, *ptr2;
-       struct kvm_assigned_dev_kernel *assigned_dev;
-
-       list_for_each_safe(ptr, ptr2, &kvm->arch.assigned_dev_head) {
-               assigned_dev = list_entry(ptr,
-                                         struct kvm_assigned_dev_kernel,
-                                         list);
-
-               kvm_free_assigned_device(kvm, assigned_dev);
-       }
-}
-
-static int assigned_device_update_intx(struct kvm *kvm,
-                       struct kvm_assigned_dev_kernel *adev,
-                       struct kvm_assigned_irq *airq)
-{
-       adev->guest_irq = airq->guest_irq;
-       adev->ack_notifier.gsi = airq->guest_irq;
-
-       if (adev->irq_requested_type & KVM_ASSIGNED_DEV_HOST_INTX)
-               return 0;
-
-       if (irqchip_in_kernel(kvm)) {
-               if (!msi2intx &&
-                   (adev->irq_requested_type & KVM_ASSIGNED_DEV_HOST_MSI)) {
-                       free_irq(adev->host_irq, (void *)adev);
-                       pci_disable_msi(adev->dev);
-               }
-
-               if (!capable(CAP_SYS_RAWIO))
-                       return -EPERM;
-
-               if (airq->host_irq)
-                       adev->host_irq = airq->host_irq;
-               else
-                       adev->host_irq = adev->dev->irq;
-
-               /* Even though this is PCI, we don't want to use shared
-                * interrupts. Sharing host devices with guest-assigned devices
-                * on the same interrupt line is not a happy situation: there
-                * are going to be long delays in accepting, acking, etc.
-                */
-               if (request_irq(adev->host_irq, kvm_assigned_dev_intr,
-                               0, "kvm_assigned_intx_device", (void *)adev))
-                       return -EIO;
-       }
-
-       adev->irq_requested_type = KVM_ASSIGNED_DEV_GUEST_INTX |
-                                  KVM_ASSIGNED_DEV_HOST_INTX;
-       return 0;
-}
-
-#ifdef CONFIG_X86
-static int assigned_device_update_msi(struct kvm *kvm,
-                       struct kvm_assigned_dev_kernel *adev,
-                       struct kvm_assigned_irq *airq)
-{
-       int r;
-
-       adev->guest_irq = airq->guest_irq;
-       if (airq->flags & KVM_DEV_IRQ_ASSIGN_ENABLE_MSI) {
-               /* x86 don't care upper address of guest msi message addr */
-               adev->irq_requested_type |= KVM_ASSIGNED_DEV_GUEST_MSI;
-               adev->irq_requested_type &= ~KVM_ASSIGNED_DEV_GUEST_INTX;
-               adev->ack_notifier.gsi = -1;
-       } else if (msi2intx) {
-               adev->irq_requested_type |= KVM_ASSIGNED_DEV_GUEST_INTX;
-               adev->irq_requested_type &= ~KVM_ASSIGNED_DEV_GUEST_MSI;
-               adev->ack_notifier.gsi = airq->guest_irq;
-       } else {
-               /*
-                * Guest require to disable device MSI, we disable MSI and
-                * re-enable INTx by default again. Notice it's only for
-                * non-msi2intx.
-                */
-               assigned_device_update_intx(kvm, adev, airq);
-               return 0;
-       }
-
-       if (adev->irq_requested_type & KVM_ASSIGNED_DEV_HOST_MSI)
-               return 0;
-
-       if (irqchip_in_kernel(kvm)) {
-               if (!msi2intx) {
-                       if (adev->irq_requested_type &
-                                       KVM_ASSIGNED_DEV_HOST_INTX)
-                               free_irq(adev->host_irq, (void *)adev);
-
-                       r = pci_enable_msi(adev->dev);
-                       if (r)
-                               return r;
-               }
-
-               adev->host_irq = adev->dev->irq;
-               if (request_irq(adev->host_irq, kvm_assigned_dev_intr, 0,
-                               "kvm_assigned_msi_device", (void *)adev))
-                       return -EIO;
-       }
-
-       if (!msi2intx)
-               adev->irq_requested_type = KVM_ASSIGNED_DEV_GUEST_MSI;
-
-       adev->irq_requested_type |= KVM_ASSIGNED_DEV_HOST_MSI;
-       return 0;
-}
-#endif
-
-static int kvm_vm_ioctl_assign_irq(struct kvm *kvm,
-                                  struct kvm_assigned_irq
-                                  *assigned_irq)
-{
-       int r = 0;
-       struct kvm_assigned_dev_kernel *match;
-       u32 current_flags = 0, changed_flags;
-
-       mutex_lock(&kvm->lock);
-
-       match = kvm_find_assigned_dev(&kvm->arch.assigned_dev_head,
-                                     assigned_irq->assigned_dev_id);
-       if (!match) {
-               mutex_unlock(&kvm->lock);
-               return -EINVAL;
-       }
-
-       if (!match->irq_requested_type) {
-               INIT_WORK(&match->interrupt_work,
-                               kvm_assigned_dev_interrupt_work_handler);
-               if (irqchip_in_kernel(kvm)) {
-                       /* Register ack nofitier */
-                       match->ack_notifier.gsi = -1;
-                       match->ack_notifier.irq_acked =
-                                       kvm_assigned_dev_ack_irq;
-                       kvm_register_irq_ack_notifier(kvm,
-                                       &match->ack_notifier);
-
-                       /* Request IRQ source ID */
-                       r = kvm_request_irq_source_id(kvm);
-                       if (r < 0)
-                               goto out_release;
-                       else
-                               match->irq_source_id = r;
-
-#ifdef CONFIG_X86
-                       /* Determine host device irq type, we can know the
-                        * result from dev->msi_enabled */
-                       if (msi2intx)
-                               pci_enable_msi(match->dev);
-#endif
-               }
-       }
-
-       if ((match->irq_requested_type & KVM_ASSIGNED_DEV_HOST_MSI) &&
-                (match->irq_requested_type & KVM_ASSIGNED_DEV_GUEST_MSI))
-               current_flags |= KVM_DEV_IRQ_ASSIGN_ENABLE_MSI;
-
-       changed_flags = assigned_irq->flags ^ current_flags;
-
-       if ((changed_flags & KVM_DEV_IRQ_ASSIGN_MSI_ACTION) ||
-           (msi2intx && match->dev->msi_enabled)) {
-#ifdef CONFIG_X86
-               r = assigned_device_update_msi(kvm, match, assigned_irq);
-               if (r) {
-                       printk(KERN_WARNING "kvm: failed to enable "
-                                       "MSI device!\n");
-                       goto out_release;
-               }
-#else
-               r = -ENOTTY;
-#endif
-       } else if (assigned_irq->host_irq == 0 && match->dev->irq == 0) {
-               /* Host device IRQ 0 means don't support INTx */
-               if (!msi2intx) {
-                       printk(KERN_WARNING
-                              "kvm: wait device to enable MSI!\n");
-                       r = 0;
-               } else {
-                       printk(KERN_WARNING
-                              "kvm: failed to enable MSI device!\n");
-                       r = -ENOTTY;
-                       goto out_release;
-               }
-       } else {
-               /* Non-sharing INTx mode */
-               r = assigned_device_update_intx(kvm, match, assigned_irq);
-               if (r) {
-                       printk(KERN_WARNING "kvm: failed to enable "
-                                       "INTx device!\n");
-                       goto out_release;
-               }
-       }
-
-       mutex_unlock(&kvm->lock);
-       return r;
-out_release:
-       mutex_unlock(&kvm->lock);
-       kvm_free_assigned_device(kvm, match);
-       return r;
-}
-
-static int kvm_vm_ioctl_assign_device(struct kvm *kvm,
-                                     struct kvm_assigned_pci_dev *assigned_dev)
-{
-       int r = 0;
-       struct kvm_assigned_dev_kernel *match;
-       struct pci_dev *dev;
-
-       down_read(&kvm->slots_lock);
-       mutex_lock(&kvm->lock);
-
-       match = kvm_find_assigned_dev(&kvm->arch.assigned_dev_head,
-                                     assigned_dev->assigned_dev_id);
-       if (match) {
-               /* device already assigned */
-               r = -EINVAL;
-               goto out;
-       }
-
-       match = kzalloc(sizeof(struct kvm_assigned_dev_kernel), GFP_KERNEL);
-       if (match == NULL) {
-               printk(KERN_INFO "%s: Couldn't allocate memory\n",
-                      __func__);
-               r = -ENOMEM;
-               goto out;
-       }
-       dev = pci_get_bus_and_slot(assigned_dev->busnr,
-                                  assigned_dev->devfn);
-       if (!dev) {
-               printk(KERN_INFO "%s: host device not found\n", __func__);
-               r = -EINVAL;
-               goto out_free;
-       }
-       if (pci_enable_device(dev)) {
-               printk(KERN_INFO "%s: Could not enable PCI device\n", __func__);
-               r = -EBUSY;
-               goto out_put;
-       }
-       r = pci_request_regions(dev, "kvm_assigned_device");
-       if (r) {
-               printk(KERN_INFO "%s: Could not get access to device regions\n",
-                      __func__);
-               goto out_disable;
-       }
-
-       pci_reset_function(dev);
-
-       match->assigned_dev_id = assigned_dev->assigned_dev_id;
-       match->host_busnr = assigned_dev->busnr;
-       match->host_devfn = assigned_dev->devfn;
-       match->flags = assigned_dev->flags;
-       match->dev = dev;
-       match->irq_source_id = -1;
-       match->kvm = kvm;
-
-       list_add(&match->list, &kvm->arch.assigned_dev_head);
-
-       if (assigned_dev->flags & KVM_DEV_ASSIGN_ENABLE_IOMMU) {
-               if (!kvm->arch.iommu_domain) {
-                       r = kvm_iommu_map_guest(kvm);
-                       if (r)
-                               goto out_list_del;
-               }
-               r = kvm_assign_device(kvm, match);
-               if (r)
-                       goto out_list_del;
-       }
-
-out:
-       mutex_unlock(&kvm->lock);
-       up_read(&kvm->slots_lock);
-       return r;
-out_list_del:
-       list_del(&match->list);
-       pci_release_regions(dev);
-out_disable:
-       pci_disable_device(dev);
-out_put:
-       pci_dev_put(dev);
-out_free:
-       kfree(match);
-       mutex_unlock(&kvm->lock);
-       up_read(&kvm->slots_lock);
-       return r;
-}
-#endif
-
-#ifdef KVM_CAP_DEVICE_DEASSIGNMENT
-static int kvm_vm_ioctl_deassign_device(struct kvm *kvm,
-               struct kvm_assigned_pci_dev *assigned_dev)
-{
-       int r = 0;
-       struct kvm_assigned_dev_kernel *match;
-
-       mutex_lock(&kvm->lock);
-
-       match = kvm_find_assigned_dev(&kvm->arch.assigned_dev_head,
-                                     assigned_dev->assigned_dev_id);
-       if (!match) {
-               printk(KERN_INFO "%s: device hasn't been assigned before, "
-                 "so cannot be deassigned\n", __func__);
-               r = -EINVAL;
-               goto out;
-       }
-
-       if (assigned_dev->flags & KVM_DEV_ASSIGN_ENABLE_IOMMU)
-               kvm_deassign_device(kvm, match);
-
-       kvm_free_assigned_device(kvm, match);
-
-out:
-       mutex_unlock(&kvm->lock);
-       return r;
-}
-#endif
-
-static inline int valid_vcpu(int n)
-{
-       return likely(n >= 0 && n < KVM_MAX_VCPUS);
-}
+static bool largepages_enabled = true;
 
 inline int kvm_is_mmio_pfn(pfn_t pfn)
 {
@@ -577,14 +134,11 @@ static bool make_all_cpus_request(struct kvm *kvm, unsigned int req)
        bool called = true;
        struct kvm_vcpu *vcpu;
 
-       if (alloc_cpumask_var(&cpus, GFP_ATOMIC))
-               cpumask_clear(cpus);
+       zalloc_cpumask_var(&cpus, GFP_ATOMIC);
 
-       me = get_cpu();
-       for (i = 0; i < KVM_MAX_VCPUS; ++i) {
-               vcpu = kvm->vcpus[i];
-               if (!vcpu)
-                       continue;
+       spin_lock(&kvm->requests_lock);
+       me = smp_processor_id();
+       kvm_for_each_vcpu(i, vcpu, kvm) {
                if (test_and_set_bit(req, &vcpu->requests))
                        continue;
                cpu = vcpu->cpu;
@@ -597,7 +151,7 @@ static bool make_all_cpus_request(struct kvm *kvm, unsigned int req)
                smp_call_function_many(cpus, ack_flush, NULL, 1);
        else
                called = false;
-       put_cpu();
+       spin_unlock(&kvm->requests_lock);
        free_cpumask_var(cpus);
        return called;
 }
@@ -692,6 +246,19 @@ static void kvm_mmu_notifier_invalidate_page(struct mmu_notifier *mn,
 
 }
 
+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);
+
+       spin_lock(&kvm->mmu_lock);
+       kvm->mmu_notifier_seq++;
+       kvm_set_spte_hva(kvm, address, pte);
+       spin_unlock(&kvm->mmu_lock);
+}
+
 static void kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn,
                                                    struct mm_struct *mm,
                                                    unsigned long start,
@@ -771,12 +338,14 @@ static const struct mmu_notifier_ops kvm_mmu_notifier_ops = {
        .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,
+       .change_pte             = kvm_mmu_notifier_change_pte,
        .release                = kvm_mmu_notifier_release,
 };
 #endif /* CONFIG_MMU_NOTIFIER && KVM_ARCH_WANT_MMU_NOTIFIER */
 
 static struct kvm *kvm_create_vm(void)
 {
+       int r = 0;
        struct kvm *kvm = kvm_arch_create_vm();
 #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
        struct page *page;
@@ -784,16 +353,21 @@ static struct kvm *kvm_create_vm(void)
 
        if (IS_ERR(kvm))
                goto out;
+
+       r = hardware_enable_all();
+       if (r)
+               goto out_err_nodisable;
+
 #ifdef CONFIG_HAVE_KVM_IRQCHIP
-       INIT_LIST_HEAD(&kvm->irq_routing);
        INIT_HLIST_HEAD(&kvm->mask_notifier_list);
+       INIT_HLIST_HEAD(&kvm->irq_ack_notifier_list);
 #endif
 
 #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
        page = alloc_page(GFP_KERNEL | __GFP_ZERO);
        if (!page) {
-               kfree(kvm);
-               return ERR_PTR(-ENOMEM);
+               r = -ENOMEM;
+               goto out_err;
        }
        kvm->coalesced_mmio_ring =
                        (struct kvm_coalesced_mmio_ring *)page_address(page);
@@ -801,15 +375,13 @@ static struct kvm *kvm_create_vm(void)
 
 #if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER)
        {
-               int err;
                kvm->mmu_notifier.ops = &kvm_mmu_notifier_ops;
-               err = mmu_notifier_register(&kvm->mmu_notifier, current->mm);
-               if (err) {
+               r = mmu_notifier_register(&kvm->mmu_notifier, current->mm);
+               if (r) {
 #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
                        put_page(page);
 #endif
-                       kfree(kvm);
-                       return ERR_PTR(err);
+                       goto out_err;
                }
        }
 #endif
@@ -817,8 +389,11 @@ static struct kvm *kvm_create_vm(void)
        kvm->mm = current->mm;
        atomic_inc(&kvm->mm->mm_count);
        spin_lock_init(&kvm->mmu_lock);
+       spin_lock_init(&kvm->requests_lock);
        kvm_io_bus_init(&kvm->pio_bus);
+       kvm_eventfd_init(kvm);
        mutex_init(&kvm->lock);
+       mutex_init(&kvm->irq_lock);
        kvm_io_bus_init(&kvm->mmio_bus);
        init_rwsem(&kvm->slots_lock);
        atomic_set(&kvm->users_count, 1);
@@ -830,6 +405,12 @@ static struct kvm *kvm_create_vm(void)
 #endif
 out:
        return kvm;
+
+out_err:
+       hardware_disable_all();
+out_err_nodisable:
+       kfree(kvm);
+       return ERR_PTR(r);
 }
 
 /*
@@ -838,19 +419,25 @@ out:
 static void kvm_free_physmem_slot(struct kvm_memory_slot *free,
                                  struct kvm_memory_slot *dont)
 {
+       int i;
+
        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);
+
+       for (i = 0; i < KVM_NR_PAGE_SIZES - 1; ++i) {
+               if (!dont || free->lpage_info[i] != dont->lpage_info[i]) {
+                       vfree(free->lpage_info[i]);
+                       free->lpage_info[i] = NULL;
+               }
+       }
 
        free->npages = 0;
        free->dirty_bitmap = NULL;
        free->rmap = NULL;
-       free->lpage_info = NULL;
 }
 
 void kvm_free_physmem(struct kvm *kvm)
@@ -878,8 +465,11 @@ static void kvm_destroy_vm(struct kvm *kvm)
 #endif
 #if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER)
        mmu_notifier_unregister(&kvm->mmu_notifier, kvm->mm);
+#else
+       kvm_arch_flush_shadow(kvm);
 #endif
        kvm_arch_destroy_vm(kvm);
+       hardware_disable_all();
        mmdrop(mm);
 }
 
@@ -901,6 +491,8 @@ 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;
 }
@@ -960,7 +552,7 @@ int __kvm_set_memory_region(struct kvm *kvm,
        for (i = 0; i < KVM_MEMORY_SLOTS; ++i) {
                struct kvm_memory_slot *s = &kvm->memslots[i];
 
-               if (s == memslot)
+               if (s == memslot || !s->npages)
                        continue;
                if (!((base_gfn + npages <= s->base_gfn) ||
                      (base_gfn >= s->base_gfn + s->npages)))
@@ -994,26 +586,51 @@ int __kvm_set_memory_region(struct kvm *kvm,
                else
                        new.userspace_addr = 0;
        }
-       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++;
+       if (!npages)
+               goto skip_lpage;
 
-               new.lpage_info = vmalloc(largepages * sizeof(*new.lpage_info));
+       for (i = 0; i < KVM_NR_PAGE_SIZES - 1; ++i) {
+               unsigned long ugfn;
+               unsigned long j;
+               int lpages;
+               int level = i + 2;
+
+               /* Avoid unused variable warning if no large pages */
+               (void)level;
+
+               if (new.lpage_info[i])
+                       continue;
 
-               if (!new.lpage_info)
+               lpages = 1 + (base_gfn + npages - 1) /
+                            KVM_PAGES_PER_HPAGE(level);
+               lpages -= base_gfn / KVM_PAGES_PER_HPAGE(level);
+
+               new.lpage_info[i] = vmalloc(lpages * sizeof(*new.lpage_info[i]));
+
+               if (!new.lpage_info[i])
                        goto out_free;
 
-               memset(new.lpage_info, 0, largepages * sizeof(*new.lpage_info));
+               memset(new.lpage_info[i], 0,
+                      lpages * sizeof(*new.lpage_info[i]));
 
-               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;
+               if (base_gfn % KVM_PAGES_PER_HPAGE(level))
+                       new.lpage_info[i][0].write_count = 1;
+               if ((base_gfn+npages) % KVM_PAGES_PER_HPAGE(level))
+                       new.lpage_info[i][lpages - 1].write_count = 1;
+               ugfn = new.userspace_addr >> PAGE_SHIFT;
+               /*
+                * If the gfn and userspace address are not aligned wrt each
+                * other, or if explicitly asked to, disable large page
+                * support for this slot
+                */
+               if ((base_gfn ^ ugfn) & (KVM_PAGES_PER_HPAGE(level) - 1) ||
+                   !largepages_enabled)
+                       for (j = 0; j < lpages; ++j)
+                               new.lpage_info[i][j].write_count = 1;
        }
 
+skip_lpage:
+
        /* 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;
@@ -1022,7 +639,13 @@ int __kvm_set_memory_region(struct kvm *kvm,
                if (!new.dirty_bitmap)
                        goto out_free;
                memset(new.dirty_bitmap, 0, dirty_bytes);
+               if (old.npages)
+                       kvm_arch_flush_shadow(kvm);
        }
+#else  /* not defined CONFIG_S390 */
+       new.user_alloc = user_alloc;
+       if (user_alloc)
+               new.userspace_addr = mem->userspace_addr;
 #endif /* not defined CONFIG_S390 */
 
        if (!npages)
@@ -1045,8 +668,10 @@ int __kvm_set_memory_region(struct kvm *kvm,
 
        kvm_free_physmem_slot(&old, npages ? &new : NULL);
        /* Slot deletion case: we have to update the current slot */
+       spin_lock(&kvm->mmu_lock);
        if (!npages)
                *memslot = old;
+       spin_unlock(&kvm->mmu_lock);
 #ifdef CONFIG_DMAR
        /* map the pages in iommu page table */
        r = kvm_iommu_map_pages(kvm, base_gfn, npages);
@@ -1120,6 +745,12 @@ out:
        return r;
 }
 
+void kvm_disable_largepages(void)
+{
+       largepages_enabled = false;
+}
+EXPORT_SYMBOL_GPL(kvm_disable_largepages);
+
 int is_error_page(struct page *page)
 {
        return page == bad_page;
@@ -1441,8 +1072,8 @@ void mark_page_dirty(struct kvm *kvm, gfn_t gfn)
                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);
+               if (!generic_test_le_bit(rel_gfn, memslot->dirty_bitmap))
+                       generic___set_le_bit(rel_gfn, memslot->dirty_bitmap);
        }
 }
 
@@ -1456,18 +1087,16 @@ void kvm_vcpu_block(struct kvm_vcpu *vcpu)
        for (;;) {
                prepare_to_wait(&vcpu->wq, &wait, TASK_INTERRUPTIBLE);
 
-               if (kvm_cpu_has_interrupt(vcpu) ||
-                   kvm_cpu_has_pending_timer(vcpu) ||
-                   kvm_arch_vcpu_runnable(vcpu)) {
+               if (kvm_arch_vcpu_runnable(vcpu)) {
                        set_bit(KVM_REQ_UNHALT, &vcpu->requests);
                        break;
                }
+               if (kvm_cpu_has_pending_timer(vcpu))
+                       break;
                if (signal_pending(current))
                        break;
 
-               vcpu_put(vcpu);
                schedule();
-               vcpu_load(vcpu);
        }
 
        finish_wait(&vcpu->wq, &wait);
@@ -1481,6 +1110,21 @@ void kvm_resched(struct kvm_vcpu *vcpu)
 }
 EXPORT_SYMBOL_GPL(kvm_resched);
 
+void kvm_vcpu_on_spin(struct kvm_vcpu *vcpu)
+{
+       ktime_t expires;
+       DEFINE_WAIT(wait);
+
+       prepare_to_wait(&vcpu->wq, &wait, TASK_INTERRUPTIBLE);
+
+       /* Sleep for 100 us, and hope lock-holder got scheduled */
+       expires = ktime_add_ns(ktime_get(), 100000UL);
+       schedule_hrtimeout(&expires, HRTIMER_MODE_ABS);
+
+       finish_wait(&vcpu->wq, &wait);
+}
+EXPORT_SYMBOL_GPL(kvm_vcpu_on_spin);
+
 static int kvm_vcpu_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 {
        struct kvm_vcpu *vcpu = vma->vm_file->private_data;
@@ -1503,7 +1147,7 @@ static int kvm_vcpu_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
        return 0;
 }
 
-static struct vm_operations_struct kvm_vcpu_vm_ops = {
+static const struct vm_operations_struct kvm_vcpu_vm_ops = {
        .fault = kvm_vcpu_fault,
 };
 
@@ -1533,24 +1177,18 @@ static struct file_operations kvm_vcpu_fops = {
  */
 static int create_vcpu_fd(struct kvm_vcpu *vcpu)
 {
-       int fd = anon_inode_getfd("kvm-vcpu", &kvm_vcpu_fops, vcpu, 0);
-       if (fd < 0)
-               kvm_put_kvm(vcpu->kvm);
-       return fd;
+       return anon_inode_getfd("kvm-vcpu", &kvm_vcpu_fops, vcpu, O_RDWR);
 }
 
 /*
  * Creates some virtual cpus.  Good luck creating more than one.
  */
-static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, int n)
+static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, u32 id)
 {
        int r;
-       struct kvm_vcpu *vcpu;
-
-       if (!valid_vcpu(n))
-               return -EINVAL;
+       struct kvm_vcpu *vcpu, *v;
 
-       vcpu = kvm_arch_vcpu_create(kvm, n);
+       vcpu = kvm_arch_vcpu_create(kvm, id);
        if (IS_ERR(vcpu))
                return PTR_ERR(vcpu);
 
@@ -1561,23 +1199,38 @@ static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, int n)
                return r;
 
        mutex_lock(&kvm->lock);
-       if (kvm->vcpus[n]) {
-               r = -EEXIST;
+       if (atomic_read(&kvm->online_vcpus) == KVM_MAX_VCPUS) {
+               r = -EINVAL;
                goto vcpu_destroy;
        }
-       kvm->vcpus[n] = vcpu;
-       mutex_unlock(&kvm->lock);
+
+       kvm_for_each_vcpu(r, v, kvm)
+               if (v->vcpu_id == id) {
+                       r = -EEXIST;
+                       goto vcpu_destroy;
+               }
+
+       BUG_ON(kvm->vcpus[atomic_read(&kvm->online_vcpus)]);
 
        /* Now it's all set up, let userspace reach it */
        kvm_get_kvm(kvm);
        r = create_vcpu_fd(vcpu);
-       if (r < 0)
-               goto unlink;
+       if (r < 0) {
+               kvm_put_kvm(kvm);
+               goto vcpu_destroy;
+       }
+
+       kvm->vcpus[atomic_read(&kvm->online_vcpus)] = vcpu;
+       smp_wmb();
+       atomic_inc(&kvm->online_vcpus);
+
+#ifdef CONFIG_KVM_APIC_ARCHITECTURE
+       if (kvm->bsp_vcpu_id == id)
+               kvm->bsp_vcpu = vcpu;
+#endif
+       mutex_unlock(&kvm->lock);
        return r;
 
-unlink:
-       mutex_lock(&kvm->lock);
-       kvm->vcpus[n] = NULL;
 vcpu_destroy:
        mutex_unlock(&kvm->lock);
        kvm_arch_vcpu_destroy(vcpu);
@@ -1853,79 +1506,89 @@ static long kvm_vm_ioctl(struct file *filp,
                break;
        }
 #endif
-#ifdef KVM_CAP_DEVICE_ASSIGNMENT
-       case KVM_ASSIGN_PCI_DEVICE: {
-               struct kvm_assigned_pci_dev assigned_dev;
+       case KVM_IRQFD: {
+               struct kvm_irqfd data;
 
                r = -EFAULT;
-               if (copy_from_user(&assigned_dev, argp, sizeof assigned_dev))
-                       goto out;
-               r = kvm_vm_ioctl_assign_device(kvm, &assigned_dev);
-               if (r)
+               if (copy_from_user(&data, argp, sizeof data))
                        goto out;
+               r = kvm_irqfd(kvm, data.fd, data.gsi, data.flags);
                break;
        }
-       case KVM_ASSIGN_IRQ: {
-               struct kvm_assigned_irq assigned_irq;
+       case KVM_IOEVENTFD: {
+               struct kvm_ioeventfd data;
 
                r = -EFAULT;
-               if (copy_from_user(&assigned_irq, argp, sizeof assigned_irq))
-                       goto out;
-               r = kvm_vm_ioctl_assign_irq(kvm, &assigned_irq);
-               if (r)
+               if (copy_from_user(&data, argp, sizeof data))
                        goto out;
+               r = kvm_ioeventfd(kvm, &data);
                break;
        }
-#endif
-#ifdef KVM_CAP_DEVICE_DEASSIGNMENT
-       case KVM_DEASSIGN_PCI_DEVICE: {
-               struct kvm_assigned_pci_dev assigned_dev;
-
-               r = -EFAULT;
-               if (copy_from_user(&assigned_dev, argp, sizeof assigned_dev))
-                       goto out;
-               r = kvm_vm_ioctl_deassign_device(kvm, &assigned_dev);
-               if (r)
-                       goto out;
+#ifdef CONFIG_KVM_APIC_ARCHITECTURE
+       case KVM_SET_BOOT_CPU_ID:
+               r = 0;
+               mutex_lock(&kvm->lock);
+               if (atomic_read(&kvm->online_vcpus) != 0)
+                       r = -EBUSY;
+               else
+                       kvm->bsp_vcpu_id = arg;
+               mutex_unlock(&kvm->lock);
                break;
-       }
 #endif
-#ifdef KVM_CAP_IRQ_ROUTING
-       case KVM_SET_GSI_ROUTING: {
-               struct kvm_irq_routing routing;
-               struct kvm_irq_routing __user *urouting;
-               struct kvm_irq_routing_entry *entries;
+       default:
+               r = kvm_arch_vm_ioctl(filp, ioctl, arg);
+               if (r == -ENOTTY)
+                       r = kvm_vm_ioctl_assigned_device(kvm, ioctl, arg);
+       }
+out:
+       return r;
+}
+
+#ifdef CONFIG_COMPAT
+struct compat_kvm_dirty_log {
+       __u32 slot;
+       __u32 padding1;
+       union {
+               compat_uptr_t dirty_bitmap; /* one bit per page */
+               __u64 padding2;
+       };
+};
+
+static long kvm_vm_compat_ioctl(struct file *filp,
+                          unsigned int ioctl, unsigned long arg)
+{
+       struct kvm *kvm = filp->private_data;
+       int r;
+
+       if (kvm->mm != current->mm)
+               return -EIO;
+       switch (ioctl) {
+       case KVM_GET_DIRTY_LOG: {
+               struct compat_kvm_dirty_log compat_log;
+               struct kvm_dirty_log log;
 
                r = -EFAULT;
-               if (copy_from_user(&routing, argp, sizeof(routing)))
-                       goto out;
-               r = -EINVAL;
-               if (routing.nr >= KVM_MAX_IRQ_ROUTES)
+               if (copy_from_user(&compat_log, (void __user *)arg,
+                                  sizeof(compat_log)))
                        goto out;
-               if (routing.flags)
-                       goto out;
-               r = -ENOMEM;
-               entries = vmalloc(routing.nr * sizeof(*entries));
-               if (!entries)
+               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);
+               if (r)
                        goto out;
-               r = -EFAULT;
-               urouting = argp;
-               if (copy_from_user(entries, urouting->entries,
-                                  routing.nr * sizeof(*entries)))
-                       goto out_free_irq_routing;
-               r = kvm_set_irq_routing(kvm, entries, routing.nr,
-                                       routing.flags);
-       out_free_irq_routing:
-               vfree(entries);
                break;
        }
-#endif
        default:
-               r = kvm_arch_vm_ioctl(filp, ioctl, arg);
+               r = kvm_vm_ioctl(filp, ioctl, arg);
        }
+
 out:
        return r;
 }
+#endif
 
 static int kvm_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 {
@@ -1948,7 +1611,7 @@ static int kvm_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
        return 0;
 }
 
-static struct vm_operations_struct kvm_vm_vm_ops = {
+static const struct vm_operations_struct kvm_vm_vm_ops = {
        .fault = kvm_vm_fault,
 };
 
@@ -1961,7 +1624,9 @@ static int kvm_vm_mmap(struct file *file, struct vm_area_struct *vma)
 static struct file_operations kvm_vm_fops = {
        .release        = kvm_vm_release,
        .unlocked_ioctl = kvm_vm_ioctl,
-       .compat_ioctl   = kvm_vm_ioctl,
+#ifdef CONFIG_COMPAT
+       .compat_ioctl   = kvm_vm_compat_ioctl,
+#endif
        .mmap           = kvm_vm_mmap,
 };
 
@@ -1973,7 +1638,7 @@ static int kvm_dev_ioctl_create_vm(void)
        kvm = kvm_create_vm();
        if (IS_ERR(kvm))
                return PTR_ERR(kvm);
-       fd = anon_inode_getfd("kvm-vm", &kvm_vm_fops, kvm, 0);
+       fd = anon_inode_getfd("kvm-vm", &kvm_vm_fops, kvm, O_RDWR);
        if (fd < 0)
                kvm_put_kvm(kvm);
 
@@ -1985,10 +1650,15 @@ static long kvm_dev_ioctl_check_extension_generic(long arg)
        switch (arg) {
        case KVM_CAP_USER_MEMORY:
        case KVM_CAP_DESTROY_MEMORY_REGION_WORKS:
+       case KVM_CAP_JOIN_MEMORY_REGIONS_WORKS:
+#ifdef CONFIG_KVM_APIC_ARCHITECTURE
+       case KVM_CAP_SET_BOOT_CPU_ID:
+#endif
+       case KVM_CAP_INTERNAL_ERROR_DATA:
                return 1;
 #ifdef CONFIG_HAVE_KVM_IRQCHIP
        case KVM_CAP_IRQ_ROUTING:
-               return 1;
+               return KVM_MAX_IRQ_ROUTES;
 #endif
        default:
                break;
@@ -2032,7 +1702,7 @@ static long kvm_dev_ioctl(struct file *filp,
        case KVM_TRACE_ENABLE:
        case KVM_TRACE_PAUSE:
        case KVM_TRACE_DISABLE:
-               r = kvm_trace_ioctl(ioctl, arg);
+               r = -EOPNOTSUPP;
                break;
        default:
                return kvm_arch_dev_ioctl(filp, ioctl, arg);
@@ -2055,11 +1725,21 @@ static struct miscdevice kvm_dev = {
 static void hardware_enable(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);
-       kvm_arch_hardware_enable(NULL);
+
+       r = kvm_arch_hardware_enable(NULL);
+
+       if (r) {
+               cpumask_clear_cpu(cpu, cpus_hardware_enabled);
+               atomic_inc(&hardware_enable_failed);
+               printk(KERN_INFO "kvm: enabling virtualization on "
+                                "CPU%d failed\n", cpu);
+       }
 }
 
 static void hardware_disable(void *junk)
@@ -2072,11 +1752,52 @@ static void hardware_disable(void *junk)
        kvm_arch_hardware_disable(NULL);
 }
 
+static void hardware_disable_all_nolock(void)
+{
+       BUG_ON(!kvm_usage_count);
+
+       kvm_usage_count--;
+       if (!kvm_usage_count)
+               on_each_cpu(hardware_disable, NULL, 1);
+}
+
+static void hardware_disable_all(void)
+{
+       spin_lock(&kvm_lock);
+       hardware_disable_all_nolock();
+       spin_unlock(&kvm_lock);
+}
+
+static int hardware_enable_all(void)
+{
+       int r = 0;
+
+       spin_lock(&kvm_lock);
+
+       kvm_usage_count++;
+       if (kvm_usage_count == 1) {
+               atomic_set(&hardware_enable_failed, 0);
+               on_each_cpu(hardware_enable, NULL, 1);
+
+               if (atomic_read(&hardware_enable_failed)) {
+                       hardware_disable_all_nolock();
+                       r = -EBUSY;
+               }
+       }
+
+       spin_unlock(&kvm_lock);
+
+       return r;
+}
+
 static int kvm_cpu_hotplug(struct notifier_block *notifier, unsigned long val,
                           void *v)
 {
        int cpu = (long)v;
 
+       if (!kvm_usage_count)
+               return NOTIFY_OK;
+
        val &= ~CPU_TASKS_FROZEN;
        switch (val) {
        case CPU_DYING:
@@ -2113,15 +1834,15 @@ EXPORT_SYMBOL_GPL(kvm_handle_fault_on_reboot);
 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");
-               kvm_rebooting = true;
-               on_each_cpu(hardware_disable, NULL, 1);
-       }
+       /*
+        * Some (well, at least mine) BIOSes hang on reboot if
+        * in vmx root mode.
+        *
+        * And Intel TXT required VMX off for all cpu when system shutdown.
+        */
+       printk(KERN_INFO "kvm: exiting hardware virtualization\n");
+       kvm_rebooting = true;
+       on_each_cpu(hardware_disable, NULL, 1);
        return NOTIFY_OK;
 }
 
@@ -2146,26 +1867,71 @@ void kvm_io_bus_destroy(struct kvm_io_bus *bus)
        }
 }
 
-struct kvm_io_device *kvm_io_bus_find_dev(struct kvm_io_bus *bus,
-                                         gpa_t addr, int len, int is_write)
+/* kvm_io_bus_write - called under kvm->slots_lock */
+int kvm_io_bus_write(struct kvm_io_bus *bus, gpa_t addr,
+                    int len, const void *val)
 {
        int i;
+       for (i = 0; i < bus->dev_count; i++)
+               if (!kvm_iodevice_write(bus->devs[i], addr, len, val))
+                       return 0;
+       return -EOPNOTSUPP;
+}
 
-       for (i = 0; i < bus->dev_count; i++) {
-               struct kvm_io_device *pos = bus->devs[i];
+/* kvm_io_bus_read - called under kvm->slots_lock */
+int kvm_io_bus_read(struct kvm_io_bus *bus, gpa_t addr, int len, void *val)
+{
+       int i;
+       for (i = 0; i < bus->dev_count; i++)
+               if (!kvm_iodevice_read(bus->devs[i], addr, len, val))
+                       return 0;
+       return -EOPNOTSUPP;
+}
 
-               if (pos->in_range(pos, addr, len, is_write))
-                       return pos;
-       }
+int kvm_io_bus_register_dev(struct kvm *kvm, struct kvm_io_bus *bus,
+                            struct kvm_io_device *dev)
+{
+       int ret;
 
-       return NULL;
+       down_write(&kvm->slots_lock);
+       ret = __kvm_io_bus_register_dev(bus, dev);
+       up_write(&kvm->slots_lock);
+
+       return ret;
 }
 
-void kvm_io_bus_register_dev(struct kvm_io_bus *bus, struct kvm_io_device *dev)
+/* An unlocked version. Caller must have write lock on slots_lock. */
+int __kvm_io_bus_register_dev(struct kvm_io_bus *bus,
+                             struct kvm_io_device *dev)
 {
-       BUG_ON(bus->dev_count > (NR_IOBUS_DEVS-1));
+       if (bus->dev_count > NR_IOBUS_DEVS-1)
+               return -ENOSPC;
 
        bus->devs[bus->dev_count++] = dev;
+
+       return 0;
+}
+
+void kvm_io_bus_unregister_dev(struct kvm *kvm,
+                              struct kvm_io_bus *bus,
+                              struct kvm_io_device *dev)
+{
+       down_write(&kvm->slots_lock);
+       __kvm_io_bus_unregister_dev(bus, dev);
+       up_write(&kvm->slots_lock);
+}
+
+/* An unlocked version. Caller must have write lock on slots_lock. */
+void __kvm_io_bus_unregister_dev(struct kvm_io_bus *bus,
+                                struct kvm_io_device *dev)
+{
+       int i;
+
+       for (i = 0; i < bus->dev_count; i++)
+               if (bus->devs[i] == dev) {
+                       bus->devs[i] = bus->devs[--bus->dev_count];
+                       break;
+               }
 }
 
 static struct notifier_block kvm_cpu_notifier = {
@@ -2198,18 +1964,16 @@ static int vcpu_stat_get(void *_offset, u64 *val)
        *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);
-               }
+               kvm_for_each_vcpu(i, vcpu, kvm)
+                       *val += *(u32 *)((void *)vcpu + offset);
+
        spin_unlock(&kvm_lock);
        return 0;
 }
 
 DEFINE_SIMPLE_ATTRIBUTE(vcpu_stat_fops, vcpu_stat_get, NULL, "%llu\n");
 
-static struct file_operations *stat_fops[] = {
+static const struct file_operations *stat_fops[] = {
        [KVM_STAT_VCPU] = &vcpu_stat_fops,
        [KVM_STAT_VM]   = &vm_stat_fops,
 };
@@ -2236,13 +2000,15 @@ static void kvm_exit_debug(void)
 
 static int kvm_suspend(struct sys_device *dev, pm_message_t state)
 {
-       hardware_disable(NULL);
+       if (kvm_usage_count)
+               hardware_disable(NULL);
        return 0;
 }
 
 static int kvm_resume(struct sys_device *dev)
 {
-       hardware_enable(NULL);
+       if (kvm_usage_count)
+               hardware_enable(NULL);
        return 0;
 }
 
@@ -2287,8 +2053,6 @@ int kvm_init(void *opaque, unsigned int vcpu_size,
        int r;
        int cpu;
 
-       kvm_init_debug();
-
        r = kvm_arch_init(opaque);
        if (r)
                goto out_fail;
@@ -2302,7 +2066,7 @@ int kvm_init(void *opaque, unsigned int vcpu_size,
 
        bad_pfn = page_to_pfn(bad_page);
 
-       if (!alloc_cpumask_var(&cpus_hardware_enabled, GFP_KERNEL)) {
+       if (!zalloc_cpumask_var(&cpus_hardware_enabled, GFP_KERNEL)) {
                r = -ENOMEM;
                goto out_free_0;
        }
@@ -2319,7 +2083,6 @@ int kvm_init(void *opaque, unsigned int vcpu_size,
                        goto out_free_1;
        }
 
-       on_each_cpu(hardware_enable, NULL, 1);
        r = register_cpu_notifier(&kvm_cpu_notifier);
        if (r)
                goto out_free_2;
@@ -2354,9 +2117,8 @@ int kvm_init(void *opaque, unsigned int vcpu_size,
 
        kvm_preempt_ops.sched_in = kvm_sched_in;
        kvm_preempt_ops.sched_out = kvm_sched_out;
-#ifndef CONFIG_X86
-       msi2intx = 0;
-#endif
+
+       kvm_init_debug();
 
        return 0;
 
@@ -2370,7 +2132,6 @@ out_free_3:
        unregister_reboot_notifier(&kvm_reboot_notifier);
        unregister_cpu_notifier(&kvm_cpu_notifier);
 out_free_2:
-       on_each_cpu(hardware_disable, NULL, 1);
 out_free_1:
        kvm_arch_hardware_unsetup();
 out_free_0a:
@@ -2379,7 +2140,6 @@ out_free_0:
        __free_page(bad_page);
 out:
        kvm_arch_exit();
-       kvm_exit_debug();
 out_fail:
        return r;
 }
@@ -2387,7 +2147,8 @@ EXPORT_SYMBOL_GPL(kvm_init);
 
 void kvm_exit(void)
 {
-       kvm_trace_cleanup();
+       tracepoint_synchronize_unregister();
+       kvm_exit_debug();
        misc_deregister(&kvm_dev);
        kmem_cache_destroy(kvm_vcpu_cache);
        sysdev_unregister(&kvm_sysdev);
@@ -2397,7 +2158,6 @@ void kvm_exit(void)
        on_each_cpu(hardware_disable, NULL, 1);
        kvm_arch_hardware_unsetup();
        kvm_arch_exit();
-       kvm_exit_debug();
        free_cpumask_var(cpus_hardware_enabled);
        __free_page(bad_page);
 }