Merge git://git.kernel.org/pub/scm/linux/kernel/git/lethal/fbdev-2.6
[cascardo/linux.git] / virt / kvm / kvm_main.c
index 5225052..7f68625 100644 (file)
@@ -55,6 +55,7 @@
 #include <asm-generic/bitops/le.h>
 
 #include "coalesced_mmio.h"
+#include "async_pf.h"
 
 #define CREATE_TRACE_POINTS
 #include <trace/events/kvm.h>
@@ -89,7 +90,8 @@ static void hardware_disable_all(void);
 
 static void kvm_io_bus_destroy(struct kvm_io_bus *bus);
 
-static bool kvm_rebooting;
+bool kvm_rebooting;
+EXPORT_SYMBOL_GPL(kvm_rebooting);
 
 static bool largepages_enabled = true;
 
@@ -167,8 +169,12 @@ static bool make_all_cpus_request(struct kvm *kvm, unsigned int req)
 
 void kvm_flush_remote_tlbs(struct kvm *kvm)
 {
+       int dirty_count = kvm->tlbs_dirty;
+
+       smp_mb();
        if (make_all_cpus_request(kvm, KVM_REQ_TLB_FLUSH))
                ++kvm->stat.remote_tlb_flush;
+       cmpxchg(&kvm->tlbs_dirty, dirty_count, 0);
 }
 
 void kvm_reload_remote_mmus(struct kvm *kvm)
@@ -186,6 +192,7 @@ int kvm_vcpu_init(struct kvm_vcpu *vcpu, struct kvm *kvm, unsigned id)
        vcpu->kvm = kvm;
        vcpu->vcpu_id = id;
        init_waitqueue_head(&vcpu->wq);
+       kvm_async_pf_vcpu_init(vcpu);
 
        page = alloc_page(GFP_KERNEL | __GFP_ZERO);
        if (!page) {
@@ -247,7 +254,7 @@ static void kvm_mmu_notifier_invalidate_page(struct mmu_notifier *mn,
        idx = srcu_read_lock(&kvm->srcu);
        spin_lock(&kvm->mmu_lock);
        kvm->mmu_notifier_seq++;
-       need_tlb_flush = kvm_unmap_hva(kvm, address);
+       need_tlb_flush = kvm_unmap_hva(kvm, address) | kvm->tlbs_dirty;
        spin_unlock(&kvm->mmu_lock);
        srcu_read_unlock(&kvm->srcu, idx);
 
@@ -291,6 +298,7 @@ static void kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn,
        kvm->mmu_notifier_count++;
        for (; start < end; start += PAGE_SIZE)
                need_tlb_flush |= kvm_unmap_hva(kvm, start);
+       need_tlb_flush |= kvm->tlbs_dirty;
        spin_unlock(&kvm->mmu_lock);
        srcu_read_unlock(&kvm->srcu, idx);
 
@@ -381,11 +389,15 @@ static int kvm_init_mmu_notifier(struct kvm *kvm)
 
 static struct kvm *kvm_create_vm(void)
 {
-       int r = 0, i;
-       struct kvm *kvm = kvm_arch_create_vm();
+       int r, i;
+       struct kvm *kvm = kvm_arch_alloc_vm();
 
-       if (IS_ERR(kvm))
-               goto out;
+       if (!kvm)
+               return ERR_PTR(-ENOMEM);
+
+       r = kvm_arch_init_vm(kvm);
+       if (r)
+               goto out_err_nodisable;
 
        r = hardware_enable_all();
        if (r)
@@ -399,23 +411,19 @@ static struct kvm *kvm_create_vm(void)
        r = -ENOMEM;
        kvm->memslots = kzalloc(sizeof(struct kvm_memslots), GFP_KERNEL);
        if (!kvm->memslots)
-               goto out_err;
+               goto out_err_nosrcu;
        if (init_srcu_struct(&kvm->srcu))
-               goto out_err;
+               goto out_err_nosrcu;
        for (i = 0; i < KVM_NR_BUSES; i++) {
                kvm->buses[i] = kzalloc(sizeof(struct kvm_io_bus),
                                        GFP_KERNEL);
-               if (!kvm->buses[i]) {
-                       cleanup_srcu_struct(&kvm->srcu);
+               if (!kvm->buses[i])
                        goto out_err;
-               }
        }
 
        r = kvm_init_mmu_notifier(kvm);
-       if (r) {
-               cleanup_srcu_struct(&kvm->srcu);
+       if (r)
                goto out_err;
-       }
 
        kvm->mm = current->mm;
        atomic_inc(&kvm->mm->mm_count);
@@ -429,19 +437,35 @@ static struct kvm *kvm_create_vm(void)
        spin_lock(&kvm_lock);
        list_add(&kvm->vm_list, &vm_list);
        spin_unlock(&kvm_lock);
-out:
+
        return kvm;
 
 out_err:
+       cleanup_srcu_struct(&kvm->srcu);
+out_err_nosrcu:
        hardware_disable_all();
 out_err_nodisable:
        for (i = 0; i < KVM_NR_BUSES; i++)
                kfree(kvm->buses[i]);
        kfree(kvm->memslots);
-       kfree(kvm);
+       kvm_arch_free_vm(kvm);
        return ERR_PTR(r);
 }
 
+static void kvm_destroy_dirty_bitmap(struct kvm_memory_slot *memslot)
+{
+       if (!memslot->dirty_bitmap)
+               return;
+
+       if (2 * kvm_dirty_bitmap_bytes(memslot) > PAGE_SIZE)
+               vfree(memslot->dirty_bitmap_head);
+       else
+               kfree(memslot->dirty_bitmap_head);
+
+       memslot->dirty_bitmap = NULL;
+       memslot->dirty_bitmap_head = NULL;
+}
+
 /*
  * Free any memory in @free but not in @dont.
  */
@@ -454,7 +478,7 @@ static void kvm_free_physmem_slot(struct kvm_memory_slot *free,
                vfree(free->rmap);
 
        if (!dont || free->dirty_bitmap != dont->dirty_bitmap)
-               vfree(free->dirty_bitmap);
+               kvm_destroy_dirty_bitmap(free);
 
 
        for (i = 0; i < KVM_NR_PAGE_SIZES - 1; ++i) {
@@ -465,7 +489,6 @@ static void kvm_free_physmem_slot(struct kvm_memory_slot *free,
        }
 
        free->npages = 0;
-       free->dirty_bitmap = NULL;
        free->rmap = NULL;
 }
 
@@ -499,6 +522,9 @@ static void kvm_destroy_vm(struct kvm *kvm)
        kvm_arch_flush_shadow(kvm);
 #endif
        kvm_arch_destroy_vm(kvm);
+       kvm_free_physmem(kvm);
+       cleanup_srcu_struct(&kvm->srcu);
+       kvm_arch_free_vm(kvm);
        hardware_disable_all();
        mmdrop(mm);
 }
@@ -527,6 +553,27 @@ static int kvm_vm_release(struct inode *inode, struct file *filp)
        return 0;
 }
 
+/*
+ * Allocation size is twice as large as the actual dirty bitmap size.
+ * This makes it possible to do double buffering: see x86's
+ * kvm_vm_ioctl_get_dirty_log().
+ */
+static int kvm_create_dirty_bitmap(struct kvm_memory_slot *memslot)
+{
+       unsigned long dirty_bytes = 2 * kvm_dirty_bitmap_bytes(memslot);
+
+       if (dirty_bytes > PAGE_SIZE)
+               memslot->dirty_bitmap = vzalloc(dirty_bytes);
+       else
+               memslot->dirty_bitmap = kzalloc(dirty_bytes, GFP_KERNEL);
+
+       if (!memslot->dirty_bitmap)
+               return -ENOMEM;
+
+       memslot->dirty_bitmap_head = memslot->dirty_bitmap;
+       return 0;
+}
+
 /*
  * Allocate some memory and give it an address in the guest physical address
  * space.
@@ -604,13 +651,11 @@ int __kvm_set_memory_region(struct kvm *kvm,
        /* Allocate if a slot is being created */
 #ifndef CONFIG_S390
        if (npages && !new.rmap) {
-               new.rmap = vmalloc(npages * sizeof(*new.rmap));
+               new.rmap = vzalloc(npages * sizeof(*new.rmap));
 
                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;
        }
@@ -633,14 +678,11 @@ int __kvm_set_memory_region(struct kvm *kvm,
                             >> KVM_HPAGE_GFN_SHIFT(level));
                lpages -= base_gfn >> KVM_HPAGE_GFN_SHIFT(level);
 
-               new.lpage_info[i] = vmalloc(lpages * sizeof(*new.lpage_info[i]));
+               new.lpage_info[i] = vzalloc(lpages * sizeof(*new.lpage_info[i]));
 
                if (!new.lpage_info[i])
                        goto out_free;
 
-               memset(new.lpage_info[i], 0,
-                      lpages * sizeof(*new.lpage_info[i]));
-
                if (base_gfn & (KVM_PAGES_PER_HPAGE(level) - 1))
                        new.lpage_info[i][0].write_count = 1;
                if ((base_gfn+npages) & (KVM_PAGES_PER_HPAGE(level) - 1))
@@ -661,12 +703,8 @@ skip_lpage:
 
        /* Allocate page dirty bitmap if needed */
        if ((new.flags & KVM_MEM_LOG_DIRTY_PAGES) && !new.dirty_bitmap) {
-               unsigned long dirty_bytes = kvm_dirty_bitmap_bytes(&new);
-
-               new.dirty_bitmap = vmalloc(dirty_bytes);
-               if (!new.dirty_bitmap)
+               if (kvm_create_dirty_bitmap(&new) < 0)
                        goto out_free;
-               memset(new.dirty_bitmap, 0, dirty_bytes);
                /* destroy any largepage mappings for dirty tracking */
                if (old.npages)
                        flush_shadow = 1;
@@ -685,6 +723,7 @@ skip_lpage:
                memcpy(slots, kvm->memslots, sizeof(struct kvm_memslots));
                if (mem->slot >= slots->nmemslots)
                        slots->nmemslots = mem->slot + 1;
+               slots->generation++;
                slots->memslots[mem->slot].flags |= KVM_MEMSLOT_INVALID;
 
                old_memslots = kvm->memslots;
@@ -719,6 +758,7 @@ skip_lpage:
        memcpy(slots, kvm->memslots, sizeof(struct kvm_memslots));
        if (mem->slot >= slots->nmemslots)
                slots->nmemslots = mem->slot + 1;
+       slots->generation++;
 
        /* actual memory is freed via old in kvm_free_physmem_slot below */
        if (!npages) {
@@ -849,10 +889,10 @@ int kvm_is_error_hva(unsigned long addr)
 }
 EXPORT_SYMBOL_GPL(kvm_is_error_hva);
 
-struct kvm_memory_slot *gfn_to_memslot(struct kvm *kvm, gfn_t gfn)
+static struct kvm_memory_slot *__gfn_to_memslot(struct kvm_memslots *slots,
+                                               gfn_t gfn)
 {
        int i;
-       struct kvm_memslots *slots = kvm_memslots(kvm);
 
        for (i = 0; i < slots->nmemslots; ++i) {
                struct kvm_memory_slot *memslot = &slots->memslots[i];
@@ -863,6 +903,11 @@ struct kvm_memory_slot *gfn_to_memslot(struct kvm *kvm, gfn_t gfn)
        }
        return NULL;
 }
+
+struct kvm_memory_slot *gfn_to_memslot(struct kvm *kvm, gfn_t gfn)
+{
+       return __gfn_to_memslot(kvm_memslots(kvm), gfn);
+}
 EXPORT_SYMBOL_GPL(gfn_to_memslot);
 
 int kvm_is_visible_gfn(struct kvm *kvm, gfn_t gfn)
@@ -925,12 +970,9 @@ int memslot_id(struct kvm *kvm, gfn_t gfn)
        return memslot - slots->memslots;
 }
 
-static unsigned long gfn_to_hva_many(struct kvm *kvm, gfn_t gfn,
+static unsigned long gfn_to_hva_many(struct kvm_memory_slot *slot, gfn_t gfn,
                                     gfn_t *nr_pages)
 {
-       struct kvm_memory_slot *slot;
-
-       slot = gfn_to_memslot(kvm, gfn);
        if (!slot || slot->flags & KVM_MEMSLOT_INVALID)
                return bad_hva();
 
@@ -942,28 +984,61 @@ static unsigned long gfn_to_hva_many(struct kvm *kvm, gfn_t gfn,
 
 unsigned long gfn_to_hva(struct kvm *kvm, gfn_t gfn)
 {
-       return gfn_to_hva_many(kvm, gfn, NULL);
+       return gfn_to_hva_many(gfn_to_memslot(kvm, gfn), gfn, NULL);
 }
 EXPORT_SYMBOL_GPL(gfn_to_hva);
 
-static pfn_t hva_to_pfn(struct kvm *kvm, unsigned long addr, bool atomic)
+static pfn_t get_fault_pfn(void)
+{
+       get_page(fault_page);
+       return fault_pfn;
+}
+
+static pfn_t hva_to_pfn(struct kvm *kvm, unsigned long addr, bool atomic,
+                       bool *async, bool write_fault, bool *writable)
 {
        struct page *page[1];
-       int npages;
+       int npages = 0;
        pfn_t pfn;
 
-       if (atomic)
+       /* we can do it either atomically or asynchronously, not both */
+       BUG_ON(atomic && async);
+
+       BUG_ON(!write_fault && !writable);
+
+       if (writable)
+               *writable = true;
+
+       if (atomic || async)
                npages = __get_user_pages_fast(addr, 1, 1, page);
-       else {
+
+       if (unlikely(npages != 1) && !atomic) {
                might_sleep();
-               npages = get_user_pages_fast(addr, 1, 1, page);
+
+               if (writable)
+                       *writable = write_fault;
+
+               npages = get_user_pages_fast(addr, 1, write_fault, page);
+
+               /* map read fault as writable if possible */
+               if (unlikely(!write_fault) && npages == 1) {
+                       struct page *wpage[1];
+
+                       npages = __get_user_pages_fast(addr, 1, 1, wpage);
+                       if (npages == 1) {
+                               *writable = true;
+                               put_page(page[0]);
+                               page[0] = wpage[0];
+                       }
+                       npages = 1;
+               }
        }
 
        if (unlikely(npages != 1)) {
                struct vm_area_struct *vma;
 
                if (atomic)
-                       goto return_fault_page;
+                       return get_fault_pfn();
 
                down_read(&current->mm->mmap_sem);
                if (is_hwpoison_address(addr)) {
@@ -972,19 +1047,20 @@ static pfn_t hva_to_pfn(struct kvm *kvm, unsigned long addr, bool atomic)
                        return page_to_pfn(hwpoison_page);
                }
 
-               vma = find_vma(current->mm, addr);
-
-               if (vma == NULL || addr < vma->vm_start ||
-                   !(vma->vm_flags & VM_PFNMAP)) {
-                       up_read(&current->mm->mmap_sem);
-return_fault_page:
-                       get_page(fault_page);
-                       return page_to_pfn(fault_page);
+               vma = find_vma_intersection(current->mm, addr, addr+1);
+
+               if (vma == NULL)
+                       pfn = get_fault_pfn();
+               else if ((vma->vm_flags & VM_PFNMAP)) {
+                       pfn = ((addr - vma->vm_start) >> PAGE_SHIFT) +
+                               vma->vm_pgoff;
+                       BUG_ON(!kvm_is_mmio_pfn(pfn));
+               } else {
+                       if (async && (vma->vm_flags & VM_WRITE))
+                               *async = true;
+                       pfn = get_fault_pfn();
                }
-
-               pfn = ((addr - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff;
                up_read(&current->mm->mmap_sem);
-               BUG_ON(!kvm_is_mmio_pfn(pfn));
        } else
                pfn = page_to_pfn(page[0]);
 
@@ -993,40 +1069,58 @@ return_fault_page:
 
 pfn_t hva_to_pfn_atomic(struct kvm *kvm, unsigned long addr)
 {
-       return hva_to_pfn(kvm, addr, true);
+       return hva_to_pfn(kvm, addr, true, NULL, true, NULL);
 }
 EXPORT_SYMBOL_GPL(hva_to_pfn_atomic);
 
-static pfn_t __gfn_to_pfn(struct kvm *kvm, gfn_t gfn, bool atomic)
+static pfn_t __gfn_to_pfn(struct kvm *kvm, gfn_t gfn, bool atomic, bool *async,
+                         bool write_fault, bool *writable)
 {
        unsigned long addr;
 
+       if (async)
+               *async = false;
+
        addr = gfn_to_hva(kvm, gfn);
        if (kvm_is_error_hva(addr)) {
                get_page(bad_page);
                return page_to_pfn(bad_page);
        }
 
-       return hva_to_pfn(kvm, addr, atomic);
+       return hva_to_pfn(kvm, addr, atomic, async, write_fault, writable);
 }
 
 pfn_t gfn_to_pfn_atomic(struct kvm *kvm, gfn_t gfn)
 {
-       return __gfn_to_pfn(kvm, gfn, true);
+       return __gfn_to_pfn(kvm, gfn, true, NULL, true, NULL);
 }
 EXPORT_SYMBOL_GPL(gfn_to_pfn_atomic);
 
+pfn_t gfn_to_pfn_async(struct kvm *kvm, gfn_t gfn, bool *async,
+                      bool write_fault, bool *writable)
+{
+       return __gfn_to_pfn(kvm, gfn, false, async, write_fault, writable);
+}
+EXPORT_SYMBOL_GPL(gfn_to_pfn_async);
+
 pfn_t gfn_to_pfn(struct kvm *kvm, gfn_t gfn)
 {
-       return __gfn_to_pfn(kvm, gfn, false);
+       return __gfn_to_pfn(kvm, gfn, false, NULL, true, NULL);
 }
 EXPORT_SYMBOL_GPL(gfn_to_pfn);
 
+pfn_t gfn_to_pfn_prot(struct kvm *kvm, gfn_t gfn, bool write_fault,
+                     bool *writable)
+{
+       return __gfn_to_pfn(kvm, gfn, false, NULL, write_fault, writable);
+}
+EXPORT_SYMBOL_GPL(gfn_to_pfn_prot);
+
 pfn_t gfn_to_pfn_memslot(struct kvm *kvm,
                         struct kvm_memory_slot *slot, gfn_t gfn)
 {
        unsigned long addr = gfn_to_hva_memslot(slot, gfn);
-       return hva_to_pfn(kvm, addr, false);
+       return hva_to_pfn(kvm, addr, false, NULL, true, NULL);
 }
 
 int gfn_to_page_many_atomic(struct kvm *kvm, gfn_t gfn, struct page **pages,
@@ -1035,7 +1129,7 @@ int gfn_to_page_many_atomic(struct kvm *kvm, gfn_t gfn, struct page **pages,
        unsigned long addr;
        gfn_t entry;
 
-       addr = gfn_to_hva_many(kvm, gfn, &entry);
+       addr = gfn_to_hva_many(gfn_to_memslot(kvm, gfn), gfn, &entry);
        if (kvm_is_error_hva(addr))
                return -1;
 
@@ -1219,9 +1313,51 @@ int kvm_write_guest(struct kvm *kvm, gpa_t gpa, const void *data,
        return 0;
 }
 
+int kvm_gfn_to_hva_cache_init(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
+                             gpa_t gpa)
+{
+       struct kvm_memslots *slots = kvm_memslots(kvm);
+       int offset = offset_in_page(gpa);
+       gfn_t gfn = gpa >> PAGE_SHIFT;
+
+       ghc->gpa = gpa;
+       ghc->generation = slots->generation;
+       ghc->memslot = __gfn_to_memslot(slots, gfn);
+       ghc->hva = gfn_to_hva_many(ghc->memslot, gfn, NULL);
+       if (!kvm_is_error_hva(ghc->hva))
+               ghc->hva += offset;
+       else
+               return -EFAULT;
+
+       return 0;
+}
+EXPORT_SYMBOL_GPL(kvm_gfn_to_hva_cache_init);
+
+int kvm_write_guest_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
+                          void *data, unsigned long len)
+{
+       struct kvm_memslots *slots = kvm_memslots(kvm);
+       int r;
+
+       if (slots->generation != ghc->generation)
+               kvm_gfn_to_hva_cache_init(kvm, ghc, ghc->gpa);
+
+       if (kvm_is_error_hva(ghc->hva))
+               return -EFAULT;
+
+       r = copy_to_user((void __user *)ghc->hva, data, len);
+       if (r)
+               return -EFAULT;
+       mark_page_dirty_in_slot(kvm, ghc->memslot, ghc->gpa >> PAGE_SHIFT);
+
+       return 0;
+}
+EXPORT_SYMBOL_GPL(kvm_write_guest_cached);
+
 int kvm_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);
+       return kvm_write_guest_page(kvm, gfn, (const void *) empty_zero_page,
+                                   offset, len);
 }
 EXPORT_SYMBOL_GPL(kvm_clear_guest_page);
 
@@ -1244,11 +1380,9 @@ int kvm_clear_guest(struct kvm *kvm, gpa_t gpa, unsigned long len)
 }
 EXPORT_SYMBOL_GPL(kvm_clear_guest);
 
-void mark_page_dirty(struct kvm *kvm, gfn_t gfn)
+void mark_page_dirty_in_slot(struct kvm *kvm, struct kvm_memory_slot *memslot,
+                            gfn_t gfn)
 {
-       struct kvm_memory_slot *memslot;
-
-       memslot = gfn_to_memslot(kvm, gfn);
        if (memslot && memslot->dirty_bitmap) {
                unsigned long rel_gfn = gfn - memslot->base_gfn;
 
@@ -1256,6 +1390,14 @@ void mark_page_dirty(struct kvm *kvm, gfn_t gfn)
        }
 }
 
+void mark_page_dirty(struct kvm *kvm, gfn_t gfn)
+{
+       struct kvm_memory_slot *memslot;
+
+       memslot = gfn_to_memslot(kvm, gfn);
+       mark_page_dirty_in_slot(kvm, memslot, gfn);
+}
+
 /*
  * The vCPU has executed a HLT instruction with in-kernel mode enabled.
  */
@@ -1457,6 +1599,7 @@ static long kvm_vcpu_ioctl(struct file *filp,
                if (arg)
                        goto out;
                r = kvm_arch_vcpu_ioctl_run(vcpu, vcpu->run);
+               trace_kvm_userspace_exit(vcpu->run->exit_reason, r);
                break;
        case KVM_GET_REGS: {
                struct kvm_regs *kvm_regs;
@@ -1824,7 +1967,7 @@ static struct file_operations kvm_vm_fops = {
 
 static int kvm_dev_ioctl_create_vm(void)
 {
-       int fd, r;
+       int r;
        struct kvm *kvm;
 
        kvm = kvm_create_vm();
@@ -1837,11 +1980,11 @@ static int kvm_dev_ioctl_create_vm(void)
                return r;
        }
 #endif
-       fd = anon_inode_getfd("kvm-vm", &kvm_vm_fops, kvm, O_RDWR);
-       if (fd < 0)
+       r = anon_inode_getfd("kvm-vm", &kvm_vm_fops, kvm, O_RDWR);
+       if (r < 0)
                kvm_put_kvm(kvm);
 
-       return fd;
+       return r;
 }
 
 static long kvm_dev_ioctl_check_extension_generic(long arg)
@@ -1922,7 +2065,7 @@ static struct miscdevice kvm_dev = {
        &kvm_chardev_ops,
 };
 
-static void hardware_enable(void *junk)
+static void hardware_enable_nolock(void *junk)
 {
        int cpu = raw_smp_processor_id();
        int r;
@@ -1942,7 +2085,14 @@ static void hardware_enable(void *junk)
        }
 }
 
-static void hardware_disable(void *junk)
+static void hardware_enable(void *junk)
+{
+       spin_lock(&kvm_lock);
+       hardware_enable_nolock(junk);
+       spin_unlock(&kvm_lock);
+}
+
+static void hardware_disable_nolock(void *junk)
 {
        int cpu = raw_smp_processor_id();
 
@@ -1952,13 +2102,20 @@ static void hardware_disable(void *junk)
        kvm_arch_hardware_disable(NULL);
 }
 
+static void hardware_disable(void *junk)
+{
+       spin_lock(&kvm_lock);
+       hardware_disable_nolock(junk);
+       spin_unlock(&kvm_lock);
+}
+
 static void hardware_disable_all_nolock(void)
 {
        BUG_ON(!kvm_usage_count);
 
        kvm_usage_count--;
        if (!kvm_usage_count)
-               on_each_cpu(hardware_disable, NULL, 1);
+               on_each_cpu(hardware_disable_nolock, NULL, 1);
 }
 
 static void hardware_disable_all(void)
@@ -1977,7 +2134,7 @@ static int hardware_enable_all(void)
        kvm_usage_count++;
        if (kvm_usage_count == 1) {
                atomic_set(&hardware_enable_failed, 0);
-               on_each_cpu(hardware_enable, NULL, 1);
+               on_each_cpu(hardware_enable_nolock, NULL, 1);
 
                if (atomic_read(&hardware_enable_failed)) {
                        hardware_disable_all_nolock();
@@ -2008,27 +2165,19 @@ static int kvm_cpu_hotplug(struct notifier_block *notifier, unsigned long val,
        case CPU_STARTING:
                printk(KERN_INFO "kvm: enabling virtualization on CPU%d\n",
                       cpu);
-               spin_lock(&kvm_lock);
                hardware_enable(NULL);
-               spin_unlock(&kvm_lock);
                break;
        }
        return NOTIFY_OK;
 }
 
 
-asmlinkage void kvm_handle_fault_on_reboot(void)
+asmlinkage void kvm_spurious_fault(void)
 {
-       if (kvm_rebooting) {
-               /* spin while reset goes on */
-               local_irq_enable();
-               while (true)
-                       cpu_relax();
-       }
        /* Fault while not rebooting.  We want the trace. */
        BUG();
 }
-EXPORT_SYMBOL_GPL(kvm_handle_fault_on_reboot);
+EXPORT_SYMBOL_GPL(kvm_spurious_fault);
 
 static int kvm_reboot(struct notifier_block *notifier, unsigned long val,
                      void *v)
@@ -2041,7 +2190,7 @@ static int kvm_reboot(struct notifier_block *notifier, unsigned long val,
         */
        printk(KERN_INFO "kvm: exiting hardware virtualization\n");
        kvm_rebooting = true;
-       on_each_cpu(hardware_disable, NULL, 1);
+       on_each_cpu(hardware_disable_nolock, NULL, 1);
        return NOTIFY_OK;
 }
 
@@ -2211,7 +2360,7 @@ static void kvm_exit_debug(void)
 static int kvm_suspend(struct sys_device *dev, pm_message_t state)
 {
        if (kvm_usage_count)
-               hardware_disable(NULL);
+               hardware_disable_nolock(NULL);
        return 0;
 }
 
@@ -2219,7 +2368,7 @@ static int kvm_resume(struct sys_device *dev)
 {
        if (kvm_usage_count) {
                WARN_ON(spin_is_locked(&kvm_lock));
-               hardware_enable(NULL);
+               hardware_enable_nolock(NULL);
        }
        return 0;
 }
@@ -2336,6 +2485,10 @@ int kvm_init(void *opaque, unsigned vcpu_size, unsigned vcpu_align,
                goto out_free_5;
        }
 
+       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;
@@ -2343,7 +2496,7 @@ int kvm_init(void *opaque, unsigned vcpu_size, unsigned vcpu_align,
        r = misc_register(&kvm_dev);
        if (r) {
                printk(KERN_ERR "kvm: misc device register failed\n");
-               goto out_free;
+               goto out_unreg;
        }
 
        kvm_preempt_ops.sched_in = kvm_sched_in;
@@ -2353,6 +2506,8 @@ int kvm_init(void *opaque, unsigned vcpu_size, unsigned vcpu_align,
 
        return 0;
 
+out_unreg:
+       kvm_async_pf_deinit();
 out_free:
        kmem_cache_destroy(kvm_vcpu_cache);
 out_free_5:
@@ -2385,11 +2540,12 @@ void kvm_exit(void)
        kvm_exit_debug();
        misc_deregister(&kvm_dev);
        kmem_cache_destroy(kvm_vcpu_cache);
+       kvm_async_pf_deinit();
        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, 1);
+       on_each_cpu(hardware_disable_nolock, NULL, 1);
        kvm_arch_hardware_unsetup();
        kvm_arch_exit();
        free_cpumask_var(cpus_hardware_enabled);