1 files changed, 245 insertions, 89 deletions

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 5225052aebc..7f686251f71 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -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);
 }
@@ -528,6 +554,27 @@ static int kvm_vm_release(struct inode *inode, struct file *filp)
 }
 
 /*
+ * 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);