This commit was manufactured by cvs2svn to create branch 'vserver'.
[linux-2.6.git] / drivers / kvm / kvm_main.c
diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
new file mode 100644 (file)
index 0000000..b10972e
--- /dev/null
@@ -0,0 +1,2136 @@
+/*
+ * Kernel-based Virtual Machine driver for Linux
+ *
+ * This module enables machines with Intel VT-x extensions to run virtual
+ * machines without emulation or binary translation.
+ *
+ * Copyright (C) 2006 Qumranet, Inc.
+ *
+ * Authors:
+ *   Avi Kivity   <avi@qumranet.com>
+ *   Yaniv Kamay  <yaniv@qumranet.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.  See
+ * the COPYING file in the top-level directory.
+ *
+ */
+
+#include "kvm.h"
+
+#include <linux/kvm.h>
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <asm/processor.h>
+#include <linux/percpu.h>
+#include <linux/gfp.h>
+#include <asm/msr.h>
+#include <linux/mm.h>
+#include <linux/miscdevice.h>
+#include <linux/vmalloc.h>
+#include <asm/uaccess.h>
+#include <linux/reboot.h>
+#include <asm/io.h>
+#include <linux/debugfs.h>
+#include <linux/highmem.h>
+#include <linux/file.h>
+#include <asm/desc.h>
+
+#include "x86_emulate.h"
+#include "segment_descriptor.h"
+
+MODULE_AUTHOR("Qumranet");
+MODULE_LICENSE("GPL");
+
+struct kvm_arch_ops *kvm_arch_ops;
+struct kvm_stat kvm_stat;
+EXPORT_SYMBOL_GPL(kvm_stat);
+
+static struct kvm_stats_debugfs_item {
+       const char *name;
+       u32 *data;
+       struct dentry *dentry;
+} debugfs_entries[] = {
+       { "pf_fixed", &kvm_stat.pf_fixed },
+       { "pf_guest", &kvm_stat.pf_guest },
+       { "tlb_flush", &kvm_stat.tlb_flush },
+       { "invlpg", &kvm_stat.invlpg },
+       { "exits", &kvm_stat.exits },
+       { "io_exits", &kvm_stat.io_exits },
+       { "mmio_exits", &kvm_stat.mmio_exits },
+       { "signal_exits", &kvm_stat.signal_exits },
+       { "irq_window", &kvm_stat.irq_window_exits },
+       { "halt_exits", &kvm_stat.halt_exits },
+       { "request_irq", &kvm_stat.request_irq_exits },
+       { "irq_exits", &kvm_stat.irq_exits },
+       { 0, 0 }
+};
+
+static struct dentry *debugfs_dir;
+
+#define MAX_IO_MSRS 256
+
+#define CR0_RESEVED_BITS 0xffffffff1ffaffc0ULL
+#define LMSW_GUEST_MASK 0x0eULL
+#define CR4_RESEVED_BITS (~((1ULL << 11) - 1))
+#define CR8_RESEVED_BITS (~0x0fULL)
+#define EFER_RESERVED_BITS 0xfffffffffffff2fe
+
+#ifdef CONFIG_X86_64
+// LDT or TSS descriptor in the GDT. 16 bytes.
+struct segment_descriptor_64 {
+       struct segment_descriptor s;
+       u32 base_higher;
+       u32 pad_zero;
+};
+
+#endif
+
+unsigned long segment_base(u16 selector)
+{
+       struct descriptor_table gdt;
+       struct segment_descriptor *d;
+       unsigned long table_base;
+       typedef unsigned long ul;
+       unsigned long v;
+
+       if (selector == 0)
+               return 0;
+
+       asm ("sgdt %0" : "=m"(gdt));
+       table_base = gdt.base;
+
+       if (selector & 4) {           /* from ldt */
+               u16 ldt_selector;
+
+               asm ("sldt %0" : "=g"(ldt_selector));
+               table_base = segment_base(ldt_selector);
+       }
+       d = (struct segment_descriptor *)(table_base + (selector & ~7));
+       v = d->base_low | ((ul)d->base_mid << 16) | ((ul)d->base_high << 24);
+#ifdef CONFIG_X86_64
+       if (d->system == 0
+           && (d->type == 2 || d->type == 9 || d->type == 11))
+               v |= ((ul)((struct segment_descriptor_64 *)d)->base_higher) << 32;
+#endif
+       return v;
+}
+EXPORT_SYMBOL_GPL(segment_base);
+
+static inline int valid_vcpu(int n)
+{
+       return likely(n >= 0 && n < KVM_MAX_VCPUS);
+}
+
+int kvm_read_guest(struct kvm_vcpu *vcpu,
+                            gva_t addr,
+                            unsigned long size,
+                            void *dest)
+{
+       unsigned char *host_buf = dest;
+       unsigned long req_size = size;
+
+       while (size) {
+               hpa_t paddr;
+               unsigned now;
+               unsigned offset;
+               hva_t guest_buf;
+
+               paddr = gva_to_hpa(vcpu, addr);
+
+               if (is_error_hpa(paddr))
+                       break;
+
+               guest_buf = (hva_t)kmap_atomic(
+                                       pfn_to_page(paddr >> PAGE_SHIFT),
+                                       KM_USER0);
+               offset = addr & ~PAGE_MASK;
+               guest_buf |= offset;
+               now = min(size, PAGE_SIZE - offset);
+               memcpy(host_buf, (void*)guest_buf, now);
+               host_buf += now;
+               addr += now;
+               size -= now;
+               kunmap_atomic((void *)(guest_buf & PAGE_MASK), KM_USER0);
+       }
+       return req_size - size;
+}
+EXPORT_SYMBOL_GPL(kvm_read_guest);
+
+int kvm_write_guest(struct kvm_vcpu *vcpu,
+                            gva_t addr,
+                            unsigned long size,
+                            void *data)
+{
+       unsigned char *host_buf = data;
+       unsigned long req_size = size;
+
+       while (size) {
+               hpa_t paddr;
+               unsigned now;
+               unsigned offset;
+               hva_t guest_buf;
+
+               paddr = gva_to_hpa(vcpu, addr);
+
+               if (is_error_hpa(paddr))
+                       break;
+
+               guest_buf = (hva_t)kmap_atomic(
+                               pfn_to_page(paddr >> PAGE_SHIFT), KM_USER0);
+               offset = addr & ~PAGE_MASK;
+               guest_buf |= offset;
+               now = min(size, PAGE_SIZE - offset);
+               memcpy((void*)guest_buf, host_buf, now);
+               host_buf += now;
+               addr += now;
+               size -= now;
+               kunmap_atomic((void *)(guest_buf & PAGE_MASK), KM_USER0);
+       }
+       return req_size - size;
+}
+EXPORT_SYMBOL_GPL(kvm_write_guest);
+
+static int vcpu_slot(struct kvm_vcpu *vcpu)
+{
+       return vcpu - vcpu->kvm->vcpus;
+}
+
+/*
+ * Switches to specified vcpu, until a matching vcpu_put()
+ */
+static struct kvm_vcpu *vcpu_load(struct kvm *kvm, int vcpu_slot)
+{
+       struct kvm_vcpu *vcpu = &kvm->vcpus[vcpu_slot];
+
+       mutex_lock(&vcpu->mutex);
+       if (unlikely(!vcpu->vmcs)) {
+               mutex_unlock(&vcpu->mutex);
+               return 0;
+       }
+       return kvm_arch_ops->vcpu_load(vcpu);
+}
+
+static void vcpu_put(struct kvm_vcpu *vcpu)
+{
+       kvm_arch_ops->vcpu_put(vcpu);
+       mutex_unlock(&vcpu->mutex);
+}
+
+static int kvm_dev_open(struct inode *inode, struct file *filp)
+{
+       struct kvm *kvm = kzalloc(sizeof(struct kvm), GFP_KERNEL);
+       int i;
+
+       if (!kvm)
+               return -ENOMEM;
+
+       spin_lock_init(&kvm->lock);
+       INIT_LIST_HEAD(&kvm->active_mmu_pages);
+       for (i = 0; i < KVM_MAX_VCPUS; ++i) {
+               struct kvm_vcpu *vcpu = &kvm->vcpus[i];
+
+               mutex_init(&vcpu->mutex);
+               vcpu->kvm = kvm;
+               vcpu->mmu.root_hpa = INVALID_PAGE;
+               INIT_LIST_HEAD(&vcpu->free_pages);
+       }
+       filp->private_data = kvm;
+       return 0;
+}
+
+/*
+ * Free any memory in @free but not in @dont.
+ */
+static void kvm_free_physmem_slot(struct kvm_memory_slot *free,
+                                 struct kvm_memory_slot *dont)
+{
+       int i;
+
+       if (!dont || free->phys_mem != dont->phys_mem)
+               if (free->phys_mem) {
+                       for (i = 0; i < free->npages; ++i)
+                               if (free->phys_mem[i])
+                                       __free_page(free->phys_mem[i]);
+                       vfree(free->phys_mem);
+               }
+
+       if (!dont || free->dirty_bitmap != dont->dirty_bitmap)
+               vfree(free->dirty_bitmap);
+
+       free->phys_mem = 0;
+       free->npages = 0;
+       free->dirty_bitmap = 0;
+}
+
+static void kvm_free_physmem(struct kvm *kvm)
+{
+       int i;
+
+       for (i = 0; i < kvm->nmemslots; ++i)
+               kvm_free_physmem_slot(&kvm->memslots[i], 0);
+}
+
+static void kvm_free_vcpu(struct kvm_vcpu *vcpu)
+{
+       vcpu_load(vcpu->kvm, vcpu_slot(vcpu));
+       kvm_mmu_destroy(vcpu);
+       vcpu_put(vcpu);
+       kvm_arch_ops->vcpu_free(vcpu);
+}
+
+static void kvm_free_vcpus(struct kvm *kvm)
+{
+       unsigned int i;
+
+       for (i = 0; i < KVM_MAX_VCPUS; ++i)
+               kvm_free_vcpu(&kvm->vcpus[i]);
+}
+
+static int kvm_dev_release(struct inode *inode, struct file *filp)
+{
+       struct kvm *kvm = filp->private_data;
+
+       kvm_free_vcpus(kvm);
+       kvm_free_physmem(kvm);
+       kfree(kvm);
+       return 0;
+}
+
+static void inject_gp(struct kvm_vcpu *vcpu)
+{
+       kvm_arch_ops->inject_gp(vcpu, 0);
+}
+
+/*
+ * Load the pae pdptrs.  Return true is they are all valid.
+ */
+static int load_pdptrs(struct kvm_vcpu *vcpu, unsigned long cr3)
+{
+       gfn_t pdpt_gfn = cr3 >> PAGE_SHIFT;
+       unsigned offset = ((cr3 & (PAGE_SIZE-1)) >> 5) << 2;
+       int i;
+       u64 pdpte;
+       u64 *pdpt;
+       int ret;
+       struct kvm_memory_slot *memslot;
+
+       spin_lock(&vcpu->kvm->lock);
+       memslot = gfn_to_memslot(vcpu->kvm, pdpt_gfn);
+       /* FIXME: !memslot - emulate? 0xff? */
+       pdpt = kmap_atomic(gfn_to_page(memslot, pdpt_gfn), KM_USER0);
+
+       ret = 1;
+       for (i = 0; i < 4; ++i) {
+               pdpte = pdpt[offset + i];
+               if ((pdpte & 1) && (pdpte & 0xfffffff0000001e6ull)) {
+                       ret = 0;
+                       goto out;
+               }
+       }
+
+       for (i = 0; i < 4; ++i)
+               vcpu->pdptrs[i] = pdpt[offset + i];
+
+out:
+       kunmap_atomic(pdpt, KM_USER0);
+       spin_unlock(&vcpu->kvm->lock);
+
+       return ret;
+}
+
+void set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0)
+{
+       if (cr0 & CR0_RESEVED_BITS) {
+               printk(KERN_DEBUG "set_cr0: 0x%lx #GP, reserved bits 0x%lx\n",
+                      cr0, vcpu->cr0);
+               inject_gp(vcpu);
+               return;
+       }
+
+       if ((cr0 & CR0_NW_MASK) && !(cr0 & CR0_CD_MASK)) {
+               printk(KERN_DEBUG "set_cr0: #GP, CD == 0 && NW == 1\n");
+               inject_gp(vcpu);
+               return;
+       }
+
+       if ((cr0 & CR0_PG_MASK) && !(cr0 & CR0_PE_MASK)) {
+               printk(KERN_DEBUG "set_cr0: #GP, set PG flag "
+                      "and a clear PE flag\n");
+               inject_gp(vcpu);
+               return;
+       }
+
+       if (!is_paging(vcpu) && (cr0 & CR0_PG_MASK)) {
+#ifdef CONFIG_X86_64
+               if ((vcpu->shadow_efer & EFER_LME)) {
+                       int cs_db, cs_l;
+
+                       if (!is_pae(vcpu)) {
+                               printk(KERN_DEBUG "set_cr0: #GP, start paging "
+                                      "in long mode while PAE is disabled\n");
+                               inject_gp(vcpu);
+                               return;
+                       }
+                       kvm_arch_ops->get_cs_db_l_bits(vcpu, &cs_db, &cs_l);
+                       if (cs_l) {
+                               printk(KERN_DEBUG "set_cr0: #GP, start paging "
+                                      "in long mode while CS.L == 1\n");
+                               inject_gp(vcpu);
+                               return;
+
+                       }
+               } else
+#endif
+               if (is_pae(vcpu) && !load_pdptrs(vcpu, vcpu->cr3)) {
+                       printk(KERN_DEBUG "set_cr0: #GP, pdptrs "
+                              "reserved bits\n");
+                       inject_gp(vcpu);
+                       return;
+               }
+
+       }
+
+       kvm_arch_ops->set_cr0(vcpu, cr0);
+       vcpu->cr0 = cr0;
+
+       spin_lock(&vcpu->kvm->lock);
+       kvm_mmu_reset_context(vcpu);
+       spin_unlock(&vcpu->kvm->lock);
+       return;
+}
+EXPORT_SYMBOL_GPL(set_cr0);
+
+void lmsw(struct kvm_vcpu *vcpu, unsigned long msw)
+{
+       kvm_arch_ops->decache_cr0_cr4_guest_bits(vcpu);
+       set_cr0(vcpu, (vcpu->cr0 & ~0x0ful) | (msw & 0x0f));
+}
+EXPORT_SYMBOL_GPL(lmsw);
+
+void set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
+{
+       if (cr4 & CR4_RESEVED_BITS) {
+               printk(KERN_DEBUG "set_cr4: #GP, reserved bits\n");
+               inject_gp(vcpu);
+               return;
+       }
+
+       if (is_long_mode(vcpu)) {
+               if (!(cr4 & CR4_PAE_MASK)) {
+                       printk(KERN_DEBUG "set_cr4: #GP, clearing PAE while "
+                              "in long mode\n");
+                       inject_gp(vcpu);
+                       return;
+               }
+       } else if (is_paging(vcpu) && !is_pae(vcpu) && (cr4 & CR4_PAE_MASK)
+                  && !load_pdptrs(vcpu, vcpu->cr3)) {
+               printk(KERN_DEBUG "set_cr4: #GP, pdptrs reserved bits\n");
+               inject_gp(vcpu);
+       }
+
+       if (cr4 & CR4_VMXE_MASK) {
+               printk(KERN_DEBUG "set_cr4: #GP, setting VMXE\n");
+               inject_gp(vcpu);
+               return;
+       }
+       kvm_arch_ops->set_cr4(vcpu, cr4);
+       spin_lock(&vcpu->kvm->lock);
+       kvm_mmu_reset_context(vcpu);
+       spin_unlock(&vcpu->kvm->lock);
+}
+EXPORT_SYMBOL_GPL(set_cr4);
+
+void set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3)
+{
+       if (is_long_mode(vcpu)) {
+               if ( cr3 & CR3_L_MODE_RESEVED_BITS) {
+                       printk(KERN_DEBUG "set_cr3: #GP, reserved bits\n");
+                       inject_gp(vcpu);
+                       return;
+               }
+       } else {
+               if (cr3 & CR3_RESEVED_BITS) {
+                       printk(KERN_DEBUG "set_cr3: #GP, reserved bits\n");
+                       inject_gp(vcpu);
+                       return;
+               }
+               if (is_paging(vcpu) && is_pae(vcpu) &&
+                   !load_pdptrs(vcpu, cr3)) {
+                       printk(KERN_DEBUG "set_cr3: #GP, pdptrs "
+                              "reserved bits\n");
+                       inject_gp(vcpu);
+                       return;
+               }
+       }
+
+       vcpu->cr3 = cr3;
+       spin_lock(&vcpu->kvm->lock);
+       /*
+        * Does the new cr3 value map to physical memory? (Note, we
+        * catch an invalid cr3 even in real-mode, because it would
+        * cause trouble later on when we turn on paging anyway.)
+        *
+        * A real CPU would silently accept an invalid cr3 and would
+        * attempt to use it - with largely undefined (and often hard
+        * to debug) behavior on the guest side.
+        */
+       if (unlikely(!gfn_to_memslot(vcpu->kvm, cr3 >> PAGE_SHIFT)))
+               inject_gp(vcpu);
+       else
+               vcpu->mmu.new_cr3(vcpu);
+       spin_unlock(&vcpu->kvm->lock);
+}
+EXPORT_SYMBOL_GPL(set_cr3);
+
+void set_cr8(struct kvm_vcpu *vcpu, unsigned long cr8)
+{
+       if ( cr8 & CR8_RESEVED_BITS) {
+               printk(KERN_DEBUG "set_cr8: #GP, reserved bits 0x%lx\n", cr8);
+               inject_gp(vcpu);
+               return;
+       }
+       vcpu->cr8 = cr8;
+}
+EXPORT_SYMBOL_GPL(set_cr8);
+
+void fx_init(struct kvm_vcpu *vcpu)
+{
+       struct __attribute__ ((__packed__)) fx_image_s {
+               u16 control; //fcw
+               u16 status; //fsw
+               u16 tag; // ftw
+               u16 opcode; //fop
+               u64 ip; // fpu ip
+               u64 operand;// fpu dp
+               u32 mxcsr;
+               u32 mxcsr_mask;
+
+       } *fx_image;
+
+       fx_save(vcpu->host_fx_image);
+       fpu_init();
+       fx_save(vcpu->guest_fx_image);
+       fx_restore(vcpu->host_fx_image);
+
+       fx_image = (struct fx_image_s *)vcpu->guest_fx_image;
+       fx_image->mxcsr = 0x1f80;
+       memset(vcpu->guest_fx_image + sizeof(struct fx_image_s),
+              0, FX_IMAGE_SIZE - sizeof(struct fx_image_s));
+}
+EXPORT_SYMBOL_GPL(fx_init);
+
+/*
+ * Creates some virtual cpus.  Good luck creating more than one.
+ */
+static int kvm_dev_ioctl_create_vcpu(struct kvm *kvm, int n)
+{
+       int r;
+       struct kvm_vcpu *vcpu;
+
+       r = -EINVAL;
+       if (!valid_vcpu(n))
+               goto out;
+
+       vcpu = &kvm->vcpus[n];
+
+       mutex_lock(&vcpu->mutex);
+
+       if (vcpu->vmcs) {
+               mutex_unlock(&vcpu->mutex);
+               return -EEXIST;
+       }
+
+       vcpu->host_fx_image = (char*)ALIGN((hva_t)vcpu->fx_buf,
+                                          FX_IMAGE_ALIGN);
+       vcpu->guest_fx_image = vcpu->host_fx_image + FX_IMAGE_SIZE;
+
+       vcpu->cpu = -1;  /* First load will set up TR */
+       r = kvm_arch_ops->vcpu_create(vcpu);
+       if (r < 0)
+               goto out_free_vcpus;
+
+       r = kvm_mmu_create(vcpu);
+       if (r < 0)
+               goto out_free_vcpus;
+
+       kvm_arch_ops->vcpu_load(vcpu);
+       r = kvm_mmu_setup(vcpu);
+       if (r >= 0)
+               r = kvm_arch_ops->vcpu_setup(vcpu);
+       vcpu_put(vcpu);
+
+       if (r < 0)
+               goto out_free_vcpus;
+
+       return 0;
+
+out_free_vcpus:
+       kvm_free_vcpu(vcpu);
+       mutex_unlock(&vcpu->mutex);
+out:
+       return r;
+}
+
+/*
+ * Allocate some memory and give it an address in the guest physical address
+ * space.
+ *
+ * Discontiguous memory is allowed, mostly for framebuffers.
+ */
+static int kvm_dev_ioctl_set_memory_region(struct kvm *kvm,
+                                          struct kvm_memory_region *mem)
+{
+       int r;
+       gfn_t base_gfn;
+       unsigned long npages;
+       unsigned long i;
+       struct kvm_memory_slot *memslot;
+       struct kvm_memory_slot old, new;
+       int memory_config_version;
+
+       r = -EINVAL;
+       /* General sanity checks */
+       if (mem->memory_size & (PAGE_SIZE - 1))
+               goto out;
+       if (mem->guest_phys_addr & (PAGE_SIZE - 1))
+               goto out;
+       if (mem->slot >= KVM_MEMORY_SLOTS)
+               goto out;
+       if (mem->guest_phys_addr + mem->memory_size < mem->guest_phys_addr)
+               goto out;
+
+       memslot = &kvm->memslots[mem->slot];
+       base_gfn = mem->guest_phys_addr >> PAGE_SHIFT;
+       npages = mem->memory_size >> PAGE_SHIFT;
+
+       if (!npages)
+               mem->flags &= ~KVM_MEM_LOG_DIRTY_PAGES;
+
+raced:
+       spin_lock(&kvm->lock);
+
+       memory_config_version = kvm->memory_config_version;
+       new = old = *memslot;
+
+       new.base_gfn = base_gfn;
+       new.npages = npages;
+       new.flags = mem->flags;
+
+       /* Disallow changing a memory slot's size. */
+       r = -EINVAL;
+       if (npages && old.npages && npages != old.npages)
+               goto out_unlock;
+
+       /* Check for overlaps */
+       r = -EEXIST;
+       for (i = 0; i < KVM_MEMORY_SLOTS; ++i) {
+               struct kvm_memory_slot *s = &kvm->memslots[i];
+
+               if (s == memslot)
+                       continue;
+               if (!((base_gfn + npages <= s->base_gfn) ||
+                     (base_gfn >= s->base_gfn + s->npages)))
+                       goto out_unlock;
+       }
+       /*
+        * Do memory allocations outside lock.  memory_config_version will
+        * detect any races.
+        */
+       spin_unlock(&kvm->lock);
+
+       /* Deallocate if slot is being removed */
+       if (!npages)
+               new.phys_mem = 0;
+
+       /* Free page dirty bitmap if unneeded */
+       if (!(new.flags & KVM_MEM_LOG_DIRTY_PAGES))
+               new.dirty_bitmap = 0;
+
+       r = -ENOMEM;
+
+       /* Allocate if a slot is being created */
+       if (npages && !new.phys_mem) {
+               new.phys_mem = vmalloc(npages * sizeof(struct page *));
+
+               if (!new.phys_mem)
+                       goto out_free;
+
+               memset(new.phys_mem, 0, npages * sizeof(struct page *));
+               for (i = 0; i < npages; ++i) {
+                       new.phys_mem[i] = alloc_page(GFP_HIGHUSER
+                                                    | __GFP_ZERO);
+                       if (!new.phys_mem[i])
+                               goto out_free;
+                       new.phys_mem[i]->private = 0;
+               }
+       }
+
+       /* Allocate page dirty bitmap if needed */
+       if ((new.flags & KVM_MEM_LOG_DIRTY_PAGES) && !new.dirty_bitmap) {
+               unsigned dirty_bytes = ALIGN(npages, BITS_PER_LONG) / 8;
+
+               new.dirty_bitmap = vmalloc(dirty_bytes);
+               if (!new.dirty_bitmap)
+                       goto out_free;
+               memset(new.dirty_bitmap, 0, dirty_bytes);
+       }
+
+       spin_lock(&kvm->lock);
+
+       if (memory_config_version != kvm->memory_config_version) {
+               spin_unlock(&kvm->lock);
+               kvm_free_physmem_slot(&new, &old);
+               goto raced;
+       }
+
+       r = -EAGAIN;
+       if (kvm->busy)
+               goto out_unlock;
+
+       if (mem->slot >= kvm->nmemslots)
+               kvm->nmemslots = mem->slot + 1;
+
+       *memslot = new;
+       ++kvm->memory_config_version;
+
+       spin_unlock(&kvm->lock);
+
+       for (i = 0; i < KVM_MAX_VCPUS; ++i) {
+               struct kvm_vcpu *vcpu;
+
+               vcpu = vcpu_load(kvm, i);
+               if (!vcpu)
+                       continue;
+               kvm_mmu_reset_context(vcpu);
+               vcpu_put(vcpu);
+       }
+
+       kvm_free_physmem_slot(&old, &new);
+       return 0;
+
+out_unlock:
+       spin_unlock(&kvm->lock);
+out_free:
+       kvm_free_physmem_slot(&new, &old);
+out:
+       return r;
+}
+
+static void do_remove_write_access(struct kvm_vcpu *vcpu, int slot)
+{
+       spin_lock(&vcpu->kvm->lock);
+       kvm_mmu_slot_remove_write_access(vcpu, slot);
+       spin_unlock(&vcpu->kvm->lock);
+}
+
+/*
+ * Get (and clear) the dirty memory log for a memory slot.
+ */
+static int kvm_dev_ioctl_get_dirty_log(struct kvm *kvm,
+                                      struct kvm_dirty_log *log)
+{
+       struct kvm_memory_slot *memslot;
+       int r, i;
+       int n;
+       int cleared;
+       unsigned long any = 0;
+
+       spin_lock(&kvm->lock);
+
+       /*
+        * Prevent changes to guest memory configuration even while the lock
+        * is not taken.
+        */
+       ++kvm->busy;
+       spin_unlock(&kvm->lock);
+       r = -EINVAL;
+       if (log->slot >= KVM_MEMORY_SLOTS)
+               goto out;
+
+       memslot = &kvm->memslots[log->slot];
+       r = -ENOENT;
+       if (!memslot->dirty_bitmap)
+               goto out;
+
+       n = ALIGN(memslot->npages, 8) / 8;
+
+       for (i = 0; !any && i < n; ++i)
+               any = memslot->dirty_bitmap[i];
+
+       r = -EFAULT;
+       if (copy_to_user(log->dirty_bitmap, memslot->dirty_bitmap, n))
+               goto out;
+
+
+       if (any) {
+               cleared = 0;
+               for (i = 0; i < KVM_MAX_VCPUS; ++i) {
+                       struct kvm_vcpu *vcpu = vcpu_load(kvm, i);
+
+                       if (!vcpu)
+                               continue;
+                       if (!cleared) {
+                               do_remove_write_access(vcpu, log->slot);
+                               memset(memslot->dirty_bitmap, 0, n);
+                               cleared = 1;
+                       }
+                       kvm_arch_ops->tlb_flush(vcpu);
+                       vcpu_put(vcpu);
+               }
+       }
+
+       r = 0;
+
+out:
+       spin_lock(&kvm->lock);
+       --kvm->busy;
+       spin_unlock(&kvm->lock);
+       return r;
+}
+
+struct kvm_memory_slot *gfn_to_memslot(struct kvm *kvm, gfn_t gfn)
+{
+       int i;
+
+       for (i = 0; i < kvm->nmemslots; ++i) {
+               struct kvm_memory_slot *memslot = &kvm->memslots[i];
+
+               if (gfn >= memslot->base_gfn
+                   && gfn < memslot->base_gfn + memslot->npages)
+                       return memslot;
+       }
+       return 0;
+}
+EXPORT_SYMBOL_GPL(gfn_to_memslot);
+
+void mark_page_dirty(struct kvm *kvm, gfn_t gfn)
+{
+       int i;
+       struct kvm_memory_slot *memslot = 0;
+       unsigned long rel_gfn;
+
+       for (i = 0; i < kvm->nmemslots; ++i) {
+               memslot = &kvm->memslots[i];
+
+               if (gfn >= memslot->base_gfn
+                   && gfn < memslot->base_gfn + memslot->npages) {
+
+                       if (!memslot || !memslot->dirty_bitmap)
+                               return;
+
+                       rel_gfn = gfn - memslot->base_gfn;
+
+                       /* avoid RMW */
+                       if (!test_bit(rel_gfn, memslot->dirty_bitmap))
+                               set_bit(rel_gfn, memslot->dirty_bitmap);
+                       return;
+               }
+       }
+}
+
+static int emulator_read_std(unsigned long addr,
+                            unsigned long *val,
+                            unsigned int bytes,
+                            struct x86_emulate_ctxt *ctxt)
+{
+       struct kvm_vcpu *vcpu = ctxt->vcpu;
+       void *data = val;
+
+       while (bytes) {
+               gpa_t gpa = vcpu->mmu.gva_to_gpa(vcpu, addr);
+               unsigned offset = addr & (PAGE_SIZE-1);
+               unsigned tocopy = min(bytes, (unsigned)PAGE_SIZE - offset);
+               unsigned long pfn;
+               struct kvm_memory_slot *memslot;
+               void *page;
+
+               if (gpa == UNMAPPED_GVA)
+                       return X86EMUL_PROPAGATE_FAULT;
+               pfn = gpa >> PAGE_SHIFT;
+               memslot = gfn_to_memslot(vcpu->kvm, pfn);
+               if (!memslot)
+                       return X86EMUL_UNHANDLEABLE;
+               page = kmap_atomic(gfn_to_page(memslot, pfn), KM_USER0);
+
+               memcpy(data, page + offset, tocopy);
+
+               kunmap_atomic(page, KM_USER0);
+
+               bytes -= tocopy;
+               data += tocopy;
+               addr += tocopy;
+       }
+
+       return X86EMUL_CONTINUE;
+}
+
+static int emulator_write_std(unsigned long addr,
+                             unsigned long val,
+                             unsigned int bytes,
+                             struct x86_emulate_ctxt *ctxt)
+{
+       printk(KERN_ERR "emulator_write_std: addr %lx n %d\n",
+              addr, bytes);
+       return X86EMUL_UNHANDLEABLE;
+}
+
+static int emulator_read_emulated(unsigned long addr,
+                                 unsigned long *val,
+                                 unsigned int bytes,
+                                 struct x86_emulate_ctxt *ctxt)
+{
+       struct kvm_vcpu *vcpu = ctxt->vcpu;
+
+       if (vcpu->mmio_read_completed) {
+               memcpy(val, vcpu->mmio_data, bytes);
+               vcpu->mmio_read_completed = 0;
+               return X86EMUL_CONTINUE;
+       } else if (emulator_read_std(addr, val, bytes, ctxt)
+                  == X86EMUL_CONTINUE)
+               return X86EMUL_CONTINUE;
+       else {
+               gpa_t gpa = vcpu->mmu.gva_to_gpa(vcpu, addr);
+               if (gpa == UNMAPPED_GVA)
+                       return vcpu_printf(vcpu, "not present\n"), X86EMUL_PROPAGATE_FAULT;
+               vcpu->mmio_needed = 1;
+               vcpu->mmio_phys_addr = gpa;
+               vcpu->mmio_size = bytes;
+               vcpu->mmio_is_write = 0;
+
+               return X86EMUL_UNHANDLEABLE;
+       }
+}
+
+static int emulator_write_phys(struct kvm_vcpu *vcpu, gpa_t gpa,
+                              unsigned long val, int bytes)
+{
+       struct kvm_memory_slot *m;
+       struct page *page;
+       void *virt;
+
+       if (((gpa + bytes - 1) >> PAGE_SHIFT) != (gpa >> PAGE_SHIFT))
+               return 0;
+       m = gfn_to_memslot(vcpu->kvm, gpa >> PAGE_SHIFT);
+       if (!m)
+               return 0;
+       page = gfn_to_page(m, gpa >> PAGE_SHIFT);
+       kvm_mmu_pre_write(vcpu, gpa, bytes);
+       virt = kmap_atomic(page, KM_USER0);
+       memcpy(virt + offset_in_page(gpa), &val, bytes);
+       kunmap_atomic(virt, KM_USER0);
+       kvm_mmu_post_write(vcpu, gpa, bytes);
+       return 1;
+}
+
+static int emulator_write_emulated(unsigned long addr,
+                                  unsigned long val,
+                                  unsigned int bytes,
+                                  struct x86_emulate_ctxt *ctxt)
+{
+       struct kvm_vcpu *vcpu = ctxt->vcpu;
+       gpa_t gpa = vcpu->mmu.gva_to_gpa(vcpu, addr);
+
+       if (gpa == UNMAPPED_GVA)
+               return X86EMUL_PROPAGATE_FAULT;
+
+       if (emulator_write_phys(vcpu, gpa, val, bytes))
+               return X86EMUL_CONTINUE;
+
+       vcpu->mmio_needed = 1;
+       vcpu->mmio_phys_addr = gpa;
+       vcpu->mmio_size = bytes;
+       vcpu->mmio_is_write = 1;
+       memcpy(vcpu->mmio_data, &val, bytes);
+
+       return X86EMUL_CONTINUE;
+}
+
+static int emulator_cmpxchg_emulated(unsigned long addr,
+                                    unsigned long old,
+                                    unsigned long new,
+                                    unsigned int bytes,
+                                    struct x86_emulate_ctxt *ctxt)
+{
+       static int reported;
+
+       if (!reported) {
+               reported = 1;
+               printk(KERN_WARNING "kvm: emulating exchange as write\n");
+       }
+       return emulator_write_emulated(addr, new, bytes, ctxt);
+}
+
+#ifdef CONFIG_X86_32
+
+static int emulator_cmpxchg8b_emulated(unsigned long addr,
+                                      unsigned long old_lo,
+                                      unsigned long old_hi,
+                                      unsigned long new_lo,
+                                      unsigned long new_hi,
+                                      struct x86_emulate_ctxt *ctxt)
+{
+       static int reported;
+       int r;
+
+       if (!reported) {
+               reported = 1;
+               printk(KERN_WARNING "kvm: emulating exchange8b as write\n");
+       }
+       r = emulator_write_emulated(addr, new_lo, 4, ctxt);
+       if (r != X86EMUL_CONTINUE)
+               return r;
+       return emulator_write_emulated(addr+4, new_hi, 4, ctxt);
+}
+
+#endif
+
+static unsigned long get_segment_base(struct kvm_vcpu *vcpu, int seg)
+{
+       return kvm_arch_ops->get_segment_base(vcpu, seg);
+}
+
+int emulate_invlpg(struct kvm_vcpu *vcpu, gva_t address)
+{
+       return X86EMUL_CONTINUE;
+}
+
+int emulate_clts(struct kvm_vcpu *vcpu)
+{
+       unsigned long cr0;
+
+       kvm_arch_ops->decache_cr0_cr4_guest_bits(vcpu);
+       cr0 = vcpu->cr0 & ~CR0_TS_MASK;
+       kvm_arch_ops->set_cr0(vcpu, cr0);
+       return X86EMUL_CONTINUE;
+}
+
+int emulator_get_dr(struct x86_emulate_ctxt* ctxt, int dr, unsigned long *dest)
+{
+       struct kvm_vcpu *vcpu = ctxt->vcpu;
+
+       switch (dr) {
+       case 0 ... 3:
+               *dest = kvm_arch_ops->get_dr(vcpu, dr);
+               return X86EMUL_CONTINUE;
+       default:
+               printk(KERN_DEBUG "%s: unexpected dr %u\n",
+                      __FUNCTION__, dr);
+               return X86EMUL_UNHANDLEABLE;
+       }
+}
+
+int emulator_set_dr(struct x86_emulate_ctxt *ctxt, int dr, unsigned long value)
+{
+       unsigned long mask = (ctxt->mode == X86EMUL_MODE_PROT64) ? ~0ULL : ~0U;
+       int exception;
+
+       kvm_arch_ops->set_dr(ctxt->vcpu, dr, value & mask, &exception);
+       if (exception) {
+               /* FIXME: better handling */
+               return X86EMUL_UNHANDLEABLE;
+       }
+       return X86EMUL_CONTINUE;
+}
+
+static void report_emulation_failure(struct x86_emulate_ctxt *ctxt)
+{
+       static int reported;
+       u8 opcodes[4];
+       unsigned long rip = ctxt->vcpu->rip;
+       unsigned long rip_linear;
+
+       rip_linear = rip + get_segment_base(ctxt->vcpu, VCPU_SREG_CS);
+
+       if (reported)
+               return;
+
+       emulator_read_std(rip_linear, (void *)opcodes, 4, ctxt);
+
+       printk(KERN_ERR "emulation failed but !mmio_needed?"
+              " rip %lx %02x %02x %02x %02x\n",
+              rip, opcodes[0], opcodes[1], opcodes[2], opcodes[3]);
+       reported = 1;
+}
+
+struct x86_emulate_ops emulate_ops = {
+       .read_std            = emulator_read_std,
+       .write_std           = emulator_write_std,
+       .read_emulated       = emulator_read_emulated,
+       .write_emulated      = emulator_write_emulated,
+       .cmpxchg_emulated    = emulator_cmpxchg_emulated,
+#ifdef CONFIG_X86_32
+       .cmpxchg8b_emulated  = emulator_cmpxchg8b_emulated,
+#endif
+};
+
+int emulate_instruction(struct kvm_vcpu *vcpu,
+                       struct kvm_run *run,
+                       unsigned long cr2,
+                       u16 error_code)
+{
+       struct x86_emulate_ctxt emulate_ctxt;
+       int r;
+       int cs_db, cs_l;
+
+       kvm_arch_ops->cache_regs(vcpu);
+
+       kvm_arch_ops->get_cs_db_l_bits(vcpu, &cs_db, &cs_l);
+
+       emulate_ctxt.vcpu = vcpu;
+       emulate_ctxt.eflags = kvm_arch_ops->get_rflags(vcpu);
+       emulate_ctxt.cr2 = cr2;
+       emulate_ctxt.mode = (emulate_ctxt.eflags & X86_EFLAGS_VM)
+               ? X86EMUL_MODE_REAL : cs_l
+               ? X86EMUL_MODE_PROT64 : cs_db
+               ? X86EMUL_MODE_PROT32 : X86EMUL_MODE_PROT16;
+
+       if (emulate_ctxt.mode == X86EMUL_MODE_PROT64) {
+               emulate_ctxt.cs_base = 0;
+               emulate_ctxt.ds_base = 0;
+               emulate_ctxt.es_base = 0;
+               emulate_ctxt.ss_base = 0;
+       } else {
+               emulate_ctxt.cs_base = get_segment_base(vcpu, VCPU_SREG_CS);
+               emulate_ctxt.ds_base = get_segment_base(vcpu, VCPU_SREG_DS);
+               emulate_ctxt.es_base = get_segment_base(vcpu, VCPU_SREG_ES);
+               emulate_ctxt.ss_base = get_segment_base(vcpu, VCPU_SREG_SS);
+       }
+
+       emulate_ctxt.gs_base = get_segment_base(vcpu, VCPU_SREG_GS);
+       emulate_ctxt.fs_base = get_segment_base(vcpu, VCPU_SREG_FS);
+
+       vcpu->mmio_is_write = 0;
+       r = x86_emulate_memop(&emulate_ctxt, &emulate_ops);
+
+       if ((r || vcpu->mmio_is_write) && run) {
+               run->mmio.phys_addr = vcpu->mmio_phys_addr;
+               memcpy(run->mmio.data, vcpu->mmio_data, 8);
+               run->mmio.len = vcpu->mmio_size;
+               run->mmio.is_write = vcpu->mmio_is_write;
+       }
+
+       if (r) {
+               if (kvm_mmu_unprotect_page_virt(vcpu, cr2))
+                       return EMULATE_DONE;
+               if (!vcpu->mmio_needed) {
+                       report_emulation_failure(&emulate_ctxt);
+                       return EMULATE_FAIL;
+               }
+               return EMULATE_DO_MMIO;
+       }
+
+       kvm_arch_ops->decache_regs(vcpu);
+       kvm_arch_ops->set_rflags(vcpu, emulate_ctxt.eflags);
+
+       if (vcpu->mmio_is_write)
+               return EMULATE_DO_MMIO;
+
+       return EMULATE_DONE;
+}
+EXPORT_SYMBOL_GPL(emulate_instruction);
+
+static u64 mk_cr_64(u64 curr_cr, u32 new_val)
+{
+       return (curr_cr & ~((1ULL << 32) - 1)) | new_val;
+}
+
+void realmode_lgdt(struct kvm_vcpu *vcpu, u16 limit, unsigned long base)
+{
+       struct descriptor_table dt = { limit, base };
+
+       kvm_arch_ops->set_gdt(vcpu, &dt);
+}
+
+void realmode_lidt(struct kvm_vcpu *vcpu, u16 limit, unsigned long base)
+{
+       struct descriptor_table dt = { limit, base };
+
+       kvm_arch_ops->set_idt(vcpu, &dt);
+}
+
+void realmode_lmsw(struct kvm_vcpu *vcpu, unsigned long msw,
+                  unsigned long *rflags)
+{
+       lmsw(vcpu, msw);
+       *rflags = kvm_arch_ops->get_rflags(vcpu);
+}
+
+unsigned long realmode_get_cr(struct kvm_vcpu *vcpu, int cr)
+{
+       kvm_arch_ops->decache_cr0_cr4_guest_bits(vcpu);
+       switch (cr) {
+       case 0:
+               return vcpu->cr0;
+       case 2:
+               return vcpu->cr2;
+       case 3:
+               return vcpu->cr3;
+       case 4:
+               return vcpu->cr4;
+       default:
+               vcpu_printf(vcpu, "%s: unexpected cr %u\n", __FUNCTION__, cr);
+               return 0;
+       }
+}
+
+void realmode_set_cr(struct kvm_vcpu *vcpu, int cr, unsigned long val,
+                    unsigned long *rflags)
+{
+       switch (cr) {
+       case 0:
+               set_cr0(vcpu, mk_cr_64(vcpu->cr0, val));
+               *rflags = kvm_arch_ops->get_rflags(vcpu);
+               break;
+       case 2:
+               vcpu->cr2 = val;
+               break;
+       case 3:
+               set_cr3(vcpu, val);
+               break;
+       case 4:
+               set_cr4(vcpu, mk_cr_64(vcpu->cr4, val));
+               break;
+       default:
+               vcpu_printf(vcpu, "%s: unexpected cr %u\n", __FUNCTION__, cr);
+       }
+}
+
+int kvm_get_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata)
+{
+       u64 data;
+
+       switch (msr) {
+       case 0xc0010010: /* SYSCFG */
+       case 0xc0010015: /* HWCR */
+       case MSR_IA32_PLATFORM_ID:
+       case MSR_IA32_P5_MC_ADDR:
+       case MSR_IA32_P5_MC_TYPE:
+       case MSR_IA32_MC0_CTL:
+       case MSR_IA32_MCG_STATUS:
+       case MSR_IA32_MCG_CAP:
+       case MSR_IA32_MC0_MISC:
+       case MSR_IA32_MC0_MISC+4:
+       case MSR_IA32_MC0_MISC+8:
+       case MSR_IA32_MC0_MISC+12:
+       case MSR_IA32_MC0_MISC+16:
+       case MSR_IA32_UCODE_REV:
+       case MSR_IA32_PERF_STATUS:
+               /* MTRR registers */
+       case 0xfe:
+       case 0x200 ... 0x2ff:
+               data = 0;
+               break;
+       case 0xcd: /* fsb frequency */
+               data = 3;
+               break;
+       case MSR_IA32_APICBASE:
+               data = vcpu->apic_base;
+               break;
+       case MSR_IA32_MISC_ENABLE:
+               data = vcpu->ia32_misc_enable_msr;
+               break;
+#ifdef CONFIG_X86_64
+       case MSR_EFER:
+               data = vcpu->shadow_efer;
+               break;
+#endif
+       default:
+               printk(KERN_ERR "kvm: unhandled rdmsr: 0x%x\n", msr);
+               return 1;
+       }
+       *pdata = data;
+       return 0;
+}
+EXPORT_SYMBOL_GPL(kvm_get_msr_common);
+
+/*
+ * Reads an msr value (of 'msr_index') into 'pdata'.
+ * Returns 0 on success, non-0 otherwise.
+ * Assumes vcpu_load() was already called.
+ */
+static int get_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 *pdata)
+{
+       return kvm_arch_ops->get_msr(vcpu, msr_index, pdata);
+}
+
+#ifdef CONFIG_X86_64
+
+static void set_efer(struct kvm_vcpu *vcpu, u64 efer)
+{
+       if (efer & EFER_RESERVED_BITS) {
+               printk(KERN_DEBUG "set_efer: 0x%llx #GP, reserved bits\n",
+                      efer);
+               inject_gp(vcpu);
+               return;
+       }
+
+       if (is_paging(vcpu)
+           && (vcpu->shadow_efer & EFER_LME) != (efer & EFER_LME)) {
+               printk(KERN_DEBUG "set_efer: #GP, change LME while paging\n");
+               inject_gp(vcpu);
+               return;
+       }
+
+       kvm_arch_ops->set_efer(vcpu, efer);
+
+       efer &= ~EFER_LMA;
+       efer |= vcpu->shadow_efer & EFER_LMA;
+
+       vcpu->shadow_efer = efer;
+}
+
+#endif
+
+int kvm_set_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 data)
+{
+       switch (msr) {
+#ifdef CONFIG_X86_64
+       case MSR_EFER:
+               set_efer(vcpu, data);
+               break;
+#endif
+       case MSR_IA32_MC0_STATUS:
+               printk(KERN_WARNING "%s: MSR_IA32_MC0_STATUS 0x%llx, nop\n",
+                      __FUNCTION__, data);
+               break;
+       case MSR_IA32_UCODE_REV:
+       case MSR_IA32_UCODE_WRITE:
+       case 0x200 ... 0x2ff: /* MTRRs */
+               break;
+       case MSR_IA32_APICBASE:
+               vcpu->apic_base = data;
+               break;
+       case MSR_IA32_MISC_ENABLE:
+               vcpu->ia32_misc_enable_msr = data;
+               break;
+       default:
+               printk(KERN_ERR "kvm: unhandled wrmsr: 0x%x\n", msr);
+               return 1;
+       }
+       return 0;
+}
+EXPORT_SYMBOL_GPL(kvm_set_msr_common);
+
+/*
+ * Writes msr value into into the appropriate "register".
+ * Returns 0 on success, non-0 otherwise.
+ * Assumes vcpu_load() was already called.
+ */
+static int set_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 data)
+{
+       return kvm_arch_ops->set_msr(vcpu, msr_index, data);
+}
+
+void kvm_resched(struct kvm_vcpu *vcpu)
+{
+       vcpu_put(vcpu);
+       cond_resched();
+       /* Cannot fail -  no vcpu unplug yet. */
+       vcpu_load(vcpu->kvm, vcpu_slot(vcpu));
+}
+EXPORT_SYMBOL_GPL(kvm_resched);
+
+void load_msrs(struct vmx_msr_entry *e, int n)
+{
+       int i;
+
+       for (i = 0; i < n; ++i)
+               wrmsrl(e[i].index, e[i].data);
+}
+EXPORT_SYMBOL_GPL(load_msrs);
+
+void save_msrs(struct vmx_msr_entry *e, int n)
+{
+       int i;
+
+       for (i = 0; i < n; ++i)
+               rdmsrl(e[i].index, e[i].data);
+}
+EXPORT_SYMBOL_GPL(save_msrs);
+
+static int kvm_dev_ioctl_run(struct kvm *kvm, struct kvm_run *kvm_run)
+{
+       struct kvm_vcpu *vcpu;
+       int r;
+
+       if (!valid_vcpu(kvm_run->vcpu))
+               return -EINVAL;
+
+       vcpu = vcpu_load(kvm, kvm_run->vcpu);
+       if (!vcpu)
+               return -ENOENT;
+
+       if (kvm_run->emulated) {
+               kvm_arch_ops->skip_emulated_instruction(vcpu);
+               kvm_run->emulated = 0;
+       }
+
+       if (kvm_run->mmio_completed) {
+               memcpy(vcpu->mmio_data, kvm_run->mmio.data, 8);
+               vcpu->mmio_read_completed = 1;
+       }
+
+       vcpu->mmio_needed = 0;
+
+       r = kvm_arch_ops->run(vcpu, kvm_run);
+
+       vcpu_put(vcpu);
+       return r;
+}
+
+static int kvm_dev_ioctl_get_regs(struct kvm *kvm, struct kvm_regs *regs)
+{
+       struct kvm_vcpu *vcpu;
+
+       if (!valid_vcpu(regs->vcpu))
+               return -EINVAL;
+
+       vcpu = vcpu_load(kvm, regs->vcpu);
+       if (!vcpu)
+               return -ENOENT;
+
+       kvm_arch_ops->cache_regs(vcpu);
+
+       regs->rax = vcpu->regs[VCPU_REGS_RAX];
+       regs->rbx = vcpu->regs[VCPU_REGS_RBX];
+       regs->rcx = vcpu->regs[VCPU_REGS_RCX];
+       regs->rdx = vcpu->regs[VCPU_REGS_RDX];
+       regs->rsi = vcpu->regs[VCPU_REGS_RSI];
+       regs->rdi = vcpu->regs[VCPU_REGS_RDI];
+       regs->rsp = vcpu->regs[VCPU_REGS_RSP];
+       regs->rbp = vcpu->regs[VCPU_REGS_RBP];
+#ifdef CONFIG_X86_64
+       regs->r8 = vcpu->regs[VCPU_REGS_R8];
+       regs->r9 = vcpu->regs[VCPU_REGS_R9];
+       regs->r10 = vcpu->regs[VCPU_REGS_R10];
+       regs->r11 = vcpu->regs[VCPU_REGS_R11];
+       regs->r12 = vcpu->regs[VCPU_REGS_R12];
+       regs->r13 = vcpu->regs[VCPU_REGS_R13];
+       regs->r14 = vcpu->regs[VCPU_REGS_R14];
+       regs->r15 = vcpu->regs[VCPU_REGS_R15];
+#endif
+
+       regs->rip = vcpu->rip;
+       regs->rflags = kvm_arch_ops->get_rflags(vcpu);
+
+       /*
+        * Don't leak debug flags in case they were set for guest debugging
+        */
+       if (vcpu->guest_debug.enabled && vcpu->guest_debug.singlestep)
+               regs->rflags &= ~(X86_EFLAGS_TF | X86_EFLAGS_RF);
+
+       vcpu_put(vcpu);
+
+       return 0;
+}
+
+static int kvm_dev_ioctl_set_regs(struct kvm *kvm, struct kvm_regs *regs)
+{
+       struct kvm_vcpu *vcpu;
+
+       if (!valid_vcpu(regs->vcpu))
+               return -EINVAL;
+
+       vcpu = vcpu_load(kvm, regs->vcpu);
+       if (!vcpu)
+               return -ENOENT;
+
+       vcpu->regs[VCPU_REGS_RAX] = regs->rax;
+       vcpu->regs[VCPU_REGS_RBX] = regs->rbx;
+       vcpu->regs[VCPU_REGS_RCX] = regs->rcx;
+       vcpu->regs[VCPU_REGS_RDX] = regs->rdx;
+       vcpu->regs[VCPU_REGS_RSI] = regs->rsi;
+       vcpu->regs[VCPU_REGS_RDI] = regs->rdi;
+       vcpu->regs[VCPU_REGS_RSP] = regs->rsp;
+       vcpu->regs[VCPU_REGS_RBP] = regs->rbp;
+#ifdef CONFIG_X86_64
+       vcpu->regs[VCPU_REGS_R8] = regs->r8;
+       vcpu->regs[VCPU_REGS_R9] = regs->r9;
+       vcpu->regs[VCPU_REGS_R10] = regs->r10;
+       vcpu->regs[VCPU_REGS_R11] = regs->r11;
+       vcpu->regs[VCPU_REGS_R12] = regs->r12;
+       vcpu->regs[VCPU_REGS_R13] = regs->r13;
+       vcpu->regs[VCPU_REGS_R14] = regs->r14;
+       vcpu->regs[VCPU_REGS_R15] = regs->r15;
+#endif
+
+       vcpu->rip = regs->rip;
+       kvm_arch_ops->set_rflags(vcpu, regs->rflags);
+
+       kvm_arch_ops->decache_regs(vcpu);
+
+       vcpu_put(vcpu);
+
+       return 0;
+}
+
+static void get_segment(struct kvm_vcpu *vcpu,
+                       struct kvm_segment *var, int seg)
+{
+       return kvm_arch_ops->get_segment(vcpu, var, seg);
+}
+
+static int kvm_dev_ioctl_get_sregs(struct kvm *kvm, struct kvm_sregs *sregs)
+{
+       struct kvm_vcpu *vcpu;
+       struct descriptor_table dt;
+
+       if (!valid_vcpu(sregs->vcpu))
+               return -EINVAL;
+       vcpu = vcpu_load(kvm, sregs->vcpu);
+       if (!vcpu)
+               return -ENOENT;
+
+       get_segment(vcpu, &sregs->cs, VCPU_SREG_CS);
+       get_segment(vcpu, &sregs->ds, VCPU_SREG_DS);
+       get_segment(vcpu, &sregs->es, VCPU_SREG_ES);
+       get_segment(vcpu, &sregs->fs, VCPU_SREG_FS);
+       get_segment(vcpu, &sregs->gs, VCPU_SREG_GS);
+       get_segment(vcpu, &sregs->ss, VCPU_SREG_SS);
+
+       get_segment(vcpu, &sregs->tr, VCPU_SREG_TR);
+       get_segment(vcpu, &sregs->ldt, VCPU_SREG_LDTR);
+
+       kvm_arch_ops->get_idt(vcpu, &dt);
+       sregs->idt.limit = dt.limit;
+       sregs->idt.base = dt.base;
+       kvm_arch_ops->get_gdt(vcpu, &dt);
+       sregs->gdt.limit = dt.limit;
+       sregs->gdt.base = dt.base;
+
+       kvm_arch_ops->decache_cr0_cr4_guest_bits(vcpu);
+       sregs->cr0 = vcpu->cr0;
+       sregs->cr2 = vcpu->cr2;
+       sregs->cr3 = vcpu->cr3;
+       sregs->cr4 = vcpu->cr4;
+       sregs->cr8 = vcpu->cr8;
+       sregs->efer = vcpu->shadow_efer;
+       sregs->apic_base = vcpu->apic_base;
+
+       memcpy(sregs->interrupt_bitmap, vcpu->irq_pending,
+              sizeof sregs->interrupt_bitmap);
+
+       vcpu_put(vcpu);
+
+       return 0;
+}
+
+static void set_segment(struct kvm_vcpu *vcpu,
+                       struct kvm_segment *var, int seg)
+{
+       return kvm_arch_ops->set_segment(vcpu, var, seg);
+}
+
+static int kvm_dev_ioctl_set_sregs(struct kvm *kvm, struct kvm_sregs *sregs)
+{
+       struct kvm_vcpu *vcpu;
+       int mmu_reset_needed = 0;
+       int i;
+       struct descriptor_table dt;
+
+       if (!valid_vcpu(sregs->vcpu))
+               return -EINVAL;
+       vcpu = vcpu_load(kvm, sregs->vcpu);
+       if (!vcpu)
+               return -ENOENT;
+
+       set_segment(vcpu, &sregs->cs, VCPU_SREG_CS);
+       set_segment(vcpu, &sregs->ds, VCPU_SREG_DS);
+       set_segment(vcpu, &sregs->es, VCPU_SREG_ES);
+       set_segment(vcpu, &sregs->fs, VCPU_SREG_FS);
+       set_segment(vcpu, &sregs->gs, VCPU_SREG_GS);
+       set_segment(vcpu, &sregs->ss, VCPU_SREG_SS);
+
+       set_segment(vcpu, &sregs->tr, VCPU_SREG_TR);
+       set_segment(vcpu, &sregs->ldt, VCPU_SREG_LDTR);
+
+       dt.limit = sregs->idt.limit;
+       dt.base = sregs->idt.base;
+       kvm_arch_ops->set_idt(vcpu, &dt);
+       dt.limit = sregs->gdt.limit;
+       dt.base = sregs->gdt.base;
+       kvm_arch_ops->set_gdt(vcpu, &dt);
+
+       vcpu->cr2 = sregs->cr2;
+       mmu_reset_needed |= vcpu->cr3 != sregs->cr3;
+       vcpu->cr3 = sregs->cr3;
+
+       vcpu->cr8 = sregs->cr8;
+
+       mmu_reset_needed |= vcpu->shadow_efer != sregs->efer;
+#ifdef CONFIG_X86_64
+       kvm_arch_ops->set_efer(vcpu, sregs->efer);
+#endif
+       vcpu->apic_base = sregs->apic_base;
+
+       kvm_arch_ops->decache_cr0_cr4_guest_bits(vcpu);
+
+       mmu_reset_needed |= vcpu->cr0 != sregs->cr0;
+       kvm_arch_ops->set_cr0_no_modeswitch(vcpu, sregs->cr0);
+
+       mmu_reset_needed |= vcpu->cr4 != sregs->cr4;
+       kvm_arch_ops->set_cr4(vcpu, sregs->cr4);
+       if (!is_long_mode(vcpu) && is_pae(vcpu))
+               load_pdptrs(vcpu, vcpu->cr3);
+
+       if (mmu_reset_needed)
+               kvm_mmu_reset_context(vcpu);
+
+       memcpy(vcpu->irq_pending, sregs->interrupt_bitmap,
+              sizeof vcpu->irq_pending);
+       vcpu->irq_summary = 0;
+       for (i = 0; i < NR_IRQ_WORDS; ++i)
+               if (vcpu->irq_pending[i])
+                       __set_bit(i, &vcpu->irq_summary);
+
+       vcpu_put(vcpu);
+
+       return 0;
+}
+
+/*
+ * List of msr numbers which we expose to userspace through KVM_GET_MSRS
+ * and KVM_SET_MSRS, and KVM_GET_MSR_INDEX_LIST.
+ *
+ * This list is modified at module load time to reflect the
+ * capabilities of the host cpu.
+ */
+static u32 msrs_to_save[] = {
+       MSR_IA32_SYSENTER_CS, MSR_IA32_SYSENTER_ESP, MSR_IA32_SYSENTER_EIP,
+       MSR_K6_STAR,
+#ifdef CONFIG_X86_64
+       MSR_CSTAR, MSR_KERNEL_GS_BASE, MSR_SYSCALL_MASK, MSR_LSTAR,
+#endif
+       MSR_IA32_TIME_STAMP_COUNTER,
+};
+
+static unsigned num_msrs_to_save;
+
+static u32 emulated_msrs[] = {
+       MSR_IA32_MISC_ENABLE,
+};
+
+static __init void kvm_init_msr_list(void)
+{
+       u32 dummy[2];
+       unsigned i, j;
+
+       for (i = j = 0; i < ARRAY_SIZE(msrs_to_save); i++) {
+               if (rdmsr_safe(msrs_to_save[i], &dummy[0], &dummy[1]) < 0)
+                       continue;
+               if (j < i)
+                       msrs_to_save[j] = msrs_to_save[i];
+               j++;
+       }
+       num_msrs_to_save = j;
+}
+
+/*
+ * Adapt set_msr() to msr_io()'s calling convention
+ */
+static int do_set_msr(struct kvm_vcpu *vcpu, unsigned index, u64 *data)
+{
+       return set_msr(vcpu, index, *data);
+}
+
+/*
+ * Read or write a bunch of msrs. All parameters are kernel addresses.
+ *
+ * @return number of msrs set successfully.
+ */
+static int __msr_io(struct kvm *kvm, struct kvm_msrs *msrs,
+                   struct kvm_msr_entry *entries,
+                   int (*do_msr)(struct kvm_vcpu *vcpu,
+                                 unsigned index, u64 *data))
+{
+       struct kvm_vcpu *vcpu;
+       int i;
+
+       if (!valid_vcpu(msrs->vcpu))
+               return -EINVAL;
+
+       vcpu = vcpu_load(kvm, msrs->vcpu);
+       if (!vcpu)
+               return -ENOENT;
+
+       for (i = 0; i < msrs->nmsrs; ++i)
+               if (do_msr(vcpu, entries[i].index, &entries[i].data))
+                       break;
+
+       vcpu_put(vcpu);
+
+       return i;
+}
+
+/*
+ * Read or write a bunch of msrs. Parameters are user addresses.
+ *
+ * @return number of msrs set successfully.
+ */
+static int msr_io(struct kvm *kvm, struct kvm_msrs __user *user_msrs,
+                 int (*do_msr)(struct kvm_vcpu *vcpu,
+                               unsigned index, u64 *data),
+                 int writeback)
+{
+       struct kvm_msrs msrs;
+       struct kvm_msr_entry *entries;
+       int r, n;
+       unsigned size;
+
+       r = -EFAULT;
+       if (copy_from_user(&msrs, user_msrs, sizeof msrs))
+               goto out;
+
+       r = -E2BIG;
+       if (msrs.nmsrs >= MAX_IO_MSRS)
+               goto out;
+
+       r = -ENOMEM;
+       size = sizeof(struct kvm_msr_entry) * msrs.nmsrs;
+       entries = vmalloc(size);
+       if (!entries)
+               goto out;
+
+       r = -EFAULT;
+       if (copy_from_user(entries, user_msrs->entries, size))
+               goto out_free;
+
+       r = n = __msr_io(kvm, &msrs, entries, do_msr);
+       if (r < 0)
+               goto out_free;
+
+       r = -EFAULT;
+       if (writeback && copy_to_user(user_msrs->entries, entries, size))
+               goto out_free;
+
+       r = n;
+
+out_free:
+       vfree(entries);
+out:
+       return r;
+}
+
+/*
+ * Translate a guest virtual address to a guest physical address.
+ */
+static int kvm_dev_ioctl_translate(struct kvm *kvm, struct kvm_translation *tr)
+{
+       unsigned long vaddr = tr->linear_address;
+       struct kvm_vcpu *vcpu;
+       gpa_t gpa;
+
+       vcpu = vcpu_load(kvm, tr->vcpu);
+       if (!vcpu)
+               return -ENOENT;
+       spin_lock(&kvm->lock);
+       gpa = vcpu->mmu.gva_to_gpa(vcpu, vaddr);
+       tr->physical_address = gpa;
+       tr->valid = gpa != UNMAPPED_GVA;
+       tr->writeable = 1;
+       tr->usermode = 0;
+       spin_unlock(&kvm->lock);
+       vcpu_put(vcpu);
+
+       return 0;
+}
+
+static int kvm_dev_ioctl_interrupt(struct kvm *kvm, struct kvm_interrupt *irq)
+{
+       struct kvm_vcpu *vcpu;
+
+       if (!valid_vcpu(irq->vcpu))
+               return -EINVAL;
+       if (irq->irq < 0 || irq->irq >= 256)
+               return -EINVAL;
+       vcpu = vcpu_load(kvm, irq->vcpu);
+       if (!vcpu)
+               return -ENOENT;
+
+       set_bit(irq->irq, vcpu->irq_pending);
+       set_bit(irq->irq / BITS_PER_LONG, &vcpu->irq_summary);
+
+       vcpu_put(vcpu);
+
+       return 0;
+}
+
+static int kvm_dev_ioctl_debug_guest(struct kvm *kvm,
+                                    struct kvm_debug_guest *dbg)
+{
+       struct kvm_vcpu *vcpu;
+       int r;
+
+       if (!valid_vcpu(dbg->vcpu))
+               return -EINVAL;
+       vcpu = vcpu_load(kvm, dbg->vcpu);
+       if (!vcpu)
+               return -ENOENT;
+
+       r = kvm_arch_ops->set_guest_debug(vcpu, dbg);
+
+       vcpu_put(vcpu);
+
+       return r;
+}
+
+static long kvm_dev_ioctl(struct file *filp,
+                         unsigned int ioctl, unsigned long arg)
+{
+       struct kvm *kvm = filp->private_data;
+       int r = -EINVAL;
+
+       switch (ioctl) {
+       case KVM_GET_API_VERSION:
+               r = KVM_API_VERSION;
+               break;
+       case KVM_CREATE_VCPU: {
+               r = kvm_dev_ioctl_create_vcpu(kvm, arg);
+               if (r)
+                       goto out;
+               break;
+       }
+       case KVM_RUN: {
+               struct kvm_run kvm_run;
+
+               r = -EFAULT;
+               if (copy_from_user(&kvm_run, (void *)arg, sizeof kvm_run))
+                       goto out;
+               r = kvm_dev_ioctl_run(kvm, &kvm_run);
+               if (r < 0 &&  r != -EINTR)
+                       goto out;
+               if (copy_to_user((void *)arg, &kvm_run, sizeof kvm_run)) {
+                       r = -EFAULT;
+                       goto out;
+               }
+               break;
+       }
+       case KVM_GET_REGS: {
+               struct kvm_regs kvm_regs;
+
+               r = -EFAULT;
+               if (copy_from_user(&kvm_regs, (void *)arg, sizeof kvm_regs))
+                       goto out;
+               r = kvm_dev_ioctl_get_regs(kvm, &kvm_regs);
+               if (r)
+                       goto out;
+               r = -EFAULT;
+               if (copy_to_user((void *)arg, &kvm_regs, sizeof kvm_regs))
+                       goto out;
+               r = 0;
+               break;
+       }
+       case KVM_SET_REGS: {
+               struct kvm_regs kvm_regs;
+
+               r = -EFAULT;
+               if (copy_from_user(&kvm_regs, (void *)arg, sizeof kvm_regs))
+                       goto out;
+               r = kvm_dev_ioctl_set_regs(kvm, &kvm_regs);
+               if (r)
+                       goto out;
+               r = 0;
+               break;
+       }
+       case KVM_GET_SREGS: {
+               struct kvm_sregs kvm_sregs;
+
+               r = -EFAULT;
+               if (copy_from_user(&kvm_sregs, (void *)arg, sizeof kvm_sregs))
+                       goto out;
+               r = kvm_dev_ioctl_get_sregs(kvm, &kvm_sregs);
+               if (r)
+                       goto out;
+               r = -EFAULT;
+               if (copy_to_user((void *)arg, &kvm_sregs, sizeof kvm_sregs))
+                       goto out;
+               r = 0;
+               break;
+       }
+       case KVM_SET_SREGS: {
+               struct kvm_sregs kvm_sregs;
+
+               r = -EFAULT;
+               if (copy_from_user(&kvm_sregs, (void *)arg, sizeof kvm_sregs))
+                       goto out;
+               r = kvm_dev_ioctl_set_sregs(kvm, &kvm_sregs);
+               if (r)
+                       goto out;
+               r = 0;
+               break;
+       }
+       case KVM_TRANSLATE: {
+               struct kvm_translation tr;
+
+               r = -EFAULT;
+               if (copy_from_user(&tr, (void *)arg, sizeof tr))
+                       goto out;
+               r = kvm_dev_ioctl_translate(kvm, &tr);
+               if (r)
+                       goto out;
+               r = -EFAULT;
+               if (copy_to_user((void *)arg, &tr, sizeof tr))
+                       goto out;
+               r = 0;
+               break;
+       }
+       case KVM_INTERRUPT: {
+               struct kvm_interrupt irq;
+
+               r = -EFAULT;
+               if (copy_from_user(&irq, (void *)arg, sizeof irq))
+                       goto out;
+               r = kvm_dev_ioctl_interrupt(kvm, &irq);
+               if (r)
+                       goto out;
+               r = 0;
+               break;
+       }
+       case KVM_DEBUG_GUEST: {
+               struct kvm_debug_guest dbg;
+
+               r = -EFAULT;
+               if (copy_from_user(&dbg, (void *)arg, sizeof dbg))
+                       goto out;
+               r = kvm_dev_ioctl_debug_guest(kvm, &dbg);
+               if (r)
+                       goto out;
+               r = 0;
+               break;
+       }
+       case KVM_SET_MEMORY_REGION: {
+               struct kvm_memory_region kvm_mem;
+
+               r = -EFAULT;
+               if (copy_from_user(&kvm_mem, (void *)arg, sizeof kvm_mem))
+                       goto out;
+               r = kvm_dev_ioctl_set_memory_region(kvm, &kvm_mem);
+               if (r)
+                       goto out;
+               break;
+       }
+       case KVM_GET_DIRTY_LOG: {
+               struct kvm_dirty_log log;
+
+               r = -EFAULT;
+               if (copy_from_user(&log, (void *)arg, sizeof log))
+                       goto out;
+               r = kvm_dev_ioctl_get_dirty_log(kvm, &log);
+               if (r)
+                       goto out;
+               break;
+       }
+       case KVM_GET_MSRS:
+               r = msr_io(kvm, (void __user *)arg, get_msr, 1);
+               break;
+       case KVM_SET_MSRS:
+               r = msr_io(kvm, (void __user *)arg, do_set_msr, 0);
+               break;
+       case KVM_GET_MSR_INDEX_LIST: {
+               struct kvm_msr_list __user *user_msr_list = (void __user *)arg;
+               struct kvm_msr_list msr_list;
+               unsigned n;
+
+               r = -EFAULT;
+               if (copy_from_user(&msr_list, user_msr_list, sizeof msr_list))
+                       goto out;
+               n = msr_list.nmsrs;
+               msr_list.nmsrs = num_msrs_to_save + ARRAY_SIZE(emulated_msrs);
+               if (copy_to_user(user_msr_list, &msr_list, sizeof msr_list))
+                       goto out;
+               r = -E2BIG;
+               if (n < num_msrs_to_save)
+                       goto out;
+               r = -EFAULT;
+               if (copy_to_user(user_msr_list->indices, &msrs_to_save,
+                                num_msrs_to_save * sizeof(u32)))
+                       goto out;
+               if (copy_to_user(user_msr_list->indices
+                                + num_msrs_to_save * sizeof(u32),
+                                &emulated_msrs,
+                                ARRAY_SIZE(emulated_msrs) * sizeof(u32)))
+                       goto out;
+               r = 0;
+               break;
+       }
+       default:
+               ;
+       }
+out:
+       return r;
+}
+
+static struct page *kvm_dev_nopage(struct vm_area_struct *vma,
+                                  unsigned long address,
+                                  int *type)
+{
+       struct kvm *kvm = vma->vm_file->private_data;
+       unsigned long pgoff;
+       struct kvm_memory_slot *slot;
+       struct page *page;
+
+       *type = VM_FAULT_MINOR;
+       pgoff = ((address - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff;
+       slot = gfn_to_memslot(kvm, pgoff);
+       if (!slot)
+               return NOPAGE_SIGBUS;
+       page = gfn_to_page(slot, pgoff);
+       if (!page)
+               return NOPAGE_SIGBUS;
+       get_page(page);
+       return page;
+}
+
+static struct vm_operations_struct kvm_dev_vm_ops = {
+       .nopage = kvm_dev_nopage,
+};
+
+static int kvm_dev_mmap(struct file *file, struct vm_area_struct *vma)
+{
+       vma->vm_ops = &kvm_dev_vm_ops;
+       return 0;
+}
+
+static struct file_operations kvm_chardev_ops = {
+       .open           = kvm_dev_open,
+       .release        = kvm_dev_release,
+       .unlocked_ioctl = kvm_dev_ioctl,
+       .compat_ioctl   = kvm_dev_ioctl,
+       .mmap           = kvm_dev_mmap,
+};
+
+static struct miscdevice kvm_dev = {
+       MISC_DYNAMIC_MINOR,
+       "kvm",
+       &kvm_chardev_ops,
+};
+
+static int kvm_reboot(struct notifier_block *notifier, unsigned long val,
+                       void *v)
+{
+       if (val == SYS_RESTART) {
+               /*
+                * Some (well, at least mine) BIOSes hang on reboot if
+                * in vmx root mode.
+                */
+               printk(KERN_INFO "kvm: exiting hardware virtualization\n");
+               on_each_cpu(kvm_arch_ops->hardware_disable, 0, 0, 1);
+       }
+       return NOTIFY_OK;
+}
+
+static struct notifier_block kvm_reboot_notifier = {
+       .notifier_call = kvm_reboot,
+       .priority = 0,
+};
+
+static __init void kvm_init_debug(void)
+{
+       struct kvm_stats_debugfs_item *p;
+
+       debugfs_dir = debugfs_create_dir("kvm", 0);
+       for (p = debugfs_entries; p->name; ++p)
+               p->dentry = debugfs_create_u32(p->name, 0444, debugfs_dir,
+                                              p->data);
+}
+
+static void kvm_exit_debug(void)
+{
+       struct kvm_stats_debugfs_item *p;
+
+       for (p = debugfs_entries; p->name; ++p)
+               debugfs_remove(p->dentry);
+       debugfs_remove(debugfs_dir);
+}
+
+hpa_t bad_page_address;
+
+int kvm_init_arch(struct kvm_arch_ops *ops, struct module *module)
+{
+       int r;
+
+       if (kvm_arch_ops) {
+               printk(KERN_ERR "kvm: already loaded the other module\n");
+               return -EEXIST;
+       }
+
+       if (!ops->cpu_has_kvm_support()) {
+               printk(KERN_ERR "kvm: no hardware support\n");
+               return -EOPNOTSUPP;
+       }
+       if (ops->disabled_by_bios()) {
+               printk(KERN_ERR "kvm: disabled by bios\n");
+               return -EOPNOTSUPP;
+       }
+
+       kvm_arch_ops = ops;
+
+       r = kvm_arch_ops->hardware_setup();
+       if (r < 0)
+           return r;
+
+       on_each_cpu(kvm_arch_ops->hardware_enable, 0, 0, 1);
+       register_reboot_notifier(&kvm_reboot_notifier);
+
+       kvm_chardev_ops.owner = module;
+
+       r = misc_register(&kvm_dev);
+       if (r) {
+               printk (KERN_ERR "kvm: misc device register failed\n");
+               goto out_free;
+       }
+
+       return r;
+
+out_free:
+       unregister_reboot_notifier(&kvm_reboot_notifier);
+       on_each_cpu(kvm_arch_ops->hardware_disable, 0, 0, 1);
+       kvm_arch_ops->hardware_unsetup();
+       return r;
+}
+
+void kvm_exit_arch(void)
+{
+       misc_deregister(&kvm_dev);
+
+       unregister_reboot_notifier(&kvm_reboot_notifier);
+       on_each_cpu(kvm_arch_ops->hardware_disable, 0, 0, 1);
+       kvm_arch_ops->hardware_unsetup();
+       kvm_arch_ops = NULL;
+}
+
+static __init int kvm_init(void)
+{
+       static struct page *bad_page;
+       int r = 0;
+
+       kvm_init_debug();
+
+       kvm_init_msr_list();
+
+       if ((bad_page = alloc_page(GFP_KERNEL)) == NULL) {
+               r = -ENOMEM;
+               goto out;
+       }
+
+       bad_page_address = page_to_pfn(bad_page) << PAGE_SHIFT;
+       memset(__va(bad_page_address), 0, PAGE_SIZE);
+
+       return r;
+
+out:
+       kvm_exit_debug();
+       return r;
+}
+
+static __exit void kvm_exit(void)
+{
+       kvm_exit_debug();
+       __free_page(pfn_to_page(bad_page_address >> PAGE_SHIFT));
+}
+
+module_init(kvm_init)
+module_exit(kvm_exit)
+
+EXPORT_SYMBOL_GPL(kvm_init_arch);
+EXPORT_SYMBOL_GPL(kvm_exit_arch);