KVM: Use own minor number
[safe/jmp/linux-2.6] / drivers / kvm / kvm_main.c
index 9f24f22..946ed86 100644 (file)
@@ -20,6 +20,7 @@
 #include <linux/kvm.h>
 #include <linux/module.h>
 #include <linux/errno.h>
+#include <linux/magic.h>
 #include <asm/processor.h>
 #include <linux/percpu.h>
 #include <linux/gfp.h>
 #include <linux/highmem.h>
 #include <linux/file.h>
 #include <asm/desc.h>
+#include <linux/sysdev.h>
+#include <linux/cpu.h>
+#include <linux/file.h>
+#include <linux/fs.h>
+#include <linux/mount.h>
 
 #include "x86_emulate.h"
 #include "segment_descriptor.h"
@@ -41,6 +47,9 @@
 MODULE_AUTHOR("Qumranet");
 MODULE_LICENSE("GPL");
 
+static DEFINE_SPINLOCK(kvm_lock);
+static LIST_HEAD(vm_list);
+
 struct kvm_arch_ops *kvm_arch_ops;
 struct kvm_stat kvm_stat;
 EXPORT_SYMBOL_GPL(kvm_stat);
@@ -58,12 +67,17 @@ static struct kvm_stats_debugfs_item {
        { "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 }
+       { NULL, NULL }
 };
 
 static struct dentry *debugfs_dir;
 
+struct vfsmount *kvmfs_mnt;
+
 #define MAX_IO_MSRS 256
 
 #define CR0_RESEVED_BITS 0xffffffff1ffaffc0ULL
@@ -82,6 +96,58 @@ struct segment_descriptor_64 {
 
 #endif
 
+static long kvm_vcpu_ioctl(struct file *file, unsigned int ioctl,
+                          unsigned long arg);
+
+static struct inode *kvmfs_inode(struct file_operations *fops)
+{
+       int error = -ENOMEM;
+       struct inode *inode = new_inode(kvmfs_mnt->mnt_sb);
+
+       if (!inode)
+               goto eexit_1;
+
+       inode->i_fop = fops;
+
+       /*
+        * Mark the inode dirty from the very beginning,
+        * that way it will never be moved to the dirty
+        * list because mark_inode_dirty() will think
+        * that it already _is_ on the dirty list.
+        */
+       inode->i_state = I_DIRTY;
+       inode->i_mode = S_IRUSR | S_IWUSR;
+       inode->i_uid = current->fsuid;
+       inode->i_gid = current->fsgid;
+       inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
+       return inode;
+
+eexit_1:
+       return ERR_PTR(error);
+}
+
+static struct file *kvmfs_file(struct inode *inode, void *private_data)
+{
+       struct file *file = get_empty_filp();
+
+       if (!file)
+               return ERR_PTR(-ENFILE);
+
+       file->f_path.mnt = mntget(kvmfs_mnt);
+       file->f_path.dentry = d_alloc_anon(inode);
+       if (!file->f_path.dentry)
+               return ERR_PTR(-ENOMEM);
+       file->f_mapping = inode->i_mapping;
+
+       file->f_pos = 0;
+       file->f_flags = O_RDWR;
+       file->f_op = inode->i_fop;
+       file->f_mode = FMODE_READ | FMODE_WRITE;
+       file->f_version = 0;
+       file->private_data = private_data;
+       return file;
+}
+
 unsigned long segment_base(u16 selector)
 {
        struct descriptor_table gdt;
@@ -118,10 +184,8 @@ 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)
+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;
@@ -153,10 +217,8 @@ int kvm_read_guest(struct kvm_vcpu *vcpu,
 }
 EXPORT_SYMBOL_GPL(kvm_read_guest);
 
-int kvm_write_guest(struct kvm_vcpu *vcpu,
-                            gva_t addr,
-                            unsigned long size,
-                            void *data)
+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;
@@ -166,12 +228,15 @@ int kvm_write_guest(struct kvm_vcpu *vcpu,
                unsigned now;
                unsigned offset;
                hva_t guest_buf;
+               gfn_t gfn;
 
                paddr = gva_to_hpa(vcpu, addr);
 
                if (is_error_hpa(paddr))
                        break;
 
+               gfn = vcpu->mmu.gva_to_gpa(vcpu, addr) >> PAGE_SHIFT;
+               mark_page_dirty(vcpu->kvm, gfn);
                guest_buf = (hva_t)kmap_atomic(
                                pfn_to_page(paddr >> PAGE_SHIFT), KM_USER0);
                offset = addr & ~PAGE_MASK;
@@ -187,24 +252,30 @@ int kvm_write_guest(struct kvm_vcpu *vcpu,
 }
 EXPORT_SYMBOL_GPL(kvm_write_guest);
 
-static int vcpu_slot(struct kvm_vcpu *vcpu)
+/*
+ * Switches to specified vcpu, until a matching vcpu_put()
+ */
+static void vcpu_load(struct kvm_vcpu *vcpu)
 {
-       return vcpu - vcpu->kvm->vcpus;
+       mutex_lock(&vcpu->mutex);
+       kvm_arch_ops->vcpu_load(vcpu);
 }
 
 /*
- * Switches to specified vcpu, until a matching vcpu_put()
+ * Switches to specified vcpu, until a matching vcpu_put(). Will return NULL
+ * if the slot is not populated.
  */
-static struct kvm_vcpu *vcpu_load(struct kvm *kvm, int vcpu_slot)
+static struct kvm_vcpu *vcpu_load_slot(struct kvm *kvm, int slot)
 {
-       struct kvm_vcpu *vcpu = &kvm->vcpus[vcpu_slot];
+       struct kvm_vcpu *vcpu = &kvm->vcpus[slot];
 
        mutex_lock(&vcpu->mutex);
-       if (unlikely(!vcpu->vmcs)) {
+       if (!vcpu->vmcs) {
                mutex_unlock(&vcpu->mutex);
-               return 0;
+               return NULL;
        }
-       return kvm_arch_ops->vcpu_load(vcpu);
+       kvm_arch_ops->vcpu_load(vcpu);
+       return vcpu;
 }
 
 static void vcpu_put(struct kvm_vcpu *vcpu)
@@ -213,13 +284,13 @@ static void vcpu_put(struct kvm_vcpu *vcpu)
        mutex_unlock(&vcpu->mutex);
 }
 
-static int kvm_dev_open(struct inode *inode, struct file *filp)
+static struct kvm *kvm_create_vm(void)
 {
        struct kvm *kvm = kzalloc(sizeof(struct kvm), GFP_KERNEL);
        int i;
 
        if (!kvm)
-               return -ENOMEM;
+               return ERR_PTR(-ENOMEM);
 
        spin_lock_init(&kvm->lock);
        INIT_LIST_HEAD(&kvm->active_mmu_pages);
@@ -227,10 +298,19 @@ static int kvm_dev_open(struct inode *inode, struct file *filp)
                struct kvm_vcpu *vcpu = &kvm->vcpus[i];
 
                mutex_init(&vcpu->mutex);
+               vcpu->cpu = -1;
+               vcpu->kvm = kvm;
                vcpu->mmu.root_hpa = INVALID_PAGE;
                INIT_LIST_HEAD(&vcpu->free_pages);
+               spin_lock(&kvm_lock);
+               list_add(&kvm->vm_list, &vm_list);
+               spin_unlock(&kvm_lock);
        }
-       filp->private_data = kvm;
+       return kvm;
+}
+
+static int kvm_dev_open(struct inode *inode, struct file *filp)
+{
        return 0;
 }
 
@@ -245,16 +325,17 @@ static void kvm_free_physmem_slot(struct kvm_memory_slot *free,
        if (!dont || free->phys_mem != dont->phys_mem)
                if (free->phys_mem) {
                        for (i = 0; i < free->npages; ++i)
-                               __free_page(free->phys_mem[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->phys_mem = NULL;
        free->npages = 0;
-       free->dirty_bitmap = 0;
+       free->dirty_bitmap = NULL;
 }
 
 static void kvm_free_physmem(struct kvm *kvm)
@@ -262,13 +343,18 @@ 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);
+               kvm_free_physmem_slot(&kvm->memslots[i], NULL);
 }
 
 static void kvm_free_vcpu(struct kvm_vcpu *vcpu)
 {
-       kvm_arch_ops->vcpu_free(vcpu);
+       if (!vcpu->vmcs)
+               return;
+
+       vcpu_load(vcpu);
        kvm_mmu_destroy(vcpu);
+       vcpu_put(vcpu);
+       kvm_arch_ops->vcpu_free(vcpu);
 }
 
 static void kvm_free_vcpus(struct kvm *kvm)
@@ -281,11 +367,24 @@ static void kvm_free_vcpus(struct kvm *kvm)
 
 static int kvm_dev_release(struct inode *inode, struct file *filp)
 {
-       struct kvm *kvm = filp->private_data;
+       return 0;
+}
 
+static void kvm_destroy_vm(struct kvm *kvm)
+{
+       spin_lock(&kvm_lock);
+       list_del(&kvm->vm_list);
+       spin_unlock(&kvm_lock);
        kvm_free_vcpus(kvm);
        kvm_free_physmem(kvm);
        kfree(kvm);
+}
+
+static int kvm_vm_release(struct inode *inode, struct file *filp)
+{
+       struct kvm *kvm = filp->private_data;
+
+       kvm_destroy_vm(kvm);
        return 0;
 }
 
@@ -294,14 +393,17 @@ static void inject_gp(struct kvm_vcpu *vcpu)
        kvm_arch_ops->inject_gp(vcpu, 0);
 }
 
-static int pdptrs_have_reserved_bits_set(struct kvm_vcpu *vcpu,
-                                        unsigned long cr3)
+/*
+ * 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;
+       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);
@@ -309,16 +411,23 @@ static int pdptrs_have_reserved_bits_set(struct kvm_vcpu *vcpu,
        /* 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))
-                       break;
+               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 i != 4;
+       return ret;
 }
 
 void set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0)
@@ -364,8 +473,7 @@ void set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0)
                        }
                } else
 #endif
-               if (is_pae(vcpu) &&
-                           pdptrs_have_reserved_bits_set(vcpu, vcpu->cr3)) {
+               if (is_pae(vcpu) && !load_pdptrs(vcpu, vcpu->cr3)) {
                        printk(KERN_DEBUG "set_cr0: #GP, pdptrs "
                               "reserved bits\n");
                        inject_gp(vcpu);
@@ -386,6 +494,7 @@ 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);
@@ -398,7 +507,7 @@ void set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
                return;
        }
 
-       if (kvm_arch_ops->is_long_mode(vcpu)) {
+       if (is_long_mode(vcpu)) {
                if (!(cr4 & CR4_PAE_MASK)) {
                        printk(KERN_DEBUG "set_cr4: #GP, clearing PAE while "
                               "in long mode\n");
@@ -406,7 +515,7 @@ void set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
                        return;
                }
        } else if (is_paging(vcpu) && !is_pae(vcpu) && (cr4 & CR4_PAE_MASK)
-                  && pdptrs_have_reserved_bits_set(vcpu, vcpu->cr3)) {
+                  && !load_pdptrs(vcpu, vcpu->cr3)) {
                printk(KERN_DEBUG "set_cr4: #GP, pdptrs reserved bits\n");
                inject_gp(vcpu);
        }
@@ -425,8 +534,8 @@ EXPORT_SYMBOL_GPL(set_cr4);
 
 void set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3)
 {
-       if (kvm_arch_ops->is_long_mode(vcpu)) {
-               if ( cr3 & CR3_L_MODE_RESEVED_BITS) {
+       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;
@@ -438,7 +547,7 @@ void set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3)
                        return;
                }
                if (is_paging(vcpu) && is_pae(vcpu) &&
-                   pdptrs_have_reserved_bits_set(vcpu, cr3)) {
+                   !load_pdptrs(vcpu, cr3)) {
                        printk(KERN_DEBUG "set_cr3: #GP, pdptrs "
                               "reserved bits\n");
                        inject_gp(vcpu);
@@ -448,7 +557,19 @@ void set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3)
 
        vcpu->cr3 = cr3;
        spin_lock(&vcpu->kvm->lock);
-       vcpu->mmu.new_cr3(vcpu);
+       /*
+        * 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);
@@ -490,55 +611,11 @@ void fx_init(struct kvm_vcpu *vcpu)
 }
 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)
+static void do_remove_write_access(struct kvm_vcpu *vcpu, int slot)
 {
-       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 */
-       vcpu->kvm = kvm;
-       r = kvm_arch_ops->vcpu_create(vcpu);
-       if (r < 0)
-               goto out_free_vcpus;
-
-       kvm_arch_ops->vcpu_load(vcpu);
-
-       r = kvm_arch_ops->vcpu_setup(vcpu);
-       if (r >= 0)
-               r = kvm_mmu_init(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;
+       spin_lock(&vcpu->kvm->lock);
+       kvm_mmu_slot_remove_write_access(vcpu, slot);
+       spin_unlock(&vcpu->kvm->lock);
 }
 
 /*
@@ -547,8 +624,8 @@ out:
  *
  * Discontiguous memory is allowed, mostly for framebuffers.
  */
-static int kvm_dev_ioctl_set_memory_region(struct kvm *kvm,
-                                          struct kvm_memory_region *mem)
+static int kvm_vm_ioctl_set_memory_region(struct kvm *kvm,
+                                         struct kvm_memory_region *mem)
 {
        int r;
        gfn_t base_gfn;
@@ -610,11 +687,11 @@ raced:
 
        /* Deallocate if slot is being removed */
        if (!npages)
-               new.phys_mem = 0;
+               new.phys_mem = NULL;
 
        /* Free page dirty bitmap if unneeded */
        if (!(new.flags & KVM_MEM_LOG_DIRTY_PAGES))
-               new.dirty_bitmap = 0;
+               new.dirty_bitmap = NULL;
 
        r = -ENOMEM;
 
@@ -631,6 +708,7 @@ raced:
                                                     | __GFP_ZERO);
                        if (!new.phys_mem[i])
                                goto out_free;
+                       set_page_private(new.phys_mem[i],0);
                }
        }
 
@@ -667,9 +745,11 @@ raced:
        for (i = 0; i < KVM_MAX_VCPUS; ++i) {
                struct kvm_vcpu *vcpu;
 
-               vcpu = vcpu_load(kvm, i);
+               vcpu = vcpu_load_slot(kvm, i);
                if (!vcpu)
                        continue;
+               if (new.flags & KVM_MEM_LOG_DIRTY_PAGES)
+                       do_remove_write_access(vcpu, mem->slot);
                kvm_mmu_reset_context(vcpu);
                vcpu_put(vcpu);
        }
@@ -688,12 +768,13 @@ out:
 /*
  * 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)
+static int kvm_vm_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);
@@ -713,26 +794,28 @@ static int kvm_dev_ioctl_get_dirty_log(struct kvm *kvm,
        if (!memslot->dirty_bitmap)
                goto out;
 
-       n = ALIGN(memslot->npages, 8) / 8;
+       n = ALIGN(memslot->npages, BITS_PER_LONG) / 8;
 
-       for (i = 0; !any && i < n; ++i)
+       for (i = 0; !any && i < n/sizeof(long); ++i)
                any = memslot->dirty_bitmap[i];
 
        r = -EFAULT;
        if (copy_to_user(log->dirty_bitmap, memslot->dirty_bitmap, n))
                goto out;
 
-
        if (any) {
-               spin_lock(&kvm->lock);
-               kvm_mmu_slot_remove_write_access(kvm, log->slot);
-               spin_unlock(&kvm->lock);
-               memset(memslot->dirty_bitmap, 0, n);
+               cleared = 0;
                for (i = 0; i < KVM_MAX_VCPUS; ++i) {
-                       struct kvm_vcpu *vcpu = vcpu_load(kvm, i);
+                       struct kvm_vcpu *vcpu;
 
+                       vcpu = vcpu_load_slot(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);
                }
@@ -758,14 +841,14 @@ struct kvm_memory_slot *gfn_to_memslot(struct kvm *kvm, gfn_t gfn)
                    && gfn < memslot->base_gfn + memslot->npages)
                        return memslot;
        }
-       return 0;
+       return NULL;
 }
 EXPORT_SYMBOL_GPL(gfn_to_memslot);
 
 void mark_page_dirty(struct kvm *kvm, gfn_t gfn)
 {
        int i;
-       struct kvm_memory_slot *memslot = 0;
+       struct kvm_memory_slot *memslot = NULL;
        unsigned long rel_gfn;
 
        for (i = 0; i < kvm->nmemslots; ++i) {
@@ -849,8 +932,9 @@ static int emulator_read_emulated(unsigned long addr,
                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;
+                       return X86EMUL_PROPAGATE_FAULT;
                vcpu->mmio_needed = 1;
                vcpu->mmio_phys_addr = gpa;
                vcpu->mmio_size = bytes;
@@ -860,6 +944,28 @@ static int emulator_read_emulated(unsigned long addr,
        }
 }
 
+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);
+       mark_page_dirty(vcpu->kvm, gpa >> PAGE_SHIFT);
+       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,
@@ -871,6 +977,9 @@ static int emulator_write_emulated(unsigned long 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;
@@ -895,6 +1004,30 @@ static int emulator_cmpxchg_emulated(unsigned long addr,
        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);
@@ -902,18 +1035,15 @@ static unsigned long get_segment_base(struct kvm_vcpu *vcpu, int seg)
 
 int emulate_invlpg(struct kvm_vcpu *vcpu, gva_t address)
 {
-       spin_lock(&vcpu->kvm->lock);
-       vcpu->mmu.inval_page(vcpu, address);
-       spin_unlock(&vcpu->kvm->lock);
-       kvm_arch_ops->invlpg(vcpu, address);
        return X86EMUL_CONTINUE;
 }
 
 int emulate_clts(struct kvm_vcpu *vcpu)
 {
-       unsigned long cr0 = vcpu->cr0;
+       unsigned long cr0;
 
-       cr0 &= ~CR0_TS_MASK;
+       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;
 }
@@ -972,6 +1102,9 @@ struct x86_emulate_ops emulate_ops = {
        .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,
@@ -1021,6 +1154,8 @@ int emulate_instruction(struct kvm_vcpu *vcpu,
        }
 
        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;
@@ -1038,6 +1173,42 @@ int emulate_instruction(struct kvm_vcpu *vcpu,
 }
 EXPORT_SYMBOL_GPL(emulate_instruction);
 
+int kvm_hypercall(struct kvm_vcpu *vcpu, struct kvm_run *run)
+{
+       unsigned long nr, a0, a1, a2, a3, a4, a5, ret;
+
+       kvm_arch_ops->cache_regs(vcpu);
+       ret = -KVM_EINVAL;
+#ifdef CONFIG_X86_64
+       if (is_long_mode(vcpu)) {
+               nr = vcpu->regs[VCPU_REGS_RAX];
+               a0 = vcpu->regs[VCPU_REGS_RDI];
+               a1 = vcpu->regs[VCPU_REGS_RSI];
+               a2 = vcpu->regs[VCPU_REGS_RDX];
+               a3 = vcpu->regs[VCPU_REGS_RCX];
+               a4 = vcpu->regs[VCPU_REGS_R8];
+               a5 = vcpu->regs[VCPU_REGS_R9];
+       } else
+#endif
+       {
+               nr = vcpu->regs[VCPU_REGS_RBX] & -1u;
+               a0 = vcpu->regs[VCPU_REGS_RAX] & -1u;
+               a1 = vcpu->regs[VCPU_REGS_RCX] & -1u;
+               a2 = vcpu->regs[VCPU_REGS_RDX] & -1u;
+               a3 = vcpu->regs[VCPU_REGS_RSI] & -1u;
+               a4 = vcpu->regs[VCPU_REGS_RDI] & -1u;
+               a5 = vcpu->regs[VCPU_REGS_RBP] & -1u;
+       }
+       switch (nr) {
+       default:
+               ;
+       }
+       vcpu->regs[VCPU_REGS_RAX] = ret;
+       kvm_arch_ops->decache_regs(vcpu);
+       return 1;
+}
+EXPORT_SYMBOL_GPL(kvm_hypercall);
+
 static u64 mk_cr_64(u64 curr_cr, u32 new_val)
 {
        return (curr_cr & ~((1ULL << 32) - 1)) | new_val;
@@ -1066,6 +1237,7 @@ void realmode_lmsw(struct kvm_vcpu *vcpu, unsigned long msw,
 
 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;
@@ -1104,6 +1276,123 @@ void realmode_set_cr(struct kvm_vcpu *vcpu, int cr, unsigned long val,
 }
 
 /*
+ * Register the para guest with the host:
+ */
+static int vcpu_register_para(struct kvm_vcpu *vcpu, gpa_t para_state_gpa)
+{
+       struct kvm_vcpu_para_state *para_state;
+       hpa_t para_state_hpa, hypercall_hpa;
+       struct page *para_state_page;
+       unsigned char *hypercall;
+       gpa_t hypercall_gpa;
+
+       printk(KERN_DEBUG "kvm: guest trying to enter paravirtual mode\n");
+       printk(KERN_DEBUG ".... para_state_gpa: %08Lx\n", para_state_gpa);
+
+       /*
+        * Needs to be page aligned:
+        */
+       if (para_state_gpa != PAGE_ALIGN(para_state_gpa))
+               goto err_gp;
+
+       para_state_hpa = gpa_to_hpa(vcpu, para_state_gpa);
+       printk(KERN_DEBUG ".... para_state_hpa: %08Lx\n", para_state_hpa);
+       if (is_error_hpa(para_state_hpa))
+               goto err_gp;
+
+       mark_page_dirty(vcpu->kvm, para_state_gpa >> PAGE_SHIFT);
+       para_state_page = pfn_to_page(para_state_hpa >> PAGE_SHIFT);
+       para_state = kmap_atomic(para_state_page, KM_USER0);
+
+       printk(KERN_DEBUG "....  guest version: %d\n", para_state->guest_version);
+       printk(KERN_DEBUG "....           size: %d\n", para_state->size);
+
+       para_state->host_version = KVM_PARA_API_VERSION;
+       /*
+        * We cannot support guests that try to register themselves
+        * with a newer API version than the host supports:
+        */
+       if (para_state->guest_version > KVM_PARA_API_VERSION) {
+               para_state->ret = -KVM_EINVAL;
+               goto err_kunmap_skip;
+       }
+
+       hypercall_gpa = para_state->hypercall_gpa;
+       hypercall_hpa = gpa_to_hpa(vcpu, hypercall_gpa);
+       printk(KERN_DEBUG ".... hypercall_hpa: %08Lx\n", hypercall_hpa);
+       if (is_error_hpa(hypercall_hpa)) {
+               para_state->ret = -KVM_EINVAL;
+               goto err_kunmap_skip;
+       }
+
+       printk(KERN_DEBUG "kvm: para guest successfully registered.\n");
+       vcpu->para_state_page = para_state_page;
+       vcpu->para_state_gpa = para_state_gpa;
+       vcpu->hypercall_gpa = hypercall_gpa;
+
+       mark_page_dirty(vcpu->kvm, hypercall_gpa >> PAGE_SHIFT);
+       hypercall = kmap_atomic(pfn_to_page(hypercall_hpa >> PAGE_SHIFT),
+                               KM_USER1) + (hypercall_hpa & ~PAGE_MASK);
+       kvm_arch_ops->patch_hypercall(vcpu, hypercall);
+       kunmap_atomic(hypercall, KM_USER1);
+
+       para_state->ret = 0;
+err_kunmap_skip:
+       kunmap_atomic(para_state, KM_USER0);
+       return 0;
+err_gp:
+       return 1;
+}
+
+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.
@@ -1115,7 +1404,7 @@ static int get_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 *pdata)
 
 #ifdef CONFIG_X86_64
 
-void set_efer(struct kvm_vcpu *vcpu, u64 efer)
+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",
@@ -1138,10 +1427,45 @@ void set_efer(struct kvm_vcpu *vcpu, u64 efer)
 
        vcpu->shadow_efer = efer;
 }
-EXPORT_SYMBOL_GPL(set_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;
+       /*
+        * This is the 'probe whether the host is KVM' logic:
+        */
+       case MSR_KVM_API_MAGIC:
+               return vcpu_register_para(vcpu, data);
+
+       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.
@@ -1156,8 +1480,7 @@ 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));
+       vcpu_load(vcpu);
 }
 EXPORT_SYMBOL_GPL(kvm_resched);
 
@@ -1179,17 +1502,14 @@ void save_msrs(struct vmx_msr_entry *e, int n)
 }
 EXPORT_SYMBOL_GPL(save_msrs);
 
-static int kvm_dev_ioctl_run(struct kvm *kvm, struct kvm_run *kvm_run)
+static int kvm_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
 {
-       struct kvm_vcpu *vcpu;
        int r;
 
-       if (!valid_vcpu(kvm_run->vcpu))
-               return -EINVAL;
+       vcpu_load(vcpu);
 
-       vcpu = vcpu_load(kvm, kvm_run->vcpu);
-       if (!vcpu)
-               return -ENOENT;
+       /* re-sync apic's tpr */
+       vcpu->cr8 = kvm_run->cr8;
 
        if (kvm_run->emulated) {
                kvm_arch_ops->skip_emulated_instruction(vcpu);
@@ -1209,16 +1529,10 @@ static int kvm_dev_ioctl_run(struct kvm *kvm, struct kvm_run *kvm_run)
        return r;
 }
 
-static int kvm_dev_ioctl_get_regs(struct kvm *kvm, struct kvm_regs *regs)
+static int kvm_vcpu_ioctl_get_regs(struct kvm_vcpu *vcpu,
+                                  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_load(vcpu);
 
        kvm_arch_ops->cache_regs(vcpu);
 
@@ -1255,16 +1569,10 @@ static int kvm_dev_ioctl_get_regs(struct kvm *kvm, struct kvm_regs *regs)
        return 0;
 }
 
-static int kvm_dev_ioctl_set_regs(struct kvm *kvm, struct kvm_regs *regs)
+static int kvm_vcpu_ioctl_set_regs(struct kvm_vcpu *vcpu,
+                                  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_load(vcpu);
 
        vcpu->regs[VCPU_REGS_RAX] = regs->rax;
        vcpu->regs[VCPU_REGS_RBX] = regs->rbx;
@@ -1301,16 +1609,12 @@ static void get_segment(struct kvm_vcpu *vcpu,
        return kvm_arch_ops->get_segment(vcpu, var, seg);
 }
 
-static int kvm_dev_ioctl_get_sregs(struct kvm *kvm, struct kvm_sregs *sregs)
+static int kvm_vcpu_ioctl_get_sregs(struct kvm_vcpu *vcpu,
+                                   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;
+       vcpu_load(vcpu);
 
        get_segment(vcpu, &sregs->cs, VCPU_SREG_CS);
        get_segment(vcpu, &sregs->ds, VCPU_SREG_DS);
@@ -1329,6 +1633,7 @@ static int kvm_dev_ioctl_get_sregs(struct kvm *kvm, struct kvm_sregs *sregs)
        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;
@@ -1351,18 +1656,14 @@ static void set_segment(struct kvm_vcpu *vcpu,
        return kvm_arch_ops->set_segment(vcpu, var, seg);
 }
 
-static int kvm_dev_ioctl_set_sregs(struct kvm *kvm, struct kvm_sregs *sregs)
+static int kvm_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
+                                   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;
+       vcpu_load(vcpu);
 
        set_segment(vcpu, &sregs->cs, VCPU_SREG_CS);
        set_segment(vcpu, &sregs->ds, VCPU_SREG_DS);
@@ -1393,11 +1694,15 @@ static int kvm_dev_ioctl_set_sregs(struct kvm *kvm, struct kvm_sregs *sregs)
 #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);
@@ -1432,6 +1737,10 @@ static u32 msrs_to_save[] = {
 
 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];
@@ -1460,20 +1769,14 @@ static int do_set_msr(struct kvm_vcpu *vcpu, unsigned index, u64 *data)
  *
  * @return number of msrs set successfully.
  */
-static int __msr_io(struct kvm *kvm, struct kvm_msrs *msrs,
+static int __msr_io(struct kvm_vcpu *vcpu, 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;
+       vcpu_load(vcpu);
 
        for (i = 0; i < msrs->nmsrs; ++i)
                if (do_msr(vcpu, entries[i].index, &entries[i].data))
@@ -1489,7 +1792,7 @@ static int __msr_io(struct kvm *kvm, struct kvm_msrs *msrs,
  *
  * @return number of msrs set successfully.
  */
-static int msr_io(struct kvm *kvm, struct kvm_msrs __user *user_msrs,
+static int msr_io(struct kvm_vcpu *vcpu, struct kvm_msrs __user *user_msrs,
                  int (*do_msr)(struct kvm_vcpu *vcpu,
                                unsigned index, u64 *data),
                  int writeback)
@@ -1517,7 +1820,7 @@ static int msr_io(struct kvm *kvm, struct kvm_msrs __user *user_msrs,
        if (copy_from_user(entries, user_msrs->entries, size))
                goto out_free;
 
-       r = n = __msr_io(kvm, &msrs, entries, do_msr);
+       r = n = __msr_io(vcpu, &msrs, entries, do_msr);
        if (r < 0)
                goto out_free;
 
@@ -1536,38 +1839,31 @@ out:
 /*
  * Translate a guest virtual address to a guest physical address.
  */
-static int kvm_dev_ioctl_translate(struct kvm *kvm, struct kvm_translation *tr)
+static int kvm_vcpu_ioctl_translate(struct kvm_vcpu *vcpu,
+                                   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);
+       vcpu_load(vcpu);
+       spin_lock(&vcpu->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);
+       spin_unlock(&vcpu->kvm->lock);
        vcpu_put(vcpu);
 
        return 0;
 }
 
-static int kvm_dev_ioctl_interrupt(struct kvm *kvm, struct kvm_interrupt *irq)
+static int kvm_vcpu_ioctl_interrupt(struct kvm_vcpu *vcpu,
+                                   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;
+       vcpu_load(vcpu);
 
        set_bit(irq->irq, vcpu->irq_pending);
        set_bit(irq->irq / BITS_PER_LONG, &vcpu->irq_summary);
@@ -1577,17 +1873,12 @@ static int kvm_dev_ioctl_interrupt(struct kvm *kvm, struct kvm_interrupt *irq)
        return 0;
 }
 
-static int kvm_dev_ioctl_debug_guest(struct kvm *kvm,
-                                    struct kvm_debug_guest *dbg)
+static int kvm_vcpu_ioctl_debug_guest(struct kvm_vcpu *vcpu,
+                                     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;
+       vcpu_load(vcpu);
 
        r = kvm_arch_ops->set_guest_debug(vcpu, dbg);
 
@@ -1596,48 +1887,146 @@ static int kvm_dev_ioctl_debug_guest(struct kvm *kvm,
        return r;
 }
 
-static long kvm_dev_ioctl(struct file *filp,
-                         unsigned int ioctl, unsigned long arg)
+static int kvm_vcpu_release(struct inode *inode, struct file *filp)
 {
-       struct kvm *kvm = filp->private_data;
+       struct kvm_vcpu *vcpu = filp->private_data;
+
+       fput(vcpu->kvm->filp);
+       return 0;
+}
+
+static struct file_operations kvm_vcpu_fops = {
+       .release        = kvm_vcpu_release,
+       .unlocked_ioctl = kvm_vcpu_ioctl,
+       .compat_ioctl   = kvm_vcpu_ioctl,
+};
+
+/*
+ * Allocates an inode for the vcpu.
+ */
+static int create_vcpu_fd(struct kvm_vcpu *vcpu)
+{
+       int fd, r;
+       struct inode *inode;
+       struct file *file;
+
+       atomic_inc(&vcpu->kvm->filp->f_count);
+       inode = kvmfs_inode(&kvm_vcpu_fops);
+       if (IS_ERR(inode)) {
+               r = PTR_ERR(inode);
+               goto out1;
+       }
+
+       file = kvmfs_file(inode, vcpu);
+       if (IS_ERR(file)) {
+               r = PTR_ERR(file);
+               goto out2;
+       }
+
+       r = get_unused_fd();
+       if (r < 0)
+               goto out3;
+       fd = r;
+       fd_install(fd, file);
+
+       return fd;
+
+out3:
+       fput(file);
+out2:
+       iput(inode);
+out1:
+       fput(vcpu->kvm->filp);
+       return r;
+}
+
+/*
+ * Creates some virtual cpus.  Good luck creating more than one.
+ */
+static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, int n)
+{
+       int r;
+       struct kvm_vcpu *vcpu;
+
+       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;
+
+       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;
+
+       r = create_vcpu_fd(vcpu);
+       if (r < 0)
+               goto out_free_vcpus;
+
+       return r;
+
+out_free_vcpus:
+       kvm_free_vcpu(vcpu);
+       mutex_unlock(&vcpu->mutex);
+out:
+       return r;
+}
+
+static long kvm_vcpu_ioctl(struct file *filp,
+                          unsigned int ioctl, unsigned long arg)
+{
+       struct kvm_vcpu *vcpu = filp->private_data;
+       void __user *argp = (void __user *)arg;
        int r = -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))
+               if (copy_from_user(&kvm_run, argp, sizeof kvm_run))
                        goto out;
-               r = kvm_dev_ioctl_run(kvm, &kvm_run);
-               if (r < 0)
+               r = kvm_vcpu_ioctl_run(vcpu, &kvm_run);
+               if (r < 0 &&  r != -EINTR)
                        goto out;
-               r = -EFAULT;
-               if (copy_to_user((void *)arg, &kvm_run, sizeof kvm_run))
+               if (copy_to_user(argp, &kvm_run, sizeof kvm_run)) {
+                       r = -EFAULT;
                        goto out;
-               r = 0;
+               }
                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);
+               memset(&kvm_regs, 0, sizeof kvm_regs);
+               r = kvm_vcpu_ioctl_get_regs(vcpu, &kvm_regs);
                if (r)
                        goto out;
                r = -EFAULT;
-               if (copy_to_user((void *)arg, &kvm_regs, sizeof kvm_regs))
+               if (copy_to_user(argp, &kvm_regs, sizeof kvm_regs))
                        goto out;
                r = 0;
                break;
@@ -1646,9 +2035,9 @@ static long kvm_dev_ioctl(struct file *filp,
                struct kvm_regs kvm_regs;
 
                r = -EFAULT;
-               if (copy_from_user(&kvm_regs, (void *)arg, sizeof kvm_regs))
+               if (copy_from_user(&kvm_regs, argp, sizeof kvm_regs))
                        goto out;
-               r = kvm_dev_ioctl_set_regs(kvm, &kvm_regs);
+               r = kvm_vcpu_ioctl_set_regs(vcpu, &kvm_regs);
                if (r)
                        goto out;
                r = 0;
@@ -1657,14 +2046,12 @@ static long kvm_dev_ioctl(struct file *filp,
        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);
+               memset(&kvm_sregs, 0, sizeof kvm_sregs);
+               r = kvm_vcpu_ioctl_get_sregs(vcpu, &kvm_sregs);
                if (r)
                        goto out;
                r = -EFAULT;
-               if (copy_to_user((void *)arg, &kvm_sregs, sizeof kvm_sregs))
+               if (copy_to_user(argp, &kvm_sregs, sizeof kvm_sregs))
                        goto out;
                r = 0;
                break;
@@ -1673,9 +2060,9 @@ static long kvm_dev_ioctl(struct file *filp,
                struct kvm_sregs kvm_sregs;
 
                r = -EFAULT;
-               if (copy_from_user(&kvm_sregs, (void *)arg, sizeof kvm_sregs))
+               if (copy_from_user(&kvm_sregs, argp, sizeof kvm_sregs))
                        goto out;
-               r = kvm_dev_ioctl_set_sregs(kvm, &kvm_sregs);
+               r = kvm_vcpu_ioctl_set_sregs(vcpu, &kvm_sregs);
                if (r)
                        goto out;
                r = 0;
@@ -1685,13 +2072,13 @@ static long kvm_dev_ioctl(struct file *filp,
                struct kvm_translation tr;
 
                r = -EFAULT;
-               if (copy_from_user(&tr, (void *)arg, sizeof tr))
+               if (copy_from_user(&tr, argp, sizeof tr))
                        goto out;
-               r = kvm_dev_ioctl_translate(kvm, &tr);
+               r = kvm_vcpu_ioctl_translate(vcpu, &tr);
                if (r)
                        goto out;
                r = -EFAULT;
-               if (copy_to_user((void *)arg, &tr, sizeof tr))
+               if (copy_to_user(argp, &tr, sizeof tr))
                        goto out;
                r = 0;
                break;
@@ -1700,9 +2087,9 @@ static long kvm_dev_ioctl(struct file *filp,
                struct kvm_interrupt irq;
 
                r = -EFAULT;
-               if (copy_from_user(&irq, (void *)arg, sizeof irq))
+               if (copy_from_user(&irq, argp, sizeof irq))
                        goto out;
-               r = kvm_dev_ioctl_interrupt(kvm, &irq);
+               r = kvm_vcpu_ioctl_interrupt(vcpu, &irq);
                if (r)
                        goto out;
                r = 0;
@@ -1712,21 +2099,47 @@ static long kvm_dev_ioctl(struct file *filp,
                struct kvm_debug_guest dbg;
 
                r = -EFAULT;
-               if (copy_from_user(&dbg, (void *)arg, sizeof dbg))
+               if (copy_from_user(&dbg, argp, sizeof dbg))
                        goto out;
-               r = kvm_dev_ioctl_debug_guest(kvm, &dbg);
+               r = kvm_vcpu_ioctl_debug_guest(vcpu, &dbg);
                if (r)
                        goto out;
                r = 0;
                break;
        }
+       case KVM_GET_MSRS:
+               r = msr_io(vcpu, argp, get_msr, 1);
+               break;
+       case KVM_SET_MSRS:
+               r = msr_io(vcpu, argp, do_set_msr, 0);
+               break;
+       default:
+               ;
+       }
+out:
+       return r;
+}
+
+static long kvm_vm_ioctl(struct file *filp,
+                          unsigned int ioctl, unsigned long arg)
+{
+       struct kvm *kvm = filp->private_data;
+       void __user *argp = (void __user *)arg;
+       int r = -EINVAL;
+
+       switch (ioctl) {
+       case KVM_CREATE_VCPU:
+               r = kvm_vm_ioctl_create_vcpu(kvm, arg);
+               if (r < 0)
+                       goto out;
+               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))
+               if (copy_from_user(&kvm_mem, argp, sizeof kvm_mem))
                        goto out;
-               r = kvm_dev_ioctl_set_memory_region(kvm, &kvm_mem);
+               r = kvm_vm_ioctl_set_memory_region(kvm, &kvm_mem);
                if (r)
                        goto out;
                break;
@@ -1735,40 +2148,13 @@ static long kvm_dev_ioctl(struct file *filp,
                struct kvm_dirty_log log;
 
                r = -EFAULT;
-               if (copy_from_user(&log, (void *)arg, sizeof log))
+               if (copy_from_user(&log, argp, sizeof log))
                        goto out;
-               r = kvm_dev_ioctl_get_dirty_log(kvm, &log);
+               r = kvm_vm_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;
-               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;
-               r = 0;
-       }
        default:
                ;
        }
@@ -1776,9 +2162,9 @@ out:
        return r;
 }
 
-static struct page *kvm_dev_nopage(struct vm_area_struct *vma,
-                                  unsigned long address,
-                                  int *type)
+static struct page *kvm_vm_nopage(struct vm_area_struct *vma,
+                                 unsigned long address,
+                                 int *type)
 {
        struct kvm *kvm = vma->vm_file->private_data;
        unsigned long pgoff;
@@ -1797,26 +2183,123 @@ static struct page *kvm_dev_nopage(struct vm_area_struct *vma,
        return page;
 }
 
-static struct vm_operations_struct kvm_dev_vm_ops = {
-       .nopage = kvm_dev_nopage,
+static struct vm_operations_struct kvm_vm_vm_ops = {
+       .nopage = kvm_vm_nopage,
 };
 
-static int kvm_dev_mmap(struct file *file, struct vm_area_struct *vma)
+static int kvm_vm_mmap(struct file *file, struct vm_area_struct *vma)
 {
-       vma->vm_ops = &kvm_dev_vm_ops;
+       vma->vm_ops = &kvm_vm_vm_ops;
        return 0;
 }
 
+static struct file_operations kvm_vm_fops = {
+       .release        = kvm_vm_release,
+       .unlocked_ioctl = kvm_vm_ioctl,
+       .compat_ioctl   = kvm_vm_ioctl,
+       .mmap           = kvm_vm_mmap,
+};
+
+static int kvm_dev_ioctl_create_vm(void)
+{
+       int fd, r;
+       struct inode *inode;
+       struct file *file;
+       struct kvm *kvm;
+
+       inode = kvmfs_inode(&kvm_vm_fops);
+       if (IS_ERR(inode)) {
+               r = PTR_ERR(inode);
+               goto out1;
+       }
+
+       kvm = kvm_create_vm();
+       if (IS_ERR(kvm)) {
+               r = PTR_ERR(kvm);
+               goto out2;
+       }
+
+       file = kvmfs_file(inode, kvm);
+       if (IS_ERR(file)) {
+               r = PTR_ERR(file);
+               goto out3;
+       }
+       kvm->filp = file;
+
+       r = get_unused_fd();
+       if (r < 0)
+               goto out4;
+       fd = r;
+       fd_install(fd, file);
+
+       return fd;
+
+out4:
+       fput(file);
+out3:
+       kvm_destroy_vm(kvm);
+out2:
+       iput(inode);
+out1:
+       return r;
+}
+
+static long kvm_dev_ioctl(struct file *filp,
+                         unsigned int ioctl, unsigned long arg)
+{
+       void __user *argp = (void __user *)arg;
+       int r = -EINVAL;
+
+       switch (ioctl) {
+       case KVM_GET_API_VERSION:
+               r = KVM_API_VERSION;
+               break;
+       case KVM_CREATE_VM:
+               r = kvm_dev_ioctl_create_vm();
+               break;
+       case KVM_GET_MSR_INDEX_LIST: {
+               struct kvm_msr_list __user *user_msr_list = argp;
+               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 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_MINOR,
        "kvm",
        &kvm_chardev_ops,
 };
@@ -1830,7 +2313,7 @@ static int kvm_reboot(struct notifier_block *notifier, unsigned long val,
                 * in vmx root mode.
                 */
                printk(KERN_INFO "kvm: exiting hardware virtualization\n");
-               on_each_cpu(kvm_arch_ops->hardware_disable, 0, 0, 1);
+               on_each_cpu(kvm_arch_ops->hardware_disable, NULL, 0, 1);
        }
        return NOTIFY_OK;
 }
@@ -1840,11 +2323,73 @@ static struct notifier_block kvm_reboot_notifier = {
        .priority = 0,
 };
 
+/*
+ * Make sure that a cpu that is being hot-unplugged does not have any vcpus
+ * cached on it.
+ */
+static void decache_vcpus_on_cpu(int cpu)
+{
+       struct kvm *vm;
+       struct kvm_vcpu *vcpu;
+       int i;
+
+       spin_lock(&kvm_lock);
+       list_for_each_entry(vm, &vm_list, vm_list)
+               for (i = 0; i < KVM_MAX_VCPUS; ++i) {
+                       vcpu = &vm->vcpus[i];
+                       /*
+                        * If the vcpu is locked, then it is running on some
+                        * other cpu and therefore it is not cached on the
+                        * cpu in question.
+                        *
+                        * If it's not locked, check the last cpu it executed
+                        * on.
+                        */
+                       if (mutex_trylock(&vcpu->mutex)) {
+                               if (vcpu->cpu == cpu) {
+                                       kvm_arch_ops->vcpu_decache(vcpu);
+                                       vcpu->cpu = -1;
+                               }
+                               mutex_unlock(&vcpu->mutex);
+                       }
+               }
+       spin_unlock(&kvm_lock);
+}
+
+static int kvm_cpu_hotplug(struct notifier_block *notifier, unsigned long val,
+                          void *v)
+{
+       int cpu = (long)v;
+
+       switch (val) {
+       case CPU_DOWN_PREPARE:
+       case CPU_UP_CANCELED:
+               printk(KERN_INFO "kvm: disabling virtualization on CPU%d\n",
+                      cpu);
+               decache_vcpus_on_cpu(cpu);
+               smp_call_function_single(cpu, kvm_arch_ops->hardware_disable,
+                                        NULL, 0, 1);
+               break;
+       case CPU_ONLINE:
+               printk(KERN_INFO "kvm: enabling virtualization on CPU%d\n",
+                      cpu);
+               smp_call_function_single(cpu, kvm_arch_ops->hardware_enable,
+                                        NULL, 0, 1);
+               break;
+       }
+       return NOTIFY_OK;
+}
+
+static struct notifier_block kvm_cpu_notifier = {
+       .notifier_call = kvm_cpu_hotplug,
+       .priority = 20, /* must be > scheduler priority */
+};
+
 static __init void kvm_init_debug(void)
 {
        struct kvm_stats_debugfs_item *p;
 
-       debugfs_dir = debugfs_create_dir("kvm", 0);
+       debugfs_dir = debugfs_create_dir("kvm", NULL);
        for (p = debugfs_entries; p->name; ++p)
                p->dentry = debugfs_create_u32(p->name, 0444, debugfs_dir,
                                               p->data);
@@ -1859,30 +2404,82 @@ static void kvm_exit_debug(void)
        debugfs_remove(debugfs_dir);
 }
 
+static int kvm_suspend(struct sys_device *dev, pm_message_t state)
+{
+       decache_vcpus_on_cpu(raw_smp_processor_id());
+       on_each_cpu(kvm_arch_ops->hardware_disable, NULL, 0, 1);
+       return 0;
+}
+
+static int kvm_resume(struct sys_device *dev)
+{
+       on_each_cpu(kvm_arch_ops->hardware_enable, NULL, 0, 1);
+       return 0;
+}
+
+static struct sysdev_class kvm_sysdev_class = {
+       set_kset_name("kvm"),
+       .suspend = kvm_suspend,
+       .resume = kvm_resume,
+};
+
+static struct sys_device kvm_sysdev = {
+       .id = 0,
+       .cls = &kvm_sysdev_class,
+};
+
 hpa_t bad_page_address;
 
+static int kvmfs_get_sb(struct file_system_type *fs_type, int flags,
+                       const char *dev_name, void *data, struct vfsmount *mnt)
+{
+       return get_sb_pseudo(fs_type, "kvm:", NULL, KVMFS_SUPER_MAGIC, mnt);
+}
+
+static struct file_system_type kvm_fs_type = {
+       .name           = "kvmfs",
+       .get_sb         = kvmfs_get_sb,
+       .kill_sb        = kill_anon_super,
+};
+
 int kvm_init_arch(struct kvm_arch_ops *ops, struct module *module)
 {
        int r;
 
-       kvm_arch_ops = ops;
+       if (kvm_arch_ops) {
+               printk(KERN_ERR "kvm: already loaded the other module\n");
+               return -EEXIST;
+       }
 
-       if (!kvm_arch_ops->cpu_has_kvm_support()) {
+       if (!ops->cpu_has_kvm_support()) {
                printk(KERN_ERR "kvm: no hardware support\n");
                return -EOPNOTSUPP;
        }
-       if (kvm_arch_ops->disabled_by_bios()) {
+       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;
+               goto out;
 
-       on_each_cpu(kvm_arch_ops->hardware_enable, 0, 0, 1);
+       on_each_cpu(kvm_arch_ops->hardware_enable, NULL, 0, 1);
+       r = register_cpu_notifier(&kvm_cpu_notifier);
+       if (r)
+               goto out_free_1;
        register_reboot_notifier(&kvm_reboot_notifier);
 
+       r = sysdev_class_register(&kvm_sysdev_class);
+       if (r)
+               goto out_free_2;
+
+       r = sysdev_register(&kvm_sysdev);
+       if (r)
+               goto out_free_3;
+
        kvm_chardev_ops.owner = module;
 
        r = misc_register(&kvm_dev);
@@ -1894,26 +2491,45 @@ int kvm_init_arch(struct kvm_arch_ops *ops, struct module *module)
        return r;
 
 out_free:
+       sysdev_unregister(&kvm_sysdev);
+out_free_3:
+       sysdev_class_unregister(&kvm_sysdev_class);
+out_free_2:
        unregister_reboot_notifier(&kvm_reboot_notifier);
-       on_each_cpu(kvm_arch_ops->hardware_disable, 0, 0, 1);
+       unregister_cpu_notifier(&kvm_cpu_notifier);
+out_free_1:
+       on_each_cpu(kvm_arch_ops->hardware_disable, NULL, 0, 1);
        kvm_arch_ops->hardware_unsetup();
+out:
+       kvm_arch_ops = NULL;
        return r;
 }
 
 void kvm_exit_arch(void)
 {
        misc_deregister(&kvm_dev);
-
+       sysdev_unregister(&kvm_sysdev);
+       sysdev_class_unregister(&kvm_sysdev_class);
        unregister_reboot_notifier(&kvm_reboot_notifier);
-       on_each_cpu(kvm_arch_ops->hardware_disable, 0, 0, 1);
+       unregister_cpu_notifier(&kvm_cpu_notifier);
+       on_each_cpu(kvm_arch_ops->hardware_disable, NULL, 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;
+       int r;
 
+       r = register_filesystem(&kvm_fs_type);
+       if (r)
+               goto out3;
+
+       kvmfs_mnt = kern_mount(&kvm_fs_type);
+       r = PTR_ERR(kvmfs_mnt);
+       if (IS_ERR(kvmfs_mnt))
+               goto out2;
        kvm_init_debug();
 
        kvm_init_msr_list();
@@ -1926,10 +2542,14 @@ static __init int kvm_init(void)
        bad_page_address = page_to_pfn(bad_page) << PAGE_SHIFT;
        memset(__va(bad_page_address), 0, PAGE_SIZE);
 
-       return r;
+       return 0;
 
 out:
        kvm_exit_debug();
+       mntput(kvmfs_mnt);
+out2:
+       unregister_filesystem(&kvm_fs_type);
+out3:
        return r;
 }
 
@@ -1937,6 +2557,8 @@ static __exit void kvm_exit(void)
 {
        kvm_exit_debug();
        __free_page(pfn_to_page(bad_page_address >> PAGE_SHIFT));
+       mntput(kvmfs_mnt);
+       unregister_filesystem(&kvm_fs_type);
 }
 
 module_init(kvm_init)