drivers/kvm/kvm_main.c

   1 /*
   2  * Kernel-based Virtual Machine driver for Linux
   3  *
   4  * This module enables machines with Intel VT-x extensions to run virtual
   5  * machines without emulation or binary translation.
   6  *
   7  * Copyright (C) 2006 Qumranet, Inc.
   8  *
   9  * Authors:
  10  *   Avi Kivity   <avi@qumranet.com>
  11  *   Yaniv Kamay  <yaniv@qumranet.com>
  12  *
  13  * This work is licensed under the terms of the GNU GPL, version 2.  See
  14  * the COPYING file in the top-level directory.
  15  *
  16  */
  17
  18 #include "kvm.h"
  19
  20 #include <linux/kvm.h>
  21 #include <linux/module.h>
  22 #include <linux/errno.h>
  23 #include <asm/processor.h>
  24 #include <linux/percpu.h>
  25 #include <linux/gfp.h>
  26 #include <asm/msr.h>
  27 #include <linux/mm.h>
  28 #include <linux/miscdevice.h>
  29 #include <linux/vmalloc.h>
  30 #include <asm/uaccess.h>
  31 #include <linux/reboot.h>
  32 #include <asm/io.h>
  33 #include <linux/debugfs.h>
  34 #include <linux/highmem.h>
  35 #include <linux/file.h>
  36 #include <asm/desc.h>
  37
  38 #include "x86_emulate.h"
  39 #include "segment_descriptor.h"
  40
  41 MODULE_AUTHOR("Qumranet");
  42 MODULE_LICENSE("GPL");
  43
  44 struct kvm_arch_ops *kvm_arch_ops;
  45 struct kvm_stat kvm_stat;
  46 EXPORT_SYMBOL_GPL(kvm_stat);
  47
  48 static struct kvm_stats_debugfs_item {
  49         const char *name;
  50         u32 *data;
  51         struct dentry *dentry;
  52 } debugfs_entries[] = {
  53         { "pf_fixed", &kvm_stat.pf_fixed },
  54         { "pf_guest", &kvm_stat.pf_guest },
  55         { "tlb_flush", &kvm_stat.tlb_flush },
  56         { "invlpg", &kvm_stat.invlpg },
  57         { "exits", &kvm_stat.exits },
  58         { "io_exits", &kvm_stat.io_exits },
  59         { "mmio_exits", &kvm_stat.mmio_exits },
  60         { "signal_exits", &kvm_stat.signal_exits },
  61         { "irq_exits", &kvm_stat.irq_exits },
  62         { 0, 0 }
  63 };
  64
  65 static struct dentry *debugfs_dir;
  66
  67 #define MAX_IO_MSRS 256
  68
  69 #define CR0_RESEVED_BITS 0xffffffff1ffaffc0ULL
  70 #define LMSW_GUEST_MASK 0x0eULL
  71 #define CR4_RESEVED_BITS (~((1ULL << 11) - 1))
  72 #define CR8_RESEVED_BITS (~0x0fULL)
  73 #define EFER_RESERVED_BITS 0xfffffffffffff2fe
  74
  75 #ifdef CONFIG_X86_64
  76 // LDT or TSS descriptor in the GDT. 16 bytes.
  77 struct segment_descriptor_64 {
  78         struct segment_descriptor s;
  79         u32 base_higher;
  80         u32 pad_zero;
  81 };
  82
  83 #endif
  84
  85 unsigned long segment_base(u16 selector)
  86 {
  87         struct descriptor_table gdt;
  88         struct segment_descriptor *d;
  89         unsigned long table_base;
  90         typedef unsigned long ul;
  91         unsigned long v;
  92
  93         if (selector == 0)
  94                 return 0;
  95
  96         asm ("sgdt %0" : "=m"(gdt));
  97         table_base = gdt.base;
  98
  99         if (selector & 4) {           /* from ldt */
 100                 u16 ldt_selector;
 101
 102                 asm ("sldt %0" : "=g"(ldt_selector));
 103                 table_base = segment_base(ldt_selector);
 104         }
 105         d = (struct segment_descriptor *)(table_base + (selector & ~7));
 106         v = d->base_low | ((ul)d->base_mid << 16) | ((ul)d->base_high << 24);
 107 #ifdef CONFIG_X86_64
 108         if (d->system == 0
 109             && (d->type == 2 || d->type == 9 || d->type == 11))
 110                 v |= ((ul)((struct segment_descriptor_64 *)d)->base_higher) << 32;
 111 #endif
 112         return v;
 113 }
 114 EXPORT_SYMBOL_GPL(segment_base);
 115
 116 static inline int valid_vcpu(int n)
 117 {
 118         return likely(n >= 0 && n < KVM_MAX_VCPUS);
 119 }
 120
 121 int kvm_read_guest(struct kvm_vcpu *vcpu,
 122                              gva_t addr,
 123                              unsigned long size,
 124                              void *dest)
 125 {
 126         unsigned char *host_buf = dest;
 127         unsigned long req_size = size;
 128
 129         while (size) {
 130                 hpa_t paddr;
 131                 unsigned now;
 132                 unsigned offset;
 133                 hva_t guest_buf;
 134
 135                 paddr = gva_to_hpa(vcpu, addr);
 136
 137                 if (is_error_hpa(paddr))
 138                         break;
 139
 140                 guest_buf = (hva_t)kmap_atomic(
 141                                         pfn_to_page(paddr >> PAGE_SHIFT),
 142                                         KM_USER0);
 143                 offset = addr & ~PAGE_MASK;
 144                 guest_buf |= offset;
 145                 now = min(size, PAGE_SIZE - offset);
 146                 memcpy(host_buf, (void*)guest_buf, now);
 147                 host_buf += now;
 148                 addr += now;
 149                 size -= now;
 150                 kunmap_atomic((void *)(guest_buf & PAGE_MASK), KM_USER0);
 151         }
 152         return req_size - size;
 153 }
 154 EXPORT_SYMBOL_GPL(kvm_read_guest);
 155
 156 int kvm_write_guest(struct kvm_vcpu *vcpu,
 157                              gva_t addr,
 158                              unsigned long size,
 159                              void *data)
 160 {
 161         unsigned char *host_buf = data;
 162         unsigned long req_size = size;
 163
 164         while (size) {
 165                 hpa_t paddr;
 166                 unsigned now;
 167                 unsigned offset;
 168                 hva_t guest_buf;
 169
 170                 paddr = gva_to_hpa(vcpu, addr);
 171
 172                 if (is_error_hpa(paddr))
 173                         break;
 174
 175                 guest_buf = (hva_t)kmap_atomic(
 176                                 pfn_to_page(paddr >> PAGE_SHIFT), KM_USER0);
 177                 offset = addr & ~PAGE_MASK;
 178                 guest_buf |= offset;
 179                 now = min(size, PAGE_SIZE - offset);
 180                 memcpy((void*)guest_buf, host_buf, now);
 181                 host_buf += now;
 182                 addr += now;
 183                 size -= now;
 184                 kunmap_atomic((void *)(guest_buf & PAGE_MASK), KM_USER0);
 185         }
 186         return req_size - size;
 187 }
 188 EXPORT_SYMBOL_GPL(kvm_write_guest);
 189
 190 static int vcpu_slot(struct kvm_vcpu *vcpu)
 191 {
 192         return vcpu - vcpu->kvm->vcpus;
 193 }
 194
 195 /*
 196  * Switches to specified vcpu, until a matching vcpu_put()
 197  */
 198 static struct kvm_vcpu *vcpu_load(struct kvm *kvm, int vcpu_slot)
 199 {
 200         struct kvm_vcpu *vcpu = &kvm->vcpus[vcpu_slot];
 201
 202         mutex_lock(&vcpu->mutex);
 203         if (unlikely(!vcpu->vmcs)) {
 204                 mutex_unlock(&vcpu->mutex);
 205                 return 0;
 206         }
 207         return kvm_arch_ops->vcpu_load(vcpu);
 208 }
 209
 210 static void vcpu_put(struct kvm_vcpu *vcpu)
 211 {
 212         kvm_arch_ops->vcpu_put(vcpu);
 213         mutex_unlock(&vcpu->mutex);
 214 }
 215
 216 static int kvm_dev_open(struct inode *inode, struct file *filp)
 217 {
 218         struct kvm *kvm = kzalloc(sizeof(struct kvm), GFP_KERNEL);
 219         int i;
 220
 221         if (!kvm)
 222                 return -ENOMEM;
 223
 224         spin_lock_init(&kvm->lock);
 225         INIT_LIST_HEAD(&kvm->active_mmu_pages);
 226         for (i = 0; i < KVM_MAX_VCPUS; ++i) {
 227                 struct kvm_vcpu *vcpu = &kvm->vcpus[i];
 228
 229                 mutex_init(&vcpu->mutex);
 230                 vcpu->mmu.root_hpa = INVALID_PAGE;
 231                 INIT_LIST_HEAD(&vcpu->free_pages);
 232         }
 233         filp->private_data = kvm;
 234         return 0;
 235 }
 236
 237 /*
 238  * Free any memory in @free but not in @dont.
 239  */
 240 static void kvm_free_physmem_slot(struct kvm_memory_slot *free,
 241                                   struct kvm_memory_slot *dont)
 242 {
 243         int i;
 244
 245         if (!dont || free->phys_mem != dont->phys_mem)
 246                 if (free->phys_mem) {
 247                         for (i = 0; i < free->npages; ++i)
 248                                 __free_page(free->phys_mem[i]);
 249                         vfree(free->phys_mem);
 250                 }
 251
 252         if (!dont || free->dirty_bitmap != dont->dirty_bitmap)
 253                 vfree(free->dirty_bitmap);
 254
 255         free->phys_mem = 0;
 256         free->npages = 0;
 257         free->dirty_bitmap = 0;
 258 }
 259
 260 static void kvm_free_physmem(struct kvm *kvm)
 261 {
 262         int i;
 263
 264         for (i = 0; i < kvm->nmemslots; ++i)
 265                 kvm_free_physmem_slot(&kvm->memslots[i], 0);
 266 }
 267
 268 static void kvm_free_vcpu(struct kvm_vcpu *vcpu)
 269 {
 270         kvm_arch_ops->vcpu_free(vcpu);
 271         kvm_mmu_destroy(vcpu);
 272 }
 273
 274 static void kvm_free_vcpus(struct kvm *kvm)
 275 {
 276         unsigned int i;
 277
 278         for (i = 0; i < KVM_MAX_VCPUS; ++i)
 279                 kvm_free_vcpu(&kvm->vcpus[i]);
 280 }
 281
 282 static int kvm_dev_release(struct inode *inode, struct file *filp)
 283 {
 284         struct kvm *kvm = filp->private_data;
 285
 286         kvm_free_vcpus(kvm);
 287         kvm_free_physmem(kvm);
 288         kfree(kvm);
 289         return 0;
 290 }
 291
 292 static void inject_gp(struct kvm_vcpu *vcpu)
 293 {
 294         kvm_arch_ops->inject_gp(vcpu, 0);
 295 }
 296
 297 static int pdptrs_have_reserved_bits_set(struct kvm_vcpu *vcpu,
 298                                          unsigned long cr3)
 299 {
 300         gfn_t pdpt_gfn = cr3 >> PAGE_SHIFT;
 301         unsigned offset = (cr3 & (PAGE_SIZE-1)) >> 5;
 302         int i;
 303         u64 pdpte;
 304         u64 *pdpt;
 305         struct kvm_memory_slot *memslot;
 306
 307         spin_lock(&vcpu->kvm->lock);
 308         memslot = gfn_to_memslot(vcpu->kvm, pdpt_gfn);
 309         /* FIXME: !memslot - emulate? 0xff? */
 310         pdpt = kmap_atomic(gfn_to_page(memslot, pdpt_gfn), KM_USER0);
 311
 312         for (i = 0; i < 4; ++i) {
 313                 pdpte = pdpt[offset + i];
 314                 if ((pdpte & 1) && (pdpte & 0xfffffff0000001e6ull))
 315                         break;
 316         }
 317
 318         kunmap_atomic(pdpt, KM_USER0);
 319         spin_unlock(&vcpu->kvm->lock);
 320
 321         return i != 4;
 322 }
 323
 324 void set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0)
 325 {
 326         if (cr0 & CR0_RESEVED_BITS) {
 327                 printk(KERN_DEBUG "set_cr0: 0x%lx #GP, reserved bits 0x%lx\n",
 328                        cr0, vcpu->cr0);
 329                 inject_gp(vcpu);
 330                 return;
 331         }
 332
 333         if ((cr0 & CR0_NW_MASK) && !(cr0 & CR0_CD_MASK)) {
 334                 printk(KERN_DEBUG "set_cr0: #GP, CD == 0 && NW == 1\n");
 335                 inject_gp(vcpu);
 336                 return;
 337         }
 338
 339         if ((cr0 & CR0_PG_MASK) && !(cr0 & CR0_PE_MASK)) {
 340                 printk(KERN_DEBUG "set_cr0: #GP, set PG flag "
 341                        "and a clear PE flag\n");
 342                 inject_gp(vcpu);
 343                 return;
 344         }
 345
 346         if (!is_paging(vcpu) && (cr0 & CR0_PG_MASK)) {
 347 #ifdef CONFIG_X86_64
 348                 if ((vcpu->shadow_efer & EFER_LME)) {
 349                         int cs_db, cs_l;
 350
 351                         if (!is_pae(vcpu)) {
 352                                 printk(KERN_DEBUG "set_cr0: #GP, start paging "
 353                                        "in long mode while PAE is disabled\n");
 354                                 inject_gp(vcpu);
 355                                 return;
 356                         }
 357                         kvm_arch_ops->get_cs_db_l_bits(vcpu, &cs_db, &cs_l);
 358                         if (cs_l) {
 359                                 printk(KERN_DEBUG "set_cr0: #GP, start paging "
 360                                        "in long mode while CS.L == 1\n");
 361                                 inject_gp(vcpu);
 362                                 return;
 363
 364                         }
 365                 } else
 366 #endif
 367                 if (is_pae(vcpu) &&
 368                             pdptrs_have_reserved_bits_set(vcpu, vcpu->cr3)) {
 369                         printk(KERN_DEBUG "set_cr0: #GP, pdptrs "
 370                                "reserved bits\n");
 371                         inject_gp(vcpu);
 372                         return;
 373                 }
 374
 375         }
 376
 377         kvm_arch_ops->set_cr0(vcpu, cr0);
 378         vcpu->cr0 = cr0;
 379
 380         spin_lock(&vcpu->kvm->lock);
 381         kvm_mmu_reset_context(vcpu);
 382         spin_unlock(&vcpu->kvm->lock);
 383         return;
 384 }
 385 EXPORT_SYMBOL_GPL(set_cr0);
 386
 387 void lmsw(struct kvm_vcpu *vcpu, unsigned long msw)
 388 {
 389         set_cr0(vcpu, (vcpu->cr0 & ~0x0ful) | (msw & 0x0f));
 390 }
 391 EXPORT_SYMBOL_GPL(lmsw);
 392
 393 void set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
 394 {
 395         if (cr4 & CR4_RESEVED_BITS) {
 396                 printk(KERN_DEBUG "set_cr4: #GP, reserved bits\n");
 397                 inject_gp(vcpu);
 398                 return;
 399         }
 400
 401         if (kvm_arch_ops->is_long_mode(vcpu)) {
 402                 if (!(cr4 & CR4_PAE_MASK)) {
 403                         printk(KERN_DEBUG "set_cr4: #GP, clearing PAE while "
 404                                "in long mode\n");
 405                         inject_gp(vcpu);
 406                         return;
 407                 }
 408         } else if (is_paging(vcpu) && !is_pae(vcpu) && (cr4 & CR4_PAE_MASK)
 409                    && pdptrs_have_reserved_bits_set(vcpu, vcpu->cr3)) {
 410                 printk(KERN_DEBUG "set_cr4: #GP, pdptrs reserved bits\n");
 411                 inject_gp(vcpu);
 412         }
 413
 414         if (cr4 & CR4_VMXE_MASK) {
 415                 printk(KERN_DEBUG "set_cr4: #GP, setting VMXE\n");
 416                 inject_gp(vcpu);
 417                 return;
 418         }
 419         kvm_arch_ops->set_cr4(vcpu, cr4);
 420         spin_lock(&vcpu->kvm->lock);
 421         kvm_mmu_reset_context(vcpu);
 422         spin_unlock(&vcpu->kvm->lock);
 423 }
 424 EXPORT_SYMBOL_GPL(set_cr4);
 425
 426 void set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3)
 427 {
 428         if (kvm_arch_ops->is_long_mode(vcpu)) {
 429                 if ( cr3 & CR3_L_MODE_RESEVED_BITS) {
 430                         printk(KERN_DEBUG "set_cr3: #GP, reserved bits\n");
 431                         inject_gp(vcpu);
 432                         return;
 433                 }
 434         } else {
 435                 if (cr3 & CR3_RESEVED_BITS) {
 436                         printk(KERN_DEBUG "set_cr3: #GP, reserved bits\n");
 437                         inject_gp(vcpu);
 438                         return;
 439                 }
 440                 if (is_paging(vcpu) && is_pae(vcpu) &&
 441                     pdptrs_have_reserved_bits_set(vcpu, cr3)) {
 442                         printk(KERN_DEBUG "set_cr3: #GP, pdptrs "
 443                                "reserved bits\n");
 444                         inject_gp(vcpu);
 445                         return;
 446                 }
 447         }
 448
 449         vcpu->cr3 = cr3;
 450         spin_lock(&vcpu->kvm->lock);
 451         vcpu->mmu.new_cr3(vcpu);
 452         spin_unlock(&vcpu->kvm->lock);
 453 }
 454 EXPORT_SYMBOL_GPL(set_cr3);
 455
 456 void set_cr8(struct kvm_vcpu *vcpu, unsigned long cr8)
 457 {
 458         if ( cr8 & CR8_RESEVED_BITS) {
 459                 printk(KERN_DEBUG "set_cr8: #GP, reserved bits 0x%lx\n", cr8);
 460                 inject_gp(vcpu);
 461                 return;
 462         }
 463         vcpu->cr8 = cr8;
 464 }
 465 EXPORT_SYMBOL_GPL(set_cr8);
 466
 467 void fx_init(struct kvm_vcpu *vcpu)
 468 {
 469         struct __attribute__ ((__packed__)) fx_image_s {
 470                 u16 control; //fcw
 471                 u16 status; //fsw
 472                 u16 tag; // ftw
 473                 u16 opcode; //fop
 474                 u64 ip; // fpu ip
 475                 u64 operand;// fpu dp
 476                 u32 mxcsr;
 477                 u32 mxcsr_mask;
 478
 479         } *fx_image;
 480
 481         fx_save(vcpu->host_fx_image);
 482         fpu_init();
 483         fx_save(vcpu->guest_fx_image);
 484         fx_restore(vcpu->host_fx_image);
 485
 486         fx_image = (struct fx_image_s *)vcpu->guest_fx_image;
 487         fx_image->mxcsr = 0x1f80;
 488         memset(vcpu->guest_fx_image + sizeof(struct fx_image_s),
 489                0, FX_IMAGE_SIZE - sizeof(struct fx_image_s));
 490 }
 491 EXPORT_SYMBOL_GPL(fx_init);
 492
 493 /*
 494  * Creates some virtual cpus.  Good luck creating more than one.
 495  */
 496 static int kvm_dev_ioctl_create_vcpu(struct kvm *kvm, int n)
 497 {
 498         int r;
 499         struct kvm_vcpu *vcpu;
 500
 501         r = -EINVAL;
 502         if (!valid_vcpu(n))
 503                 goto out;
 504
 505         vcpu = &kvm->vcpus[n];
 506
 507         mutex_lock(&vcpu->mutex);
 508
 509         if (vcpu->vmcs) {
 510                 mutex_unlock(&vcpu->mutex);
 511                 return -EEXIST;
 512         }
 513
 514         vcpu->host_fx_image = (char*)ALIGN((hva_t)vcpu->fx_buf,
 515                                            FX_IMAGE_ALIGN);
 516         vcpu->guest_fx_image = vcpu->host_fx_image + FX_IMAGE_SIZE;
 517
 518         vcpu->cpu = -1;  /* First load will set up TR */
 519         vcpu->kvm = kvm;
 520         r = kvm_arch_ops->vcpu_create(vcpu);
 521         if (r < 0)
 522                 goto out_free_vcpus;
 523
 524         kvm_arch_ops->vcpu_load(vcpu);
 525
 526         r = kvm_arch_ops->vcpu_setup(vcpu);
 527         if (r >= 0)
 528                 r = kvm_mmu_init(vcpu);
 529
 530         vcpu_put(vcpu);
 531
 532         if (r < 0)
 533                 goto out_free_vcpus;
 534
 535         return 0;
 536
 537 out_free_vcpus:
 538         kvm_free_vcpu(vcpu);
 539         mutex_unlock(&vcpu->mutex);
 540 out:
 541         return r;
 542 }
 543
 544 /*
 545  * Allocate some memory and give it an address in the guest physical address
 546  * space.
 547  *
 548  * Discontiguous memory is allowed, mostly for framebuffers.
 549  */
 550 static int kvm_dev_ioctl_set_memory_region(struct kvm *kvm,
 551                                            struct kvm_memory_region *mem)
 552 {
 553         int r;
 554         gfn_t base_gfn;
 555         unsigned long npages;
 556         unsigned long i;
 557         struct kvm_memory_slot *memslot;
 558         struct kvm_memory_slot old, new;
 559         int memory_config_version;
 560
 561         r = -EINVAL;
 562         /* General sanity checks */
 563         if (mem->memory_size & (PAGE_SIZE - 1))
 564                 goto out;
 565         if (mem->guest_phys_addr & (PAGE_SIZE - 1))
 566                 goto out;
 567         if (mem->slot >= KVM_MEMORY_SLOTS)
 568                 goto out;
 569         if (mem->guest_phys_addr + mem->memory_size < mem->guest_phys_addr)
 570                 goto out;
 571
 572         memslot = &kvm->memslots[mem->slot];
 573         base_gfn = mem->guest_phys_addr >> PAGE_SHIFT;
 574         npages = mem->memory_size >> PAGE_SHIFT;
 575
 576         if (!npages)
 577                 mem->flags &= ~KVM_MEM_LOG_DIRTY_PAGES;
 578
 579 raced:
 580         spin_lock(&kvm->lock);
 581
 582         memory_config_version = kvm->memory_config_version;
 583         new = old = *memslot;
 584
 585         new.base_gfn = base_gfn;
 586         new.npages = npages;
 587         new.flags = mem->flags;
 588
 589         /* Disallow changing a memory slot's size. */
 590         r = -EINVAL;
 591         if (npages && old.npages && npages != old.npages)
 592                 goto out_unlock;
 593
 594         /* Check for overlaps */
 595         r = -EEXIST;
 596         for (i = 0; i < KVM_MEMORY_SLOTS; ++i) {
 597                 struct kvm_memory_slot *s = &kvm->memslots[i];
 598
 599                 if (s == memslot)
 600                         continue;
 601                 if (!((base_gfn + npages <= s->base_gfn) ||
 602                       (base_gfn >= s->base_gfn + s->npages)))
 603                         goto out_unlock;
 604         }
 605         /*
 606          * Do memory allocations outside lock.  memory_config_version will
 607          * detect any races.
 608          */
 609         spin_unlock(&kvm->lock);
 610
 611         /* Deallocate if slot is being removed */
 612         if (!npages)
 613                 new.phys_mem = 0;
 614
 615         /* Free page dirty bitmap if unneeded */
 616         if (!(new.flags & KVM_MEM_LOG_DIRTY_PAGES))
 617                 new.dirty_bitmap = 0;
 618
 619         r = -ENOMEM;
 620
 621         /* Allocate if a slot is being created */
 622         if (npages && !new.phys_mem) {
 623                 new.phys_mem = vmalloc(npages * sizeof(struct page *));
 624
 625                 if (!new.phys_mem)
 626                         goto out_free;
 627
 628                 memset(new.phys_mem, 0, npages * sizeof(struct page *));
 629                 for (i = 0; i < npages; ++i) {
 630                         new.phys_mem[i] = alloc_page(GFP_HIGHUSER
 631                                                      | __GFP_ZERO);
 632                         if (!new.phys_mem[i])
 633                                 goto out_free;
 634                 }
 635         }
 636
 637         /* Allocate page dirty bitmap if needed */
 638         if ((new.flags & KVM_MEM_LOG_DIRTY_PAGES) && !new.dirty_bitmap) {
 639                 unsigned dirty_bytes = ALIGN(npages, BITS_PER_LONG) / 8;
 640
 641                 new.dirty_bitmap = vmalloc(dirty_bytes);
 642                 if (!new.dirty_bitmap)
 643                         goto out_free;
 644                 memset(new.dirty_bitmap, 0, dirty_bytes);
 645         }
 646
 647         spin_lock(&kvm->lock);
 648
 649         if (memory_config_version != kvm->memory_config_version) {
 650                 spin_unlock(&kvm->lock);
 651                 kvm_free_physmem_slot(&new, &old);
 652                 goto raced;
 653         }
 654
 655         r = -EAGAIN;
 656         if (kvm->busy)
 657                 goto out_unlock;
 658
 659         if (mem->slot >= kvm->nmemslots)
 660                 kvm->nmemslots = mem->slot + 1;
 661
 662         *memslot = new;
 663         ++kvm->memory_config_version;
 664
 665         spin_unlock(&kvm->lock);
 666
 667         for (i = 0; i < KVM_MAX_VCPUS; ++i) {
 668                 struct kvm_vcpu *vcpu;
 669
 670                 vcpu = vcpu_load(kvm, i);
 671                 if (!vcpu)
 672                         continue;
 673                 kvm_mmu_reset_context(vcpu);
 674                 vcpu_put(vcpu);
 675         }
 676
 677         kvm_free_physmem_slot(&old, &new);
 678         return 0;
 679
 680 out_unlock:
 681         spin_unlock(&kvm->lock);
 682 out_free:
 683         kvm_free_physmem_slot(&new, &old);
 684 out:
 685         return r;
 686 }
 687
 688 /*
 689  * Get (and clear) the dirty memory log for a memory slot.
 690  */
 691 static int kvm_dev_ioctl_get_dirty_log(struct kvm *kvm,
 692                                        struct kvm_dirty_log *log)
 693 {
 694         struct kvm_memory_slot *memslot;
 695         int r, i;
 696         int n;
 697         unsigned long any = 0;
 698
 699         spin_lock(&kvm->lock);
 700
 701         /*
 702          * Prevent changes to guest memory configuration even while the lock
 703          * is not taken.
 704          */
 705         ++kvm->busy;
 706         spin_unlock(&kvm->lock);
 707         r = -EINVAL;
 708         if (log->slot >= KVM_MEMORY_SLOTS)
 709                 goto out;
 710
 711         memslot = &kvm->memslots[log->slot];
 712         r = -ENOENT;
 713         if (!memslot->dirty_bitmap)
 714                 goto out;
 715
 716         n = ALIGN(memslot->npages, 8) / 8;
 717
 718         for (i = 0; !any && i < n; ++i)
 719                 any = memslot->dirty_bitmap[i];
 720
 721         r = -EFAULT;
 722         if (copy_to_user(log->dirty_bitmap, memslot->dirty_bitmap, n))
 723                 goto out;
 724
 725
 726         if (any) {
 727                 spin_lock(&kvm->lock);
 728                 kvm_mmu_slot_remove_write_access(kvm, log->slot);
 729                 spin_unlock(&kvm->lock);
 730                 memset(memslot->dirty_bitmap, 0, n);
 731                 for (i = 0; i < KVM_MAX_VCPUS; ++i) {
 732                         struct kvm_vcpu *vcpu = vcpu_load(kvm, i);
 733
 734                         if (!vcpu)
 735                                 continue;
 736                         kvm_arch_ops->tlb_flush(vcpu);
 737                         vcpu_put(vcpu);
 738                 }
 739         }
 740
 741         r = 0;
 742
 743 out:
 744         spin_lock(&kvm->lock);
 745         --kvm->busy;
 746         spin_unlock(&kvm->lock);
 747         return r;
 748 }
 749
 750 struct kvm_memory_slot *gfn_to_memslot(struct kvm *kvm, gfn_t gfn)
 751 {
 752         int i;
 753
 754         for (i = 0; i < kvm->nmemslots; ++i) {
 755                 struct kvm_memory_slot *memslot = &kvm->memslots[i];
 756
 757                 if (gfn >= memslot->base_gfn
 758                     && gfn < memslot->base_gfn + memslot->npages)
 759                         return memslot;
 760         }
 761         return 0;
 762 }
 763 EXPORT_SYMBOL_GPL(gfn_to_memslot);
 764
 765 void mark_page_dirty(struct kvm *kvm, gfn_t gfn)
 766 {
 767         int i;
 768         struct kvm_memory_slot *memslot = 0;
 769         unsigned long rel_gfn;
 770
 771         for (i = 0; i < kvm->nmemslots; ++i) {
 772                 memslot = &kvm->memslots[i];
 773
 774                 if (gfn >= memslot->base_gfn
 775                     && gfn < memslot->base_gfn + memslot->npages) {
 776
 777                         if (!memslot || !memslot->dirty_bitmap)
 778                                 return;
 779
 780                         rel_gfn = gfn - memslot->base_gfn;
 781
 782                         /* avoid RMW */
 783                         if (!test_bit(rel_gfn, memslot->dirty_bitmap))
 784                                 set_bit(rel_gfn, memslot->dirty_bitmap);
 785                         return;
 786                 }
 787         }
 788 }
 789
 790 static int emulator_read_std(unsigned long addr,
 791                              unsigned long *val,
 792                              unsigned int bytes,
 793                              struct x86_emulate_ctxt *ctxt)
 794 {
 795         struct kvm_vcpu *vcpu = ctxt->vcpu;
 796         void *data = val;
 797
 798         while (bytes) {
 799                 gpa_t gpa = vcpu->mmu.gva_to_gpa(vcpu, addr);
 800                 unsigned offset = addr & (PAGE_SIZE-1);
 801                 unsigned tocopy = min(bytes, (unsigned)PAGE_SIZE - offset);
 802                 unsigned long pfn;
 803                 struct kvm_memory_slot *memslot;
 804                 void *page;
 805
 806                 if (gpa == UNMAPPED_GVA)
 807                         return X86EMUL_PROPAGATE_FAULT;
 808                 pfn = gpa >> PAGE_SHIFT;
 809                 memslot = gfn_to_memslot(vcpu->kvm, pfn);
 810                 if (!memslot)
 811                         return X86EMUL_UNHANDLEABLE;
 812                 page = kmap_atomic(gfn_to_page(memslot, pfn), KM_USER0);
 813
 814                 memcpy(data, page + offset, tocopy);
 815
 816                 kunmap_atomic(page, KM_USER0);
 817
 818                 bytes -= tocopy;
 819                 data += tocopy;
 820                 addr += tocopy;
 821         }
 822
 823         return X86EMUL_CONTINUE;
 824 }
 825
 826 static int emulator_write_std(unsigned long addr,
 827                               unsigned long val,
 828                               unsigned int bytes,
 829                               struct x86_emulate_ctxt *ctxt)
 830 {
 831         printk(KERN_ERR "emulator_write_std: addr %lx n %d\n",
 832                addr, bytes);
 833         return X86EMUL_UNHANDLEABLE;
 834 }
 835
 836 static int emulator_read_emulated(unsigned long addr,
 837                                   unsigned long *val,
 838                                   unsigned int bytes,
 839                                   struct x86_emulate_ctxt *ctxt)
 840 {
 841         struct kvm_vcpu *vcpu = ctxt->vcpu;
 842
 843         if (vcpu->mmio_read_completed) {
 844                 memcpy(val, vcpu->mmio_data, bytes);
 845                 vcpu->mmio_read_completed = 0;
 846                 return X86EMUL_CONTINUE;
 847         } else if (emulator_read_std(addr, val, bytes, ctxt)
 848                    == X86EMUL_CONTINUE)
 849                 return X86EMUL_CONTINUE;
 850         else {
 851                 gpa_t gpa = vcpu->mmu.gva_to_gpa(vcpu, addr);
 852                 if (gpa == UNMAPPED_GVA)
 853                         return vcpu_printf(vcpu, "not present\n"), X86EMUL_PROPAGATE_FAULT;
 854                 vcpu->mmio_needed = 1;
 855                 vcpu->mmio_phys_addr = gpa;
 856                 vcpu->mmio_size = bytes;
 857                 vcpu->mmio_is_write = 0;
 858
 859                 return X86EMUL_UNHANDLEABLE;
 860         }
 861 }
 862
 863 static int emulator_write_emulated(unsigned long addr,
 864                                    unsigned long val,
 865                                    unsigned int bytes,
 866                                    struct x86_emulate_ctxt *ctxt)
 867 {
 868         struct kvm_vcpu *vcpu = ctxt->vcpu;
 869         gpa_t gpa = vcpu->mmu.gva_to_gpa(vcpu, addr);
 870
 871         if (gpa == UNMAPPED_GVA)
 872                 return X86EMUL_PROPAGATE_FAULT;
 873
 874         vcpu->mmio_needed = 1;
 875         vcpu->mmio_phys_addr = gpa;
 876         vcpu->mmio_size = bytes;
 877         vcpu->mmio_is_write = 1;
 878         memcpy(vcpu->mmio_data, &val, bytes);
 879
 880         return X86EMUL_CONTINUE;
 881 }
 882
 883 static int emulator_cmpxchg_emulated(unsigned long addr,
 884                                      unsigned long old,
 885                                      unsigned long new,
 886                                      unsigned int bytes,
 887                                      struct x86_emulate_ctxt *ctxt)
 888 {
 889         static int reported;
 890
 891         if (!reported) {
 892                 reported = 1;
 893                 printk(KERN_WARNING "kvm: emulating exchange as write\n");
 894         }
 895         return emulator_write_emulated(addr, new, bytes, ctxt);
 896 }
 897
 898 static unsigned long get_segment_base(struct kvm_vcpu *vcpu, int seg)
 899 {
 900         return kvm_arch_ops->get_segment_base(vcpu, seg);
 901 }
 902
 903 int emulate_invlpg(struct kvm_vcpu *vcpu, gva_t address)
 904 {
 905         spin_lock(&vcpu->kvm->lock);
 906         vcpu->mmu.inval_page(vcpu, address);
 907         spin_unlock(&vcpu->kvm->lock);
 908         kvm_arch_ops->invlpg(vcpu, address);
 909         return X86EMUL_CONTINUE;
 910 }
 911
 912 int emulate_clts(struct kvm_vcpu *vcpu)
 913 {
 914         unsigned long cr0 = vcpu->cr0;
 915
 916         cr0 &= ~CR0_TS_MASK;
 917         kvm_arch_ops->set_cr0(vcpu, cr0);
 918         return X86EMUL_CONTINUE;
 919 }
 920
 921 int emulator_get_dr(struct x86_emulate_ctxt* ctxt, int dr, unsigned long *dest)
 922 {
 923         struct kvm_vcpu *vcpu = ctxt->vcpu;
 924
 925         switch (dr) {
 926         case 0 ... 3:
 927                 *dest = kvm_arch_ops->get_dr(vcpu, dr);
 928                 return X86EMUL_CONTINUE;
 929         default:
 930                 printk(KERN_DEBUG "%s: unexpected dr %u\n",
 931                        __FUNCTION__, dr);
 932                 return X86EMUL_UNHANDLEABLE;
 933         }
 934 }
 935
 936 int emulator_set_dr(struct x86_emulate_ctxt *ctxt, int dr, unsigned long value)
 937 {
 938         unsigned long mask = (ctxt->mode == X86EMUL_MODE_PROT64) ? ~0ULL : ~0U;
 939         int exception;
 940
 941         kvm_arch_ops->set_dr(ctxt->vcpu, dr, value & mask, &exception);
 942         if (exception) {
 943                 /* FIXME: better handling */
 944                 return X86EMUL_UNHANDLEABLE;
 945         }
 946         return X86EMUL_CONTINUE;
 947 }
 948
 949 static void report_emulation_failure(struct x86_emulate_ctxt *ctxt)
 950 {
 951         static int reported;
 952         u8 opcodes[4];
 953         unsigned long rip = ctxt->vcpu->rip;
 954         unsigned long rip_linear;
 955
 956         rip_linear = rip + get_segment_base(ctxt->vcpu, VCPU_SREG_CS);
 957
 958         if (reported)
 959                 return;
 960
 961         emulator_read_std(rip_linear, (void *)opcodes, 4, ctxt);
 962
 963         printk(KERN_ERR "emulation failed but !mmio_needed?"
 964                " rip %lx %02x %02x %02x %02x\n",
 965                rip, opcodes[0], opcodes[1], opcodes[2], opcodes[3]);
 966         reported = 1;
 967 }
 968
 969 struct x86_emulate_ops emulate_ops = {
 970         .read_std            = emulator_read_std,
 971         .write_std           = emulator_write_std,
 972         .read_emulated       = emulator_read_emulated,
 973         .write_emulated      = emulator_write_emulated,
 974         .cmpxchg_emulated    = emulator_cmpxchg_emulated,
 975 };
 976
 977 int emulate_instruction(struct kvm_vcpu *vcpu,
 978                         struct kvm_run *run,
 979                         unsigned long cr2,
 980                         u16 error_code)
 981 {
 982         struct x86_emulate_ctxt emulate_ctxt;
 983         int r;
 984         int cs_db, cs_l;
 985
 986         kvm_arch_ops->cache_regs(vcpu);
 987
 988         kvm_arch_ops->get_cs_db_l_bits(vcpu, &cs_db, &cs_l);
 989
 990         emulate_ctxt.vcpu = vcpu;
 991         emulate_ctxt.eflags = kvm_arch_ops->get_rflags(vcpu);
 992         emulate_ctxt.cr2 = cr2;
 993         emulate_ctxt.mode = (emulate_ctxt.eflags & X86_EFLAGS_VM)
 994                 ? X86EMUL_MODE_REAL : cs_l
 995                 ? X86EMUL_MODE_PROT64 : cs_db
 996                 ? X86EMUL_MODE_PROT32 : X86EMUL_MODE_PROT16;
 997
 998         if (emulate_ctxt.mode == X86EMUL_MODE_PROT64) {
 999                 emulate_ctxt.cs_base = 0;
1000                 emulate_ctxt.ds_base = 0;
1001                 emulate_ctxt.es_base = 0;
1002                 emulate_ctxt.ss_base = 0;
1003         } else {
1004                 emulate_ctxt.cs_base = get_segment_base(vcpu, VCPU_SREG_CS);
1005                 emulate_ctxt.ds_base = get_segment_base(vcpu, VCPU_SREG_DS);
1006                 emulate_ctxt.es_base = get_segment_base(vcpu, VCPU_SREG_ES);
1007                 emulate_ctxt.ss_base = get_segment_base(vcpu, VCPU_SREG_SS);
1008         }
1009
1010         emulate_ctxt.gs_base = get_segment_base(vcpu, VCPU_SREG_GS);
1011         emulate_ctxt.fs_base = get_segment_base(vcpu, VCPU_SREG_FS);
1012
1013         vcpu->mmio_is_write = 0;
1014         r = x86_emulate_memop(&emulate_ctxt, &emulate_ops);
1015
1016         if ((r || vcpu->mmio_is_write) && run) {
1017                 run->mmio.phys_addr = vcpu->mmio_phys_addr;
1018                 memcpy(run->mmio.data, vcpu->mmio_data, 8);
1019                 run->mmio.len = vcpu->mmio_size;
1020                 run->mmio.is_write = vcpu->mmio_is_write;
1021         }
1022
1023         if (r) {
1024                 if (!vcpu->mmio_needed) {
1025                         report_emulation_failure(&emulate_ctxt);
1026                         return EMULATE_FAIL;
1027                 }
1028                 return EMULATE_DO_MMIO;
1029         }
1030
1031         kvm_arch_ops->decache_regs(vcpu);
1032         kvm_arch_ops->set_rflags(vcpu, emulate_ctxt.eflags);
1033
1034         if (vcpu->mmio_is_write)
1035                 return EMULATE_DO_MMIO;
1036
1037         return EMULATE_DONE;
1038 }
1039 EXPORT_SYMBOL_GPL(emulate_instruction);
1040
1041 static u64 mk_cr_64(u64 curr_cr, u32 new_val)
1042 {
1043         return (curr_cr & ~((1ULL << 32) - 1)) | new_val;
1044 }
1045
1046 void realmode_lgdt(struct kvm_vcpu *vcpu, u16 limit, unsigned long base)
1047 {
1048         struct descriptor_table dt = { limit, base };
1049
1050         kvm_arch_ops->set_gdt(vcpu, &dt);
1051 }
1052
1053 void realmode_lidt(struct kvm_vcpu *vcpu, u16 limit, unsigned long base)
1054 {
1055         struct descriptor_table dt = { limit, base };
1056
1057         kvm_arch_ops->set_idt(vcpu, &dt);
1058 }
1059
1060 void realmode_lmsw(struct kvm_vcpu *vcpu, unsigned long msw,
1061                    unsigned long *rflags)
1062 {
1063         lmsw(vcpu, msw);
1064         *rflags = kvm_arch_ops->get_rflags(vcpu);
1065 }
1066
1067 unsigned long realmode_get_cr(struct kvm_vcpu *vcpu, int cr)
1068 {
1069         switch (cr) {
1070         case 0:
1071                 return vcpu->cr0;
1072         case 2:
1073                 return vcpu->cr2;
1074         case 3:
1075                 return vcpu->cr3;
1076         case 4:
1077                 return vcpu->cr4;
1078         default:
1079                 vcpu_printf(vcpu, "%s: unexpected cr %u\n", __FUNCTION__, cr);
1080                 return 0;
1081         }
1082 }
1083
1084 void realmode_set_cr(struct kvm_vcpu *vcpu, int cr, unsigned long val,
1085                      unsigned long *rflags)
1086 {
1087         switch (cr) {
1088         case 0:
1089                 set_cr0(vcpu, mk_cr_64(vcpu->cr0, val));
1090                 *rflags = kvm_arch_ops->get_rflags(vcpu);
1091                 break;
1092         case 2:
1093                 vcpu->cr2 = val;
1094                 break;
1095         case 3:
1096                 set_cr3(vcpu, val);
1097                 break;
1098         case 4:
1099                 set_cr4(vcpu, mk_cr_64(vcpu->cr4, val));
1100                 break;
1101         default:
1102                 vcpu_printf(vcpu, "%s: unexpected cr %u\n", __FUNCTION__, cr);
1103         }
1104 }
1105
1106 /*
1107  * Reads an msr value (of 'msr_index') into 'pdata'.
1108  * Returns 0 on success, non-0 otherwise.
1109  * Assumes vcpu_load() was already called.
1110  */
1111 static int get_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 *pdata)
1112 {
1113         return kvm_arch_ops->get_msr(vcpu, msr_index, pdata);
1114 }
1115
1116 #ifdef CONFIG_X86_64
1117
1118 void set_efer(struct kvm_vcpu *vcpu, u64 efer)
1119 {
1120         if (efer & EFER_RESERVED_BITS) {
1121                 printk(KERN_DEBUG "set_efer: 0x%llx #GP, reserved bits\n",
1122                        efer);
1123                 inject_gp(vcpu);
1124                 return;
1125         }
1126
1127         if (is_paging(vcpu)
1128             && (vcpu->shadow_efer & EFER_LME) != (efer & EFER_LME)) {
1129                 printk(KERN_DEBUG "set_efer: #GP, change LME while paging\n");
1130                 inject_gp(vcpu);
1131                 return;
1132         }
1133
1134         kvm_arch_ops->set_efer(vcpu, efer);
1135
1136         efer &= ~EFER_LMA;
1137         efer |= vcpu->shadow_efer & EFER_LMA;
1138
1139         vcpu->shadow_efer = efer;
1140 }
1141 EXPORT_SYMBOL_GPL(set_efer);
1142
1143 #endif
1144
1145 /*
1146  * Writes msr value into into the appropriate "register".
1147  * Returns 0 on success, non-0 otherwise.
1148  * Assumes vcpu_load() was already called.
1149  */
1150 static int set_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 data)
1151 {
1152         return kvm_arch_ops->set_msr(vcpu, msr_index, data);
1153 }
1154
1155 void kvm_resched(struct kvm_vcpu *vcpu)
1156 {
1157         vcpu_put(vcpu);
1158         cond_resched();
1159         /* Cannot fail -  no vcpu unplug yet. */
1160         vcpu_load(vcpu->kvm, vcpu_slot(vcpu));
1161 }
1162 EXPORT_SYMBOL_GPL(kvm_resched);
1163
1164 void load_msrs(struct vmx_msr_entry *e, int n)
1165 {
1166         int i;
1167
1168         for (i = 0; i < n; ++i)
1169                 wrmsrl(e[i].index, e[i].data);
1170 }
1171 EXPORT_SYMBOL_GPL(load_msrs);
1172
1173 void save_msrs(struct vmx_msr_entry *e, int n)
1174 {
1175         int i;
1176
1177         for (i = 0; i < n; ++i)
1178                 rdmsrl(e[i].index, e[i].data);
1179 }
1180 EXPORT_SYMBOL_GPL(save_msrs);
1181
1182 static int kvm_dev_ioctl_run(struct kvm *kvm, struct kvm_run *kvm_run)
1183 {
1184         struct kvm_vcpu *vcpu;
1185         int r;
1186
1187         if (!valid_vcpu(kvm_run->vcpu))
1188                 return -EINVAL;
1189
1190         vcpu = vcpu_load(kvm, kvm_run->vcpu);
1191         if (!vcpu)
1192                 return -ENOENT;
1193
1194         if (kvm_run->emulated) {
1195                 kvm_arch_ops->skip_emulated_instruction(vcpu);
1196                 kvm_run->emulated = 0;
1197         }
1198
1199         if (kvm_run->mmio_completed) {
1200                 memcpy(vcpu->mmio_data, kvm_run->mmio.data, 8);
1201                 vcpu->mmio_read_completed = 1;
1202         }
1203
1204         vcpu->mmio_needed = 0;
1205
1206         r = kvm_arch_ops->run(vcpu, kvm_run);
1207
1208         vcpu_put(vcpu);
1209         return r;
1210 }
1211
1212 static int kvm_dev_ioctl_get_regs(struct kvm *kvm, struct kvm_regs *regs)
1213 {
1214         struct kvm_vcpu *vcpu;
1215
1216         if (!valid_vcpu(regs->vcpu))
1217                 return -EINVAL;
1218
1219         vcpu = vcpu_load(kvm, regs->vcpu);
1220         if (!vcpu)
1221                 return -ENOENT;
1222
1223         kvm_arch_ops->cache_regs(vcpu);
1224
1225         regs->rax = vcpu->regs[VCPU_REGS_RAX];
1226         regs->rbx = vcpu->regs[VCPU_REGS_RBX];
1227         regs->rcx = vcpu->regs[VCPU_REGS_RCX];
1228         regs->rdx = vcpu->regs[VCPU_REGS_RDX];
1229         regs->rsi = vcpu->regs[VCPU_REGS_RSI];
1230         regs->rdi = vcpu->regs[VCPU_REGS_RDI];
1231         regs->rsp = vcpu->regs[VCPU_REGS_RSP];
1232         regs->rbp = vcpu->regs[VCPU_REGS_RBP];
1233 #ifdef CONFIG_X86_64
1234         regs->r8 = vcpu->regs[VCPU_REGS_R8];
1235         regs->r9 = vcpu->regs[VCPU_REGS_R9];
1236         regs->r10 = vcpu->regs[VCPU_REGS_R10];
1237         regs->r11 = vcpu->regs[VCPU_REGS_R11];
1238         regs->r12 = vcpu->regs[VCPU_REGS_R12];
1239         regs->r13 = vcpu->regs[VCPU_REGS_R13];
1240         regs->r14 = vcpu->regs[VCPU_REGS_R14];
1241         regs->r15 = vcpu->regs[VCPU_REGS_R15];
1242 #endif
1243
1244         regs->rip = vcpu->rip;
1245         regs->rflags = kvm_arch_ops->get_rflags(vcpu);
1246
1247         /*
1248          * Don't leak debug flags in case they were set for guest debugging
1249          */
1250         if (vcpu->guest_debug.enabled && vcpu->guest_debug.singlestep)
1251                 regs->rflags &= ~(X86_EFLAGS_TF | X86_EFLAGS_RF);
1252
1253         vcpu_put(vcpu);
1254
1255         return 0;
1256 }
1257
1258 static int kvm_dev_ioctl_set_regs(struct kvm *kvm, struct kvm_regs *regs)
1259 {
1260         struct kvm_vcpu *vcpu;
1261
1262         if (!valid_vcpu(regs->vcpu))
1263                 return -EINVAL;
1264
1265         vcpu = vcpu_load(kvm, regs->vcpu);
1266         if (!vcpu)
1267                 return -ENOENT;
1268
1269         vcpu->regs[VCPU_REGS_RAX] = regs->rax;
1270         vcpu->regs[VCPU_REGS_RBX] = regs->rbx;
1271         vcpu->regs[VCPU_REGS_RCX] = regs->rcx;
1272         vcpu->regs[VCPU_REGS_RDX] = regs->rdx;
1273         vcpu->regs[VCPU_REGS_RSI] = regs->rsi;
1274         vcpu->regs[VCPU_REGS_RDI] = regs->rdi;
1275         vcpu->regs[VCPU_REGS_RSP] = regs->rsp;
1276         vcpu->regs[VCPU_REGS_RBP] = regs->rbp;
1277 #ifdef CONFIG_X86_64
1278         vcpu->regs[VCPU_REGS_R8] = regs->r8;
1279         vcpu->regs[VCPU_REGS_R9] = regs->r9;
1280         vcpu->regs[VCPU_REGS_R10] = regs->r10;
1281         vcpu->regs[VCPU_REGS_R11] = regs->r11;
1282         vcpu->regs[VCPU_REGS_R12] = regs->r12;
1283         vcpu->regs[VCPU_REGS_R13] = regs->r13;
1284         vcpu->regs[VCPU_REGS_R14] = regs->r14;
1285         vcpu->regs[VCPU_REGS_R15] = regs->r15;
1286 #endif
1287
1288         vcpu->rip = regs->rip;
1289         kvm_arch_ops->set_rflags(vcpu, regs->rflags);
1290
1291         kvm_arch_ops->decache_regs(vcpu);
1292
1293         vcpu_put(vcpu);
1294
1295         return 0;
1296 }
1297
1298 static void get_segment(struct kvm_vcpu *vcpu,
1299                         struct kvm_segment *var, int seg)
1300 {
1301         return kvm_arch_ops->get_segment(vcpu, var, seg);
1302 }
1303
1304 static int kvm_dev_ioctl_get_sregs(struct kvm *kvm, struct kvm_sregs *sregs)
1305 {
1306         struct kvm_vcpu *vcpu;
1307         struct descriptor_table dt;
1308
1309         if (!valid_vcpu(sregs->vcpu))
1310                 return -EINVAL;
1311         vcpu = vcpu_load(kvm, sregs->vcpu);
1312         if (!vcpu)
1313                 return -ENOENT;
1314
1315         get_segment(vcpu, &sregs->cs, VCPU_SREG_CS);
1316         get_segment(vcpu, &sregs->ds, VCPU_SREG_DS);
1317         get_segment(vcpu, &sregs->es, VCPU_SREG_ES);
1318         get_segment(vcpu, &sregs->fs, VCPU_SREG_FS);
1319         get_segment(vcpu, &sregs->gs, VCPU_SREG_GS);
1320         get_segment(vcpu, &sregs->ss, VCPU_SREG_SS);
1321
1322         get_segment(vcpu, &sregs->tr, VCPU_SREG_TR);
1323         get_segment(vcpu, &sregs->ldt, VCPU_SREG_LDTR);
1324
1325         kvm_arch_ops->get_idt(vcpu, &dt);
1326         sregs->idt.limit = dt.limit;
1327         sregs->idt.base = dt.base;
1328         kvm_arch_ops->get_gdt(vcpu, &dt);
1329         sregs->gdt.limit = dt.limit;
1330         sregs->gdt.base = dt.base;
1331
1332         sregs->cr0 = vcpu->cr0;
1333         sregs->cr2 = vcpu->cr2;
1334         sregs->cr3 = vcpu->cr3;
1335         sregs->cr4 = vcpu->cr4;
1336         sregs->cr8 = vcpu->cr8;
1337         sregs->efer = vcpu->shadow_efer;
1338         sregs->apic_base = vcpu->apic_base;
1339
1340         memcpy(sregs->interrupt_bitmap, vcpu->irq_pending,
1341                sizeof sregs->interrupt_bitmap);
1342
1343         vcpu_put(vcpu);
1344
1345         return 0;
1346 }
1347
1348 static void set_segment(struct kvm_vcpu *vcpu,
1349                         struct kvm_segment *var, int seg)
1350 {
1351         return kvm_arch_ops->set_segment(vcpu, var, seg);
1352 }
1353
1354 static int kvm_dev_ioctl_set_sregs(struct kvm *kvm, struct kvm_sregs *sregs)
1355 {
1356         struct kvm_vcpu *vcpu;
1357         int mmu_reset_needed = 0;
1358         int i;
1359         struct descriptor_table dt;
1360
1361         if (!valid_vcpu(sregs->vcpu))
1362                 return -EINVAL;
1363         vcpu = vcpu_load(kvm, sregs->vcpu);
1364         if (!vcpu)
1365                 return -ENOENT;
1366
1367         set_segment(vcpu, &sregs->cs, VCPU_SREG_CS);
1368         set_segment(vcpu, &sregs->ds, VCPU_SREG_DS);
1369         set_segment(vcpu, &sregs->es, VCPU_SREG_ES);
1370         set_segment(vcpu, &sregs->fs, VCPU_SREG_FS);
1371         set_segment(vcpu, &sregs->gs, VCPU_SREG_GS);
1372         set_segment(vcpu, &sregs->ss, VCPU_SREG_SS);
1373
1374         set_segment(vcpu, &sregs->tr, VCPU_SREG_TR);
1375         set_segment(vcpu, &sregs->ldt, VCPU_SREG_LDTR);
1376
1377         dt.limit = sregs->idt.limit;
1378         dt.base = sregs->idt.base;
1379         kvm_arch_ops->set_idt(vcpu, &dt);
1380         dt.limit = sregs->gdt.limit;
1381         dt.base = sregs->gdt.base;
1382         kvm_arch_ops->set_gdt(vcpu, &dt);
1383
1384         vcpu->cr2 = sregs->cr2;
1385         mmu_reset_needed |= vcpu->cr3 != sregs->cr3;
1386         vcpu->cr3 = sregs->cr3;
1387
1388         vcpu->cr8 = sregs->cr8;
1389
1390         mmu_reset_needed |= vcpu->shadow_efer != sregs->efer;
1391 #ifdef CONFIG_X86_64
1392         kvm_arch_ops->set_efer(vcpu, sregs->efer);
1393 #endif
1394         vcpu->apic_base = sregs->apic_base;
1395
1396         mmu_reset_needed |= vcpu->cr0 != sregs->cr0;
1397         kvm_arch_ops->set_cr0_no_modeswitch(vcpu, sregs->cr0);
1398
1399         mmu_reset_needed |= vcpu->cr4 != sregs->cr4;
1400         kvm_arch_ops->set_cr4(vcpu, sregs->cr4);
1401
1402         if (mmu_reset_needed)
1403                 kvm_mmu_reset_context(vcpu);
1404
1405         memcpy(vcpu->irq_pending, sregs->interrupt_bitmap,
1406                sizeof vcpu->irq_pending);
1407         vcpu->irq_summary = 0;
1408         for (i = 0; i < NR_IRQ_WORDS; ++i)
1409                 if (vcpu->irq_pending[i])
1410                         __set_bit(i, &vcpu->irq_summary);
1411
1412         vcpu_put(vcpu);
1413
1414         return 0;
1415 }
1416
1417 /*
1418  * List of msr numbers which we expose to userspace through KVM_GET_MSRS
1419  * and KVM_SET_MSRS, and KVM_GET_MSR_INDEX_LIST.
1420  *
1421  * This list is modified at module load time to reflect the
1422  * capabilities of the host cpu.
1423  */
1424 static u32 msrs_to_save[] = {
1425         MSR_IA32_SYSENTER_CS, MSR_IA32_SYSENTER_ESP, MSR_IA32_SYSENTER_EIP,
1426         MSR_K6_STAR,
1427 #ifdef CONFIG_X86_64
1428         MSR_CSTAR, MSR_KERNEL_GS_BASE, MSR_SYSCALL_MASK, MSR_LSTAR,
1429 #endif
1430         MSR_IA32_TIME_STAMP_COUNTER,
1431 };
1432
1433 static unsigned num_msrs_to_save;
1434
1435 static __init void kvm_init_msr_list(void)
1436 {
1437         u32 dummy[2];
1438         unsigned i, j;
1439
1440         for (i = j = 0; i < ARRAY_SIZE(msrs_to_save); i++) {
1441                 if (rdmsr_safe(msrs_to_save[i], &dummy[0], &dummy[1]) < 0)
1442                         continue;
1443                 if (j < i)
1444                         msrs_to_save[j] = msrs_to_save[i];
1445                 j++;
1446         }
1447         num_msrs_to_save = j;
1448 }
1449
1450 /*
1451  * Adapt set_msr() to msr_io()'s calling convention
1452  */
1453 static int do_set_msr(struct kvm_vcpu *vcpu, unsigned index, u64 *data)
1454 {
1455         return set_msr(vcpu, index, *data);
1456 }
1457
1458 /*
1459  * Read or write a bunch of msrs. All parameters are kernel addresses.
1460  *
1461  * @return number of msrs set successfully.
1462  */
1463 static int __msr_io(struct kvm *kvm, struct kvm_msrs *msrs,
1464                     struct kvm_msr_entry *entries,
1465                     int (*do_msr)(struct kvm_vcpu *vcpu,
1466                                   unsigned index, u64 *data))
1467 {
1468         struct kvm_vcpu *vcpu;
1469         int i;
1470
1471         if (!valid_vcpu(msrs->vcpu))
1472                 return -EINVAL;
1473
1474         vcpu = vcpu_load(kvm, msrs->vcpu);
1475         if (!vcpu)
1476                 return -ENOENT;
1477
1478         for (i = 0; i < msrs->nmsrs; ++i)
1479                 if (do_msr(vcpu, entries[i].index, &entries[i].data))
1480                         break;
1481
1482         vcpu_put(vcpu);
1483
1484         return i;
1485 }
1486
1487 /*
1488  * Read or write a bunch of msrs. Parameters are user addresses.
1489  *
1490  * @return number of msrs set successfully.
1491  */
1492 static int msr_io(struct kvm *kvm, struct kvm_msrs __user *user_msrs,
1493                   int (*do_msr)(struct kvm_vcpu *vcpu,
1494                                 unsigned index, u64 *data),
1495                   int writeback)
1496 {
1497         struct kvm_msrs msrs;
1498         struct kvm_msr_entry *entries;
1499         int r, n;
1500         unsigned size;
1501
1502         r = -EFAULT;
1503         if (copy_from_user(&msrs, user_msrs, sizeof msrs))
1504                 goto out;
1505
1506         r = -E2BIG;
1507         if (msrs.nmsrs >= MAX_IO_MSRS)
1508                 goto out;
1509
1510         r = -ENOMEM;
1511         size = sizeof(struct kvm_msr_entry) * msrs.nmsrs;
1512         entries = vmalloc(size);
1513         if (!entries)
1514                 goto out;
1515
1516         r = -EFAULT;
1517         if (copy_from_user(entries, user_msrs->entries, size))
1518                 goto out_free;
1519
1520         r = n = __msr_io(kvm, &msrs, entries, do_msr);
1521         if (r < 0)
1522                 goto out_free;
1523
1524         r = -EFAULT;
1525         if (writeback && copy_to_user(user_msrs->entries, entries, size))
1526                 goto out_free;
1527
1528         r = n;
1529
1530 out_free:
1531         vfree(entries);
1532 out:
1533         return r;
1534 }
1535
1536 /*
1537  * Translate a guest virtual address to a guest physical address.
1538  */
1539 static int kvm_dev_ioctl_translate(struct kvm *kvm, struct kvm_translation *tr)
1540 {
1541         unsigned long vaddr = tr->linear_address;
1542         struct kvm_vcpu *vcpu;
1543         gpa_t gpa;
1544
1545         vcpu = vcpu_load(kvm, tr->vcpu);
1546         if (!vcpu)
1547                 return -ENOENT;
1548         spin_lock(&kvm->lock);
1549         gpa = vcpu->mmu.gva_to_gpa(vcpu, vaddr);
1550         tr->physical_address = gpa;
1551         tr->valid = gpa != UNMAPPED_GVA;
1552         tr->writeable = 1;
1553         tr->usermode = 0;
1554         spin_unlock(&kvm->lock);
1555         vcpu_put(vcpu);
1556
1557         return 0;
1558 }
1559
1560 static int kvm_dev_ioctl_interrupt(struct kvm *kvm, struct kvm_interrupt *irq)
1561 {
1562         struct kvm_vcpu *vcpu;
1563
1564         if (!valid_vcpu(irq->vcpu))
1565                 return -EINVAL;
1566         if (irq->irq < 0 || irq->irq >= 256)
1567                 return -EINVAL;
1568         vcpu = vcpu_load(kvm, irq->vcpu);
1569         if (!vcpu)
1570                 return -ENOENT;
1571
1572         set_bit(irq->irq, vcpu->irq_pending);
1573         set_bit(irq->irq / BITS_PER_LONG, &vcpu->irq_summary);
1574
1575         vcpu_put(vcpu);
1576
1577         return 0;
1578 }
1579
1580 static int kvm_dev_ioctl_debug_guest(struct kvm *kvm,
1581                                      struct kvm_debug_guest *dbg)
1582 {
1583         struct kvm_vcpu *vcpu;
1584         int r;
1585
1586         if (!valid_vcpu(dbg->vcpu))
1587                 return -EINVAL;
1588         vcpu = vcpu_load(kvm, dbg->vcpu);
1589         if (!vcpu)
1590                 return -ENOENT;
1591
1592         r = kvm_arch_ops->set_guest_debug(vcpu, dbg);
1593
1594         vcpu_put(vcpu);
1595
1596         return r;
1597 }
1598
1599 static long kvm_dev_ioctl(struct file *filp,
1600                           unsigned int ioctl, unsigned long arg)
1601 {
1602         struct kvm *kvm = filp->private_data;
1603         int r = -EINVAL;
1604
1605         switch (ioctl) {
1606         case KVM_GET_API_VERSION:
1607                 r = KVM_API_VERSION;
1608                 break;
1609         case KVM_CREATE_VCPU: {
1610                 r = kvm_dev_ioctl_create_vcpu(kvm, arg);
1611                 if (r)
1612                         goto out;
1613                 break;
1614         }
1615         case KVM_RUN: {
1616                 struct kvm_run kvm_run;
1617
1618                 r = -EFAULT;
1619                 if (copy_from_user(&kvm_run, (void *)arg, sizeof kvm_run))
1620                         goto out;
1621                 r = kvm_dev_ioctl_run(kvm, &kvm_run);
1622                 if (r < 0)
1623                         goto out;
1624                 r = -EFAULT;
1625                 if (copy_to_user((void *)arg, &kvm_run, sizeof kvm_run))
1626                         goto out;
1627                 r = 0;
1628                 break;
1629         }
1630         case KVM_GET_REGS: {
1631                 struct kvm_regs kvm_regs;
1632
1633                 r = -EFAULT;
1634                 if (copy_from_user(&kvm_regs, (void *)arg, sizeof kvm_regs))
1635                         goto out;
1636                 r = kvm_dev_ioctl_get_regs(kvm, &kvm_regs);
1637                 if (r)
1638                         goto out;
1639                 r = -EFAULT;
1640                 if (copy_to_user((void *)arg, &kvm_regs, sizeof kvm_regs))
1641                         goto out;
1642                 r = 0;
1643                 break;
1644         }
1645         case KVM_SET_REGS: {
1646                 struct kvm_regs kvm_regs;
1647
1648                 r = -EFAULT;
1649                 if (copy_from_user(&kvm_regs, (void *)arg, sizeof kvm_regs))
1650                         goto out;
1651                 r = kvm_dev_ioctl_set_regs(kvm, &kvm_regs);
1652                 if (r)
1653                         goto out;
1654                 r = 0;
1655                 break;
1656         }
1657         case KVM_GET_SREGS: {
1658                 struct kvm_sregs kvm_sregs;
1659
1660                 r = -EFAULT;
1661                 if (copy_from_user(&kvm_sregs, (void *)arg, sizeof kvm_sregs))
1662                         goto out;
1663                 r = kvm_dev_ioctl_get_sregs(kvm, &kvm_sregs);
1664                 if (r)
1665                         goto out;
1666                 r = -EFAULT;
1667                 if (copy_to_user((void *)arg, &kvm_sregs, sizeof kvm_sregs))
1668                         goto out;
1669                 r = 0;
1670                 break;
1671         }
1672         case KVM_SET_SREGS: {
1673                 struct kvm_sregs kvm_sregs;
1674
1675                 r = -EFAULT;
1676                 if (copy_from_user(&kvm_sregs, (void *)arg, sizeof kvm_sregs))
1677                         goto out;
1678                 r = kvm_dev_ioctl_set_sregs(kvm, &kvm_sregs);
1679                 if (r)
1680                         goto out;
1681                 r = 0;
1682                 break;
1683         }
1684         case KVM_TRANSLATE: {
1685                 struct kvm_translation tr;
1686
1687                 r = -EFAULT;
1688                 if (copy_from_user(&tr, (void *)arg, sizeof tr))
1689                         goto out;
1690                 r = kvm_dev_ioctl_translate(kvm, &tr);
1691                 if (r)
1692                         goto out;
1693                 r = -EFAULT;
1694                 if (copy_to_user((void *)arg, &tr, sizeof tr))
1695                         goto out;
1696                 r = 0;
1697                 break;
1698         }
1699         case KVM_INTERRUPT: {
1700                 struct kvm_interrupt irq;
1701
1702                 r = -EFAULT;
1703                 if (copy_from_user(&irq, (void *)arg, sizeof irq))
1704                         goto out;
1705                 r = kvm_dev_ioctl_interrupt(kvm, &irq);
1706                 if (r)
1707                         goto out;
1708                 r = 0;
1709                 break;
1710         }
1711         case KVM_DEBUG_GUEST: {
1712                 struct kvm_debug_guest dbg;
1713
1714                 r = -EFAULT;
1715                 if (copy_from_user(&dbg, (void *)arg, sizeof dbg))
1716                         goto out;
1717                 r = kvm_dev_ioctl_debug_guest(kvm, &dbg);
1718                 if (r)
1719                         goto out;
1720                 r = 0;
1721                 break;
1722         }
1723         case KVM_SET_MEMORY_REGION: {
1724                 struct kvm_memory_region kvm_mem;
1725
1726                 r = -EFAULT;
1727                 if (copy_from_user(&kvm_mem, (void *)arg, sizeof kvm_mem))
1728                         goto out;
1729                 r = kvm_dev_ioctl_set_memory_region(kvm, &kvm_mem);
1730                 if (r)
1731                         goto out;
1732                 break;
1733         }
1734         case KVM_GET_DIRTY_LOG: {
1735                 struct kvm_dirty_log log;
1736
1737                 r = -EFAULT;
1738                 if (copy_from_user(&log, (void *)arg, sizeof log))
1739                         goto out;
1740                 r = kvm_dev_ioctl_get_dirty_log(kvm, &log);
1741                 if (r)
1742                         goto out;
1743                 break;
1744         }
1745         case KVM_GET_MSRS:
1746                 r = msr_io(kvm, (void __user *)arg, get_msr, 1);
1747                 break;
1748         case KVM_SET_MSRS:
1749                 r = msr_io(kvm, (void __user *)arg, do_set_msr, 0);
1750                 break;
1751         case KVM_GET_MSR_INDEX_LIST: {
1752                 struct kvm_msr_list __user *user_msr_list = (void __user *)arg;
1753                 struct kvm_msr_list msr_list;
1754                 unsigned n;
1755
1756                 r = -EFAULT;
1757                 if (copy_from_user(&msr_list, user_msr_list, sizeof msr_list))
1758                         goto out;
1759                 n = msr_list.nmsrs;
1760                 msr_list.nmsrs = num_msrs_to_save;
1761                 if (copy_to_user(user_msr_list, &msr_list, sizeof msr_list))
1762                         goto out;
1763                 r = -E2BIG;
1764                 if (n < num_msrs_to_save)
1765                         goto out;
1766                 r = -EFAULT;
1767                 if (copy_to_user(user_msr_list->indices, &msrs_to_save,
1768                                  num_msrs_to_save * sizeof(u32)))
1769                         goto out;
1770                 r = 0;
1771         }
1772         default:
1773                 ;
1774         }
1775 out:
1776         return r;
1777 }
1778
1779 static struct page *kvm_dev_nopage(struct vm_area_struct *vma,
1780                                    unsigned long address,
1781                                    int *type)
1782 {
1783         struct kvm *kvm = vma->vm_file->private_data;
1784         unsigned long pgoff;
1785         struct kvm_memory_slot *slot;
1786         struct page *page;
1787
1788         *type = VM_FAULT_MINOR;
1789         pgoff = ((address - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff;
1790         slot = gfn_to_memslot(kvm, pgoff);
1791         if (!slot)
1792                 return NOPAGE_SIGBUS;
1793         page = gfn_to_page(slot, pgoff);
1794         if (!page)
1795                 return NOPAGE_SIGBUS;
1796         get_page(page);
1797         return page;
1798 }
1799
1800 static struct vm_operations_struct kvm_dev_vm_ops = {
1801         .nopage = kvm_dev_nopage,
1802 };
1803
1804 static int kvm_dev_mmap(struct file *file, struct vm_area_struct *vma)
1805 {
1806         vma->vm_ops = &kvm_dev_vm_ops;
1807         return 0;
1808 }
1809
1810 static struct file_operations kvm_chardev_ops = {
1811         .open           = kvm_dev_open,
1812         .release        = kvm_dev_release,
1813         .unlocked_ioctl = kvm_dev_ioctl,
1814         .compat_ioctl   = kvm_dev_ioctl,
1815         .mmap           = kvm_dev_mmap,
1816 };
1817
1818 static struct miscdevice kvm_dev = {
1819         MISC_DYNAMIC_MINOR,
1820         "kvm",
1821         &kvm_chardev_ops,
1822 };
1823
1824 static int kvm_reboot(struct notifier_block *notifier, unsigned long val,
1825                        void *v)
1826 {
1827         if (val == SYS_RESTART) {
1828                 /*
1829                  * Some (well, at least mine) BIOSes hang on reboot if
1830                  * in vmx root mode.
1831                  */
1832                 printk(KERN_INFO "kvm: exiting hardware virtualization\n");
1833                 on_each_cpu(kvm_arch_ops->hardware_disable, 0, 0, 1);
1834         }
1835         return NOTIFY_OK;
1836 }
1837
1838 static struct notifier_block kvm_reboot_notifier = {
1839         .notifier_call = kvm_reboot,
1840         .priority = 0,
1841 };
1842
1843 static __init void kvm_init_debug(void)
1844 {
1845         struct kvm_stats_debugfs_item *p;
1846
1847         debugfs_dir = debugfs_create_dir("kvm", 0);
1848         for (p = debugfs_entries; p->name; ++p)
1849                 p->dentry = debugfs_create_u32(p->name, 0444, debugfs_dir,
1850                                                p->data);
1851 }
1852
1853 static void kvm_exit_debug(void)
1854 {
1855         struct kvm_stats_debugfs_item *p;
1856
1857         for (p = debugfs_entries; p->name; ++p)
1858                 debugfs_remove(p->dentry);
1859         debugfs_remove(debugfs_dir);
1860 }
1861
1862 hpa_t bad_page_address;
1863
1864 int kvm_init_arch(struct kvm_arch_ops *ops, struct module *module)
1865 {
1866         int r;
1867
1868         kvm_arch_ops = ops;
1869
1870         if (!kvm_arch_ops->cpu_has_kvm_support()) {
1871                 printk(KERN_ERR "kvm: no hardware support\n");
1872                 return -EOPNOTSUPP;
1873         }
1874         if (kvm_arch_ops->disabled_by_bios()) {
1875                 printk(KERN_ERR "kvm: disabled by bios\n");
1876                 return -EOPNOTSUPP;
1877         }
1878
1879         r = kvm_arch_ops->hardware_setup();
1880         if (r < 0)
1881             return r;
1882
1883         on_each_cpu(kvm_arch_ops->hardware_enable, 0, 0, 1);
1884         register_reboot_notifier(&kvm_reboot_notifier);
1885
1886         kvm_chardev_ops.owner = module;
1887
1888         r = misc_register(&kvm_dev);
1889         if (r) {
1890                 printk (KERN_ERR "kvm: misc device register failed\n");
1891                 goto out_free;
1892         }
1893
1894         return r;
1895
1896 out_free:
1897         unregister_reboot_notifier(&kvm_reboot_notifier);
1898         on_each_cpu(kvm_arch_ops->hardware_disable, 0, 0, 1);
1899         kvm_arch_ops->hardware_unsetup();
1900         return r;
1901 }
1902
1903 void kvm_exit_arch(void)
1904 {
1905         misc_deregister(&kvm_dev);
1906
1907         unregister_reboot_notifier(&kvm_reboot_notifier);
1908         on_each_cpu(kvm_arch_ops->hardware_disable, 0, 0, 1);
1909         kvm_arch_ops->hardware_unsetup();
1910 }
1911
1912 static __init int kvm_init(void)
1913 {
1914         static struct page *bad_page;
1915         int r = 0;
1916
1917         kvm_init_debug();
1918
1919         kvm_init_msr_list();
1920
1921         if ((bad_page = alloc_page(GFP_KERNEL)) == NULL) {
1922                 r = -ENOMEM;
1923                 goto out;
1924         }
1925
1926         bad_page_address = page_to_pfn(bad_page) << PAGE_SHIFT;
1927         memset(__va(bad_page_address), 0, PAGE_SIZE);
1928
1929         return r;
1930
1931 out:
1932         kvm_exit_debug();
1933         return r;
1934 }
1935
1936 static __exit void kvm_exit(void)
1937 {
1938         kvm_exit_debug();
1939         __free_page(pfn_to_page(bad_page_address >> PAGE_SHIFT));
1940 }
1941
1942 module_init(kvm_init)
1943 module_exit(kvm_exit)
1944
1945 EXPORT_SYMBOL_GPL(kvm_init_arch);
1946 EXPORT_SYMBOL_GPL(kvm_exit_arch);