arch/powerpc/kernel/kvm.c

   1 /*
   2  * Copyright (C) 2010 SUSE Linux Products GmbH. All rights reserved.
   3  *
   4  * Authors:
   5  *     Alexander Graf <agraf@suse.de>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License, version 2, as
   9  * published by the Free Software Foundation.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  19  */
  20
  21 #include <linux/kvm_host.h>
  22 #include <linux/init.h>
  23 #include <linux/export.h>
  24 #include <linux/kvm_para.h>
  25 #include <linux/slab.h>
  26 #include <linux/of.h>
  27
  28 #include <asm/reg.h>
  29 #include <asm/sections.h>
  30 #include <asm/cacheflush.h>
  31 #include <asm/disassemble.h>
  32
  33 #define KVM_MAGIC_PAGE          (-4096L)
  34 #define magic_var(x) KVM_MAGIC_PAGE + offsetof(struct kvm_vcpu_arch_shared, x)
  35
  36 #define KVM_INST_LWZ            0x80000000
  37 #define KVM_INST_STW            0x90000000
  38 #define KVM_INST_LD             0xe8000000
  39 #define KVM_INST_STD            0xf8000000
  40 #define KVM_INST_NOP            0x60000000
  41 #define KVM_INST_B              0x48000000
  42 #define KVM_INST_B_MASK         0x03ffffff
  43 #define KVM_INST_B_MAX          0x01ffffff
  44
  45 #define KVM_MASK_RT             0x03e00000
  46 #define KVM_RT_30               0x03c00000
  47 #define KVM_MASK_RB             0x0000f800
  48 #define KVM_INST_MFMSR          0x7c0000a6
  49 #define KVM_INST_MFSPR_SPRG0    0x7c1042a6
  50 #define KVM_INST_MFSPR_SPRG1    0x7c1142a6
  51 #define KVM_INST_MFSPR_SPRG2    0x7c1242a6
  52 #define KVM_INST_MFSPR_SPRG3    0x7c1342a6
  53 #define KVM_INST_MFSPR_SRR0     0x7c1a02a6
  54 #define KVM_INST_MFSPR_SRR1     0x7c1b02a6
  55 #define KVM_INST_MFSPR_DAR      0x7c1302a6
  56 #define KVM_INST_MFSPR_DSISR    0x7c1202a6
  57
  58 #define KVM_INST_MTSPR_SPRG0    0x7c1043a6
  59 #define KVM_INST_MTSPR_SPRG1    0x7c1143a6
  60 #define KVM_INST_MTSPR_SPRG2    0x7c1243a6
  61 #define KVM_INST_MTSPR_SPRG3    0x7c1343a6
  62 #define KVM_INST_MTSPR_SRR0     0x7c1a03a6
  63 #define KVM_INST_MTSPR_SRR1     0x7c1b03a6
  64 #define KVM_INST_MTSPR_DAR      0x7c1303a6
  65 #define KVM_INST_MTSPR_DSISR    0x7c1203a6
  66
  67 #define KVM_INST_TLBSYNC        0x7c00046c
  68 #define KVM_INST_MTMSRD_L0      0x7c000164
  69 #define KVM_INST_MTMSRD_L1      0x7c010164
  70 #define KVM_INST_MTMSR          0x7c000124
  71
  72 #define KVM_INST_WRTEEI_0       0x7c000146
  73 #define KVM_INST_WRTEEI_1       0x7c008146
  74
  75 #define KVM_INST_MTSRIN         0x7c0001e4
  76
  77 static bool kvm_patching_worked = true;
  78 static char kvm_tmp[1024 * 1024];
  79 static int kvm_tmp_index;
  80
  81 static inline void kvm_patch_ins(u32 *inst, u32 new_inst)
  82 {
  83         *inst = new_inst;
  84         flush_icache_range((ulong)inst, (ulong)inst + 4);
  85 }
  86
  87 static void kvm_patch_ins_ll(u32 *inst, long addr, u32 rt)
  88 {
  89 #ifdef CONFIG_64BIT
  90         kvm_patch_ins(inst, KVM_INST_LD | rt | (addr & 0x0000fffc));
  91 #else
  92         kvm_patch_ins(inst, KVM_INST_LWZ | rt | (addr & 0x0000fffc));
  93 #endif
  94 }
  95
  96 static void kvm_patch_ins_ld(u32 *inst, long addr, u32 rt)
  97 {
  98 #ifdef CONFIG_64BIT
  99         kvm_patch_ins(inst, KVM_INST_LD | rt | (addr & 0x0000fffc));
 100 #else
 101         kvm_patch_ins(inst, KVM_INST_LWZ | rt | ((addr + 4) & 0x0000fffc));
 102 #endif
 103 }
 104
 105 static void kvm_patch_ins_lwz(u32 *inst, long addr, u32 rt)
 106 {
 107         kvm_patch_ins(inst, KVM_INST_LWZ | rt | (addr & 0x0000ffff));
 108 }
 109
 110 static void kvm_patch_ins_std(u32 *inst, long addr, u32 rt)
 111 {
 112 #ifdef CONFIG_64BIT
 113         kvm_patch_ins(inst, KVM_INST_STD | rt | (addr & 0x0000fffc));
 114 #else
 115         kvm_patch_ins(inst, KVM_INST_STW | rt | ((addr + 4) & 0x0000fffc));
 116 #endif
 117 }
 118
 119 static void kvm_patch_ins_stw(u32 *inst, long addr, u32 rt)
 120 {
 121         kvm_patch_ins(inst, KVM_INST_STW | rt | (addr & 0x0000fffc));
 122 }
 123
 124 static void kvm_patch_ins_nop(u32 *inst)
 125 {
 126         kvm_patch_ins(inst, KVM_INST_NOP);
 127 }
 128
 129 static void kvm_patch_ins_b(u32 *inst, int addr)
 130 {
 131 #if defined(CONFIG_RELOCATABLE) && defined(CONFIG_PPC_BOOK3S)
 132         /* On relocatable kernels interrupts handlers and our code
 133            can be in different regions, so we don't patch them */
 134
 135         extern u32 __end_interrupts;
 136         if ((ulong)inst < (ulong)&__end_interrupts)
 137                 return;
 138 #endif
 139
 140         kvm_patch_ins(inst, KVM_INST_B | (addr & KVM_INST_B_MASK));
 141 }
 142
 143 static u32 *kvm_alloc(int len)
 144 {
 145         u32 *p;
 146
 147         if ((kvm_tmp_index + len) > ARRAY_SIZE(kvm_tmp)) {
 148                 printk(KERN_ERR "KVM: No more space (%d + %d)\n",
 149                                 kvm_tmp_index, len);
 150                 kvm_patching_worked = false;
 151                 return NULL;
 152         }
 153
 154         p = (void*)&kvm_tmp[kvm_tmp_index];
 155         kvm_tmp_index += len;
 156
 157         return p;
 158 }
 159
 160 extern u32 kvm_emulate_mtmsrd_branch_offs;
 161 extern u32 kvm_emulate_mtmsrd_reg_offs;
 162 extern u32 kvm_emulate_mtmsrd_orig_ins_offs;
 163 extern u32 kvm_emulate_mtmsrd_len;
 164 extern u32 kvm_emulate_mtmsrd[];
 165
 166 static void kvm_patch_ins_mtmsrd(u32 *inst, u32 rt)
 167 {
 168         u32 *p;
 169         int distance_start;
 170         int distance_end;
 171         ulong next_inst;
 172
 173         p = kvm_alloc(kvm_emulate_mtmsrd_len * 4);
 174         if (!p)
 175                 return;
 176
 177         /* Find out where we are and put everything there */
 178         distance_start = (ulong)p - (ulong)inst;
 179         next_inst = ((ulong)inst + 4);
 180         distance_end = next_inst - (ulong)&p[kvm_emulate_mtmsrd_branch_offs];
 181
 182         /* Make sure we only write valid b instructions */
 183         if (distance_start > KVM_INST_B_MAX) {
 184                 kvm_patching_worked = false;
 185                 return;
 186         }
 187
 188         /* Modify the chunk to fit the invocation */
 189         memcpy(p, kvm_emulate_mtmsrd, kvm_emulate_mtmsrd_len * 4);
 190         p[kvm_emulate_mtmsrd_branch_offs] |= distance_end & KVM_INST_B_MASK;
 191         switch (get_rt(rt)) {
 192         case 30:
 193                 kvm_patch_ins_ll(&p[kvm_emulate_mtmsrd_reg_offs],
 194                                  magic_var(scratch2), KVM_RT_30);
 195                 break;
 196         case 31:
 197                 kvm_patch_ins_ll(&p[kvm_emulate_mtmsrd_reg_offs],
 198                                  magic_var(scratch1), KVM_RT_30);
 199                 break;
 200         default:
 201                 p[kvm_emulate_mtmsrd_reg_offs] |= rt;
 202                 break;
 203         }
 204
 205         p[kvm_emulate_mtmsrd_orig_ins_offs] = *inst;
 206         flush_icache_range((ulong)p, (ulong)p + kvm_emulate_mtmsrd_len * 4);
 207
 208         /* Patch the invocation */
 209         kvm_patch_ins_b(inst, distance_start);
 210 }
 211
 212 extern u32 kvm_emulate_mtmsr_branch_offs;
 213 extern u32 kvm_emulate_mtmsr_reg1_offs;
 214 extern u32 kvm_emulate_mtmsr_reg2_offs;
 215 extern u32 kvm_emulate_mtmsr_orig_ins_offs;
 216 extern u32 kvm_emulate_mtmsr_len;
 217 extern u32 kvm_emulate_mtmsr[];
 218
 219 static void kvm_patch_ins_mtmsr(u32 *inst, u32 rt)
 220 {
 221         u32 *p;
 222         int distance_start;
 223         int distance_end;
 224         ulong next_inst;
 225
 226         p = kvm_alloc(kvm_emulate_mtmsr_len * 4);
 227         if (!p)
 228                 return;
 229
 230         /* Find out where we are and put everything there */
 231         distance_start = (ulong)p - (ulong)inst;
 232         next_inst = ((ulong)inst + 4);
 233         distance_end = next_inst - (ulong)&p[kvm_emulate_mtmsr_branch_offs];
 234
 235         /* Make sure we only write valid b instructions */
 236         if (distance_start > KVM_INST_B_MAX) {
 237                 kvm_patching_worked = false;
 238                 return;
 239         }
 240
 241         /* Modify the chunk to fit the invocation */
 242         memcpy(p, kvm_emulate_mtmsr, kvm_emulate_mtmsr_len * 4);
 243         p[kvm_emulate_mtmsr_branch_offs] |= distance_end & KVM_INST_B_MASK;
 244
 245         /* Make clobbered registers work too */
 246         switch (get_rt(rt)) {
 247         case 30:
 248                 kvm_patch_ins_ll(&p[kvm_emulate_mtmsr_reg1_offs],
 249                                  magic_var(scratch2), KVM_RT_30);
 250                 kvm_patch_ins_ll(&p[kvm_emulate_mtmsr_reg2_offs],
 251                                  magic_var(scratch2), KVM_RT_30);
 252                 break;
 253         case 31:
 254                 kvm_patch_ins_ll(&p[kvm_emulate_mtmsr_reg1_offs],
 255                                  magic_var(scratch1), KVM_RT_30);
 256                 kvm_patch_ins_ll(&p[kvm_emulate_mtmsr_reg2_offs],
 257                                  magic_var(scratch1), KVM_RT_30);
 258                 break;
 259         default:
 260                 p[kvm_emulate_mtmsr_reg1_offs] |= rt;
 261                 p[kvm_emulate_mtmsr_reg2_offs] |= rt;
 262                 break;
 263         }
 264
 265         p[kvm_emulate_mtmsr_orig_ins_offs] = *inst;
 266         flush_icache_range((ulong)p, (ulong)p + kvm_emulate_mtmsr_len * 4);
 267
 268         /* Patch the invocation */
 269         kvm_patch_ins_b(inst, distance_start);
 270 }
 271
 272 #ifdef CONFIG_BOOKE
 273
 274 extern u32 kvm_emulate_wrteei_branch_offs;
 275 extern u32 kvm_emulate_wrteei_ee_offs;
 276 extern u32 kvm_emulate_wrteei_len;
 277 extern u32 kvm_emulate_wrteei[];
 278
 279 static void kvm_patch_ins_wrteei(u32 *inst)
 280 {
 281         u32 *p;
 282         int distance_start;
 283         int distance_end;
 284         ulong next_inst;
 285
 286         p = kvm_alloc(kvm_emulate_wrteei_len * 4);
 287         if (!p)
 288                 return;
 289
 290         /* Find out where we are and put everything there */
 291         distance_start = (ulong)p - (ulong)inst;
 292         next_inst = ((ulong)inst + 4);
 293         distance_end = next_inst - (ulong)&p[kvm_emulate_wrteei_branch_offs];
 294
 295         /* Make sure we only write valid b instructions */
 296         if (distance_start > KVM_INST_B_MAX) {
 297                 kvm_patching_worked = false;
 298                 return;
 299         }
 300
 301         /* Modify the chunk to fit the invocation */
 302         memcpy(p, kvm_emulate_wrteei, kvm_emulate_wrteei_len * 4);
 303         p[kvm_emulate_wrteei_branch_offs] |= distance_end & KVM_INST_B_MASK;
 304         p[kvm_emulate_wrteei_ee_offs] |= (*inst & MSR_EE);
 305         flush_icache_range((ulong)p, (ulong)p + kvm_emulate_wrteei_len * 4);
 306
 307         /* Patch the invocation */
 308         kvm_patch_ins_b(inst, distance_start);
 309 }
 310
 311 #endif
 312
 313 #ifdef CONFIG_PPC_BOOK3S_32
 314
 315 extern u32 kvm_emulate_mtsrin_branch_offs;
 316 extern u32 kvm_emulate_mtsrin_reg1_offs;
 317 extern u32 kvm_emulate_mtsrin_reg2_offs;
 318 extern u32 kvm_emulate_mtsrin_orig_ins_offs;
 319 extern u32 kvm_emulate_mtsrin_len;
 320 extern u32 kvm_emulate_mtsrin[];
 321
 322 static void kvm_patch_ins_mtsrin(u32 *inst, u32 rt, u32 rb)
 323 {
 324         u32 *p;
 325         int distance_start;
 326         int distance_end;
 327         ulong next_inst;
 328
 329         p = kvm_alloc(kvm_emulate_mtsrin_len * 4);
 330         if (!p)
 331                 return;
 332
 333         /* Find out where we are and put everything there */
 334         distance_start = (ulong)p - (ulong)inst;
 335         next_inst = ((ulong)inst + 4);
 336         distance_end = next_inst - (ulong)&p[kvm_emulate_mtsrin_branch_offs];
 337
 338         /* Make sure we only write valid b instructions */
 339         if (distance_start > KVM_INST_B_MAX) {
 340                 kvm_patching_worked = false;
 341                 return;
 342         }
 343
 344         /* Modify the chunk to fit the invocation */
 345         memcpy(p, kvm_emulate_mtsrin, kvm_emulate_mtsrin_len * 4);
 346         p[kvm_emulate_mtsrin_branch_offs] |= distance_end & KVM_INST_B_MASK;
 347         p[kvm_emulate_mtsrin_reg1_offs] |= (rb << 10);
 348         p[kvm_emulate_mtsrin_reg2_offs] |= rt;
 349         p[kvm_emulate_mtsrin_orig_ins_offs] = *inst;
 350         flush_icache_range((ulong)p, (ulong)p + kvm_emulate_mtsrin_len * 4);
 351
 352         /* Patch the invocation */
 353         kvm_patch_ins_b(inst, distance_start);
 354 }
 355
 356 #endif
 357
 358 static void kvm_map_magic_page(void *data)
 359 {
 360         u32 *features = data;
 361
 362         ulong in[8];
 363         ulong out[8];
 364
 365         in[0] = KVM_MAGIC_PAGE;
 366         in[1] = KVM_MAGIC_PAGE;
 367
 368         kvm_hypercall(in, out, HC_VENDOR_KVM | KVM_HC_PPC_MAP_MAGIC_PAGE);
 369
 370         *features = out[0];
 371 }
 372
 373 static void kvm_check_ins(u32 *inst, u32 features)
 374 {
 375         u32 _inst = *inst;
 376         u32 inst_no_rt = _inst & ~KVM_MASK_RT;
 377         u32 inst_rt = _inst & KVM_MASK_RT;
 378
 379         switch (inst_no_rt) {
 380         /* Loads */
 381         case KVM_INST_MFMSR:
 382                 kvm_patch_ins_ld(inst, magic_var(msr), inst_rt);
 383                 break;
 384         case KVM_INST_MFSPR_SPRG0:
 385                 kvm_patch_ins_ld(inst, magic_var(sprg0), inst_rt);
 386                 break;
 387         case KVM_INST_MFSPR_SPRG1:
 388                 kvm_patch_ins_ld(inst, magic_var(sprg1), inst_rt);
 389                 break;
 390         case KVM_INST_MFSPR_SPRG2:
 391                 kvm_patch_ins_ld(inst, magic_var(sprg2), inst_rt);
 392                 break;
 393         case KVM_INST_MFSPR_SPRG3:
 394                 kvm_patch_ins_ld(inst, magic_var(sprg3), inst_rt);
 395                 break;
 396         case KVM_INST_MFSPR_SRR0:
 397                 kvm_patch_ins_ld(inst, magic_var(srr0), inst_rt);
 398                 break;
 399         case KVM_INST_MFSPR_SRR1:
 400                 kvm_patch_ins_ld(inst, magic_var(srr1), inst_rt);
 401                 break;
 402         case KVM_INST_MFSPR_DAR:
 403                 kvm_patch_ins_ld(inst, magic_var(dar), inst_rt);
 404                 break;
 405         case KVM_INST_MFSPR_DSISR:
 406                 kvm_patch_ins_lwz(inst, magic_var(dsisr), inst_rt);
 407                 break;
 408
 409         /* Stores */
 410         case KVM_INST_MTSPR_SPRG0:
 411                 kvm_patch_ins_std(inst, magic_var(sprg0), inst_rt);
 412                 break;
 413         case KVM_INST_MTSPR_SPRG1:
 414                 kvm_patch_ins_std(inst, magic_var(sprg1), inst_rt);
 415                 break;
 416         case KVM_INST_MTSPR_SPRG2:
 417                 kvm_patch_ins_std(inst, magic_var(sprg2), inst_rt);
 418                 break;
 419         case KVM_INST_MTSPR_SPRG3:
 420                 kvm_patch_ins_std(inst, magic_var(sprg3), inst_rt);
 421                 break;
 422         case KVM_INST_MTSPR_SRR0:
 423                 kvm_patch_ins_std(inst, magic_var(srr0), inst_rt);
 424                 break;
 425         case KVM_INST_MTSPR_SRR1:
 426                 kvm_patch_ins_std(inst, magic_var(srr1), inst_rt);
 427                 break;
 428         case KVM_INST_MTSPR_DAR:
 429                 kvm_patch_ins_std(inst, magic_var(dar), inst_rt);
 430                 break;
 431         case KVM_INST_MTSPR_DSISR:
 432                 kvm_patch_ins_stw(inst, magic_var(dsisr), inst_rt);
 433                 break;
 434
 435         /* Nops */
 436         case KVM_INST_TLBSYNC:
 437                 kvm_patch_ins_nop(inst);
 438                 break;
 439
 440         /* Rewrites */
 441         case KVM_INST_MTMSRD_L1:
 442                 kvm_patch_ins_mtmsrd(inst, inst_rt);
 443                 break;
 444         case KVM_INST_MTMSR:
 445         case KVM_INST_MTMSRD_L0:
 446                 kvm_patch_ins_mtmsr(inst, inst_rt);
 447                 break;
 448         }
 449
 450         switch (inst_no_rt & ~KVM_MASK_RB) {
 451 #ifdef CONFIG_PPC_BOOK3S_32
 452         case KVM_INST_MTSRIN:
 453                 if (features & KVM_MAGIC_FEAT_SR) {
 454                         u32 inst_rb = _inst & KVM_MASK_RB;
 455                         kvm_patch_ins_mtsrin(inst, inst_rt, inst_rb);
 456                 }
 457                 break;
 458                 break;
 459 #endif
 460         }
 461
 462         switch (_inst) {
 463 #ifdef CONFIG_BOOKE
 464         case KVM_INST_WRTEEI_0:
 465         case KVM_INST_WRTEEI_1:
 466                 kvm_patch_ins_wrteei(inst);
 467                 break;
 468 #endif
 469         }
 470 }
 471
 472 static void kvm_use_magic_page(void)
 473 {
 474         u32 *p;
 475         u32 *start, *end;
 476         u32 tmp;
 477         u32 features;
 478
 479         /* Tell the host to map the magic page to -4096 on all CPUs */
 480         on_each_cpu(kvm_map_magic_page, &features, 1);
 481
 482         /* Quick self-test to see if the mapping works */
 483         if (__get_user(tmp, (u32*)KVM_MAGIC_PAGE)) {
 484                 kvm_patching_worked = false;
 485                 return;
 486         }
 487
 488         /* Now loop through all code and find instructions */
 489         start = (void*)_stext;
 490         end = (void*)_etext;
 491
 492         for (p = start; p < end; p++)
 493                 kvm_check_ins(p, features);
 494
 495         printk(KERN_INFO "KVM: Live patching for a fast VM %s\n",
 496                          kvm_patching_worked ? "worked" : "failed");
 497 }
 498
 499 unsigned long kvm_hypercall(unsigned long *in,
 500                             unsigned long *out,
 501                             unsigned long nr)
 502 {
 503         unsigned long register r0 asm("r0");
 504         unsigned long register r3 asm("r3") = in[0];
 505         unsigned long register r4 asm("r4") = in[1];
 506         unsigned long register r5 asm("r5") = in[2];
 507         unsigned long register r6 asm("r6") = in[3];
 508         unsigned long register r7 asm("r7") = in[4];
 509         unsigned long register r8 asm("r8") = in[5];
 510         unsigned long register r9 asm("r9") = in[6];
 511         unsigned long register r10 asm("r10") = in[7];
 512         unsigned long register r11 asm("r11") = nr;
 513         unsigned long register r12 asm("r12");
 514
 515         asm volatile("bl        kvm_hypercall_start"
 516                      : "=r"(r0), "=r"(r3), "=r"(r4), "=r"(r5), "=r"(r6),
 517                        "=r"(r7), "=r"(r8), "=r"(r9), "=r"(r10), "=r"(r11),
 518                        "=r"(r12)
 519                      : "r"(r3), "r"(r4), "r"(r5), "r"(r6), "r"(r7), "r"(r8),
 520                        "r"(r9), "r"(r10), "r"(r11)
 521                      : "memory", "cc", "xer", "ctr", "lr");
 522
 523         out[0] = r4;
 524         out[1] = r5;
 525         out[2] = r6;
 526         out[3] = r7;
 527         out[4] = r8;
 528         out[5] = r9;
 529         out[6] = r10;
 530         out[7] = r11;
 531
 532         return r3;
 533 }
 534 EXPORT_SYMBOL_GPL(kvm_hypercall);
 535
 536 static int kvm_para_setup(void)
 537 {
 538         extern u32 kvm_hypercall_start;
 539         struct device_node *hyper_node;
 540         u32 *insts;
 541         int len, i;
 542
 543         hyper_node = of_find_node_by_path("/hypervisor");
 544         if (!hyper_node)
 545                 return -1;
 546
 547         insts = (u32*)of_get_property(hyper_node, "hcall-instructions", &len);
 548         if (len % 4)
 549                 return -1;
 550         if (len > (4 * 4))
 551                 return -1;
 552
 553         for (i = 0; i < (len / 4); i++)
 554                 kvm_patch_ins(&(&kvm_hypercall_start)[i], insts[i]);
 555
 556         return 0;
 557 }
 558
 559 static __init void kvm_free_tmp(void)
 560 {
 561         unsigned long start, end;
 562
 563         start = (ulong)&kvm_tmp[kvm_tmp_index + (PAGE_SIZE - 1)] & PAGE_MASK;
 564         end = (ulong)&kvm_tmp[ARRAY_SIZE(kvm_tmp)] & PAGE_MASK;
 565
 566         /* Free the tmp space we don't need */
 567         for (; start < end; start += PAGE_SIZE) {
 568                 ClearPageReserved(virt_to_page(start));
 569                 init_page_count(virt_to_page(start));
 570                 free_page(start);
 571                 totalram_pages++;
 572         }
 573 }
 574
 575 static int __init kvm_guest_init(void)
 576 {
 577         if (!kvm_para_available())
 578                 goto free_tmp;
 579
 580         if (kvm_para_setup())
 581                 goto free_tmp;
 582
 583         if (kvm_para_has_feature(KVM_FEATURE_MAGIC_PAGE))
 584                 kvm_use_magic_page();
 585
 586 #ifdef CONFIG_PPC_BOOK3S_64
 587         /* Enable napping */
 588         powersave_nap = 1;
 589 #endif
 590
 591 free_tmp:
 592         kvm_free_tmp();
 593
 594         return 0;
 595 }
 596
 597 postcore_initcall(kvm_guest_init);