arch/powerpc/kernel/kvm.c

   1 /*
   2  * Copyright (C) 2010 SUSE Linux Products GmbH. All rights reserved.
   3  * Copyright 2010-2011 Freescale Semiconductor, Inc.
   4  *
   5  * Authors:
   6  *     Alexander Graf <agraf@suse.de>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License, version 2, as
  10  * published by the Free Software Foundation.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  20  */
  21
  22 #include <linux/kvm_host.h>
  23 #include <linux/init.h>
  24 #include <linux/export.h>
  25 #include <linux/kvm_para.h>
  26 #include <linux/slab.h>
  27 #include <linux/of.h>
  28
  29 #include <asm/reg.h>
  30 #include <asm/sections.h>
  31 #include <asm/cacheflush.h>
  32 #include <asm/disassemble.h>
  33 #include <asm/ppc-opcode.h>
  34
  35 #define KVM_MAGIC_PAGE          (-4096L)
  36 #define magic_var(x) KVM_MAGIC_PAGE + offsetof(struct kvm_vcpu_arch_shared, x)
  37
  38 #define KVM_INST_LWZ            0x80000000
  39 #define KVM_INST_STW            0x90000000
  40 #define KVM_INST_LD             0xe8000000
  41 #define KVM_INST_STD            0xf8000000
  42 #define KVM_INST_NOP            0x60000000
  43 #define KVM_INST_B              0x48000000
  44 #define KVM_INST_B_MASK         0x03ffffff
  45 #define KVM_INST_B_MAX          0x01ffffff
  46 #define KVM_INST_LI             0x38000000
  47
  48 #define KVM_MASK_RT             0x03e00000
  49 #define KVM_RT_30               0x03c00000
  50 #define KVM_MASK_RB             0x0000f800
  51 #define KVM_INST_MFMSR          0x7c0000a6
  52 #define KVM_INST_MFSPR_SPRG0    0x7c1042a6
  53 #define KVM_INST_MFSPR_SPRG1    0x7c1142a6
  54 #define KVM_INST_MFSPR_SPRG2    0x7c1242a6
  55 #define KVM_INST_MFSPR_SPRG3    0x7c1342a6
  56 #define KVM_INST_MFSPR_SRR0     0x7c1a02a6
  57 #define KVM_INST_MFSPR_SRR1     0x7c1b02a6
  58 #define KVM_INST_MFSPR_DAR      0x7c1302a6
  59 #define KVM_INST_MFSPR_DSISR    0x7c1202a6
  60
  61 #define KVM_INST_MTSPR_SPRG0    0x7c1043a6
  62 #define KVM_INST_MTSPR_SPRG1    0x7c1143a6
  63 #define KVM_INST_MTSPR_SPRG2    0x7c1243a6
  64 #define KVM_INST_MTSPR_SPRG3    0x7c1343a6
  65 #define KVM_INST_MTSPR_SRR0     0x7c1a03a6
  66 #define KVM_INST_MTSPR_SRR1     0x7c1b03a6
  67 #define KVM_INST_MTSPR_DAR      0x7c1303a6
  68 #define KVM_INST_MTSPR_DSISR    0x7c1203a6
  69
  70 #define KVM_INST_TLBSYNC        0x7c00046c
  71 #define KVM_INST_MTMSRD_L0      0x7c000164
  72 #define KVM_INST_MTMSRD_L1      0x7c010164
  73 #define KVM_INST_MTMSR          0x7c000124
  74
  75 #define KVM_INST_WRTEE          0x7c000106
  76 #define KVM_INST_WRTEEI_0       0x7c000146
  77 #define KVM_INST_WRTEEI_1       0x7c008146
  78
  79 #define KVM_INST_MTSRIN         0x7c0001e4
  80
  81 static bool kvm_patching_worked = true;
  82 static char kvm_tmp[1024 * 1024];
  83 static int kvm_tmp_index;
  84
  85 static inline void kvm_patch_ins(u32 *inst, u32 new_inst)
  86 {
  87         *inst = new_inst;
  88         flush_icache_range((ulong)inst, (ulong)inst + 4);
  89 }
  90
  91 static void kvm_patch_ins_ll(u32 *inst, long addr, u32 rt)
  92 {
  93 #ifdef CONFIG_64BIT
  94         kvm_patch_ins(inst, KVM_INST_LD | rt | (addr & 0x0000fffc));
  95 #else
  96         kvm_patch_ins(inst, KVM_INST_LWZ | rt | (addr & 0x0000fffc));
  97 #endif
  98 }
  99
 100 static void kvm_patch_ins_ld(u32 *inst, long addr, u32 rt)
 101 {
 102 #ifdef CONFIG_64BIT
 103         kvm_patch_ins(inst, KVM_INST_LD | rt | (addr & 0x0000fffc));
 104 #else
 105         kvm_patch_ins(inst, KVM_INST_LWZ | rt | ((addr + 4) & 0x0000fffc));
 106 #endif
 107 }
 108
 109 static void kvm_patch_ins_lwz(u32 *inst, long addr, u32 rt)
 110 {
 111         kvm_patch_ins(inst, KVM_INST_LWZ | rt | (addr & 0x0000ffff));
 112 }
 113
 114 static void kvm_patch_ins_std(u32 *inst, long addr, u32 rt)
 115 {
 116 #ifdef CONFIG_64BIT
 117         kvm_patch_ins(inst, KVM_INST_STD | rt | (addr & 0x0000fffc));
 118 #else
 119         kvm_patch_ins(inst, KVM_INST_STW | rt | ((addr + 4) & 0x0000fffc));
 120 #endif
 121 }
 122
 123 static void kvm_patch_ins_stw(u32 *inst, long addr, u32 rt)
 124 {
 125         kvm_patch_ins(inst, KVM_INST_STW | rt | (addr & 0x0000fffc));
 126 }
 127
 128 static void kvm_patch_ins_nop(u32 *inst)
 129 {
 130         kvm_patch_ins(inst, KVM_INST_NOP);
 131 }
 132
 133 static void kvm_patch_ins_b(u32 *inst, int addr)
 134 {
 135 #if defined(CONFIG_RELOCATABLE) && defined(CONFIG_PPC_BOOK3S)
 136         /* On relocatable kernels interrupts handlers and our code
 137            can be in different regions, so we don't patch them */
 138
 139         if ((ulong)inst < (ulong)&__end_interrupts)
 140                 return;
 141 #endif
 142
 143         kvm_patch_ins(inst, KVM_INST_B | (addr & KVM_INST_B_MASK));
 144 }
 145
 146 static u32 *kvm_alloc(int len)
 147 {
 148         u32 *p;
 149
 150         if ((kvm_tmp_index + len) > ARRAY_SIZE(kvm_tmp)) {
 151                 printk(KERN_ERR "KVM: No more space (%d + %d)\n",
 152                                 kvm_tmp_index, len);
 153                 kvm_patching_worked = false;
 154                 return NULL;
 155         }
 156
 157         p = (void*)&kvm_tmp[kvm_tmp_index];
 158         kvm_tmp_index += len;
 159
 160         return p;
 161 }
 162
 163 extern u32 kvm_emulate_mtmsrd_branch_offs;
 164 extern u32 kvm_emulate_mtmsrd_reg_offs;
 165 extern u32 kvm_emulate_mtmsrd_orig_ins_offs;
 166 extern u32 kvm_emulate_mtmsrd_len;
 167 extern u32 kvm_emulate_mtmsrd[];
 168
 169 static void kvm_patch_ins_mtmsrd(u32 *inst, u32 rt)
 170 {
 171         u32 *p;
 172         int distance_start;
 173         int distance_end;
 174         ulong next_inst;
 175
 176         p = kvm_alloc(kvm_emulate_mtmsrd_len * 4);
 177         if (!p)
 178                 return;
 179
 180         /* Find out where we are and put everything there */
 181         distance_start = (ulong)p - (ulong)inst;
 182         next_inst = ((ulong)inst + 4);
 183         distance_end = next_inst - (ulong)&p[kvm_emulate_mtmsrd_branch_offs];
 184
 185         /* Make sure we only write valid b instructions */
 186         if (distance_start > KVM_INST_B_MAX) {
 187                 kvm_patching_worked = false;
 188                 return;
 189         }
 190
 191         /* Modify the chunk to fit the invocation */
 192         memcpy(p, kvm_emulate_mtmsrd, kvm_emulate_mtmsrd_len * 4);
 193         p[kvm_emulate_mtmsrd_branch_offs] |= distance_end & KVM_INST_B_MASK;
 194         switch (get_rt(rt)) {
 195         case 30:
 196                 kvm_patch_ins_ll(&p[kvm_emulate_mtmsrd_reg_offs],
 197                                  magic_var(scratch2), KVM_RT_30);
 198                 break;
 199         case 31:
 200                 kvm_patch_ins_ll(&p[kvm_emulate_mtmsrd_reg_offs],
 201                                  magic_var(scratch1), KVM_RT_30);
 202                 break;
 203         default:
 204                 p[kvm_emulate_mtmsrd_reg_offs] |= rt;
 205                 break;
 206         }
 207
 208         p[kvm_emulate_mtmsrd_orig_ins_offs] = *inst;
 209         flush_icache_range((ulong)p, (ulong)p + kvm_emulate_mtmsrd_len * 4);
 210
 211         /* Patch the invocation */
 212         kvm_patch_ins_b(inst, distance_start);
 213 }
 214
 215 extern u32 kvm_emulate_mtmsr_branch_offs;
 216 extern u32 kvm_emulate_mtmsr_reg1_offs;
 217 extern u32 kvm_emulate_mtmsr_reg2_offs;
 218 extern u32 kvm_emulate_mtmsr_orig_ins_offs;
 219 extern u32 kvm_emulate_mtmsr_len;
 220 extern u32 kvm_emulate_mtmsr[];
 221
 222 static void kvm_patch_ins_mtmsr(u32 *inst, u32 rt)
 223 {
 224         u32 *p;
 225         int distance_start;
 226         int distance_end;
 227         ulong next_inst;
 228
 229         p = kvm_alloc(kvm_emulate_mtmsr_len * 4);
 230         if (!p)
 231                 return;
 232
 233         /* Find out where we are and put everything there */
 234         distance_start = (ulong)p - (ulong)inst;
 235         next_inst = ((ulong)inst + 4);
 236         distance_end = next_inst - (ulong)&p[kvm_emulate_mtmsr_branch_offs];
 237
 238         /* Make sure we only write valid b instructions */
 239         if (distance_start > KVM_INST_B_MAX) {
 240                 kvm_patching_worked = false;
 241                 return;
 242         }
 243
 244         /* Modify the chunk to fit the invocation */
 245         memcpy(p, kvm_emulate_mtmsr, kvm_emulate_mtmsr_len * 4);
 246         p[kvm_emulate_mtmsr_branch_offs] |= distance_end & KVM_INST_B_MASK;
 247
 248         /* Make clobbered registers work too */
 249         switch (get_rt(rt)) {
 250         case 30:
 251                 kvm_patch_ins_ll(&p[kvm_emulate_mtmsr_reg1_offs],
 252                                  magic_var(scratch2), KVM_RT_30);
 253                 kvm_patch_ins_ll(&p[kvm_emulate_mtmsr_reg2_offs],
 254                                  magic_var(scratch2), KVM_RT_30);
 255                 break;
 256         case 31:
 257                 kvm_patch_ins_ll(&p[kvm_emulate_mtmsr_reg1_offs],
 258                                  magic_var(scratch1), KVM_RT_30);
 259                 kvm_patch_ins_ll(&p[kvm_emulate_mtmsr_reg2_offs],
 260                                  magic_var(scratch1), KVM_RT_30);
 261                 break;
 262         default:
 263                 p[kvm_emulate_mtmsr_reg1_offs] |= rt;
 264                 p[kvm_emulate_mtmsr_reg2_offs] |= rt;
 265                 break;
 266         }
 267
 268         p[kvm_emulate_mtmsr_orig_ins_offs] = *inst;
 269         flush_icache_range((ulong)p, (ulong)p + kvm_emulate_mtmsr_len * 4);
 270
 271         /* Patch the invocation */
 272         kvm_patch_ins_b(inst, distance_start);
 273 }
 274
 275 #ifdef CONFIG_BOOKE
 276
 277 extern u32 kvm_emulate_wrtee_branch_offs;
 278 extern u32 kvm_emulate_wrtee_reg_offs;
 279 extern u32 kvm_emulate_wrtee_orig_ins_offs;
 280 extern u32 kvm_emulate_wrtee_len;
 281 extern u32 kvm_emulate_wrtee[];
 282
 283 static void kvm_patch_ins_wrtee(u32 *inst, u32 rt, int imm_one)
 284 {
 285         u32 *p;
 286         int distance_start;
 287         int distance_end;
 288         ulong next_inst;
 289
 290         p = kvm_alloc(kvm_emulate_wrtee_len * 4);
 291         if (!p)
 292                 return;
 293
 294         /* Find out where we are and put everything there */
 295         distance_start = (ulong)p - (ulong)inst;
 296         next_inst = ((ulong)inst + 4);
 297         distance_end = next_inst - (ulong)&p[kvm_emulate_wrtee_branch_offs];
 298
 299         /* Make sure we only write valid b instructions */
 300         if (distance_start > KVM_INST_B_MAX) {
 301                 kvm_patching_worked = false;
 302                 return;
 303         }
 304
 305         /* Modify the chunk to fit the invocation */
 306         memcpy(p, kvm_emulate_wrtee, kvm_emulate_wrtee_len * 4);
 307         p[kvm_emulate_wrtee_branch_offs] |= distance_end & KVM_INST_B_MASK;
 308
 309         if (imm_one) {
 310                 p[kvm_emulate_wrtee_reg_offs] =
 311                         KVM_INST_LI | __PPC_RT(30) | MSR_EE;
 312         } else {
 313                 /* Make clobbered registers work too */
 314                 switch (get_rt(rt)) {
 315                 case 30:
 316                         kvm_patch_ins_ll(&p[kvm_emulate_wrtee_reg_offs],
 317                                          magic_var(scratch2), KVM_RT_30);
 318                         break;
 319                 case 31:
 320                         kvm_patch_ins_ll(&p[kvm_emulate_wrtee_reg_offs],
 321                                          magic_var(scratch1), KVM_RT_30);
 322                         break;
 323                 default:
 324                         p[kvm_emulate_wrtee_reg_offs] |= rt;
 325                         break;
 326                 }
 327         }
 328
 329         p[kvm_emulate_wrtee_orig_ins_offs] = *inst;
 330         flush_icache_range((ulong)p, (ulong)p + kvm_emulate_wrtee_len * 4);
 331
 332         /* Patch the invocation */
 333         kvm_patch_ins_b(inst, distance_start);
 334 }
 335
 336 extern u32 kvm_emulate_wrteei_0_branch_offs;
 337 extern u32 kvm_emulate_wrteei_0_len;
 338 extern u32 kvm_emulate_wrteei_0[];
 339
 340 static void kvm_patch_ins_wrteei_0(u32 *inst)
 341 {
 342         u32 *p;
 343         int distance_start;
 344         int distance_end;
 345         ulong next_inst;
 346
 347         p = kvm_alloc(kvm_emulate_wrteei_0_len * 4);
 348         if (!p)
 349                 return;
 350
 351         /* Find out where we are and put everything there */
 352         distance_start = (ulong)p - (ulong)inst;
 353         next_inst = ((ulong)inst + 4);
 354         distance_end = next_inst - (ulong)&p[kvm_emulate_wrteei_0_branch_offs];
 355
 356         /* Make sure we only write valid b instructions */
 357         if (distance_start > KVM_INST_B_MAX) {
 358                 kvm_patching_worked = false;
 359                 return;
 360         }
 361
 362         memcpy(p, kvm_emulate_wrteei_0, kvm_emulate_wrteei_0_len * 4);
 363         p[kvm_emulate_wrteei_0_branch_offs] |= distance_end & KVM_INST_B_MASK;
 364         flush_icache_range((ulong)p, (ulong)p + kvm_emulate_wrteei_0_len * 4);
 365
 366         /* Patch the invocation */
 367         kvm_patch_ins_b(inst, distance_start);
 368 }
 369
 370 #endif
 371
 372 #ifdef CONFIG_PPC_BOOK3S_32
 373
 374 extern u32 kvm_emulate_mtsrin_branch_offs;
 375 extern u32 kvm_emulate_mtsrin_reg1_offs;
 376 extern u32 kvm_emulate_mtsrin_reg2_offs;
 377 extern u32 kvm_emulate_mtsrin_orig_ins_offs;
 378 extern u32 kvm_emulate_mtsrin_len;
 379 extern u32 kvm_emulate_mtsrin[];
 380
 381 static void kvm_patch_ins_mtsrin(u32 *inst, u32 rt, u32 rb)
 382 {
 383         u32 *p;
 384         int distance_start;
 385         int distance_end;
 386         ulong next_inst;
 387
 388         p = kvm_alloc(kvm_emulate_mtsrin_len * 4);
 389         if (!p)
 390                 return;
 391
 392         /* Find out where we are and put everything there */
 393         distance_start = (ulong)p - (ulong)inst;
 394         next_inst = ((ulong)inst + 4);
 395         distance_end = next_inst - (ulong)&p[kvm_emulate_mtsrin_branch_offs];
 396
 397         /* Make sure we only write valid b instructions */
 398         if (distance_start > KVM_INST_B_MAX) {
 399                 kvm_patching_worked = false;
 400                 return;
 401         }
 402
 403         /* Modify the chunk to fit the invocation */
 404         memcpy(p, kvm_emulate_mtsrin, kvm_emulate_mtsrin_len * 4);
 405         p[kvm_emulate_mtsrin_branch_offs] |= distance_end & KVM_INST_B_MASK;
 406         p[kvm_emulate_mtsrin_reg1_offs] |= (rb << 10);
 407         p[kvm_emulate_mtsrin_reg2_offs] |= rt;
 408         p[kvm_emulate_mtsrin_orig_ins_offs] = *inst;
 409         flush_icache_range((ulong)p, (ulong)p + kvm_emulate_mtsrin_len * 4);
 410
 411         /* Patch the invocation */
 412         kvm_patch_ins_b(inst, distance_start);
 413 }
 414
 415 #endif
 416
 417 static void kvm_map_magic_page(void *data)
 418 {
 419         u32 *features = data;
 420
 421         ulong in[8];
 422         ulong out[8];
 423
 424         in[0] = KVM_MAGIC_PAGE;
 425         in[1] = KVM_MAGIC_PAGE;
 426
 427         kvm_hypercall(in, out, HC_VENDOR_KVM | KVM_HC_PPC_MAP_MAGIC_PAGE);
 428
 429         *features = out[0];
 430 }
 431
 432 static void kvm_check_ins(u32 *inst, u32 features)
 433 {
 434         u32 _inst = *inst;
 435         u32 inst_no_rt = _inst & ~KVM_MASK_RT;
 436         u32 inst_rt = _inst & KVM_MASK_RT;
 437
 438         switch (inst_no_rt) {
 439         /* Loads */
 440         case KVM_INST_MFMSR:
 441                 kvm_patch_ins_ld(inst, magic_var(msr), inst_rt);
 442                 break;
 443         case KVM_INST_MFSPR_SPRG0:
 444                 kvm_patch_ins_ld(inst, magic_var(sprg0), inst_rt);
 445                 break;
 446         case KVM_INST_MFSPR_SPRG1:
 447                 kvm_patch_ins_ld(inst, magic_var(sprg1), inst_rt);
 448                 break;
 449         case KVM_INST_MFSPR_SPRG2:
 450                 kvm_patch_ins_ld(inst, magic_var(sprg2), inst_rt);
 451                 break;
 452         case KVM_INST_MFSPR_SPRG3:
 453                 kvm_patch_ins_ld(inst, magic_var(sprg3), inst_rt);
 454                 break;
 455         case KVM_INST_MFSPR_SRR0:
 456                 kvm_patch_ins_ld(inst, magic_var(srr0), inst_rt);
 457                 break;
 458         case KVM_INST_MFSPR_SRR1:
 459                 kvm_patch_ins_ld(inst, magic_var(srr1), inst_rt);
 460                 break;
 461         case KVM_INST_MFSPR_DAR:
 462                 kvm_patch_ins_ld(inst, magic_var(dar), inst_rt);
 463                 break;
 464         case KVM_INST_MFSPR_DSISR:
 465                 kvm_patch_ins_lwz(inst, magic_var(dsisr), inst_rt);
 466                 break;
 467
 468         /* Stores */
 469         case KVM_INST_MTSPR_SPRG0:
 470                 kvm_patch_ins_std(inst, magic_var(sprg0), inst_rt);
 471                 break;
 472         case KVM_INST_MTSPR_SPRG1:
 473                 kvm_patch_ins_std(inst, magic_var(sprg1), inst_rt);
 474                 break;
 475         case KVM_INST_MTSPR_SPRG2:
 476                 kvm_patch_ins_std(inst, magic_var(sprg2), inst_rt);
 477                 break;
 478         case KVM_INST_MTSPR_SPRG3:
 479                 kvm_patch_ins_std(inst, magic_var(sprg3), inst_rt);
 480                 break;
 481         case KVM_INST_MTSPR_SRR0:
 482                 kvm_patch_ins_std(inst, magic_var(srr0), inst_rt);
 483                 break;
 484         case KVM_INST_MTSPR_SRR1:
 485                 kvm_patch_ins_std(inst, magic_var(srr1), inst_rt);
 486                 break;
 487         case KVM_INST_MTSPR_DAR:
 488                 kvm_patch_ins_std(inst, magic_var(dar), inst_rt);
 489                 break;
 490         case KVM_INST_MTSPR_DSISR:
 491                 kvm_patch_ins_stw(inst, magic_var(dsisr), inst_rt);
 492                 break;
 493
 494         /* Nops */
 495         case KVM_INST_TLBSYNC:
 496                 kvm_patch_ins_nop(inst);
 497                 break;
 498
 499         /* Rewrites */
 500         case KVM_INST_MTMSRD_L1:
 501                 kvm_patch_ins_mtmsrd(inst, inst_rt);
 502                 break;
 503         case KVM_INST_MTMSR:
 504         case KVM_INST_MTMSRD_L0:
 505                 kvm_patch_ins_mtmsr(inst, inst_rt);
 506                 break;
 507 #ifdef CONFIG_BOOKE
 508         case KVM_INST_WRTEE:
 509                 kvm_patch_ins_wrtee(inst, inst_rt, 0);
 510                 break;
 511 #endif
 512         }
 513
 514         switch (inst_no_rt & ~KVM_MASK_RB) {
 515 #ifdef CONFIG_PPC_BOOK3S_32
 516         case KVM_INST_MTSRIN:
 517                 if (features & KVM_MAGIC_FEAT_SR) {
 518                         u32 inst_rb = _inst & KVM_MASK_RB;
 519                         kvm_patch_ins_mtsrin(inst, inst_rt, inst_rb);
 520                 }
 521                 break;
 522                 break;
 523 #endif
 524         }
 525
 526         switch (_inst) {
 527 #ifdef CONFIG_BOOKE
 528         case KVM_INST_WRTEEI_0:
 529                 kvm_patch_ins_wrteei_0(inst);
 530                 break;
 531
 532         case KVM_INST_WRTEEI_1:
 533                 kvm_patch_ins_wrtee(inst, 0, 1);
 534                 break;
 535 #endif
 536         }
 537 }
 538
 539 static void kvm_use_magic_page(void)
 540 {
 541         u32 *p;
 542         u32 *start, *end;
 543         u32 tmp;
 544         u32 features;
 545
 546         /* Tell the host to map the magic page to -4096 on all CPUs */
 547         on_each_cpu(kvm_map_magic_page, &features, 1);
 548
 549         /* Quick self-test to see if the mapping works */
 550         if (__get_user(tmp, (u32*)KVM_MAGIC_PAGE)) {
 551                 kvm_patching_worked = false;
 552                 return;
 553         }
 554
 555         /* Now loop through all code and find instructions */
 556         start = (void*)_stext;
 557         end = (void*)_etext;
 558
 559         for (p = start; p < end; p++)
 560                 kvm_check_ins(p, features);
 561
 562         printk(KERN_INFO "KVM: Live patching for a fast VM %s\n",
 563                          kvm_patching_worked ? "worked" : "failed");
 564 }
 565
 566 unsigned long kvm_hypercall(unsigned long *in,
 567                             unsigned long *out,
 568                             unsigned long nr)
 569 {
 570         unsigned long register r0 asm("r0");
 571         unsigned long register r3 asm("r3") = in[0];
 572         unsigned long register r4 asm("r4") = in[1];
 573         unsigned long register r5 asm("r5") = in[2];
 574         unsigned long register r6 asm("r6") = in[3];
 575         unsigned long register r7 asm("r7") = in[4];
 576         unsigned long register r8 asm("r8") = in[5];
 577         unsigned long register r9 asm("r9") = in[6];
 578         unsigned long register r10 asm("r10") = in[7];
 579         unsigned long register r11 asm("r11") = nr;
 580         unsigned long register r12 asm("r12");
 581
 582         asm volatile("bl        kvm_hypercall_start"
 583                      : "=r"(r0), "=r"(r3), "=r"(r4), "=r"(r5), "=r"(r6),
 584                        "=r"(r7), "=r"(r8), "=r"(r9), "=r"(r10), "=r"(r11),
 585                        "=r"(r12)
 586                      : "r"(r3), "r"(r4), "r"(r5), "r"(r6), "r"(r7), "r"(r8),
 587                        "r"(r9), "r"(r10), "r"(r11)
 588                      : "memory", "cc", "xer", "ctr", "lr");
 589
 590         out[0] = r4;
 591         out[1] = r5;
 592         out[2] = r6;
 593         out[3] = r7;
 594         out[4] = r8;
 595         out[5] = r9;
 596         out[6] = r10;
 597         out[7] = r11;
 598
 599         return r3;
 600 }
 601 EXPORT_SYMBOL_GPL(kvm_hypercall);
 602
 603 static int kvm_para_setup(void)
 604 {
 605         extern u32 kvm_hypercall_start;
 606         struct device_node *hyper_node;
 607         u32 *insts;
 608         int len, i;
 609
 610         hyper_node = of_find_node_by_path("/hypervisor");
 611         if (!hyper_node)
 612                 return -1;
 613
 614         insts = (u32*)of_get_property(hyper_node, "hcall-instructions", &len);
 615         if (len % 4)
 616                 return -1;
 617         if (len > (4 * 4))
 618                 return -1;
 619
 620         for (i = 0; i < (len / 4); i++)
 621                 kvm_patch_ins(&(&kvm_hypercall_start)[i], insts[i]);
 622
 623         return 0;
 624 }
 625
 626 static __init void kvm_free_tmp(void)
 627 {
 628         unsigned long start, end;
 629
 630         start = (ulong)&kvm_tmp[kvm_tmp_index + (PAGE_SIZE - 1)] & PAGE_MASK;
 631         end = (ulong)&kvm_tmp[ARRAY_SIZE(kvm_tmp)] & PAGE_MASK;
 632
 633         /* Free the tmp space we don't need */
 634         for (; start < end; start += PAGE_SIZE) {
 635                 ClearPageReserved(virt_to_page(start));
 636                 init_page_count(virt_to_page(start));
 637                 free_page(start);
 638                 totalram_pages++;
 639         }
 640 }
 641
 642 static int __init kvm_guest_init(void)
 643 {
 644         if (!kvm_para_available())
 645                 goto free_tmp;
 646
 647         if (kvm_para_setup())
 648                 goto free_tmp;
 649
 650         if (kvm_para_has_feature(KVM_FEATURE_MAGIC_PAGE))
 651                 kvm_use_magic_page();
 652
 653 #ifdef CONFIG_PPC_BOOK3S_64
 654         /* Enable napping */
 655         powersave_nap = 1;
 656 #endif
 657
 658 free_tmp:
 659         kvm_free_tmp();
 660
 661         return 0;
 662 }
 663
 664 postcore_initcall(kvm_guest_init);