release/src-rt-6.x.4708/linux/linux-2.6.36/arch/powerpc/kvm/emulate.c

   1 /*
   2  * This program is free software; you can redistribute it and/or modify
   3  * it under the terms of the GNU General Public License, version 2, as
   4  * published by the Free Software Foundation.
   5  *
   6  * This program is distributed in the hope that it will be useful,
   7  * but WITHOUT ANY WARRANTY; without even the implied warranty of
   8  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   9  * GNU General Public License for more details.
  10  *
  11  * You should have received a copy of the GNU General Public License
  12  * along with this program; if not, write to the Free Software
  13  * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  14  *
  15  * Copyright IBM Corp. 2007
  16  *
  17  * Authors: Hollis Blanchard <hollisb@us.ibm.com>
  18  */
  19
  20 #include <linux/jiffies.h>
  21 #include <linux/hrtimer.h>
  22 #include <linux/types.h>
  23 #include <linux/string.h>
  24 #include <linux/kvm_host.h>
  25
  26 #include <asm/reg.h>
  27 #include <asm/time.h>
  28 #include <asm/byteorder.h>
  29 #include <asm/kvm_ppc.h>
  30 #include <asm/disassemble.h>
  31 #include "timing.h"
  32 #include "trace.h"
  33
  34 #define OP_TRAP 3
  35 #define OP_TRAP_64 2
  36
  37 #define OP_31_XOP_LWZX      23
  38 #define OP_31_XOP_LBZX      87
  39 #define OP_31_XOP_STWX      151
  40 #define OP_31_XOP_STBX      215
  41 #define OP_31_XOP_LBZUX     119
  42 #define OP_31_XOP_STBUX     247
  43 #define OP_31_XOP_LHZX      279
  44 #define OP_31_XOP_LHZUX     311
  45 #define OP_31_XOP_MFSPR     339
  46 #define OP_31_XOP_LHAX      343
  47 #define OP_31_XOP_STHX      407
  48 #define OP_31_XOP_STHUX     439
  49 #define OP_31_XOP_MTSPR     467
  50 #define OP_31_XOP_DCBI      470
  51 #define OP_31_XOP_LWBRX     534
  52 #define OP_31_XOP_TLBSYNC   566
  53 #define OP_31_XOP_STWBRX    662
  54 #define OP_31_XOP_LHBRX     790
  55 #define OP_31_XOP_STHBRX    918
  56
  57 #define OP_LWZ  32
  58 #define OP_LWZU 33
  59 #define OP_LBZ  34
  60 #define OP_LBZU 35
  61 #define OP_STW  36
  62 #define OP_STWU 37
  63 #define OP_STB  38
  64 #define OP_STBU 39
  65 #define OP_LHZ  40
  66 #define OP_LHZU 41
  67 #define OP_LHA  42
  68 #define OP_LHAU 43
  69 #define OP_STH  44
  70 #define OP_STHU 45
  71
  72 #ifdef CONFIG_PPC_BOOK3S
  73 static int kvmppc_dec_enabled(struct kvm_vcpu *vcpu)
  74 {
  75         return 1;
  76 }
  77 #else
  78 static int kvmppc_dec_enabled(struct kvm_vcpu *vcpu)
  79 {
  80         return vcpu->arch.tcr & TCR_DIE;
  81 }
  82 #endif
  83
  84 void kvmppc_emulate_dec(struct kvm_vcpu *vcpu)
  85 {
  86         unsigned long dec_nsec;
  87
  88         pr_debug("mtDEC: %x\n", vcpu->arch.dec);
  89 #ifdef CONFIG_PPC_BOOK3S
  90         /* mtdec lowers the interrupt line when positive. */
  91         kvmppc_core_dequeue_dec(vcpu);
  92
  93         /* POWER4+ triggers a dec interrupt if the value is < 0 */
  94         if (vcpu->arch.dec & 0x80000000) {
  95                 hrtimer_try_to_cancel(&vcpu->arch.dec_timer);
  96                 kvmppc_core_queue_dec(vcpu);
  97                 return;
  98         }
  99 #endif
 100         if (kvmppc_dec_enabled(vcpu)) {
 101                 /* The decrementer ticks at the same rate as the timebase, so
 102                  * that's how we convert the guest DEC value to the number of
 103                  * host ticks. */
 104
 105                 hrtimer_try_to_cancel(&vcpu->arch.dec_timer);
 106                 dec_nsec = vcpu->arch.dec;
 107                 dec_nsec *= 1000;
 108                 dec_nsec /= tb_ticks_per_usec;
 109                 hrtimer_start(&vcpu->arch.dec_timer, ktime_set(0, dec_nsec),
 110                               HRTIMER_MODE_REL);
 111                 vcpu->arch.dec_jiffies = get_tb();
 112         } else {
 113                 hrtimer_try_to_cancel(&vcpu->arch.dec_timer);
 114         }
 115 }
 116
 117 int kvmppc_emulate_instruction(struct kvm_run *run, struct kvm_vcpu *vcpu)
 118 {
 119         u32 inst = kvmppc_get_last_inst(vcpu);
 120         u32 ea;
 121         int ra;
 122         int rb;
 123         int rs;
 124         int rt;
 125         int sprn;
 126         enum emulation_result emulated = EMULATE_DONE;
 127         int advance = 1;
 128
 129         /* this default type might be overwritten by subcategories */
 130         kvmppc_set_exit_type(vcpu, EMULATED_INST_EXITS);
 131
 132         pr_debug(KERN_INFO "Emulating opcode %d / %d\n", get_op(inst), get_xop(inst));
 133
 134         switch (get_op(inst)) {
 135         case OP_TRAP:
 136 #ifdef CONFIG_PPC_BOOK3S
 137         case OP_TRAP_64:
 138                 kvmppc_core_queue_program(vcpu, SRR1_PROGTRAP);
 139 #else
 140                 kvmppc_core_queue_program(vcpu, vcpu->arch.esr | ESR_PTR);
 141 #endif
 142                 advance = 0;
 143                 break;
 144
 145         case 31:
 146                 switch (get_xop(inst)) {
 147
 148                 case OP_31_XOP_LWZX:
 149                         rt = get_rt(inst);
 150                         emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
 151                         break;
 152
 153                 case OP_31_XOP_LBZX:
 154                         rt = get_rt(inst);
 155                         emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
 156                         break;
 157
 158                 case OP_31_XOP_LBZUX:
 159                         rt = get_rt(inst);
 160                         ra = get_ra(inst);
 161                         rb = get_rb(inst);
 162
 163                         ea = kvmppc_get_gpr(vcpu, rb);
 164                         if (ra)
 165                                 ea += kvmppc_get_gpr(vcpu, ra);
 166
 167                         emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
 168                         kvmppc_set_gpr(vcpu, ra, ea);
 169                         break;
 170
 171                 case OP_31_XOP_STWX:
 172                         rs = get_rs(inst);
 173                         emulated = kvmppc_handle_store(run, vcpu,
 174                                                        kvmppc_get_gpr(vcpu, rs),
 175                                                        4, 1);
 176                         break;
 177
 178                 case OP_31_XOP_STBX:
 179                         rs = get_rs(inst);
 180                         emulated = kvmppc_handle_store(run, vcpu,
 181                                                        kvmppc_get_gpr(vcpu, rs),
 182                                                        1, 1);
 183                         break;
 184
 185                 case OP_31_XOP_STBUX:
 186                         rs = get_rs(inst);
 187                         ra = get_ra(inst);
 188                         rb = get_rb(inst);
 189
 190                         ea = kvmppc_get_gpr(vcpu, rb);
 191                         if (ra)
 192                                 ea += kvmppc_get_gpr(vcpu, ra);
 193
 194                         emulated = kvmppc_handle_store(run, vcpu,
 195                                                        kvmppc_get_gpr(vcpu, rs),
 196                                                        1, 1);
 197                         kvmppc_set_gpr(vcpu, rs, ea);
 198                         break;
 199
 200                 case OP_31_XOP_LHAX:
 201                         rt = get_rt(inst);
 202                         emulated = kvmppc_handle_loads(run, vcpu, rt, 2, 1);
 203                         break;
 204
 205                 case OP_31_XOP_LHZX:
 206                         rt = get_rt(inst);
 207                         emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 208                         break;
 209
 210                 case OP_31_XOP_LHZUX:
 211                         rt = get_rt(inst);
 212                         ra = get_ra(inst);
 213                         rb = get_rb(inst);
 214
 215                         ea = kvmppc_get_gpr(vcpu, rb);
 216                         if (ra)
 217                                 ea += kvmppc_get_gpr(vcpu, ra);
 218
 219                         emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 220                         kvmppc_set_gpr(vcpu, ra, ea);
 221                         break;
 222
 223                 case OP_31_XOP_MFSPR:
 224                         sprn = get_sprn(inst);
 225                         rt = get_rt(inst);
 226
 227                         switch (sprn) {
 228                         case SPRN_SRR0:
 229                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.srr0); break;
 230                         case SPRN_SRR1:
 231                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.srr1); break;
 232                         case SPRN_PVR:
 233                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.pvr); break;
 234                         case SPRN_PIR:
 235                                 kvmppc_set_gpr(vcpu, rt, vcpu->vcpu_id); break;
 236                         case SPRN_MSSSR0:
 237                                 kvmppc_set_gpr(vcpu, rt, 0); break;
 238
 239                         /* Note: mftb and TBRL/TBWL are user-accessible, so
 240                          * the guest can always access the real TB anyways.
 241                          * In fact, we probably will never see these traps. */
 242                         case SPRN_TBWL:
 243                                 kvmppc_set_gpr(vcpu, rt, get_tb() >> 32); break;
 244                         case SPRN_TBWU:
 245                                 kvmppc_set_gpr(vcpu, rt, get_tb()); break;
 246
 247                         case SPRN_SPRG0:
 248                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.sprg0); break;
 249                         case SPRN_SPRG1:
 250                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.sprg1); break;
 251                         case SPRN_SPRG2:
 252                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.sprg2); break;
 253                         case SPRN_SPRG3:
 254                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.sprg3); break;
 255                         /* Note: SPRG4-7 are user-readable, so we don't get
 256                          * a trap. */
 257
 258                         case SPRN_DEC:
 259                         {
 260                                 u64 jd = get_tb() - vcpu->arch.dec_jiffies;
 261                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.dec - jd);
 262                                 pr_debug(KERN_INFO "mfDEC: %x - %llx = %lx\n",
 263                                          vcpu->arch.dec, jd,
 264                                          kvmppc_get_gpr(vcpu, rt));
 265                                 break;
 266                         }
 267                         default:
 268                                 emulated = kvmppc_core_emulate_mfspr(vcpu, sprn, rt);
 269                                 if (emulated == EMULATE_FAIL) {
 270                                         printk("mfspr: unknown spr %x\n", sprn);
 271                                         kvmppc_set_gpr(vcpu, rt, 0);
 272                                 }
 273                                 break;
 274                         }
 275                         break;
 276
 277                 case OP_31_XOP_STHX:
 278                         rs = get_rs(inst);
 279                         ra = get_ra(inst);
 280                         rb = get_rb(inst);
 281
 282                         emulated = kvmppc_handle_store(run, vcpu,
 283                                                        kvmppc_get_gpr(vcpu, rs),
 284                                                        2, 1);
 285                         break;
 286
 287                 case OP_31_XOP_STHUX:
 288                         rs = get_rs(inst);
 289                         ra = get_ra(inst);
 290                         rb = get_rb(inst);
 291
 292                         ea = kvmppc_get_gpr(vcpu, rb);
 293                         if (ra)
 294                                 ea += kvmppc_get_gpr(vcpu, ra);
 295
 296                         emulated = kvmppc_handle_store(run, vcpu,
 297                                                        kvmppc_get_gpr(vcpu, rs),
 298                                                        2, 1);
 299                         kvmppc_set_gpr(vcpu, ra, ea);
 300                         break;
 301
 302                 case OP_31_XOP_MTSPR:
 303                         sprn = get_sprn(inst);
 304                         rs = get_rs(inst);
 305                         switch (sprn) {
 306                         case SPRN_SRR0:
 307                                 vcpu->arch.srr0 = kvmppc_get_gpr(vcpu, rs); break;
 308                         case SPRN_SRR1:
 309                                 vcpu->arch.srr1 = kvmppc_get_gpr(vcpu, rs); break;
 310
 311                         case SPRN_TBWL: break;
 312                         case SPRN_TBWU: break;
 313
 314                         case SPRN_MSSSR0: break;
 315
 316                         case SPRN_DEC:
 317                                 vcpu->arch.dec = kvmppc_get_gpr(vcpu, rs);
 318                                 kvmppc_emulate_dec(vcpu);
 319                                 break;
 320
 321                         case SPRN_SPRG0:
 322                                 vcpu->arch.sprg0 = kvmppc_get_gpr(vcpu, rs); break;
 323                         case SPRN_SPRG1:
 324                                 vcpu->arch.sprg1 = kvmppc_get_gpr(vcpu, rs); break;
 325                         case SPRN_SPRG2:
 326                                 vcpu->arch.sprg2 = kvmppc_get_gpr(vcpu, rs); break;
 327                         case SPRN_SPRG3:
 328                                 vcpu->arch.sprg3 = kvmppc_get_gpr(vcpu, rs); break;
 329
 330                         default:
 331                                 emulated = kvmppc_core_emulate_mtspr(vcpu, sprn, rs);
 332                                 if (emulated == EMULATE_FAIL)
 333                                         printk("mtspr: unknown spr %x\n", sprn);
 334                                 break;
 335                         }
 336                         break;
 337
 338                 case OP_31_XOP_DCBI:
 339                         /* Do nothing. The guest is performing dcbi because
 340                          * hardware DMA is not snooped by the dcache, but
 341                          * emulated DMA either goes through the dcache as
 342                          * normal writes, or the host kernel has handled dcache
 343                          * coherence. */
 344                         break;
 345
 346                 case OP_31_XOP_LWBRX:
 347                         rt = get_rt(inst);
 348                         emulated = kvmppc_handle_load(run, vcpu, rt, 4, 0);
 349                         break;
 350
 351                 case OP_31_XOP_TLBSYNC:
 352                         break;
 353
 354                 case OP_31_XOP_STWBRX:
 355                         rs = get_rs(inst);
 356                         ra = get_ra(inst);
 357                         rb = get_rb(inst);
 358
 359                         emulated = kvmppc_handle_store(run, vcpu,
 360                                                        kvmppc_get_gpr(vcpu, rs),
 361                                                        4, 0);
 362                         break;
 363
 364                 case OP_31_XOP_LHBRX:
 365                         rt = get_rt(inst);
 366                         emulated = kvmppc_handle_load(run, vcpu, rt, 2, 0);
 367                         break;
 368
 369                 case OP_31_XOP_STHBRX:
 370                         rs = get_rs(inst);
 371                         ra = get_ra(inst);
 372                         rb = get_rb(inst);
 373
 374                         emulated = kvmppc_handle_store(run, vcpu,
 375                                                        kvmppc_get_gpr(vcpu, rs),
 376                                                        2, 0);
 377                         break;
 378
 379                 default:
 380                         /* Attempt core-specific emulation below. */
 381                         emulated = EMULATE_FAIL;
 382                 }
 383                 break;
 384
 385         case OP_LWZ:
 386                 rt = get_rt(inst);
 387                 emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
 388                 break;
 389
 390         case OP_LWZU:
 391                 ra = get_ra(inst);
 392                 rt = get_rt(inst);
 393                 emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
 394                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.paddr_accessed);
 395                 break;
 396
 397         case OP_LBZ:
 398                 rt = get_rt(inst);
 399                 emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
 400                 break;
 401
 402         case OP_LBZU:
 403                 ra = get_ra(inst);
 404                 rt = get_rt(inst);
 405                 emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
 406                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.paddr_accessed);
 407                 break;
 408
 409         case OP_STW:
 410                 rs = get_rs(inst);
 411                 emulated = kvmppc_handle_store(run, vcpu,
 412                                                kvmppc_get_gpr(vcpu, rs),
 413                                                4, 1);
 414                 break;
 415
 416         case OP_STWU:
 417                 ra = get_ra(inst);
 418                 rs = get_rs(inst);
 419                 emulated = kvmppc_handle_store(run, vcpu,
 420                                                kvmppc_get_gpr(vcpu, rs),
 421                                                4, 1);
 422                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.paddr_accessed);
 423                 break;
 424
 425         case OP_STB:
 426                 rs = get_rs(inst);
 427                 emulated = kvmppc_handle_store(run, vcpu,
 428                                                kvmppc_get_gpr(vcpu, rs),
 429                                                1, 1);
 430                 break;
 431
 432         case OP_STBU:
 433                 ra = get_ra(inst);
 434                 rs = get_rs(inst);
 435                 emulated = kvmppc_handle_store(run, vcpu,
 436                                                kvmppc_get_gpr(vcpu, rs),
 437                                                1, 1);
 438                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.paddr_accessed);
 439                 break;
 440
 441         case OP_LHZ:
 442                 rt = get_rt(inst);
 443                 emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 444                 break;
 445
 446         case OP_LHZU:
 447                 ra = get_ra(inst);
 448                 rt = get_rt(inst);
 449                 emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 450                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.paddr_accessed);
 451                 break;
 452
 453         case OP_LHA:
 454                 rt = get_rt(inst);
 455                 emulated = kvmppc_handle_loads(run, vcpu, rt, 2, 1);
 456                 break;
 457
 458         case OP_LHAU:
 459                 ra = get_ra(inst);
 460                 rt = get_rt(inst);
 461                 emulated = kvmppc_handle_loads(run, vcpu, rt, 2, 1);
 462                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.paddr_accessed);
 463                 break;
 464
 465         case OP_STH:
 466                 rs = get_rs(inst);
 467                 emulated = kvmppc_handle_store(run, vcpu,
 468                                                kvmppc_get_gpr(vcpu, rs),
 469                                                2, 1);
 470                 break;
 471
 472         case OP_STHU:
 473                 ra = get_ra(inst);
 474                 rs = get_rs(inst);
 475                 emulated = kvmppc_handle_store(run, vcpu,
 476                                                kvmppc_get_gpr(vcpu, rs),
 477                                                2, 1);
 478                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.paddr_accessed);
 479                 break;
 480
 481         default:
 482                 emulated = EMULATE_FAIL;
 483         }
 484
 485         if (emulated == EMULATE_FAIL) {
 486                 emulated = kvmppc_core_emulate_op(run, vcpu, inst, &advance);
 487                 if (emulated == EMULATE_AGAIN) {
 488                         advance = 0;
 489                 } else if (emulated == EMULATE_FAIL) {
 490                         advance = 0;
 491                         printk(KERN_ERR "Couldn't emulate instruction 0x%08x "
 492                                "(op %d xop %d)\n", inst, get_op(inst), get_xop(inst));
 493                         kvmppc_core_queue_program(vcpu, 0);
 494                 }
 495         }
 496
 497         trace_kvm_ppc_instr(inst, kvmppc_get_pc(vcpu), emulated);
 498
 499         /* Advance past emulated instruction. */
 500         if (advance)
 501                 kvmppc_set_pc(vcpu, kvmppc_get_pc(vcpu) + 4);
 502
 503         return emulated;
 504 }