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  * Copyright 2011 Freescale Semiconductor, Inc.
  17  *
  18  * Authors: Hollis Blanchard <hollisb@us.ibm.com>
  19  */
  20
  21 #include <linux/jiffies.h>
  22 #include <linux/hrtimer.h>
  23 #include <linux/types.h>
  24 #include <linux/string.h>
  25 #include <linux/kvm_host.h>
  26
  27 #include <asm/reg.h>
  28 #include <asm/time.h>
  29 #include <asm/byteorder.h>
  30 #include <asm/kvm_ppc.h>
  31 #include <asm/disassemble.h>
  32 #include "timing.h"
  33 #include "trace.h"
  34
  35 #define OP_TRAP 3
  36 #define OP_TRAP_64 2
  37
  38 #define OP_31_XOP_LWZX      23
  39 #define OP_31_XOP_LBZX      87
  40 #define OP_31_XOP_STWX      151
  41 #define OP_31_XOP_STBX      215
  42 #define OP_31_XOP_LBZUX     119
  43 #define OP_31_XOP_STBUX     247
  44 #define OP_31_XOP_LHZX      279
  45 #define OP_31_XOP_LHZUX     311
  46 #define OP_31_XOP_MFSPR     339
  47 #define OP_31_XOP_LHAX      343
  48 #define OP_31_XOP_STHX      407
  49 #define OP_31_XOP_STHUX     439
  50 #define OP_31_XOP_MTSPR     467
  51 #define OP_31_XOP_DCBI      470
  52 #define OP_31_XOP_LWBRX     534
  53 #define OP_31_XOP_TLBSYNC   566
  54 #define OP_31_XOP_STWBRX    662
  55 #define OP_31_XOP_LHBRX     790
  56 #define OP_31_XOP_STHBRX    918
  57
  58 #define OP_LWZ  32
  59 #define OP_LWZU 33
  60 #define OP_LBZ  34
  61 #define OP_LBZU 35
  62 #define OP_STW  36
  63 #define OP_STWU 37
  64 #define OP_STB  38
  65 #define OP_STBU 39
  66 #define OP_LHZ  40
  67 #define OP_LHZU 41
  68 #define OP_LHA  42
  69 #define OP_LHAU 43
  70 #define OP_STH  44
  71 #define OP_STHU 45
  72
  73 void kvmppc_emulate_dec(struct kvm_vcpu *vcpu)
  74 {
  75         unsigned long dec_nsec;
  76         unsigned long long dec_time;
  77
  78         pr_debug("mtDEC: %x\n", vcpu->arch.dec);
  79         hrtimer_try_to_cancel(&vcpu->arch.dec_timer);
  80
  81 #ifdef CONFIG_PPC_BOOK3S
  82         /* mtdec lowers the interrupt line when positive. */
  83         kvmppc_core_dequeue_dec(vcpu);
  84
  85         /* POWER4+ triggers a dec interrupt if the value is < 0 */
  86         if (vcpu->arch.dec & 0x80000000) {
  87                 kvmppc_core_queue_dec(vcpu);
  88                 return;
  89         }
  90 #endif
  91
  92 #ifdef CONFIG_BOOKE
  93         /* On BOOKE, DEC = 0 is as good as decrementer not enabled */
  94         if (vcpu->arch.dec == 0)
  95                 return;
  96 #endif
  97
  98         /*
  99          * The decrementer ticks at the same rate as the timebase, so
 100          * that's how we convert the guest DEC value to the number of
 101          * host ticks.
 102          */
 103
 104         dec_time = vcpu->arch.dec;
 105         dec_time *= 1000;
 106         do_div(dec_time, tb_ticks_per_usec);
 107         dec_nsec = do_div(dec_time, NSEC_PER_SEC);
 108         hrtimer_start(&vcpu->arch.dec_timer,
 109                 ktime_set(dec_time, dec_nsec), HRTIMER_MODE_REL);
 110         vcpu->arch.dec_jiffies = get_tb();
 111 }
 112
 113 u32 kvmppc_get_dec(struct kvm_vcpu *vcpu, u64 tb)
 114 {
 115         u64 jd = tb - vcpu->arch.dec_jiffies;
 116
 117 #ifdef CONFIG_BOOKE
 118         if (vcpu->arch.dec < jd)
 119                 return 0;
 120 #endif
 121
 122         return vcpu->arch.dec - jd;
 123 }
 124
 125 /* XXX to do:
 126  * lhax
 127  * lhaux
 128  * lswx
 129  * lswi
 130  * stswx
 131  * stswi
 132  * lha
 133  * lhau
 134  * lmw
 135  * stmw
 136  *
 137  * XXX is_bigendian should depend on MMU mapping or MSR[LE]
 138  */
 139 /* XXX Should probably auto-generate instruction decoding for a particular core
 140  * from opcode tables in the future. */
 141 int kvmppc_emulate_instruction(struct kvm_run *run, struct kvm_vcpu *vcpu)
 142 {
 143         u32 inst = kvmppc_get_last_inst(vcpu);
 144         int ra;
 145         int rb;
 146         int rs;
 147         int rt;
 148         int sprn;
 149         enum emulation_result emulated = EMULATE_DONE;
 150         int advance = 1;
 151
 152         /* this default type might be overwritten by subcategories */
 153         kvmppc_set_exit_type(vcpu, EMULATED_INST_EXITS);
 154
 155         pr_debug("Emulating opcode %d / %d\n", get_op(inst), get_xop(inst));
 156
 157         switch (get_op(inst)) {
 158         case OP_TRAP:
 159 #ifdef CONFIG_PPC_BOOK3S
 160         case OP_TRAP_64:
 161                 kvmppc_core_queue_program(vcpu, SRR1_PROGTRAP);
 162 #else
 163                 kvmppc_core_queue_program(vcpu,
 164                                           vcpu->arch.shared->esr | ESR_PTR);
 165 #endif
 166                 advance = 0;
 167                 break;
 168
 169         case 31:
 170                 switch (get_xop(inst)) {
 171
 172                 case OP_31_XOP_LWZX:
 173                         rt = get_rt(inst);
 174                         emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
 175                         break;
 176
 177                 case OP_31_XOP_LBZX:
 178                         rt = get_rt(inst);
 179                         emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
 180                         break;
 181
 182                 case OP_31_XOP_LBZUX:
 183                         rt = get_rt(inst);
 184                         ra = get_ra(inst);
 185                         rb = get_rb(inst);
 186
 187                         emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
 188                         kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
 189                         break;
 190
 191                 case OP_31_XOP_STWX:
 192                         rs = get_rs(inst);
 193                         emulated = kvmppc_handle_store(run, vcpu,
 194                                                        kvmppc_get_gpr(vcpu, rs),
 195                                                        4, 1);
 196                         break;
 197
 198                 case OP_31_XOP_STBX:
 199                         rs = get_rs(inst);
 200                         emulated = kvmppc_handle_store(run, vcpu,
 201                                                        kvmppc_get_gpr(vcpu, rs),
 202                                                        1, 1);
 203                         break;
 204
 205                 case OP_31_XOP_STBUX:
 206                         rs = get_rs(inst);
 207                         ra = get_ra(inst);
 208                         rb = get_rb(inst);
 209
 210                         emulated = kvmppc_handle_store(run, vcpu,
 211                                                        kvmppc_get_gpr(vcpu, rs),
 212                                                        1, 1);
 213                         kvmppc_set_gpr(vcpu, rs, vcpu->arch.vaddr_accessed);
 214                         break;
 215
 216                 case OP_31_XOP_LHAX:
 217                         rt = get_rt(inst);
 218                         emulated = kvmppc_handle_loads(run, vcpu, rt, 2, 1);
 219                         break;
 220
 221                 case OP_31_XOP_LHZX:
 222                         rt = get_rt(inst);
 223                         emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 224                         break;
 225
 226                 case OP_31_XOP_LHZUX:
 227                         rt = get_rt(inst);
 228                         ra = get_ra(inst);
 229                         rb = get_rb(inst);
 230
 231                         emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 232                         kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
 233                         break;
 234
 235                 case OP_31_XOP_MFSPR:
 236                         sprn = get_sprn(inst);
 237                         rt = get_rt(inst);
 238
 239                         switch (sprn) {
 240                         case SPRN_SRR0:
 241                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.shared->srr0);
 242                                 break;
 243                         case SPRN_SRR1:
 244                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.shared->srr1);
 245                                 break;
 246                         case SPRN_PVR:
 247                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.pvr); break;
 248                         case SPRN_PIR:
 249                                 kvmppc_set_gpr(vcpu, rt, vcpu->vcpu_id); break;
 250                         case SPRN_MSSSR0:
 251                                 kvmppc_set_gpr(vcpu, rt, 0); break;
 252
 253                         /* Note: mftb and TBRL/TBWL are user-accessible, so
 254                          * the guest can always access the real TB anyways.
 255                          * In fact, we probably will never see these traps. */
 256                         case SPRN_TBWL:
 257                                 kvmppc_set_gpr(vcpu, rt, get_tb() >> 32); break;
 258                         case SPRN_TBWU:
 259                                 kvmppc_set_gpr(vcpu, rt, get_tb()); break;
 260
 261                         case SPRN_SPRG0:
 262                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.shared->sprg0);
 263                                 break;
 264                         case SPRN_SPRG1:
 265                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.shared->sprg1);
 266                                 break;
 267                         case SPRN_SPRG2:
 268                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.shared->sprg2);
 269                                 break;
 270                         case SPRN_SPRG3:
 271                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.shared->sprg3);
 272                                 break;
 273                         /* Note: SPRG4-7 are user-readable, so we don't get
 274                          * a trap. */
 275
 276                         case SPRN_DEC:
 277                         {
 278                                 kvmppc_set_gpr(vcpu, rt,
 279                                                kvmppc_get_dec(vcpu, get_tb()));
 280                                 break;
 281                         }
 282                         default:
 283                                 emulated = kvmppc_core_emulate_mfspr(vcpu, sprn, rt);
 284                                 if (emulated == EMULATE_FAIL) {
 285                                         printk("mfspr: unknown spr %x\n", sprn);
 286                                         kvmppc_set_gpr(vcpu, rt, 0);
 287                                 }
 288                                 break;
 289                         }
 290                         kvmppc_set_exit_type(vcpu, EMULATED_MFSPR_EXITS);
 291                         break;
 292
 293                 case OP_31_XOP_STHX:
 294                         rs = get_rs(inst);
 295                         ra = get_ra(inst);
 296                         rb = get_rb(inst);
 297
 298                         emulated = kvmppc_handle_store(run, vcpu,
 299                                                        kvmppc_get_gpr(vcpu, rs),
 300                                                        2, 1);
 301                         break;
 302
 303                 case OP_31_XOP_STHUX:
 304                         rs = get_rs(inst);
 305                         ra = get_ra(inst);
 306                         rb = get_rb(inst);
 307
 308                         emulated = kvmppc_handle_store(run, vcpu,
 309                                                        kvmppc_get_gpr(vcpu, rs),
 310                                                        2, 1);
 311                         kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
 312                         break;
 313
 314                 case OP_31_XOP_MTSPR:
 315                         sprn = get_sprn(inst);
 316                         rs = get_rs(inst);
 317                         switch (sprn) {
 318                         case SPRN_SRR0:
 319                                 vcpu->arch.shared->srr0 = kvmppc_get_gpr(vcpu, rs);
 320                                 break;
 321                         case SPRN_SRR1:
 322                                 vcpu->arch.shared->srr1 = kvmppc_get_gpr(vcpu, rs);
 323                                 break;
 324
 325                         /* XXX We need to context-switch the timebase for
 326                          * watchdog and FIT. */
 327                         case SPRN_TBWL: break;
 328                         case SPRN_TBWU: break;
 329
 330                         case SPRN_MSSSR0: break;
 331
 332                         case SPRN_DEC:
 333                                 vcpu->arch.dec = kvmppc_get_gpr(vcpu, rs);
 334                                 kvmppc_emulate_dec(vcpu);
 335                                 break;
 336
 337                         case SPRN_SPRG0:
 338                                 vcpu->arch.shared->sprg0 = kvmppc_get_gpr(vcpu, rs);
 339                                 break;
 340                         case SPRN_SPRG1:
 341                                 vcpu->arch.shared->sprg1 = kvmppc_get_gpr(vcpu, rs);
 342                                 break;
 343                         case SPRN_SPRG2:
 344                                 vcpu->arch.shared->sprg2 = kvmppc_get_gpr(vcpu, rs);
 345                                 break;
 346                         case SPRN_SPRG3:
 347                                 vcpu->arch.shared->sprg3 = kvmppc_get_gpr(vcpu, rs);
 348                                 break;
 349
 350                         default:
 351                                 emulated = kvmppc_core_emulate_mtspr(vcpu, sprn, rs);
 352                                 if (emulated == EMULATE_FAIL)
 353                                         printk("mtspr: unknown spr %x\n", sprn);
 354                                 break;
 355                         }
 356                         kvmppc_set_exit_type(vcpu, EMULATED_MTSPR_EXITS);
 357                         break;
 358
 359                 case OP_31_XOP_DCBI:
 360                         /* Do nothing. The guest is performing dcbi because
 361                          * hardware DMA is not snooped by the dcache, but
 362                          * emulated DMA either goes through the dcache as
 363                          * normal writes, or the host kernel has handled dcache
 364                          * coherence. */
 365                         break;
 366
 367                 case OP_31_XOP_LWBRX:
 368                         rt = get_rt(inst);
 369                         emulated = kvmppc_handle_load(run, vcpu, rt, 4, 0);
 370                         break;
 371
 372                 case OP_31_XOP_TLBSYNC:
 373                         break;
 374
 375                 case OP_31_XOP_STWBRX:
 376                         rs = get_rs(inst);
 377                         ra = get_ra(inst);
 378                         rb = get_rb(inst);
 379
 380                         emulated = kvmppc_handle_store(run, vcpu,
 381                                                        kvmppc_get_gpr(vcpu, rs),
 382                                                        4, 0);
 383                         break;
 384
 385                 case OP_31_XOP_LHBRX:
 386                         rt = get_rt(inst);
 387                         emulated = kvmppc_handle_load(run, vcpu, rt, 2, 0);
 388                         break;
 389
 390                 case OP_31_XOP_STHBRX:
 391                         rs = get_rs(inst);
 392                         ra = get_ra(inst);
 393                         rb = get_rb(inst);
 394
 395                         emulated = kvmppc_handle_store(run, vcpu,
 396                                                        kvmppc_get_gpr(vcpu, rs),
 397                                                        2, 0);
 398                         break;
 399
 400                 default:
 401                         /* Attempt core-specific emulation below. */
 402                         emulated = EMULATE_FAIL;
 403                 }
 404                 break;
 405
 406         case OP_LWZ:
 407                 rt = get_rt(inst);
 408                 emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
 409                 break;
 410
 411         case OP_LWZU:
 412                 ra = get_ra(inst);
 413                 rt = get_rt(inst);
 414                 emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
 415                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
 416                 break;
 417
 418         case OP_LBZ:
 419                 rt = get_rt(inst);
 420                 emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
 421                 break;
 422
 423         case OP_LBZU:
 424                 ra = get_ra(inst);
 425                 rt = get_rt(inst);
 426                 emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
 427                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
 428                 break;
 429
 430         case OP_STW:
 431                 rs = get_rs(inst);
 432                 emulated = kvmppc_handle_store(run, vcpu,
 433                                                kvmppc_get_gpr(vcpu, rs),
 434                                                4, 1);
 435                 break;
 436
 437         case OP_STWU:
 438                 ra = get_ra(inst);
 439                 rs = get_rs(inst);
 440                 emulated = kvmppc_handle_store(run, vcpu,
 441                                                kvmppc_get_gpr(vcpu, rs),
 442                                                4, 1);
 443                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
 444                 break;
 445
 446         case OP_STB:
 447                 rs = get_rs(inst);
 448                 emulated = kvmppc_handle_store(run, vcpu,
 449                                                kvmppc_get_gpr(vcpu, rs),
 450                                                1, 1);
 451                 break;
 452
 453         case OP_STBU:
 454                 ra = get_ra(inst);
 455                 rs = get_rs(inst);
 456                 emulated = kvmppc_handle_store(run, vcpu,
 457                                                kvmppc_get_gpr(vcpu, rs),
 458                                                1, 1);
 459                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
 460                 break;
 461
 462         case OP_LHZ:
 463                 rt = get_rt(inst);
 464                 emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 465                 break;
 466
 467         case OP_LHZU:
 468                 ra = get_ra(inst);
 469                 rt = get_rt(inst);
 470                 emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 471                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
 472                 break;
 473
 474         case OP_LHA:
 475                 rt = get_rt(inst);
 476                 emulated = kvmppc_handle_loads(run, vcpu, rt, 2, 1);
 477                 break;
 478
 479         case OP_LHAU:
 480                 ra = get_ra(inst);
 481                 rt = get_rt(inst);
 482                 emulated = kvmppc_handle_loads(run, vcpu, rt, 2, 1);
 483                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
 484                 break;
 485
 486         case OP_STH:
 487                 rs = get_rs(inst);
 488                 emulated = kvmppc_handle_store(run, vcpu,
 489                                                kvmppc_get_gpr(vcpu, rs),
 490                                                2, 1);
 491                 break;
 492
 493         case OP_STHU:
 494                 ra = get_ra(inst);
 495                 rs = get_rs(inst);
 496                 emulated = kvmppc_handle_store(run, vcpu,
 497                                                kvmppc_get_gpr(vcpu, rs),
 498                                                2, 1);
 499                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
 500                 break;
 501
 502         default:
 503                 emulated = EMULATE_FAIL;
 504         }
 505
 506         if (emulated == EMULATE_FAIL) {
 507                 emulated = kvmppc_core_emulate_op(run, vcpu, inst, &advance);
 508                 if (emulated == EMULATE_AGAIN) {
 509                         advance = 0;
 510                 } else if (emulated == EMULATE_FAIL) {
 511                         advance = 0;
 512                         printk(KERN_ERR "Couldn't emulate instruction 0x%08x "
 513                                "(op %d xop %d)\n", inst, get_op(inst), get_xop(inst));
 514                         kvmppc_core_queue_program(vcpu, 0);
 515                 }
 516         }
 517
 518         trace_kvm_ppc_instr(inst, kvmppc_get_pc(vcpu), emulated);
 519
 520         /* Advance past emulated instruction. */
 521         if (advance)
 522                 kvmppc_set_pc(vcpu, kvmppc_get_pc(vcpu) + 4);
 523
 524         return emulated;
 525 }