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 #include <linux/clockchips.h>
  27
  28 #include <asm/reg.h>
  29 #include <asm/time.h>
  30 #include <asm/byteorder.h>
  31 #include <asm/kvm_ppc.h>
  32 #include <asm/disassemble.h>
  33 #include "timing.h"
  34 #include "trace.h"
  35
  36 #define OP_TRAP 3
  37 #define OP_TRAP_64 2
  38
  39 #define OP_31_XOP_TRAP      4
  40 #define OP_31_XOP_LWZX      23
  41 #define OP_31_XOP_TRAP_64   68
  42 #define OP_31_XOP_DCBF      86
  43 #define OP_31_XOP_LBZX      87
  44 #define OP_31_XOP_STWX      151
  45 #define OP_31_XOP_STBX      215
  46 #define OP_31_XOP_LBZUX     119
  47 #define OP_31_XOP_STBUX     247
  48 #define OP_31_XOP_LHZX      279
  49 #define OP_31_XOP_LHZUX     311
  50 #define OP_31_XOP_MFSPR     339
  51 #define OP_31_XOP_LHAX      343
  52 #define OP_31_XOP_STHX      407
  53 #define OP_31_XOP_STHUX     439
  54 #define OP_31_XOP_MTSPR     467
  55 #define OP_31_XOP_DCBI      470
  56 #define OP_31_XOP_LWBRX     534
  57 #define OP_31_XOP_TLBSYNC   566
  58 #define OP_31_XOP_STWBRX    662
  59 #define OP_31_XOP_LHBRX     790
  60 #define OP_31_XOP_STHBRX    918
  61
  62 #define OP_LWZ  32
  63 #define OP_LD   58
  64 #define OP_LWZU 33
  65 #define OP_LBZ  34
  66 #define OP_LBZU 35
  67 #define OP_STW  36
  68 #define OP_STWU 37
  69 #define OP_STD  62
  70 #define OP_STB  38
  71 #define OP_STBU 39
  72 #define OP_LHZ  40
  73 #define OP_LHZU 41
  74 #define OP_LHA  42
  75 #define OP_LHAU 43
  76 #define OP_STH  44
  77 #define OP_STHU 45
  78
  79 void kvmppc_emulate_dec(struct kvm_vcpu *vcpu)
  80 {
  81         unsigned long dec_nsec;
  82         unsigned long long dec_time;
  83
  84         pr_debug("mtDEC: %x\n", vcpu->arch.dec);
  85         hrtimer_try_to_cancel(&vcpu->arch.dec_timer);
  86
  87 #ifdef CONFIG_PPC_BOOK3S
  88         /* mtdec lowers the interrupt line when positive. */
  89         kvmppc_core_dequeue_dec(vcpu);
  90
  91         /* POWER4+ triggers a dec interrupt if the value is < 0 */
  92         if (vcpu->arch.dec & 0x80000000) {
  93                 kvmppc_core_queue_dec(vcpu);
  94                 return;
  95         }
  96 #endif
  97
  98 #ifdef CONFIG_BOOKE
  99         /* On BOOKE, DEC = 0 is as good as decrementer not enabled */
 100         if (vcpu->arch.dec == 0)
 101                 return;
 102 #endif
 103
 104         /*
 105          * The decrementer ticks at the same rate as the timebase, so
 106          * that's how we convert the guest DEC value to the number of
 107          * host ticks.
 108          */
 109
 110         dec_time = vcpu->arch.dec;
 111         /*
 112          * Guest timebase ticks at the same frequency as host decrementer.
 113          * So use the host decrementer calculations for decrementer emulation.
 114          */
 115         dec_time = dec_time << decrementer_clockevent.shift;
 116         do_div(dec_time, decrementer_clockevent.mult);
 117         dec_nsec = do_div(dec_time, NSEC_PER_SEC);
 118         hrtimer_start(&vcpu->arch.dec_timer,
 119                 ktime_set(dec_time, dec_nsec), HRTIMER_MODE_REL);
 120         vcpu->arch.dec_jiffies = get_tb();
 121 }
 122
 123 u32 kvmppc_get_dec(struct kvm_vcpu *vcpu, u64 tb)
 124 {
 125         u64 jd = tb - vcpu->arch.dec_jiffies;
 126
 127 #ifdef CONFIG_BOOKE
 128         if (vcpu->arch.dec < jd)
 129                 return 0;
 130 #endif
 131
 132         return vcpu->arch.dec - jd;
 133 }
 134
 135 static int kvmppc_emulate_mtspr(struct kvm_vcpu *vcpu, int sprn, int rs)
 136 {
 137         enum emulation_result emulated = EMULATE_DONE;
 138         ulong spr_val = kvmppc_get_gpr(vcpu, rs);
 139
 140         switch (sprn) {
 141         case SPRN_SRR0:
 142                 vcpu->arch.shared->srr0 = spr_val;
 143                 break;
 144         case SPRN_SRR1:
 145                 vcpu->arch.shared->srr1 = spr_val;
 146                 break;
 147
 148         /* XXX We need to context-switch the timebase for
 149          * watchdog and FIT. */
 150         case SPRN_TBWL: break;
 151         case SPRN_TBWU: break;
 152
 153         case SPRN_MSSSR0: break;
 154
 155         case SPRN_DEC:
 156                 vcpu->arch.dec = spr_val;
 157                 kvmppc_emulate_dec(vcpu);
 158                 break;
 159
 160         case SPRN_SPRG0:
 161                 vcpu->arch.shared->sprg0 = spr_val;
 162                 break;
 163         case SPRN_SPRG1:
 164                 vcpu->arch.shared->sprg1 = spr_val;
 165                 break;
 166         case SPRN_SPRG2:
 167                 vcpu->arch.shared->sprg2 = spr_val;
 168                 break;
 169         case SPRN_SPRG3:
 170                 vcpu->arch.shared->sprg3 = spr_val;
 171                 break;
 172
 173         default:
 174                 emulated = kvmppc_core_emulate_mtspr(vcpu, sprn,
 175                                                      spr_val);
 176                 if (emulated == EMULATE_FAIL)
 177                         printk(KERN_INFO "mtspr: unknown spr "
 178                                 "0x%x\n", sprn);
 179                 break;
 180         }
 181
 182         kvmppc_set_exit_type(vcpu, EMULATED_MTSPR_EXITS);
 183
 184         return emulated;
 185 }
 186
 187 static int kvmppc_emulate_mfspr(struct kvm_vcpu *vcpu, int sprn, int rt)
 188 {
 189         enum emulation_result emulated = EMULATE_DONE;
 190         ulong spr_val = 0;
 191
 192         switch (sprn) {
 193         case SPRN_SRR0:
 194                 spr_val = vcpu->arch.shared->srr0;
 195                 break;
 196         case SPRN_SRR1:
 197                 spr_val = vcpu->arch.shared->srr1;
 198                 break;
 199         case SPRN_PVR:
 200                 spr_val = vcpu->arch.pvr;
 201                 break;
 202         case SPRN_PIR:
 203                 spr_val = vcpu->vcpu_id;
 204                 break;
 205         case SPRN_MSSSR0:
 206                 spr_val = 0;
 207                 break;
 208
 209         /* Note: mftb and TBRL/TBWL are user-accessible, so
 210          * the guest can always access the real TB anyways.
 211          * In fact, we probably will never see these traps. */
 212         case SPRN_TBWL:
 213                 spr_val = get_tb() >> 32;
 214                 break;
 215         case SPRN_TBWU:
 216                 spr_val = get_tb();
 217                 break;
 218
 219         case SPRN_SPRG0:
 220                 spr_val = vcpu->arch.shared->sprg0;
 221                 break;
 222         case SPRN_SPRG1:
 223                 spr_val = vcpu->arch.shared->sprg1;
 224                 break;
 225         case SPRN_SPRG2:
 226                 spr_val = vcpu->arch.shared->sprg2;
 227                 break;
 228         case SPRN_SPRG3:
 229                 spr_val = vcpu->arch.shared->sprg3;
 230                 break;
 231         /* Note: SPRG4-7 are user-readable, so we don't get
 232          * a trap. */
 233
 234         case SPRN_DEC:
 235                 spr_val = kvmppc_get_dec(vcpu, get_tb());
 236                 break;
 237         default:
 238                 emulated = kvmppc_core_emulate_mfspr(vcpu, sprn,
 239                                                      &spr_val);
 240                 if (unlikely(emulated == EMULATE_FAIL)) {
 241                         printk(KERN_INFO "mfspr: unknown spr "
 242                                 "0x%x\n", sprn);
 243                 }
 244                 break;
 245         }
 246
 247         if (emulated == EMULATE_DONE)
 248                 kvmppc_set_gpr(vcpu, rt, spr_val);
 249         kvmppc_set_exit_type(vcpu, EMULATED_MFSPR_EXITS);
 250
 251         return emulated;
 252 }
 253
 254 /* XXX to do:
 255  * lhax
 256  * lhaux
 257  * lswx
 258  * lswi
 259  * stswx
 260  * stswi
 261  * lha
 262  * lhau
 263  * lmw
 264  * stmw
 265  *
 266  * XXX is_bigendian should depend on MMU mapping or MSR[LE]
 267  */
 268 /* XXX Should probably auto-generate instruction decoding for a particular core
 269  * from opcode tables in the future. */
 270 int kvmppc_emulate_instruction(struct kvm_run *run, struct kvm_vcpu *vcpu)
 271 {
 272         u32 inst = kvmppc_get_last_inst(vcpu);
 273         int ra = get_ra(inst);
 274         int rs = get_rs(inst);
 275         int rt = get_rt(inst);
 276         int sprn = get_sprn(inst);
 277         enum emulation_result emulated = EMULATE_DONE;
 278         int advance = 1;
 279
 280         /* this default type might be overwritten by subcategories */
 281         kvmppc_set_exit_type(vcpu, EMULATED_INST_EXITS);
 282
 283         pr_debug("Emulating opcode %d / %d\n", get_op(inst), get_xop(inst));
 284
 285         switch (get_op(inst)) {
 286         case OP_TRAP:
 287 #ifdef CONFIG_PPC_BOOK3S
 288         case OP_TRAP_64:
 289                 kvmppc_core_queue_program(vcpu, SRR1_PROGTRAP);
 290 #else
 291                 kvmppc_core_queue_program(vcpu,
 292                                           vcpu->arch.shared->esr | ESR_PTR);
 293 #endif
 294                 advance = 0;
 295                 break;
 296
 297         case 31:
 298                 switch (get_xop(inst)) {
 299
 300                 case OP_31_XOP_TRAP:
 301 #ifdef CONFIG_64BIT
 302                 case OP_31_XOP_TRAP_64:
 303 #endif
 304 #ifdef CONFIG_PPC_BOOK3S
 305                         kvmppc_core_queue_program(vcpu, SRR1_PROGTRAP);
 306 #else
 307                         kvmppc_core_queue_program(vcpu,
 308                                         vcpu->arch.shared->esr | ESR_PTR);
 309 #endif
 310                         advance = 0;
 311                         break;
 312                 case OP_31_XOP_LWZX:
 313                         emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
 314                         break;
 315
 316                 case OP_31_XOP_LBZX:
 317                         emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
 318                         break;
 319
 320                 case OP_31_XOP_LBZUX:
 321                         emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
 322                         kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
 323                         break;
 324
 325                 case OP_31_XOP_STWX:
 326                         emulated = kvmppc_handle_store(run, vcpu,
 327                                                        kvmppc_get_gpr(vcpu, rs),
 328                                                        4, 1);
 329                         break;
 330
 331                 case OP_31_XOP_STBX:
 332                         emulated = kvmppc_handle_store(run, vcpu,
 333                                                        kvmppc_get_gpr(vcpu, rs),
 334                                                        1, 1);
 335                         break;
 336
 337                 case OP_31_XOP_STBUX:
 338                         emulated = kvmppc_handle_store(run, vcpu,
 339                                                        kvmppc_get_gpr(vcpu, rs),
 340                                                        1, 1);
 341                         kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
 342                         break;
 343
 344                 case OP_31_XOP_LHAX:
 345                         emulated = kvmppc_handle_loads(run, vcpu, rt, 2, 1);
 346                         break;
 347
 348                 case OP_31_XOP_LHZX:
 349                         emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 350                         break;
 351
 352                 case OP_31_XOP_LHZUX:
 353                         emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 354                         kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
 355                         break;
 356
 357                 case OP_31_XOP_MFSPR:
 358                         emulated = kvmppc_emulate_mfspr(vcpu, sprn, rt);
 359                         break;
 360
 361                 case OP_31_XOP_STHX:
 362                         emulated = kvmppc_handle_store(run, vcpu,
 363                                                        kvmppc_get_gpr(vcpu, rs),
 364                                                        2, 1);
 365                         break;
 366
 367                 case OP_31_XOP_STHUX:
 368                         emulated = kvmppc_handle_store(run, vcpu,
 369                                                        kvmppc_get_gpr(vcpu, rs),
 370                                                        2, 1);
 371                         kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
 372                         break;
 373
 374                 case OP_31_XOP_MTSPR:
 375                         emulated = kvmppc_emulate_mtspr(vcpu, sprn, rs);
 376                         break;
 377
 378                 case OP_31_XOP_DCBF:
 379                 case OP_31_XOP_DCBI:
 380                         /* Do nothing. The guest is performing dcbi because
 381                          * hardware DMA is not snooped by the dcache, but
 382                          * emulated DMA either goes through the dcache as
 383                          * normal writes, or the host kernel has handled dcache
 384                          * coherence. */
 385                         break;
 386
 387                 case OP_31_XOP_LWBRX:
 388                         emulated = kvmppc_handle_load(run, vcpu, rt, 4, 0);
 389                         break;
 390
 391                 case OP_31_XOP_TLBSYNC:
 392                         break;
 393
 394                 case OP_31_XOP_STWBRX:
 395                         emulated = kvmppc_handle_store(run, vcpu,
 396                                                        kvmppc_get_gpr(vcpu, rs),
 397                                                        4, 0);
 398                         break;
 399
 400                 case OP_31_XOP_LHBRX:
 401                         emulated = kvmppc_handle_load(run, vcpu, rt, 2, 0);
 402                         break;
 403
 404                 case OP_31_XOP_STHBRX:
 405                         emulated = kvmppc_handle_store(run, vcpu,
 406                                                        kvmppc_get_gpr(vcpu, rs),
 407                                                        2, 0);
 408                         break;
 409
 410                 default:
 411                         /* Attempt core-specific emulation below. */
 412                         emulated = EMULATE_FAIL;
 413                 }
 414                 break;
 415
 416         case OP_LWZ:
 417                 emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
 418                 break;
 419
 420         /* TBD: Add support for other 64 bit load variants like ldu, ldux, ldx etc. */
 421         case OP_LD:
 422                 rt = get_rt(inst);
 423                 emulated = kvmppc_handle_load(run, vcpu, rt, 8, 1);
 424                 break;
 425
 426         case OP_LWZU:
 427                 emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
 428                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
 429                 break;
 430
 431         case OP_LBZ:
 432                 emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
 433                 break;
 434
 435         case OP_LBZU:
 436                 emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
 437                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
 438                 break;
 439
 440         case OP_STW:
 441                 emulated = kvmppc_handle_store(run, vcpu,
 442                                                kvmppc_get_gpr(vcpu, rs),
 443                                                4, 1);
 444                 break;
 445
 446         /* TBD: Add support for other 64 bit store variants like stdu, stdux, stdx etc. */
 447         case OP_STD:
 448                 rs = get_rs(inst);
 449                 emulated = kvmppc_handle_store(run, vcpu,
 450                                                kvmppc_get_gpr(vcpu, rs),
 451                                                8, 1);
 452                 break;
 453
 454         case OP_STWU:
 455                 emulated = kvmppc_handle_store(run, vcpu,
 456                                                kvmppc_get_gpr(vcpu, rs),
 457                                                4, 1);
 458                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
 459                 break;
 460
 461         case OP_STB:
 462                 emulated = kvmppc_handle_store(run, vcpu,
 463                                                kvmppc_get_gpr(vcpu, rs),
 464                                                1, 1);
 465                 break;
 466
 467         case OP_STBU:
 468                 emulated = kvmppc_handle_store(run, vcpu,
 469                                                kvmppc_get_gpr(vcpu, rs),
 470                                                1, 1);
 471                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
 472                 break;
 473
 474         case OP_LHZ:
 475                 emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 476                 break;
 477
 478         case OP_LHZU:
 479                 emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 480                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
 481                 break;
 482
 483         case OP_LHA:
 484                 emulated = kvmppc_handle_loads(run, vcpu, rt, 2, 1);
 485                 break;
 486
 487         case OP_LHAU:
 488                 emulated = kvmppc_handle_loads(run, vcpu, rt, 2, 1);
 489                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
 490                 break;
 491
 492         case OP_STH:
 493                 emulated = kvmppc_handle_store(run, vcpu,
 494                                                kvmppc_get_gpr(vcpu, rs),
 495                                                2, 1);
 496                 break;
 497
 498         case OP_STHU:
 499                 emulated = kvmppc_handle_store(run, vcpu,
 500                                                kvmppc_get_gpr(vcpu, rs),
 501                                                2, 1);
 502                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
 503                 break;
 504
 505         default:
 506                 emulated = EMULATE_FAIL;
 507         }
 508
 509         if (emulated == EMULATE_FAIL) {
 510                 emulated = kvmppc_core_emulate_op(run, vcpu, inst, &advance);
 511                 if (emulated == EMULATE_AGAIN) {
 512                         advance = 0;
 513                 } else if (emulated == EMULATE_FAIL) {
 514                         advance = 0;
 515                         printk(KERN_ERR "Couldn't emulate instruction 0x%08x "
 516                                "(op %d xop %d)\n", inst, get_op(inst), get_xop(inst));
 517                         kvmppc_core_queue_program(vcpu, 0);
 518                 }
 519         }
 520
 521         trace_kvm_ppc_instr(inst, kvmppc_get_pc(vcpu), emulated);
 522
 523         /* Advance past emulated instruction. */
 524         if (advance)
 525                 kvmppc_set_pc(vcpu, kvmppc_get_pc(vcpu) + 4);
 526
 527         return emulated;
 528 }