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