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_DCBST     54
  42 #define OP_31_XOP_TRAP_64   68
  43 #define OP_31_XOP_DCBF      86
  44 #define OP_31_XOP_LBZX      87
  45 #define OP_31_XOP_STWX      151
  46 #define OP_31_XOP_STBX      215
  47 #define OP_31_XOP_LBZUX     119
  48 #define OP_31_XOP_STBUX     247
  49 #define OP_31_XOP_LHZX      279
  50 #define OP_31_XOP_LHZUX     311
  51 #define OP_31_XOP_MFSPR     339
  52 #define OP_31_XOP_LHAX      343
  53 #define OP_31_XOP_STHX      407
  54 #define OP_31_XOP_STHUX     439
  55 #define OP_31_XOP_MTSPR     467
  56 #define OP_31_XOP_DCBI      470
  57 #define OP_31_XOP_LWBRX     534
  58 #define OP_31_XOP_TLBSYNC   566
  59 #define OP_31_XOP_STWBRX    662
  60 #define OP_31_XOP_LHBRX     790
  61 #define OP_31_XOP_STHBRX    918
  62
  63 #define OP_LWZ  32
  64 #define OP_LD   58
  65 #define OP_LWZU 33
  66 #define OP_LBZ  34
  67 #define OP_LBZU 35
  68 #define OP_STW  36
  69 #define OP_STWU 37
  70 #define OP_STD  62
  71 #define OP_STB  38
  72 #define OP_STBU 39
  73 #define OP_LHZ  40
  74 #define OP_LHZU 41
  75 #define OP_LHA  42
  76 #define OP_LHAU 43
  77 #define OP_STH  44
  78 #define OP_STHU 45
  79
  80 void kvmppc_emulate_dec(struct kvm_vcpu *vcpu)
  81 {
  82         unsigned long dec_nsec;
  83         unsigned long long dec_time;
  84
  85         pr_debug("mtDEC: %x\n", vcpu->arch.dec);
  86         hrtimer_try_to_cancel(&vcpu->arch.dec_timer);
  87
  88 #ifdef CONFIG_PPC_BOOK3S
  89         /* mtdec lowers the interrupt line when positive. */
  90         kvmppc_core_dequeue_dec(vcpu);
  91
  92         /* POWER4+ triggers a dec interrupt if the value is < 0 */
  93         if (vcpu->arch.dec & 0x80000000) {
  94                 kvmppc_core_queue_dec(vcpu);
  95                 return;
  96         }
  97 #endif
  98
  99 #ifdef CONFIG_BOOKE
 100         /* On BOOKE, DEC = 0 is as good as decrementer not enabled */
 101         if (vcpu->arch.dec == 0)
 102                 return;
 103 #endif
 104
 105         /*
 106          * The decrementer ticks at the same rate as the timebase, so
 107          * that's how we convert the guest DEC value to the number of
 108          * host ticks.
 109          */
 110
 111         dec_time = vcpu->arch.dec;
 112         /*
 113          * Guest timebase ticks at the same frequency as host decrementer.
 114          * So use the host decrementer calculations for decrementer emulation.
 115          */
 116         dec_time = dec_time << decrementer_clockevent.shift;
 117         do_div(dec_time, decrementer_clockevent.mult);
 118         dec_nsec = do_div(dec_time, NSEC_PER_SEC);
 119         hrtimer_start(&vcpu->arch.dec_timer,
 120                 ktime_set(dec_time, dec_nsec), HRTIMER_MODE_REL);
 121         vcpu->arch.dec_jiffies = get_tb();
 122 }
 123
 124 u32 kvmppc_get_dec(struct kvm_vcpu *vcpu, u64 tb)
 125 {
 126         u64 jd = tb - vcpu->arch.dec_jiffies;
 127
 128 #ifdef CONFIG_BOOKE
 129         if (vcpu->arch.dec < jd)
 130                 return 0;
 131 #endif
 132
 133         return vcpu->arch.dec - jd;
 134 }
 135
 136 static int kvmppc_emulate_mtspr(struct kvm_vcpu *vcpu, int sprn, int rs)
 137 {
 138         enum emulation_result emulated = EMULATE_DONE;
 139         ulong spr_val = kvmppc_get_gpr(vcpu, rs);
 140
 141         switch (sprn) {
 142         case SPRN_SRR0:
 143                 vcpu->arch.shared->srr0 = spr_val;
 144                 break;
 145         case SPRN_SRR1:
 146                 vcpu->arch.shared->srr1 = spr_val;
 147                 break;
 148
 149         /* XXX We need to context-switch the timebase for
 150          * watchdog and FIT. */
 151         case SPRN_TBWL: break;
 152         case SPRN_TBWU: break;
 153
 154         case SPRN_DEC:
 155                 vcpu->arch.dec = spr_val;
 156                 kvmppc_emulate_dec(vcpu);
 157                 break;
 158
 159         case SPRN_SPRG0:
 160                 vcpu->arch.shared->sprg0 = spr_val;
 161                 break;
 162         case SPRN_SPRG1:
 163                 vcpu->arch.shared->sprg1 = spr_val;
 164                 break;
 165         case SPRN_SPRG2:
 166                 vcpu->arch.shared->sprg2 = spr_val;
 167                 break;
 168         case SPRN_SPRG3:
 169                 vcpu->arch.shared->sprg3 = spr_val;
 170                 break;
 171
 172         default:
 173                 emulated = kvmppc_core_emulate_mtspr(vcpu, sprn,
 174                                                      spr_val);
 175                 if (emulated == EMULATE_FAIL)
 176                         printk(KERN_INFO "mtspr: unknown spr "
 177                                 "0x%x\n", sprn);
 178                 break;
 179         }
 180
 181         kvmppc_set_exit_type(vcpu, EMULATED_MTSPR_EXITS);
 182
 183         return emulated;
 184 }
 185
 186 static int kvmppc_emulate_mfspr(struct kvm_vcpu *vcpu, int sprn, int rt)
 187 {
 188         enum emulation_result emulated = EMULATE_DONE;
 189         ulong spr_val = 0;
 190
 191         switch (sprn) {
 192         case SPRN_SRR0:
 193                 spr_val = vcpu->arch.shared->srr0;
 194                 break;
 195         case SPRN_SRR1:
 196                 spr_val = vcpu->arch.shared->srr1;
 197                 break;
 198         case SPRN_PVR:
 199                 spr_val = vcpu->arch.pvr;
 200                 break;
 201         case SPRN_PIR:
 202                 spr_val = vcpu->vcpu_id;
 203                 break;
 204
 205         /* Note: mftb and TBRL/TBWL are user-accessible, so
 206          * the guest can always access the real TB anyways.
 207          * In fact, we probably will never see these traps. */
 208         case SPRN_TBWL:
 209                 spr_val = get_tb() >> 32;
 210                 break;
 211         case SPRN_TBWU:
 212                 spr_val = get_tb();
 213                 break;
 214
 215         case SPRN_SPRG0:
 216                 spr_val = vcpu->arch.shared->sprg0;
 217                 break;
 218         case SPRN_SPRG1:
 219                 spr_val = vcpu->arch.shared->sprg1;
 220                 break;
 221         case SPRN_SPRG2:
 222                 spr_val = vcpu->arch.shared->sprg2;
 223                 break;
 224         case SPRN_SPRG3:
 225                 spr_val = vcpu->arch.shared->sprg3;
 226                 break;
 227         /* Note: SPRG4-7 are user-readable, so we don't get
 228          * a trap. */
 229
 230         case SPRN_DEC:
 231                 spr_val = kvmppc_get_dec(vcpu, get_tb());
 232                 break;
 233         default:
 234                 emulated = kvmppc_core_emulate_mfspr(vcpu, sprn,
 235                                                      &spr_val);
 236                 if (unlikely(emulated == EMULATE_FAIL)) {
 237                         printk(KERN_INFO "mfspr: unknown spr "
 238                                 "0x%x\n", sprn);
 239                 }
 240                 break;
 241         }
 242
 243         if (emulated == EMULATE_DONE)
 244                 kvmppc_set_gpr(vcpu, rt, spr_val);
 245         kvmppc_set_exit_type(vcpu, EMULATED_MFSPR_EXITS);
 246
 247         return emulated;
 248 }
 249
 250 /* XXX to do:
 251  * lhax
 252  * lhaux
 253  * lswx
 254  * lswi
 255  * stswx
 256  * stswi
 257  * lha
 258  * lhau
 259  * lmw
 260  * stmw
 261  *
 262  * XXX is_bigendian should depend on MMU mapping or MSR[LE]
 263  */
 264 /* XXX Should probably auto-generate instruction decoding for a particular core
 265  * from opcode tables in the future. */
 266 int kvmppc_emulate_instruction(struct kvm_run *run, struct kvm_vcpu *vcpu)
 267 {
 268         u32 inst = kvmppc_get_last_inst(vcpu);
 269         int ra = get_ra(inst);
 270         int rs = get_rs(inst);
 271         int rt = get_rt(inst);
 272         int sprn = get_sprn(inst);
 273         enum emulation_result emulated = EMULATE_DONE;
 274         int advance = 1;
 275
 276         /* this default type might be overwritten by subcategories */
 277         kvmppc_set_exit_type(vcpu, EMULATED_INST_EXITS);
 278
 279         pr_debug("Emulating opcode %d / %d\n", get_op(inst), get_xop(inst));
 280
 281         switch (get_op(inst)) {
 282         case OP_TRAP:
 283 #ifdef CONFIG_PPC_BOOK3S
 284         case OP_TRAP_64:
 285                 kvmppc_core_queue_program(vcpu, SRR1_PROGTRAP);
 286 #else
 287                 kvmppc_core_queue_program(vcpu,
 288                                           vcpu->arch.shared->esr | ESR_PTR);
 289 #endif
 290                 advance = 0;
 291                 break;
 292
 293         case 31:
 294                 switch (get_xop(inst)) {
 295
 296                 case OP_31_XOP_TRAP:
 297 #ifdef CONFIG_64BIT
 298                 case OP_31_XOP_TRAP_64:
 299 #endif
 300 #ifdef CONFIG_PPC_BOOK3S
 301                         kvmppc_core_queue_program(vcpu, SRR1_PROGTRAP);
 302 #else
 303                         kvmppc_core_queue_program(vcpu,
 304                                         vcpu->arch.shared->esr | ESR_PTR);
 305 #endif
 306                         advance = 0;
 307                         break;
 308                 case OP_31_XOP_LWZX:
 309                         emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
 310                         break;
 311
 312                 case OP_31_XOP_LBZX:
 313                         emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
 314                         break;
 315
 316                 case OP_31_XOP_LBZUX:
 317                         emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
 318                         kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
 319                         break;
 320
 321                 case OP_31_XOP_STWX:
 322                         emulated = kvmppc_handle_store(run, vcpu,
 323                                                        kvmppc_get_gpr(vcpu, rs),
 324                                                        4, 1);
 325                         break;
 326
 327                 case OP_31_XOP_STBX:
 328                         emulated = kvmppc_handle_store(run, vcpu,
 329                                                        kvmppc_get_gpr(vcpu, rs),
 330                                                        1, 1);
 331                         break;
 332
 333                 case OP_31_XOP_STBUX:
 334                         emulated = kvmppc_handle_store(run, vcpu,
 335                                                        kvmppc_get_gpr(vcpu, rs),
 336                                                        1, 1);
 337                         kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
 338                         break;
 339
 340                 case OP_31_XOP_LHAX:
 341                         emulated = kvmppc_handle_loads(run, vcpu, rt, 2, 1);
 342                         break;
 343
 344                 case OP_31_XOP_LHZX:
 345                         emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 346                         break;
 347
 348                 case OP_31_XOP_LHZUX:
 349                         emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 350                         kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
 351                         break;
 352
 353                 case OP_31_XOP_MFSPR:
 354                         emulated = kvmppc_emulate_mfspr(vcpu, sprn, rt);
 355                         break;
 356
 357                 case OP_31_XOP_STHX:
 358                         emulated = kvmppc_handle_store(run, vcpu,
 359                                                        kvmppc_get_gpr(vcpu, rs),
 360                                                        2, 1);
 361                         break;
 362
 363                 case OP_31_XOP_STHUX:
 364                         emulated = kvmppc_handle_store(run, vcpu,
 365                                                        kvmppc_get_gpr(vcpu, rs),
 366                                                        2, 1);
 367                         kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
 368                         break;
 369
 370                 case OP_31_XOP_MTSPR:
 371                         emulated = kvmppc_emulate_mtspr(vcpu, sprn, rs);
 372                         break;
 373
 374                 case OP_31_XOP_DCBST:
 375                 case OP_31_XOP_DCBF:
 376                 case OP_31_XOP_DCBI:
 377                         /* Do nothing. The guest is performing dcbi because
 378                          * hardware DMA is not snooped by the dcache, but
 379                          * emulated DMA either goes through the dcache as
 380                          * normal writes, or the host kernel has handled dcache
 381                          * coherence. */
 382                         break;
 383
 384                 case OP_31_XOP_LWBRX:
 385                         emulated = kvmppc_handle_load(run, vcpu, rt, 4, 0);
 386                         break;
 387
 388                 case OP_31_XOP_TLBSYNC:
 389                         break;
 390
 391                 case OP_31_XOP_STWBRX:
 392                         emulated = kvmppc_handle_store(run, vcpu,
 393                                                        kvmppc_get_gpr(vcpu, rs),
 394                                                        4, 0);
 395                         break;
 396
 397                 case OP_31_XOP_LHBRX:
 398                         emulated = kvmppc_handle_load(run, vcpu, rt, 2, 0);
 399                         break;
 400
 401                 case OP_31_XOP_STHBRX:
 402                         emulated = kvmppc_handle_store(run, vcpu,
 403                                                        kvmppc_get_gpr(vcpu, rs),
 404                                                        2, 0);
 405                         break;
 406
 407                 default:
 408                         /* Attempt core-specific emulation below. */
 409                         emulated = EMULATE_FAIL;
 410                 }
 411                 break;
 412
 413         case OP_LWZ:
 414                 emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
 415                 break;
 416
 417         /* TBD: Add support for other 64 bit load variants like ldu, ldux, ldx etc. */
 418         case OP_LD:
 419                 rt = get_rt(inst);
 420                 emulated = kvmppc_handle_load(run, vcpu, rt, 8, 1);
 421                 break;
 422
 423         case OP_LWZU:
 424                 emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
 425                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
 426                 break;
 427
 428         case OP_LBZ:
 429                 emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
 430                 break;
 431
 432         case OP_LBZU:
 433                 emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
 434                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
 435                 break;
 436
 437         case OP_STW:
 438                 emulated = kvmppc_handle_store(run, vcpu,
 439                                                kvmppc_get_gpr(vcpu, rs),
 440                                                4, 1);
 441                 break;
 442
 443         /* TBD: Add support for other 64 bit store variants like stdu, stdux, stdx etc. */
 444         case OP_STD:
 445                 rs = get_rs(inst);
 446                 emulated = kvmppc_handle_store(run, vcpu,
 447                                                kvmppc_get_gpr(vcpu, rs),
 448                                                8, 1);
 449                 break;
 450
 451         case OP_STWU:
 452                 emulated = kvmppc_handle_store(run, vcpu,
 453                                                kvmppc_get_gpr(vcpu, rs),
 454                                                4, 1);
 455                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
 456                 break;
 457
 458         case OP_STB:
 459                 emulated = kvmppc_handle_store(run, vcpu,
 460                                                kvmppc_get_gpr(vcpu, rs),
 461                                                1, 1);
 462                 break;
 463
 464         case OP_STBU:
 465                 emulated = kvmppc_handle_store(run, vcpu,
 466                                                kvmppc_get_gpr(vcpu, rs),
 467                                                1, 1);
 468                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
 469                 break;
 470
 471         case OP_LHZ:
 472                 emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 473                 break;
 474
 475         case OP_LHZU:
 476                 emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 477                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
 478                 break;
 479
 480         case OP_LHA:
 481                 emulated = kvmppc_handle_loads(run, vcpu, rt, 2, 1);
 482                 break;
 483
 484         case OP_LHAU:
 485                 emulated = kvmppc_handle_loads(run, vcpu, rt, 2, 1);
 486                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
 487                 break;
 488
 489         case OP_STH:
 490                 emulated = kvmppc_handle_store(run, vcpu,
 491                                                kvmppc_get_gpr(vcpu, rs),
 492                                                2, 1);
 493                 break;
 494
 495         case OP_STHU:
 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 }