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/timer.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
  36 #define OP_31_XOP_LWZX      23
  37 #define OP_31_XOP_LBZX      87
  38 #define OP_31_XOP_STWX      151
  39 #define OP_31_XOP_STBX      215
  40 #define OP_31_XOP_STBUX     247
  41 #define OP_31_XOP_LHZX      279
  42 #define OP_31_XOP_LHZUX     311
  43 #define OP_31_XOP_MFSPR     339
  44 #define OP_31_XOP_STHX      407
  45 #define OP_31_XOP_STHUX     439
  46 #define OP_31_XOP_MTSPR     467
  47 #define OP_31_XOP_DCBI      470
  48 #define OP_31_XOP_LWBRX     534
  49 #define OP_31_XOP_TLBSYNC   566
  50 #define OP_31_XOP_STWBRX    662
  51 #define OP_31_XOP_LHBRX     790
  52 #define OP_31_XOP_STHBRX    918
  53
  54 #define OP_LWZ  32
  55 #define OP_LWZU 33
  56 #define OP_LBZ  34
  57 #define OP_LBZU 35
  58 #define OP_STW  36
  59 #define OP_STWU 37
  60 #define OP_STB  38
  61 #define OP_STBU 39
  62 #define OP_LHZ  40
  63 #define OP_LHZU 41
  64 #define OP_STH  44
  65 #define OP_STHU 45
  66
  67 void kvmppc_emulate_dec(struct kvm_vcpu *vcpu)
  68 {
  69         if (vcpu->arch.tcr & TCR_DIE) {
  70                 /* The decrementer ticks at the same rate as the timebase, so
  71                  * that's how we convert the guest DEC value to the number of
  72                  * host ticks. */
  73                 unsigned long nr_jiffies;
  74
  75                 nr_jiffies = vcpu->arch.dec / tb_ticks_per_jiffy;
  76                 mod_timer(&vcpu->arch.dec_timer,
  77                           get_jiffies_64() + nr_jiffies);
  78         } else {
  79                 del_timer(&vcpu->arch.dec_timer);
  80         }
  81 }
  82
  83 /* XXX to do:
  84  * lhax
  85  * lhaux
  86  * lswx
  87  * lswi
  88  * stswx
  89  * stswi
  90  * lha
  91  * lhau
  92  * lmw
  93  * stmw
  94  *
  95  * XXX is_bigendian should depend on MMU mapping or MSR[LE]
  96  */
  97 /* XXX Should probably auto-generate instruction decoding for a particular core
  98  * from opcode tables in the future. */
  99 int kvmppc_emulate_instruction(struct kvm_run *run, struct kvm_vcpu *vcpu)
 100 {
 101         u32 inst = vcpu->arch.last_inst;
 102         u32 ea;
 103         int ra;
 104         int rb;
 105         int rs;
 106         int rt;
 107         int sprn;
 108         enum emulation_result emulated = EMULATE_DONE;
 109         int advance = 1;
 110
 111         /* this default type might be overwritten by subcategories */
 112         kvmppc_set_exit_type(vcpu, EMULATED_INST_EXITS);
 113
 114         switch (get_op(inst)) {
 115         case OP_TRAP:
 116                 vcpu->arch.esr |= ESR_PTR;
 117                 kvmppc_core_queue_program(vcpu);
 118                 advance = 0;
 119                 break;
 120
 121         case 31:
 122                 switch (get_xop(inst)) {
 123
 124                 case OP_31_XOP_LWZX:
 125                         rt = get_rt(inst);
 126                         emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
 127                         break;
 128
 129                 case OP_31_XOP_LBZX:
 130                         rt = get_rt(inst);
 131                         emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
 132                         break;
 133
 134                 case OP_31_XOP_STWX:
 135                         rs = get_rs(inst);
 136                         emulated = kvmppc_handle_store(run, vcpu,
 137                                                        vcpu->arch.gpr[rs],
 138                                                        4, 1);
 139                         break;
 140
 141                 case OP_31_XOP_STBX:
 142                         rs = get_rs(inst);
 143                         emulated = kvmppc_handle_store(run, vcpu,
 144                                                        vcpu->arch.gpr[rs],
 145                                                        1, 1);
 146                         break;
 147
 148                 case OP_31_XOP_STBUX:
 149                         rs = get_rs(inst);
 150                         ra = get_ra(inst);
 151                         rb = get_rb(inst);
 152
 153                         ea = vcpu->arch.gpr[rb];
 154                         if (ra)
 155                                 ea += vcpu->arch.gpr[ra];
 156
 157                         emulated = kvmppc_handle_store(run, vcpu,
 158                                                        vcpu->arch.gpr[rs],
 159                                                        1, 1);
 160                         vcpu->arch.gpr[rs] = ea;
 161                         break;
 162
 163                 case OP_31_XOP_LHZX:
 164                         rt = get_rt(inst);
 165                         emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 166                         break;
 167
 168                 case OP_31_XOP_LHZUX:
 169                         rt = get_rt(inst);
 170                         ra = get_ra(inst);
 171                         rb = get_rb(inst);
 172
 173                         ea = vcpu->arch.gpr[rb];
 174                         if (ra)
 175                                 ea += vcpu->arch.gpr[ra];
 176
 177                         emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 178                         vcpu->arch.gpr[ra] = ea;
 179                         break;
 180
 181                 case OP_31_XOP_MFSPR:
 182                         sprn = get_sprn(inst);
 183                         rt = get_rt(inst);
 184
 185                         switch (sprn) {
 186                         case SPRN_SRR0:
 187                                 vcpu->arch.gpr[rt] = vcpu->arch.srr0; break;
 188                         case SPRN_SRR1:
 189                                 vcpu->arch.gpr[rt] = vcpu->arch.srr1; break;
 190                         case SPRN_PVR:
 191                                 vcpu->arch.gpr[rt] = mfspr(SPRN_PVR); break;
 192                         case SPRN_PIR:
 193                                 vcpu->arch.gpr[rt] = mfspr(SPRN_PIR); break;
 194
 195                         /* Note: mftb and TBRL/TBWL are user-accessible, so
 196                          * the guest can always access the real TB anyways.
 197                          * In fact, we probably will never see these traps. */
 198                         case SPRN_TBWL:
 199                                 vcpu->arch.gpr[rt] = mftbl(); break;
 200                         case SPRN_TBWU:
 201                                 vcpu->arch.gpr[rt] = mftbu(); break;
 202
 203                         case SPRN_SPRG0:
 204                                 vcpu->arch.gpr[rt] = vcpu->arch.sprg0; break;
 205                         case SPRN_SPRG1:
 206                                 vcpu->arch.gpr[rt] = vcpu->arch.sprg1; break;
 207                         case SPRN_SPRG2:
 208                                 vcpu->arch.gpr[rt] = vcpu->arch.sprg2; break;
 209                         case SPRN_SPRG3:
 210                                 vcpu->arch.gpr[rt] = vcpu->arch.sprg3; break;
 211                         /* Note: SPRG4-7 are user-readable, so we don't get
 212                          * a trap. */
 213
 214                         default:
 215                                 emulated = kvmppc_core_emulate_mfspr(vcpu, sprn, rt);
 216                                 if (emulated == EMULATE_FAIL) {
 217                                         printk("mfspr: unknown spr %x\n", sprn);
 218                                         vcpu->arch.gpr[rt] = 0;
 219                                 }
 220                                 break;
 221                         }
 222                         break;
 223
 224                 case OP_31_XOP_STHX:
 225                         rs = get_rs(inst);
 226                         ra = get_ra(inst);
 227                         rb = get_rb(inst);
 228
 229                         emulated = kvmppc_handle_store(run, vcpu,
 230                                                        vcpu->arch.gpr[rs],
 231                                                        2, 1);
 232                         break;
 233
 234                 case OP_31_XOP_STHUX:
 235                         rs = get_rs(inst);
 236                         ra = get_ra(inst);
 237                         rb = get_rb(inst);
 238
 239                         ea = vcpu->arch.gpr[rb];
 240                         if (ra)
 241                                 ea += vcpu->arch.gpr[ra];
 242
 243                         emulated = kvmppc_handle_store(run, vcpu,
 244                                                        vcpu->arch.gpr[rs],
 245                                                        2, 1);
 246                         vcpu->arch.gpr[ra] = ea;
 247                         break;
 248
 249                 case OP_31_XOP_MTSPR:
 250                         sprn = get_sprn(inst);
 251                         rs = get_rs(inst);
 252                         switch (sprn) {
 253                         case SPRN_SRR0:
 254                                 vcpu->arch.srr0 = vcpu->arch.gpr[rs]; break;
 255                         case SPRN_SRR1:
 256                                 vcpu->arch.srr1 = vcpu->arch.gpr[rs]; break;
 257
 258                         /* XXX We need to context-switch the timebase for
 259                          * watchdog and FIT. */
 260                         case SPRN_TBWL: break;
 261                         case SPRN_TBWU: break;
 262
 263                         case SPRN_DEC:
 264                                 vcpu->arch.dec = vcpu->arch.gpr[rs];
 265                                 kvmppc_emulate_dec(vcpu);
 266                                 break;
 267
 268                         case SPRN_SPRG0:
 269                                 vcpu->arch.sprg0 = vcpu->arch.gpr[rs]; break;
 270                         case SPRN_SPRG1:
 271                                 vcpu->arch.sprg1 = vcpu->arch.gpr[rs]; break;
 272                         case SPRN_SPRG2:
 273                                 vcpu->arch.sprg2 = vcpu->arch.gpr[rs]; break;
 274                         case SPRN_SPRG3:
 275                                 vcpu->arch.sprg3 = vcpu->arch.gpr[rs]; break;
 276
 277                         default:
 278                                 emulated = kvmppc_core_emulate_mtspr(vcpu, sprn, rs);
 279                                 if (emulated == EMULATE_FAIL)
 280                                         printk("mtspr: unknown spr %x\n", sprn);
 281                                 break;
 282                         }
 283                         break;
 284
 285                 case OP_31_XOP_DCBI:
 286                         /* Do nothing. The guest is performing dcbi because
 287                          * hardware DMA is not snooped by the dcache, but
 288                          * emulated DMA either goes through the dcache as
 289                          * normal writes, or the host kernel has handled dcache
 290                          * coherence. */
 291                         break;
 292
 293                 case OP_31_XOP_LWBRX:
 294                         rt = get_rt(inst);
 295                         emulated = kvmppc_handle_load(run, vcpu, rt, 4, 0);
 296                         break;
 297
 298                 case OP_31_XOP_TLBSYNC:
 299                         break;
 300
 301                 case OP_31_XOP_STWBRX:
 302                         rs = get_rs(inst);
 303                         ra = get_ra(inst);
 304                         rb = get_rb(inst);
 305
 306                         emulated = kvmppc_handle_store(run, vcpu,
 307                                                        vcpu->arch.gpr[rs],
 308                                                        4, 0);
 309                         break;
 310
 311                 case OP_31_XOP_LHBRX:
 312                         rt = get_rt(inst);
 313                         emulated = kvmppc_handle_load(run, vcpu, rt, 2, 0);
 314                         break;
 315
 316                 case OP_31_XOP_STHBRX:
 317                         rs = get_rs(inst);
 318                         ra = get_ra(inst);
 319                         rb = get_rb(inst);
 320
 321                         emulated = kvmppc_handle_store(run, vcpu,
 322                                                        vcpu->arch.gpr[rs],
 323                                                        2, 0);
 324                         break;
 325
 326                 default:
 327                         /* Attempt core-specific emulation below. */
 328                         emulated = EMULATE_FAIL;
 329                 }
 330                 break;
 331
 332         case OP_LWZ:
 333                 rt = get_rt(inst);
 334                 emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
 335                 break;
 336
 337         case OP_LWZU:
 338                 ra = get_ra(inst);
 339                 rt = get_rt(inst);
 340                 emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
 341                 vcpu->arch.gpr[ra] = vcpu->arch.paddr_accessed;
 342                 break;
 343
 344         case OP_LBZ:
 345                 rt = get_rt(inst);
 346                 emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
 347                 break;
 348
 349         case OP_LBZU:
 350                 ra = get_ra(inst);
 351                 rt = get_rt(inst);
 352                 emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
 353                 vcpu->arch.gpr[ra] = vcpu->arch.paddr_accessed;
 354                 break;
 355
 356         case OP_STW:
 357                 rs = get_rs(inst);
 358                 emulated = kvmppc_handle_store(run, vcpu, vcpu->arch.gpr[rs],
 359                                                4, 1);
 360                 break;
 361
 362         case OP_STWU:
 363                 ra = get_ra(inst);
 364                 rs = get_rs(inst);
 365                 emulated = kvmppc_handle_store(run, vcpu, vcpu->arch.gpr[rs],
 366                                                4, 1);
 367                 vcpu->arch.gpr[ra] = vcpu->arch.paddr_accessed;
 368                 break;
 369
 370         case OP_STB:
 371                 rs = get_rs(inst);
 372                 emulated = kvmppc_handle_store(run, vcpu, vcpu->arch.gpr[rs],
 373                                                1, 1);
 374                 break;
 375
 376         case OP_STBU:
 377                 ra = get_ra(inst);
 378                 rs = get_rs(inst);
 379                 emulated = kvmppc_handle_store(run, vcpu, vcpu->arch.gpr[rs],
 380                                                1, 1);
 381                 vcpu->arch.gpr[ra] = vcpu->arch.paddr_accessed;
 382                 break;
 383
 384         case OP_LHZ:
 385                 rt = get_rt(inst);
 386                 emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 387                 break;
 388
 389         case OP_LHZU:
 390                 ra = get_ra(inst);
 391                 rt = get_rt(inst);
 392                 emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 393                 vcpu->arch.gpr[ra] = vcpu->arch.paddr_accessed;
 394                 break;
 395
 396         case OP_STH:
 397                 rs = get_rs(inst);
 398                 emulated = kvmppc_handle_store(run, vcpu, vcpu->arch.gpr[rs],
 399                                                2, 1);
 400                 break;
 401
 402         case OP_STHU:
 403                 ra = get_ra(inst);
 404                 rs = get_rs(inst);
 405                 emulated = kvmppc_handle_store(run, vcpu, vcpu->arch.gpr[rs],
 406                                                2, 1);
 407                 vcpu->arch.gpr[ra] = vcpu->arch.paddr_accessed;
 408                 break;
 409
 410         default:
 411                 emulated = EMULATE_FAIL;
 412         }
 413
 414         if (emulated == EMULATE_FAIL) {
 415                 emulated = kvmppc_core_emulate_op(run, vcpu, inst, &advance);
 416                 if (emulated == EMULATE_FAIL) {
 417                         advance = 0;
 418                         printk(KERN_ERR "Couldn't emulate instruction 0x%08x "
 419                                "(op %d xop %d)\n", inst, get_op(inst), get_xop(inst));
 420                 }
 421         }
 422
 423         trace_kvm_ppc_instr(inst, vcpu->arch.pc, emulated);
 424
 425         if (advance)
 426                 vcpu->arch.pc += 4; /* Advance past emulated instruction. */
 427
 428         return emulated;
 429 }