LXR linux/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
  67void 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. */
  99int 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}
 430