arch/s390/kvm/intercept.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * in-kernel handling for sie intercepts
   4  *
   5  * Copyright IBM Corp. 2008, 2014
   6  *
   7  *    Author(s): Carsten Otte <cotte@de.ibm.com>
   8  *               Christian Borntraeger <borntraeger@de.ibm.com>
   9  */
  10
  11 #include <linux/kvm_host.h>
  12 #include <linux/errno.h>
  13 #include <linux/pagemap.h>
  14
  15 #include <asm/kvm_host.h>
  16 #include <asm/asm-offsets.h>
  17 #include <asm/irq.h>
  18 #include <asm/sysinfo.h>
  19
  20 #include "kvm-s390.h"
  21 #include "gaccess.h"
  22 #include "trace.h"
  23 #include "trace-s390.h"
  24
  25
  26 static const intercept_handler_t instruction_handlers[256] = {
  27         [0x01] = kvm_s390_handle_01,
  28         [0x82] = kvm_s390_handle_lpsw,
  29         [0x83] = kvm_s390_handle_diag,
  30         [0xaa] = kvm_s390_handle_aa,
  31         [0xae] = kvm_s390_handle_sigp,
  32         [0xb2] = kvm_s390_handle_b2,
  33         [0xb6] = kvm_s390_handle_stctl,
  34         [0xb7] = kvm_s390_handle_lctl,
  35         [0xb9] = kvm_s390_handle_b9,
  36         [0xe3] = kvm_s390_handle_e3,
  37         [0xe5] = kvm_s390_handle_e5,
  38         [0xeb] = kvm_s390_handle_eb,
  39 };
  40
  41 u8 kvm_s390_get_ilen(struct kvm_vcpu *vcpu)
  42 {
  43         struct kvm_s390_sie_block *sie_block = vcpu->arch.sie_block;
  44         u8 ilen = 0;
  45
  46         switch (vcpu->arch.sie_block->icptcode) {
  47         case ICPT_INST:
  48         case ICPT_INSTPROGI:
  49         case ICPT_OPEREXC:
  50         case ICPT_PARTEXEC:
  51         case ICPT_IOINST:
  52                 /* instruction only stored for these icptcodes */
  53                 ilen = insn_length(vcpu->arch.sie_block->ipa >> 8);
  54                 /* Use the length of the EXECUTE instruction if necessary */
  55                 if (sie_block->icptstatus & 1) {
  56                         ilen = (sie_block->icptstatus >> 4) & 0x6;
  57                         if (!ilen)
  58                                 ilen = 4;
  59                 }
  60                 break;
  61         case ICPT_PROGI:
  62                 /* bit 1+2 of pgmilc are the ilc, so we directly get ilen */
  63                 ilen = vcpu->arch.sie_block->pgmilc & 0x6;
  64                 break;
  65         }
  66         return ilen;
  67 }
  68
  69 static int handle_noop(struct kvm_vcpu *vcpu)
  70 {
  71         switch (vcpu->arch.sie_block->icptcode) {
  72         case 0x10:
  73                 vcpu->stat.exit_external_request++;
  74                 break;
  75         default:
  76                 break; /* nothing */
  77         }
  78         return 0;
  79 }
  80
  81 static int handle_stop(struct kvm_vcpu *vcpu)
  82 {
  83         struct kvm_s390_local_interrupt *li = &vcpu->arch.local_int;
  84         int rc = 0;
  85         uint8_t flags, stop_pending;
  86
  87         vcpu->stat.exit_stop_request++;
  88
  89         /* delay the stop if any non-stop irq is pending */
  90         if (kvm_s390_vcpu_has_irq(vcpu, 1))
  91                 return 0;
  92
  93         /* avoid races with the injection/SIGP STOP code */
  94         spin_lock(&li->lock);
  95         flags = li->irq.stop.flags;
  96         stop_pending = kvm_s390_is_stop_irq_pending(vcpu);
  97         spin_unlock(&li->lock);
  98
  99         trace_kvm_s390_stop_request(stop_pending, flags);
 100         if (!stop_pending)
 101                 return 0;
 102
 103         if (flags & KVM_S390_STOP_FLAG_STORE_STATUS) {
 104                 rc = kvm_s390_vcpu_store_status(vcpu,
 105                                                 KVM_S390_STORE_STATUS_NOADDR);
 106                 if (rc)
 107                         return rc;
 108         }
 109
 110         if (!kvm_s390_user_cpu_state_ctrl(vcpu->kvm))
 111                 kvm_s390_vcpu_stop(vcpu);
 112         return -EOPNOTSUPP;
 113 }
 114
 115 static int handle_validity(struct kvm_vcpu *vcpu)
 116 {
 117         int viwhy = vcpu->arch.sie_block->ipb >> 16;
 118
 119         vcpu->stat.exit_validity++;
 120         trace_kvm_s390_intercept_validity(vcpu, viwhy);
 121         KVM_EVENT(3, "validity intercept 0x%x for pid %u (kvm 0x%pK)", viwhy,
 122                   current->pid, vcpu->kvm);
 123
 124         /* do not warn on invalid runtime instrumentation mode */
 125         WARN_ONCE(viwhy != 0x44, "kvm: unhandled validity intercept 0x%x\n",
 126                   viwhy);
 127         return -EINVAL;
 128 }
 129
 130 static int handle_instruction(struct kvm_vcpu *vcpu)
 131 {
 132         intercept_handler_t handler;
 133
 134         vcpu->stat.exit_instruction++;
 135         trace_kvm_s390_intercept_instruction(vcpu,
 136                                              vcpu->arch.sie_block->ipa,
 137                                              vcpu->arch.sie_block->ipb);
 138         handler = instruction_handlers[vcpu->arch.sie_block->ipa >> 8];
 139         if (handler)
 140                 return handler(vcpu);
 141         return -EOPNOTSUPP;
 142 }
 143
 144 static int inject_prog_on_prog_intercept(struct kvm_vcpu *vcpu)
 145 {
 146         struct kvm_s390_pgm_info pgm_info = {
 147                 .code = vcpu->arch.sie_block->iprcc,
 148                 /* the PSW has already been rewound */
 149                 .flags = KVM_S390_PGM_FLAGS_NO_REWIND,
 150         };
 151
 152         switch (vcpu->arch.sie_block->iprcc & ~PGM_PER) {
 153         case PGM_AFX_TRANSLATION:
 154         case PGM_ASX_TRANSLATION:
 155         case PGM_EX_TRANSLATION:
 156         case PGM_LFX_TRANSLATION:
 157         case PGM_LSTE_SEQUENCE:
 158         case PGM_LSX_TRANSLATION:
 159         case PGM_LX_TRANSLATION:
 160         case PGM_PRIMARY_AUTHORITY:
 161         case PGM_SECONDARY_AUTHORITY:
 162         case PGM_SPACE_SWITCH:
 163                 pgm_info.trans_exc_code = vcpu->arch.sie_block->tecmc;
 164                 break;
 165         case PGM_ALEN_TRANSLATION:
 166         case PGM_ALE_SEQUENCE:
 167         case PGM_ASTE_INSTANCE:
 168         case PGM_ASTE_SEQUENCE:
 169         case PGM_ASTE_VALIDITY:
 170         case PGM_EXTENDED_AUTHORITY:
 171                 pgm_info.exc_access_id = vcpu->arch.sie_block->eai;
 172                 break;
 173         case PGM_ASCE_TYPE:
 174         case PGM_PAGE_TRANSLATION:
 175         case PGM_REGION_FIRST_TRANS:
 176         case PGM_REGION_SECOND_TRANS:
 177         case PGM_REGION_THIRD_TRANS:
 178         case PGM_SEGMENT_TRANSLATION:
 179                 pgm_info.trans_exc_code = vcpu->arch.sie_block->tecmc;
 180                 pgm_info.exc_access_id  = vcpu->arch.sie_block->eai;
 181                 pgm_info.op_access_id  = vcpu->arch.sie_block->oai;
 182                 break;
 183         case PGM_MONITOR:
 184                 pgm_info.mon_class_nr = vcpu->arch.sie_block->mcn;
 185                 pgm_info.mon_code = vcpu->arch.sie_block->tecmc;
 186                 break;
 187         case PGM_VECTOR_PROCESSING:
 188         case PGM_DATA:
 189                 pgm_info.data_exc_code = vcpu->arch.sie_block->dxc;
 190                 break;
 191         case PGM_PROTECTION:
 192                 pgm_info.trans_exc_code = vcpu->arch.sie_block->tecmc;
 193                 pgm_info.exc_access_id  = vcpu->arch.sie_block->eai;
 194                 break;
 195         default:
 196                 break;
 197         }
 198
 199         if (vcpu->arch.sie_block->iprcc & PGM_PER) {
 200                 pgm_info.per_code = vcpu->arch.sie_block->perc;
 201                 pgm_info.per_atmid = vcpu->arch.sie_block->peratmid;
 202                 pgm_info.per_address = vcpu->arch.sie_block->peraddr;
 203                 pgm_info.per_access_id = vcpu->arch.sie_block->peraid;
 204         }
 205         return kvm_s390_inject_prog_irq(vcpu, &pgm_info);
 206 }
 207
 208 /*
 209  * restore ITDB to program-interruption TDB in guest lowcore
 210  * and set TX abort indication if required
 211 */
 212 static int handle_itdb(struct kvm_vcpu *vcpu)
 213 {
 214         struct kvm_s390_itdb *itdb;
 215         int rc;
 216
 217         if (!IS_TE_ENABLED(vcpu) || !IS_ITDB_VALID(vcpu))
 218                 return 0;
 219         if (current->thread.per_flags & PER_FLAG_NO_TE)
 220                 return 0;
 221         itdb = (struct kvm_s390_itdb *)vcpu->arch.sie_block->itdba;
 222         rc = write_guest_lc(vcpu, __LC_PGM_TDB, itdb, sizeof(*itdb));
 223         if (rc)
 224                 return rc;
 225         memset(itdb, 0, sizeof(*itdb));
 226
 227         return 0;
 228 }
 229
 230 #define per_event(vcpu) (vcpu->arch.sie_block->iprcc & PGM_PER)
 231
 232 static int handle_prog(struct kvm_vcpu *vcpu)
 233 {
 234         psw_t psw;
 235         int rc;
 236
 237         vcpu->stat.exit_program_interruption++;
 238
 239         if (guestdbg_enabled(vcpu) && per_event(vcpu)) {
 240                 rc = kvm_s390_handle_per_event(vcpu);
 241                 if (rc)
 242                         return rc;
 243                 /* the interrupt might have been filtered out completely */
 244                 if (vcpu->arch.sie_block->iprcc == 0)
 245                         return 0;
 246         }
 247
 248         trace_kvm_s390_intercept_prog(vcpu, vcpu->arch.sie_block->iprcc);
 249         if (vcpu->arch.sie_block->iprcc == PGM_SPECIFICATION) {
 250                 rc = read_guest_lc(vcpu, __LC_PGM_NEW_PSW, &psw, sizeof(psw_t));
 251                 if (rc)
 252                         return rc;
 253                 /* Avoid endless loops of specification exceptions */
 254                 if (!is_valid_psw(&psw))
 255                         return -EOPNOTSUPP;
 256         }
 257         rc = handle_itdb(vcpu);
 258         if (rc)
 259                 return rc;
 260
 261         return inject_prog_on_prog_intercept(vcpu);
 262 }
 263
 264 /**
 265  * handle_external_interrupt - used for external interruption interceptions
 266  *
 267  * This interception only occurs if the CPUSTAT_EXT_INT bit was set, or if
 268  * the new PSW does not have external interrupts disabled. In the first case,
 269  * we've got to deliver the interrupt manually, and in the second case, we
 270  * drop to userspace to handle the situation there.
 271  */
 272 static int handle_external_interrupt(struct kvm_vcpu *vcpu)
 273 {
 274         u16 eic = vcpu->arch.sie_block->eic;
 275         struct kvm_s390_irq irq;
 276         psw_t newpsw;
 277         int rc;
 278
 279         vcpu->stat.exit_external_interrupt++;
 280
 281         rc = read_guest_lc(vcpu, __LC_EXT_NEW_PSW, &newpsw, sizeof(psw_t));
 282         if (rc)
 283                 return rc;
 284         /* We can not handle clock comparator or timer interrupt with bad PSW */
 285         if ((eic == EXT_IRQ_CLK_COMP || eic == EXT_IRQ_CPU_TIMER) &&
 286             (newpsw.mask & PSW_MASK_EXT))
 287                 return -EOPNOTSUPP;
 288
 289         switch (eic) {
 290         case EXT_IRQ_CLK_COMP:
 291                 irq.type = KVM_S390_INT_CLOCK_COMP;
 292                 break;
 293         case EXT_IRQ_CPU_TIMER:
 294                 irq.type = KVM_S390_INT_CPU_TIMER;
 295                 break;
 296         case EXT_IRQ_EXTERNAL_CALL:
 297                 irq.type = KVM_S390_INT_EXTERNAL_CALL;
 298                 irq.u.extcall.code = vcpu->arch.sie_block->extcpuaddr;
 299                 rc = kvm_s390_inject_vcpu(vcpu, &irq);
 300                 /* ignore if another external call is already pending */
 301                 if (rc == -EBUSY)
 302                         return 0;
 303                 return rc;
 304         default:
 305                 return -EOPNOTSUPP;
 306         }
 307
 308         return kvm_s390_inject_vcpu(vcpu, &irq);
 309 }
 310
 311 /**
 312  * Handle MOVE PAGE partial execution interception.
 313  *
 314  * This interception can only happen for guests with DAT disabled and
 315  * addresses that are currently not mapped in the host. Thus we try to
 316  * set up the mappings for the corresponding user pages here (or throw
 317  * addressing exceptions in case of illegal guest addresses).
 318  */
 319 static int handle_mvpg_pei(struct kvm_vcpu *vcpu)
 320 {
 321         unsigned long srcaddr, dstaddr;
 322         int reg1, reg2, rc;
 323
 324         kvm_s390_get_regs_rre(vcpu, &reg1, &reg2);
 325
 326         /* Make sure that the source is paged-in */
 327         rc = guest_translate_address(vcpu, vcpu->run->s.regs.gprs[reg2],
 328                                      reg2, &srcaddr, GACC_FETCH);
 329         if (rc)
 330                 return kvm_s390_inject_prog_cond(vcpu, rc);
 331         rc = kvm_arch_fault_in_page(vcpu, srcaddr, 0);
 332         if (rc != 0)
 333                 return rc;
 334
 335         /* Make sure that the destination is paged-in */
 336         rc = guest_translate_address(vcpu, vcpu->run->s.regs.gprs[reg1],
 337                                      reg1, &dstaddr, GACC_STORE);
 338         if (rc)
 339                 return kvm_s390_inject_prog_cond(vcpu, rc);
 340         rc = kvm_arch_fault_in_page(vcpu, dstaddr, 1);
 341         if (rc != 0)
 342                 return rc;
 343
 344         kvm_s390_retry_instr(vcpu);
 345
 346         return 0;
 347 }
 348
 349 static int handle_partial_execution(struct kvm_vcpu *vcpu)
 350 {
 351         vcpu->stat.exit_pei++;
 352
 353         if (vcpu->arch.sie_block->ipa == 0xb254)        /* MVPG */
 354                 return handle_mvpg_pei(vcpu);
 355         if (vcpu->arch.sie_block->ipa >> 8 == 0xae)     /* SIGP */
 356                 return kvm_s390_handle_sigp_pei(vcpu);
 357
 358         return -EOPNOTSUPP;
 359 }
 360
 361 /*
 362  * Handle the sthyi instruction that provides the guest with system
 363  * information, like current CPU resources available at each level of
 364  * the machine.
 365  */
 366 int handle_sthyi(struct kvm_vcpu *vcpu)
 367 {
 368         int reg1, reg2, r = 0;
 369         u64 code, addr, cc = 0, rc = 0;
 370         struct sthyi_sctns *sctns = NULL;
 371
 372         if (!test_kvm_facility(vcpu->kvm, 74))
 373                 return kvm_s390_inject_program_int(vcpu, PGM_OPERATION);
 374
 375         kvm_s390_get_regs_rre(vcpu, &reg1, &reg2);
 376         code = vcpu->run->s.regs.gprs[reg1];
 377         addr = vcpu->run->s.regs.gprs[reg2];
 378
 379         vcpu->stat.instruction_sthyi++;
 380         VCPU_EVENT(vcpu, 3, "STHYI: fc: %llu addr: 0x%016llx", code, addr);
 381         trace_kvm_s390_handle_sthyi(vcpu, code, addr);
 382
 383         if (reg1 == reg2 || reg1 & 1 || reg2 & 1)
 384                 return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
 385
 386         if (code & 0xffff) {
 387                 cc = 3;
 388                 rc = 4;
 389                 goto out;
 390         }
 391
 392         if (addr & ~PAGE_MASK)
 393                 return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
 394
 395         sctns = (void *)get_zeroed_page(GFP_KERNEL);
 396         if (!sctns)
 397                 return -ENOMEM;
 398
 399         cc = sthyi_fill(sctns, &rc);
 400
 401 out:
 402         if (!cc) {
 403                 r = write_guest(vcpu, addr, reg2, sctns, PAGE_SIZE);
 404                 if (r) {
 405                         free_page((unsigned long)sctns);
 406                         return kvm_s390_inject_prog_cond(vcpu, r);
 407                 }
 408         }
 409
 410         free_page((unsigned long)sctns);
 411         vcpu->run->s.regs.gprs[reg2 + 1] = rc;
 412         kvm_s390_set_psw_cc(vcpu, cc);
 413         return r;
 414 }
 415
 416 static int handle_operexc(struct kvm_vcpu *vcpu)
 417 {
 418         psw_t oldpsw, newpsw;
 419         int rc;
 420
 421         vcpu->stat.exit_operation_exception++;
 422         trace_kvm_s390_handle_operexc(vcpu, vcpu->arch.sie_block->ipa,
 423                                       vcpu->arch.sie_block->ipb);
 424
 425         if (vcpu->arch.sie_block->ipa == 0xb256)
 426                 return handle_sthyi(vcpu);
 427
 428         if (vcpu->arch.sie_block->ipa == 0 && vcpu->kvm->arch.user_instr0)
 429                 return -EOPNOTSUPP;
 430         rc = read_guest_lc(vcpu, __LC_PGM_NEW_PSW, &newpsw, sizeof(psw_t));
 431         if (rc)
 432                 return rc;
 433         /*
 434          * Avoid endless loops of operation exceptions, if the pgm new
 435          * PSW will cause a new operation exception.
 436          * The heuristic checks if the pgm new psw is within 6 bytes before
 437          * the faulting psw address (with same DAT, AS settings) and the
 438          * new psw is not a wait psw and the fault was not triggered by
 439          * problem state.
 440          */
 441         oldpsw = vcpu->arch.sie_block->gpsw;
 442         if (oldpsw.addr - newpsw.addr <= 6 &&
 443             !(newpsw.mask & PSW_MASK_WAIT) &&
 444             !(oldpsw.mask & PSW_MASK_PSTATE) &&
 445             (newpsw.mask & PSW_MASK_ASC) == (oldpsw.mask & PSW_MASK_ASC) &&
 446             (newpsw.mask & PSW_MASK_DAT) == (oldpsw.mask & PSW_MASK_DAT))
 447                 return -EOPNOTSUPP;
 448
 449         return kvm_s390_inject_program_int(vcpu, PGM_OPERATION);
 450 }
 451
 452 int kvm_handle_sie_intercept(struct kvm_vcpu *vcpu)
 453 {
 454         int rc, per_rc = 0;
 455
 456         if (kvm_is_ucontrol(vcpu->kvm))
 457                 return -EOPNOTSUPP;
 458
 459         switch (vcpu->arch.sie_block->icptcode) {
 460         case ICPT_EXTREQ:
 461         case ICPT_IOREQ:
 462                 return handle_noop(vcpu);
 463         case ICPT_INST:
 464                 rc = handle_instruction(vcpu);
 465                 break;
 466         case ICPT_PROGI:
 467                 return handle_prog(vcpu);
 468         case ICPT_EXTINT:
 469                 return handle_external_interrupt(vcpu);
 470         case ICPT_WAIT:
 471                 return kvm_s390_handle_wait(vcpu);
 472         case ICPT_VALIDITY:
 473                 return handle_validity(vcpu);
 474         case ICPT_STOP:
 475                 return handle_stop(vcpu);
 476         case ICPT_OPEREXC:
 477                 rc = handle_operexc(vcpu);
 478                 break;
 479         case ICPT_PARTEXEC:
 480                 rc = handle_partial_execution(vcpu);
 481                 break;
 482         case ICPT_KSS:
 483                 rc = kvm_s390_skey_check_enable(vcpu);
 484                 break;
 485         default:
 486                 return -EOPNOTSUPP;
 487         }
 488
 489         /* process PER, also if the instrution is processed in user space */
 490         if (vcpu->arch.sie_block->icptstatus & 0x02 &&
 491             (!rc || rc == -EOPNOTSUPP))
 492                 per_rc = kvm_s390_handle_per_ifetch_icpt(vcpu);
 493         return per_rc ? per_rc : rc;
 494 }