arch/s390/kvm/intercept.c

   1 /*
   2  * in-kernel handling for sie intercepts
   3  *
   4  * Copyright IBM Corp. 2008, 2014
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License (version 2 only)
   8  * as published by the Free Software Foundation.
   9  *
  10  *    Author(s): Carsten Otte <cotte@de.ibm.com>
  11  *               Christian Borntraeger <borntraeger@de.ibm.com>
  12  */
  13
  14 #include <linux/kvm_host.h>
  15 #include <linux/errno.h>
  16 #include <linux/pagemap.h>
  17
  18 #include <asm/kvm_host.h>
  19 #include <asm/asm-offsets.h>
  20 #include <asm/irq.h>
  21 #include <asm/sysinfo.h>
  22
  23 #include "kvm-s390.h"
  24 #include "gaccess.h"
  25 #include "trace.h"
  26 #include "trace-s390.h"
  27
  28
  29 static const intercept_handler_t instruction_handlers[256] = {
  30         [0x01] = kvm_s390_handle_01,
  31         [0x82] = kvm_s390_handle_lpsw,
  32         [0x83] = kvm_s390_handle_diag,
  33         [0xaa] = kvm_s390_handle_aa,
  34         [0xae] = kvm_s390_handle_sigp,
  35         [0xb2] = kvm_s390_handle_b2,
  36         [0xb6] = kvm_s390_handle_stctl,
  37         [0xb7] = kvm_s390_handle_lctl,
  38         [0xb9] = kvm_s390_handle_b9,
  39         [0xe3] = kvm_s390_handle_e3,
  40         [0xe5] = kvm_s390_handle_e5,
  41         [0xeb] = kvm_s390_handle_eb,
  42 };
  43
  44 u8 kvm_s390_get_ilen(struct kvm_vcpu *vcpu)
  45 {
  46         struct kvm_s390_sie_block *sie_block = vcpu->arch.sie_block;
  47         u8 ilen = 0;
  48
  49         switch (vcpu->arch.sie_block->icptcode) {
  50         case ICPT_INST:
  51         case ICPT_INSTPROGI:
  52         case ICPT_OPEREXC:
  53         case ICPT_PARTEXEC:
  54         case ICPT_IOINST:
  55                 /* instruction only stored for these icptcodes */
  56                 ilen = insn_length(vcpu->arch.sie_block->ipa >> 8);
  57                 /* Use the length of the EXECUTE instruction if necessary */
  58                 if (sie_block->icptstatus & 1) {
  59                         ilen = (sie_block->icptstatus >> 4) & 0x6;
  60                         if (!ilen)
  61                                 ilen = 4;
  62                 }
  63                 break;
  64         case ICPT_PROGI:
  65                 /* bit 1+2 of pgmilc are the ilc, so we directly get ilen */
  66                 ilen = vcpu->arch.sie_block->pgmilc & 0x6;
  67                 break;
  68         }
  69         return ilen;
  70 }
  71
  72 static int handle_noop(struct kvm_vcpu *vcpu)
  73 {
  74         switch (vcpu->arch.sie_block->icptcode) {
  75         case 0x10:
  76                 vcpu->stat.exit_external_request++;
  77                 break;
  78         default:
  79                 break; /* nothing */
  80         }
  81         return 0;
  82 }
  83
  84 static int handle_stop(struct kvm_vcpu *vcpu)
  85 {
  86         struct kvm_s390_local_interrupt *li = &vcpu->arch.local_int;
  87         int rc = 0;
  88         uint8_t flags, stop_pending;
  89
  90         vcpu->stat.exit_stop_request++;
  91
  92         /* delay the stop if any non-stop irq is pending */
  93         if (kvm_s390_vcpu_has_irq(vcpu, 1))
  94                 return 0;
  95
  96         /* avoid races with the injection/SIGP STOP code */
  97         spin_lock(&li->lock);
  98         flags = li->irq.stop.flags;
  99         stop_pending = kvm_s390_is_stop_irq_pending(vcpu);
 100         spin_unlock(&li->lock);
 101
 102         trace_kvm_s390_stop_request(stop_pending, flags);
 103         if (!stop_pending)
 104                 return 0;
 105
 106         if (flags & KVM_S390_STOP_FLAG_STORE_STATUS) {
 107                 rc = kvm_s390_vcpu_store_status(vcpu,
 108                                                 KVM_S390_STORE_STATUS_NOADDR);
 109                 if (rc)
 110                         return rc;
 111         }
 112
 113         if (!kvm_s390_user_cpu_state_ctrl(vcpu->kvm))
 114                 kvm_s390_vcpu_stop(vcpu);
 115         return -EOPNOTSUPP;
 116 }
 117
 118 static int handle_validity(struct kvm_vcpu *vcpu)
 119 {
 120         int viwhy = vcpu->arch.sie_block->ipb >> 16;
 121
 122         vcpu->stat.exit_validity++;
 123         trace_kvm_s390_intercept_validity(vcpu, viwhy);
 124         KVM_EVENT(3, "validity intercept 0x%x for pid %u (kvm 0x%pK)", viwhy,
 125                   current->pid, vcpu->kvm);
 126
 127         /* do not warn on invalid runtime instrumentation mode */
 128         WARN_ONCE(viwhy != 0x44, "kvm: unhandled validity intercept 0x%x\n",
 129                   viwhy);
 130         return -EINVAL;
 131 }
 132
 133 static int handle_instruction(struct kvm_vcpu *vcpu)
 134 {
 135         intercept_handler_t handler;
 136
 137         vcpu->stat.exit_instruction++;
 138         trace_kvm_s390_intercept_instruction(vcpu,
 139                                              vcpu->arch.sie_block->ipa,
 140                                              vcpu->arch.sie_block->ipb);
 141         handler = instruction_handlers[vcpu->arch.sie_block->ipa >> 8];
 142         if (handler)
 143                 return handler(vcpu);
 144         return -EOPNOTSUPP;
 145 }
 146
 147 static int inject_prog_on_prog_intercept(struct kvm_vcpu *vcpu)
 148 {
 149         struct kvm_s390_pgm_info pgm_info = {
 150                 .code = vcpu->arch.sie_block->iprcc,
 151                 /* the PSW has already been rewound */
 152                 .flags = KVM_S390_PGM_FLAGS_NO_REWIND,
 153         };
 154
 155         switch (vcpu->arch.sie_block->iprcc & ~PGM_PER) {
 156         case PGM_AFX_TRANSLATION:
 157         case PGM_ASX_TRANSLATION:
 158         case PGM_EX_TRANSLATION:
 159         case PGM_LFX_TRANSLATION:
 160         case PGM_LSTE_SEQUENCE:
 161         case PGM_LSX_TRANSLATION:
 162         case PGM_LX_TRANSLATION:
 163         case PGM_PRIMARY_AUTHORITY:
 164         case PGM_SECONDARY_AUTHORITY:
 165         case PGM_SPACE_SWITCH:
 166                 pgm_info.trans_exc_code = vcpu->arch.sie_block->tecmc;
 167                 break;
 168         case PGM_ALEN_TRANSLATION:
 169         case PGM_ALE_SEQUENCE:
 170         case PGM_ASTE_INSTANCE:
 171         case PGM_ASTE_SEQUENCE:
 172         case PGM_ASTE_VALIDITY:
 173         case PGM_EXTENDED_AUTHORITY:
 174                 pgm_info.exc_access_id = vcpu->arch.sie_block->eai;
 175                 break;
 176         case PGM_ASCE_TYPE:
 177         case PGM_PAGE_TRANSLATION:
 178         case PGM_REGION_FIRST_TRANS:
 179         case PGM_REGION_SECOND_TRANS:
 180         case PGM_REGION_THIRD_TRANS:
 181         case PGM_SEGMENT_TRANSLATION:
 182                 pgm_info.trans_exc_code = vcpu->arch.sie_block->tecmc;
 183                 pgm_info.exc_access_id  = vcpu->arch.sie_block->eai;
 184                 pgm_info.op_access_id  = vcpu->arch.sie_block->oai;
 185                 break;
 186         case PGM_MONITOR:
 187                 pgm_info.mon_class_nr = vcpu->arch.sie_block->mcn;
 188                 pgm_info.mon_code = vcpu->arch.sie_block->tecmc;
 189                 break;
 190         case PGM_VECTOR_PROCESSING:
 191         case PGM_DATA:
 192                 pgm_info.data_exc_code = vcpu->arch.sie_block->dxc;
 193                 break;
 194         case PGM_PROTECTION:
 195                 pgm_info.trans_exc_code = vcpu->arch.sie_block->tecmc;
 196                 pgm_info.exc_access_id  = vcpu->arch.sie_block->eai;
 197                 break;
 198         default:
 199                 break;
 200         }
 201
 202         if (vcpu->arch.sie_block->iprcc & PGM_PER) {
 203                 pgm_info.per_code = vcpu->arch.sie_block->perc;
 204                 pgm_info.per_atmid = vcpu->arch.sie_block->peratmid;
 205                 pgm_info.per_address = vcpu->arch.sie_block->peraddr;
 206                 pgm_info.per_access_id = vcpu->arch.sie_block->peraid;
 207         }
 208         return kvm_s390_inject_prog_irq(vcpu, &pgm_info);
 209 }
 210
 211 /*
 212  * restore ITDB to program-interruption TDB in guest lowcore
 213  * and set TX abort indication if required
 214 */
 215 static int handle_itdb(struct kvm_vcpu *vcpu)
 216 {
 217         struct kvm_s390_itdb *itdb;
 218         int rc;
 219
 220         if (!IS_TE_ENABLED(vcpu) || !IS_ITDB_VALID(vcpu))
 221                 return 0;
 222         if (current->thread.per_flags & PER_FLAG_NO_TE)
 223                 return 0;
 224         itdb = (struct kvm_s390_itdb *)vcpu->arch.sie_block->itdba;
 225         rc = write_guest_lc(vcpu, __LC_PGM_TDB, itdb, sizeof(*itdb));
 226         if (rc)
 227                 return rc;
 228         memset(itdb, 0, sizeof(*itdb));
 229
 230         return 0;
 231 }
 232
 233 #define per_event(vcpu) (vcpu->arch.sie_block->iprcc & PGM_PER)
 234
 235 static int handle_prog(struct kvm_vcpu *vcpu)
 236 {
 237         psw_t psw;
 238         int rc;
 239
 240         vcpu->stat.exit_program_interruption++;
 241
 242         if (guestdbg_enabled(vcpu) && per_event(vcpu)) {
 243                 rc = kvm_s390_handle_per_event(vcpu);
 244                 if (rc)
 245                         return rc;
 246                 /* the interrupt might have been filtered out completely */
 247                 if (vcpu->arch.sie_block->iprcc == 0)
 248                         return 0;
 249         }
 250
 251         trace_kvm_s390_intercept_prog(vcpu, vcpu->arch.sie_block->iprcc);
 252         if (vcpu->arch.sie_block->iprcc == PGM_SPECIFICATION) {
 253                 rc = read_guest_lc(vcpu, __LC_PGM_NEW_PSW, &psw, sizeof(psw_t));
 254                 if (rc)
 255                         return rc;
 256                 /* Avoid endless loops of specification exceptions */
 257                 if (!is_valid_psw(&psw))
 258                         return -EOPNOTSUPP;
 259         }
 260         rc = handle_itdb(vcpu);
 261         if (rc)
 262                 return rc;
 263
 264         return inject_prog_on_prog_intercept(vcpu);
 265 }
 266
 267 /**
 268  * handle_external_interrupt - used for external interruption interceptions
 269  *
 270  * This interception only occurs if the CPUSTAT_EXT_INT bit was set, or if
 271  * the new PSW does not have external interrupts disabled. In the first case,
 272  * we've got to deliver the interrupt manually, and in the second case, we
 273  * drop to userspace to handle the situation there.
 274  */
 275 static int handle_external_interrupt(struct kvm_vcpu *vcpu)
 276 {
 277         u16 eic = vcpu->arch.sie_block->eic;
 278         struct kvm_s390_irq irq;
 279         psw_t newpsw;
 280         int rc;
 281
 282         vcpu->stat.exit_external_interrupt++;
 283
 284         rc = read_guest_lc(vcpu, __LC_EXT_NEW_PSW, &newpsw, sizeof(psw_t));
 285         if (rc)
 286                 return rc;
 287         /* We can not handle clock comparator or timer interrupt with bad PSW */
 288         if ((eic == EXT_IRQ_CLK_COMP || eic == EXT_IRQ_CPU_TIMER) &&
 289             (newpsw.mask & PSW_MASK_EXT))
 290                 return -EOPNOTSUPP;
 291
 292         switch (eic) {
 293         case EXT_IRQ_CLK_COMP:
 294                 irq.type = KVM_S390_INT_CLOCK_COMP;
 295                 break;
 296         case EXT_IRQ_CPU_TIMER:
 297                 irq.type = KVM_S390_INT_CPU_TIMER;
 298                 break;
 299         case EXT_IRQ_EXTERNAL_CALL:
 300                 irq.type = KVM_S390_INT_EXTERNAL_CALL;
 301                 irq.u.extcall.code = vcpu->arch.sie_block->extcpuaddr;
 302                 rc = kvm_s390_inject_vcpu(vcpu, &irq);
 303                 /* ignore if another external call is already pending */
 304                 if (rc == -EBUSY)
 305                         return 0;
 306                 return rc;
 307         default:
 308                 return -EOPNOTSUPP;
 309         }
 310
 311         return kvm_s390_inject_vcpu(vcpu, &irq);
 312 }
 313
 314 /**
 315  * Handle MOVE PAGE partial execution interception.
 316  *
 317  * This interception can only happen for guests with DAT disabled and
 318  * addresses that are currently not mapped in the host. Thus we try to
 319  * set up the mappings for the corresponding user pages here (or throw
 320  * addressing exceptions in case of illegal guest addresses).
 321  */
 322 static int handle_mvpg_pei(struct kvm_vcpu *vcpu)
 323 {
 324         unsigned long srcaddr, dstaddr;
 325         int reg1, reg2, rc;
 326
 327         kvm_s390_get_regs_rre(vcpu, &reg1, &reg2);
 328
 329         /* Make sure that the source is paged-in */
 330         rc = guest_translate_address(vcpu, vcpu->run->s.regs.gprs[reg2],
 331                                      reg2, &srcaddr, GACC_FETCH);
 332         if (rc)
 333                 return kvm_s390_inject_prog_cond(vcpu, rc);
 334         rc = kvm_arch_fault_in_page(vcpu, srcaddr, 0);
 335         if (rc != 0)
 336                 return rc;
 337
 338         /* Make sure that the destination is paged-in */
 339         rc = guest_translate_address(vcpu, vcpu->run->s.regs.gprs[reg1],
 340                                      reg1, &dstaddr, GACC_STORE);
 341         if (rc)
 342                 return kvm_s390_inject_prog_cond(vcpu, rc);
 343         rc = kvm_arch_fault_in_page(vcpu, dstaddr, 1);
 344         if (rc != 0)
 345                 return rc;
 346
 347         kvm_s390_retry_instr(vcpu);
 348
 349         return 0;
 350 }
 351
 352 static int handle_partial_execution(struct kvm_vcpu *vcpu)
 353 {
 354         vcpu->stat.exit_pei++;
 355
 356         if (vcpu->arch.sie_block->ipa == 0xb254)        /* MVPG */
 357                 return handle_mvpg_pei(vcpu);
 358         if (vcpu->arch.sie_block->ipa >> 8 == 0xae)     /* SIGP */
 359                 return kvm_s390_handle_sigp_pei(vcpu);
 360
 361         return -EOPNOTSUPP;
 362 }
 363
 364 /*
 365  * Handle the sthyi instruction that provides the guest with system
 366  * information, like current CPU resources available at each level of
 367  * the machine.
 368  */
 369 int handle_sthyi(struct kvm_vcpu *vcpu)
 370 {
 371         int reg1, reg2, r = 0;
 372         u64 code, addr, cc = 0, rc = 0;
 373         struct sthyi_sctns *sctns = NULL;
 374
 375         if (!test_kvm_facility(vcpu->kvm, 74))
 376                 return kvm_s390_inject_program_int(vcpu, PGM_OPERATION);
 377
 378         kvm_s390_get_regs_rre(vcpu, &reg1, &reg2);
 379         code = vcpu->run->s.regs.gprs[reg1];
 380         addr = vcpu->run->s.regs.gprs[reg2];
 381
 382         vcpu->stat.instruction_sthyi++;
 383         VCPU_EVENT(vcpu, 3, "STHYI: fc: %llu addr: 0x%016llx", code, addr);
 384         trace_kvm_s390_handle_sthyi(vcpu, code, addr);
 385
 386         if (reg1 == reg2 || reg1 & 1 || reg2 & 1)
 387                 return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
 388
 389         if (code & 0xffff) {
 390                 cc = 3;
 391                 rc = 4;
 392                 goto out;
 393         }
 394
 395         if (addr & ~PAGE_MASK)
 396                 return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
 397
 398         sctns = (void *)get_zeroed_page(GFP_KERNEL);
 399         if (!sctns)
 400                 return -ENOMEM;
 401
 402         cc = sthyi_fill(sctns, &rc);
 403
 404 out:
 405         if (!cc) {
 406                 r = write_guest(vcpu, addr, reg2, sctns, PAGE_SIZE);
 407                 if (r) {
 408                         free_page((unsigned long)sctns);
 409                         return kvm_s390_inject_prog_cond(vcpu, r);
 410                 }
 411         }
 412
 413         free_page((unsigned long)sctns);
 414         vcpu->run->s.regs.gprs[reg2 + 1] = rc;
 415         kvm_s390_set_psw_cc(vcpu, cc);
 416         return r;
 417 }
 418
 419 static int handle_operexc(struct kvm_vcpu *vcpu)
 420 {
 421         psw_t oldpsw, newpsw;
 422         int rc;
 423
 424         vcpu->stat.exit_operation_exception++;
 425         trace_kvm_s390_handle_operexc(vcpu, vcpu->arch.sie_block->ipa,
 426                                       vcpu->arch.sie_block->ipb);
 427
 428         if (vcpu->arch.sie_block->ipa == 0xb256)
 429                 return handle_sthyi(vcpu);
 430
 431         if (vcpu->arch.sie_block->ipa == 0 && vcpu->kvm->arch.user_instr0)
 432                 return -EOPNOTSUPP;
 433         rc = read_guest_lc(vcpu, __LC_PGM_NEW_PSW, &newpsw, sizeof(psw_t));
 434         if (rc)
 435                 return rc;
 436         /*
 437          * Avoid endless loops of operation exceptions, if the pgm new
 438          * PSW will cause a new operation exception.
 439          * The heuristic checks if the pgm new psw is within 6 bytes before
 440          * the faulting psw address (with same DAT, AS settings) and the
 441          * new psw is not a wait psw and the fault was not triggered by
 442          * problem state.
 443          */
 444         oldpsw = vcpu->arch.sie_block->gpsw;
 445         if (oldpsw.addr - newpsw.addr <= 6 &&
 446             !(newpsw.mask & PSW_MASK_WAIT) &&
 447             !(oldpsw.mask & PSW_MASK_PSTATE) &&
 448             (newpsw.mask & PSW_MASK_ASC) == (oldpsw.mask & PSW_MASK_ASC) &&
 449             (newpsw.mask & PSW_MASK_DAT) == (oldpsw.mask & PSW_MASK_DAT))
 450                 return -EOPNOTSUPP;
 451
 452         return kvm_s390_inject_program_int(vcpu, PGM_OPERATION);
 453 }
 454
 455 int kvm_handle_sie_intercept(struct kvm_vcpu *vcpu)
 456 {
 457         int rc, per_rc = 0;
 458
 459         if (kvm_is_ucontrol(vcpu->kvm))
 460                 return -EOPNOTSUPP;
 461
 462         switch (vcpu->arch.sie_block->icptcode) {
 463         case ICPT_EXTREQ:
 464         case ICPT_IOREQ:
 465                 return handle_noop(vcpu);
 466         case ICPT_INST:
 467                 rc = handle_instruction(vcpu);
 468                 break;
 469         case ICPT_PROGI:
 470                 return handle_prog(vcpu);
 471         case ICPT_EXTINT:
 472                 return handle_external_interrupt(vcpu);
 473         case ICPT_WAIT:
 474                 return kvm_s390_handle_wait(vcpu);
 475         case ICPT_VALIDITY:
 476                 return handle_validity(vcpu);
 477         case ICPT_STOP:
 478                 return handle_stop(vcpu);
 479         case ICPT_OPEREXC:
 480                 rc = handle_operexc(vcpu);
 481                 break;
 482         case ICPT_PARTEXEC:
 483                 rc = handle_partial_execution(vcpu);
 484                 break;
 485         case ICPT_KSS:
 486                 rc = kvm_s390_skey_check_enable(vcpu);
 487                 break;
 488         default:
 489                 return -EOPNOTSUPP;
 490         }
 491
 492         /* process PER, also if the instrution is processed in user space */
 493         if (vcpu->arch.sie_block->icptstatus & 0x02 &&
 494             (!rc || rc == -EOPNOTSUPP))
 495                 per_rc = kvm_s390_handle_per_ifetch_icpt(vcpu);
 496         return per_rc ? per_rc : rc;
 497 }