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