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