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         [0xe5] = kvm_s390_handle_e5,
  39         [0xeb] = kvm_s390_handle_eb,
  40 };
  41
  42 u8 kvm_s390_get_ilen(struct kvm_vcpu *vcpu)
  43 {
  44         struct kvm_s390_sie_block *sie_block = vcpu->arch.sie_block;
  45         u8 ilen = 0;
  46
  47         switch (vcpu->arch.sie_block->icptcode) {
  48         case ICPT_INST:
  49         case ICPT_INSTPROGI:
  50         case ICPT_OPEREXC:
  51         case ICPT_PARTEXEC:
  52         case ICPT_IOINST:
  53                 /* instruction only stored for these icptcodes */
  54                 ilen = insn_length(vcpu->arch.sie_block->ipa >> 8);
  55                 /* Use the length of the EXECUTE instruction if necessary */
  56                 if (sie_block->icptstatus & 1) {
  57                         ilen = (sie_block->icptstatus >> 4) & 0x6;
  58                         if (!ilen)
  59                                 ilen = 4;
  60                 }
  61                 break;
  62         case ICPT_PROGI:
  63                 /* bit 1+2 of pgmilc are the ilc, so we directly get ilen */
  64                 ilen = vcpu->arch.sie_block->pgmilc & 0x6;
  65                 break;
  66         }
  67         return ilen;
  68 }
  69
  70 static int handle_noop(struct kvm_vcpu *vcpu)
  71 {
  72         switch (vcpu->arch.sie_block->icptcode) {
  73         case 0x10:
  74                 vcpu->stat.exit_external_request++;
  75                 break;
  76         default:
  77                 break; /* nothing */
  78         }
  79         return 0;
  80 }
  81
  82 static int handle_stop(struct kvm_vcpu *vcpu)
  83 {
  84         struct kvm_s390_local_interrupt *li = &vcpu->arch.local_int;
  85         int rc = 0;
  86         uint8_t flags, stop_pending;
  87
  88         vcpu->stat.exit_stop_request++;
  89
  90         /* delay the stop if any non-stop irq is pending */
  91         if (kvm_s390_vcpu_has_irq(vcpu, 1))
  92                 return 0;
  93
  94         /* avoid races with the injection/SIGP STOP code */
  95         spin_lock(&li->lock);
  96         flags = li->irq.stop.flags;
  97         stop_pending = kvm_s390_is_stop_irq_pending(vcpu);
  98         spin_unlock(&li->lock);
  99
 100         trace_kvm_s390_stop_request(stop_pending, flags);
 101         if (!stop_pending)
 102                 return 0;
 103
 104         if (flags & KVM_S390_STOP_FLAG_STORE_STATUS) {
 105                 rc = kvm_s390_vcpu_store_status(vcpu,
 106                                                 KVM_S390_STORE_STATUS_NOADDR);
 107                 if (rc)
 108                         return rc;
 109         }
 110
 111         if (!kvm_s390_user_cpu_state_ctrl(vcpu->kvm))
 112                 kvm_s390_vcpu_stop(vcpu);
 113         return -EOPNOTSUPP;
 114 }
 115
 116 static int handle_validity(struct kvm_vcpu *vcpu)
 117 {
 118         int viwhy = vcpu->arch.sie_block->ipb >> 16;
 119
 120         vcpu->stat.exit_validity++;
 121         trace_kvm_s390_intercept_validity(vcpu, viwhy);
 122         KVM_EVENT(3, "validity intercept 0x%x for pid %u (kvm 0x%pK)", viwhy,
 123                   current->pid, vcpu->kvm);
 124
 125         /* do not warn on invalid runtime instrumentation mode */
 126         WARN_ONCE(viwhy != 0x44, "kvm: unhandled validity intercept 0x%x\n",
 127                   viwhy);
 128         return -EINVAL;
 129 }
 130
 131 static int handle_instruction(struct kvm_vcpu *vcpu)
 132 {
 133         intercept_handler_t handler;
 134
 135         vcpu->stat.exit_instruction++;
 136         trace_kvm_s390_intercept_instruction(vcpu,
 137                                              vcpu->arch.sie_block->ipa,
 138                                              vcpu->arch.sie_block->ipb);
 139         handler = instruction_handlers[vcpu->arch.sie_block->ipa >> 8];
 140         if (handler)
 141                 return handler(vcpu);
 142         return -EOPNOTSUPP;
 143 }
 144
 145 static int inject_prog_on_prog_intercept(struct kvm_vcpu *vcpu)
 146 {
 147         struct kvm_s390_pgm_info pgm_info = {
 148                 .code = vcpu->arch.sie_block->iprcc,
 149                 /* the PSW has already been rewound */
 150                 .flags = KVM_S390_PGM_FLAGS_NO_REWIND,
 151         };
 152
 153         switch (vcpu->arch.sie_block->iprcc & ~PGM_PER) {
 154         case PGM_AFX_TRANSLATION:
 155         case PGM_ASX_TRANSLATION:
 156         case PGM_EX_TRANSLATION:
 157         case PGM_LFX_TRANSLATION:
 158         case PGM_LSTE_SEQUENCE:
 159         case PGM_LSX_TRANSLATION:
 160         case PGM_LX_TRANSLATION:
 161         case PGM_PRIMARY_AUTHORITY:
 162         case PGM_SECONDARY_AUTHORITY:
 163         case PGM_SPACE_SWITCH:
 164                 pgm_info.trans_exc_code = vcpu->arch.sie_block->tecmc;
 165                 break;
 166         case PGM_ALEN_TRANSLATION:
 167         case PGM_ALE_SEQUENCE:
 168         case PGM_ASTE_INSTANCE:
 169         case PGM_ASTE_SEQUENCE:
 170         case PGM_ASTE_VALIDITY:
 171         case PGM_EXTENDED_AUTHORITY:
 172                 pgm_info.exc_access_id = vcpu->arch.sie_block->eai;
 173                 break;
 174         case PGM_ASCE_TYPE:
 175         case PGM_PAGE_TRANSLATION:
 176         case PGM_REGION_FIRST_TRANS:
 177         case PGM_REGION_SECOND_TRANS:
 178         case PGM_REGION_THIRD_TRANS:
 179         case PGM_SEGMENT_TRANSLATION:
 180                 pgm_info.trans_exc_code = vcpu->arch.sie_block->tecmc;
 181                 pgm_info.exc_access_id  = vcpu->arch.sie_block->eai;
 182                 pgm_info.op_access_id  = vcpu->arch.sie_block->oai;
 183                 break;
 184         case PGM_MONITOR:
 185                 pgm_info.mon_class_nr = vcpu->arch.sie_block->mcn;
 186                 pgm_info.mon_code = vcpu->arch.sie_block->tecmc;
 187                 break;
 188         case PGM_VECTOR_PROCESSING:
 189         case PGM_DATA:
 190                 pgm_info.data_exc_code = vcpu->arch.sie_block->dxc;
 191                 break;
 192         case PGM_PROTECTION:
 193                 pgm_info.trans_exc_code = vcpu->arch.sie_block->tecmc;
 194                 pgm_info.exc_access_id  = vcpu->arch.sie_block->eai;
 195                 break;
 196         default:
 197                 break;
 198         }
 199
 200         if (vcpu->arch.sie_block->iprcc & PGM_PER) {
 201                 pgm_info.per_code = vcpu->arch.sie_block->perc;
 202                 pgm_info.per_atmid = vcpu->arch.sie_block->peratmid;
 203                 pgm_info.per_address = vcpu->arch.sie_block->peraddr;
 204                 pgm_info.per_access_id = vcpu->arch.sie_block->peraid;
 205         }
 206         return kvm_s390_inject_prog_irq(vcpu, &pgm_info);
 207 }
 208
 209 /*
 210  * restore ITDB to program-interruption TDB in guest lowcore
 211  * and set TX abort indication if required
 212 */
 213 static int handle_itdb(struct kvm_vcpu *vcpu)
 214 {
 215         struct kvm_s390_itdb *itdb;
 216         int rc;
 217
 218         if (!IS_TE_ENABLED(vcpu) || !IS_ITDB_VALID(vcpu))
 219                 return 0;
 220         if (current->thread.per_flags & PER_FLAG_NO_TE)
 221                 return 0;
 222         itdb = (struct kvm_s390_itdb *)vcpu->arch.sie_block->itdba;
 223         rc = write_guest_lc(vcpu, __LC_PGM_TDB, itdb, sizeof(*itdb));
 224         if (rc)
 225                 return rc;
 226         memset(itdb, 0, sizeof(*itdb));
 227
 228         return 0;
 229 }
 230
 231 #define per_event(vcpu) (vcpu->arch.sie_block->iprcc & PGM_PER)
 232
 233 static int handle_prog(struct kvm_vcpu *vcpu)
 234 {
 235         psw_t psw;
 236         int rc;
 237
 238         vcpu->stat.exit_program_interruption++;
 239
 240         if (guestdbg_enabled(vcpu) && per_event(vcpu)) {
 241                 rc = kvm_s390_handle_per_event(vcpu);
 242                 if (rc)
 243                         return rc;
 244                 /* the interrupt might have been filtered out completely */
 245                 if (vcpu->arch.sie_block->iprcc == 0)
 246                         return 0;
 247         }
 248
 249         trace_kvm_s390_intercept_prog(vcpu, vcpu->arch.sie_block->iprcc);
 250         if (vcpu->arch.sie_block->iprcc == PGM_SPECIFICATION) {
 251                 rc = read_guest_lc(vcpu, __LC_PGM_NEW_PSW, &psw, sizeof(psw_t));
 252                 if (rc)
 253                         return rc;
 254                 /* Avoid endless loops of specification exceptions */
 255                 if (!is_valid_psw(&psw))
 256                         return -EOPNOTSUPP;
 257         }
 258         rc = handle_itdb(vcpu);
 259         if (rc)
 260                 return rc;
 261
 262         return inject_prog_on_prog_intercept(vcpu);
 263 }
 264
 265 /**
 266  * handle_external_interrupt - used for external interruption interceptions
 267  *
 268  * This interception only occurs if the CPUSTAT_EXT_INT bit was set, or if
 269  * the new PSW does not have external interrupts disabled. In the first case,
 270  * we've got to deliver the interrupt manually, and in the second case, we
 271  * drop to userspace to handle the situation there.
 272  */
 273 static int handle_external_interrupt(struct kvm_vcpu *vcpu)
 274 {
 275         u16 eic = vcpu->arch.sie_block->eic;
 276         struct kvm_s390_irq irq;
 277         psw_t newpsw;
 278         int rc;
 279
 280         vcpu->stat.exit_external_interrupt++;
 281
 282         rc = read_guest_lc(vcpu, __LC_EXT_NEW_PSW, &newpsw, sizeof(psw_t));
 283         if (rc)
 284                 return rc;
 285         /* We can not handle clock comparator or timer interrupt with bad PSW */
 286         if ((eic == EXT_IRQ_CLK_COMP || eic == EXT_IRQ_CPU_TIMER) &&
 287             (newpsw.mask & PSW_MASK_EXT))
 288                 return -EOPNOTSUPP;
 289
 290         switch (eic) {
 291         case EXT_IRQ_CLK_COMP:
 292                 irq.type = KVM_S390_INT_CLOCK_COMP;
 293                 break;
 294         case EXT_IRQ_CPU_TIMER:
 295                 irq.type = KVM_S390_INT_CPU_TIMER;
 296                 break;
 297         case EXT_IRQ_EXTERNAL_CALL:
 298                 irq.type = KVM_S390_INT_EXTERNAL_CALL;
 299                 irq.u.extcall.code = vcpu->arch.sie_block->extcpuaddr;
 300                 rc = kvm_s390_inject_vcpu(vcpu, &irq);
 301                 /* ignore if another external call is already pending */
 302                 if (rc == -EBUSY)
 303                         return 0;
 304                 return rc;
 305         default:
 306                 return -EOPNOTSUPP;
 307         }
 308
 309         return kvm_s390_inject_vcpu(vcpu, &irq);
 310 }
 311
 312 /**
 313  * Handle MOVE PAGE partial execution interception.
 314  *
 315  * This interception can only happen for guests with DAT disabled and
 316  * addresses that are currently not mapped in the host. Thus we try to
 317  * set up the mappings for the corresponding user pages here (or throw
 318  * addressing exceptions in case of illegal guest addresses).
 319  */
 320 static int handle_mvpg_pei(struct kvm_vcpu *vcpu)
 321 {
 322         unsigned long srcaddr, dstaddr;
 323         int reg1, reg2, rc;
 324
 325         kvm_s390_get_regs_rre(vcpu, &reg1, &reg2);
 326
 327         /* Make sure that the source is paged-in */
 328         rc = guest_translate_address(vcpu, vcpu->run->s.regs.gprs[reg2],
 329                                      reg2, &srcaddr, GACC_FETCH);
 330         if (rc)
 331                 return kvm_s390_inject_prog_cond(vcpu, rc);
 332         rc = kvm_arch_fault_in_page(vcpu, srcaddr, 0);
 333         if (rc != 0)
 334                 return rc;
 335
 336         /* Make sure that the destination is paged-in */
 337         rc = guest_translate_address(vcpu, vcpu->run->s.regs.gprs[reg1],
 338                                      reg1, &dstaddr, GACC_STORE);
 339         if (rc)
 340                 return kvm_s390_inject_prog_cond(vcpu, rc);
 341         rc = kvm_arch_fault_in_page(vcpu, dstaddr, 1);
 342         if (rc != 0)
 343                 return rc;
 344
 345         kvm_s390_retry_instr(vcpu);
 346
 347         return 0;
 348 }
 349
 350 static int handle_partial_execution(struct kvm_vcpu *vcpu)
 351 {
 352         vcpu->stat.exit_pei++;
 353
 354         if (vcpu->arch.sie_block->ipa == 0xb254)        /* MVPG */
 355                 return handle_mvpg_pei(vcpu);
 356         if (vcpu->arch.sie_block->ipa >> 8 == 0xae)     /* SIGP */
 357                 return kvm_s390_handle_sigp_pei(vcpu);
 358
 359         return -EOPNOTSUPP;
 360 }
 361
 362 static int handle_operexc(struct kvm_vcpu *vcpu)
 363 {
 364         psw_t oldpsw, newpsw;
 365         int rc;
 366
 367         vcpu->stat.exit_operation_exception++;
 368         trace_kvm_s390_handle_operexc(vcpu, vcpu->arch.sie_block->ipa,
 369                                       vcpu->arch.sie_block->ipb);
 370
 371         if (vcpu->arch.sie_block->ipa == 0xb256 &&
 372             test_kvm_facility(vcpu->kvm, 74))
 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 0x10:
 408         case 0x18:
 409                 return handle_noop(vcpu);
 410         case 0x04:
 411                 rc = handle_instruction(vcpu);
 412                 break;
 413         case 0x08:
 414                 return handle_prog(vcpu);
 415         case 0x14:
 416                 return handle_external_interrupt(vcpu);
 417         case 0x1c:
 418                 return kvm_s390_handle_wait(vcpu);
 419         case 0x20:
 420                 return handle_validity(vcpu);
 421         case 0x28:
 422                 return handle_stop(vcpu);
 423         case 0x2c:
 424                 rc = handle_operexc(vcpu);
 425                 break;
 426         case 0x38:
 427                 rc = handle_partial_execution(vcpu);
 428                 break;
 429         default:
 430                 return -EOPNOTSUPP;
 431         }
 432
 433         /* process PER, also if the instrution is processed in user space */
 434         if (vcpu->arch.sie_block->icptstatus & 0x02 &&
 435             (!rc || rc == -EOPNOTSUPP))
 436                 per_rc = kvm_s390_handle_per_ifetch_icpt(vcpu);
 437         return per_rc ? per_rc : rc;
 438 }