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         [0xae] = kvm_s390_handle_sigp,
  33         [0xb2] = kvm_s390_handle_b2,
  34         [0xb6] = kvm_s390_handle_stctl,
  35         [0xb7] = kvm_s390_handle_lctl,
  36         [0xb9] = kvm_s390_handle_b9,
  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         WARN_ONCE(true, "kvm: unhandled validity intercept 0x%x\n", viwhy);
 122         return -EOPNOTSUPP;
 123 }
 124
 125 static int handle_instruction(struct kvm_vcpu *vcpu)
 126 {
 127         intercept_handler_t handler;
 128
 129         vcpu->stat.exit_instruction++;
 130         trace_kvm_s390_intercept_instruction(vcpu,
 131                                              vcpu->arch.sie_block->ipa,
 132                                              vcpu->arch.sie_block->ipb);
 133         handler = instruction_handlers[vcpu->arch.sie_block->ipa >> 8];
 134         if (handler)
 135                 return handler(vcpu);
 136         return -EOPNOTSUPP;
 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                 kvm_s390_handle_per_event(vcpu);
 236                 /* the interrupt might have been filtered out completely */
 237                 if (vcpu->arch.sie_block->iprcc == 0)
 238                         return 0;
 239         }
 240
 241         trace_kvm_s390_intercept_prog(vcpu, vcpu->arch.sie_block->iprcc);
 242         if (vcpu->arch.sie_block->iprcc == PGM_SPECIFICATION) {
 243                 rc = read_guest_lc(vcpu, __LC_PGM_NEW_PSW, &psw, sizeof(psw_t));
 244                 if (rc)
 245                         return rc;
 246                 /* Avoid endless loops of specification exceptions */
 247                 if (!is_valid_psw(&psw))
 248                         return -EOPNOTSUPP;
 249         }
 250         rc = handle_itdb(vcpu);
 251         if (rc)
 252                 return rc;
 253
 254         return inject_prog_on_prog_intercept(vcpu);
 255 }
 256
 257 /**
 258  * handle_external_interrupt - used for external interruption interceptions
 259  *
 260  * This interception only occurs if the CPUSTAT_EXT_INT bit was set, or if
 261  * the new PSW does not have external interrupts disabled. In the first case,
 262  * we've got to deliver the interrupt manually, and in the second case, we
 263  * drop to userspace to handle the situation there.
 264  */
 265 static int handle_external_interrupt(struct kvm_vcpu *vcpu)
 266 {
 267         u16 eic = vcpu->arch.sie_block->eic;
 268         struct kvm_s390_irq irq;
 269         psw_t newpsw;
 270         int rc;
 271
 272         vcpu->stat.exit_external_interrupt++;
 273
 274         rc = read_guest_lc(vcpu, __LC_EXT_NEW_PSW, &newpsw, sizeof(psw_t));
 275         if (rc)
 276                 return rc;
 277         /* We can not handle clock comparator or timer interrupt with bad PSW */
 278         if ((eic == EXT_IRQ_CLK_COMP || eic == EXT_IRQ_CPU_TIMER) &&
 279             (newpsw.mask & PSW_MASK_EXT))
 280                 return -EOPNOTSUPP;
 281
 282         switch (eic) {
 283         case EXT_IRQ_CLK_COMP:
 284                 irq.type = KVM_S390_INT_CLOCK_COMP;
 285                 break;
 286         case EXT_IRQ_CPU_TIMER:
 287                 irq.type = KVM_S390_INT_CPU_TIMER;
 288                 break;
 289         case EXT_IRQ_EXTERNAL_CALL:
 290                 irq.type = KVM_S390_INT_EXTERNAL_CALL;
 291                 irq.u.extcall.code = vcpu->arch.sie_block->extcpuaddr;
 292                 rc = kvm_s390_inject_vcpu(vcpu, &irq);
 293                 /* ignore if another external call is already pending */
 294                 if (rc == -EBUSY)
 295                         return 0;
 296                 return rc;
 297         default:
 298                 return -EOPNOTSUPP;
 299         }
 300
 301         return kvm_s390_inject_vcpu(vcpu, &irq);
 302 }
 303
 304 /**
 305  * Handle MOVE PAGE partial execution interception.
 306  *
 307  * This interception can only happen for guests with DAT disabled and
 308  * addresses that are currently not mapped in the host. Thus we try to
 309  * set up the mappings for the corresponding user pages here (or throw
 310  * addressing exceptions in case of illegal guest addresses).
 311  */
 312 static int handle_mvpg_pei(struct kvm_vcpu *vcpu)
 313 {
 314         unsigned long srcaddr, dstaddr;
 315         int reg1, reg2, rc;
 316
 317         kvm_s390_get_regs_rre(vcpu, &reg1, &reg2);
 318
 319         /* Make sure that the source is paged-in */
 320         rc = guest_translate_address(vcpu, vcpu->run->s.regs.gprs[reg2],
 321                                      reg2, &srcaddr, GACC_FETCH);
 322         if (rc)
 323                 return kvm_s390_inject_prog_cond(vcpu, rc);
 324         rc = kvm_arch_fault_in_page(vcpu, srcaddr, 0);
 325         if (rc != 0)
 326                 return rc;
 327
 328         /* Make sure that the destination is paged-in */
 329         rc = guest_translate_address(vcpu, vcpu->run->s.regs.gprs[reg1],
 330                                      reg1, &dstaddr, GACC_STORE);
 331         if (rc)
 332                 return kvm_s390_inject_prog_cond(vcpu, rc);
 333         rc = kvm_arch_fault_in_page(vcpu, dstaddr, 1);
 334         if (rc != 0)
 335                 return rc;
 336
 337         kvm_s390_retry_instr(vcpu);
 338
 339         return 0;
 340 }
 341
 342 static int handle_partial_execution(struct kvm_vcpu *vcpu)
 343 {
 344         vcpu->stat.exit_pei++;
 345
 346         if (vcpu->arch.sie_block->ipa == 0xb254)        /* MVPG */
 347                 return handle_mvpg_pei(vcpu);
 348         if (vcpu->arch.sie_block->ipa >> 8 == 0xae)     /* SIGP */
 349                 return kvm_s390_handle_sigp_pei(vcpu);
 350
 351         return -EOPNOTSUPP;
 352 }
 353
 354 static int handle_operexc(struct kvm_vcpu *vcpu)
 355 {
 356         vcpu->stat.exit_operation_exception++;
 357         trace_kvm_s390_handle_operexc(vcpu, vcpu->arch.sie_block->ipa,
 358                                       vcpu->arch.sie_block->ipb);
 359
 360         if (vcpu->arch.sie_block->ipa == 0xb256 &&
 361             test_kvm_facility(vcpu->kvm, 74))
 362                 return handle_sthyi(vcpu);
 363
 364         if (vcpu->arch.sie_block->ipa == 0 && vcpu->kvm->arch.user_instr0)
 365                 return -EOPNOTSUPP;
 366
 367         return kvm_s390_inject_program_int(vcpu, PGM_OPERATION);
 368 }
 369
 370 int kvm_handle_sie_intercept(struct kvm_vcpu *vcpu)
 371 {
 372         int rc, per_rc = 0;
 373
 374         if (kvm_is_ucontrol(vcpu->kvm))
 375                 return -EOPNOTSUPP;
 376
 377         switch (vcpu->arch.sie_block->icptcode) {
 378         case 0x10:
 379         case 0x18:
 380                 return handle_noop(vcpu);
 381         case 0x04:
 382                 rc = handle_instruction(vcpu);
 383                 break;
 384         case 0x08:
 385                 return handle_prog(vcpu);
 386         case 0x14:
 387                 return handle_external_interrupt(vcpu);
 388         case 0x1c:
 389                 return kvm_s390_handle_wait(vcpu);
 390         case 0x20:
 391                 return handle_validity(vcpu);
 392         case 0x28:
 393                 return handle_stop(vcpu);
 394         case 0x2c:
 395                 rc = handle_operexc(vcpu);
 396                 break;
 397         case 0x38:
 398                 rc = handle_partial_execution(vcpu);
 399                 break;
 400         default:
 401                 return -EOPNOTSUPP;
 402         }
 403
 404         /* process PER, also if the instrution is processed in user space */
 405         if (vcpu->arch.sie_block->icptstatus & 0x02 &&
 406             (!rc || rc == -EOPNOTSUPP))
 407                 per_rc = kvm_s390_handle_per_ifetch_icpt(vcpu);
 408         return per_rc ? per_rc : rc;
 409 }