kernel/arch/s390/kvm/sigp.c

   1 /*
   2  * handling interprocessor communication
   3  *
   4  * Copyright IBM Corp. 2008, 2013
   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  *               Christian Ehrhardt <ehrhardt@de.ibm.com>
  13  */
  14
  15 #include <linux/kvm.h>
  16 #include <linux/kvm_host.h>
  17 #include <linux/slab.h>
  18 #include <asm/sigp.h>
  19 #include "gaccess.h"
  20 #include "kvm-s390.h"
  21 #include "trace.h"
  22
  23 static int __sigp_sense(struct kvm_vcpu *vcpu, struct kvm_vcpu *dst_vcpu,
  24                         u64 *reg)
  25 {
  26         struct kvm_s390_local_interrupt *li;
  27         int cpuflags;
  28         int rc;
  29         int ext_call_pending;
  30
  31         li = &dst_vcpu->arch.local_int;
  32
  33         cpuflags = atomic_read(li->cpuflags);
  34         ext_call_pending = kvm_s390_ext_call_pending(dst_vcpu);
  35         if (!(cpuflags & CPUSTAT_STOPPED) && !ext_call_pending)
  36                 rc = SIGP_CC_ORDER_CODE_ACCEPTED;
  37         else {
  38                 *reg &= 0xffffffff00000000UL;
  39                 if (ext_call_pending)
  40                         *reg |= SIGP_STATUS_EXT_CALL_PENDING;
  41                 if (cpuflags & CPUSTAT_STOPPED)
  42                         *reg |= SIGP_STATUS_STOPPED;
  43                 rc = SIGP_CC_STATUS_STORED;
  44         }
  45
  46         VCPU_EVENT(vcpu, 4, "sensed status of cpu %x rc %x", dst_vcpu->vcpu_id,
  47                    rc);
  48         return rc;
  49 }
  50
  51 static int __inject_sigp_emergency(struct kvm_vcpu *vcpu,
  52                                     struct kvm_vcpu *dst_vcpu)
  53 {
  54         struct kvm_s390_irq irq = {
  55                 .type = KVM_S390_INT_EMERGENCY,
  56                 .u.emerg.code = vcpu->vcpu_id,
  57         };
  58         int rc = 0;
  59
  60         rc = kvm_s390_inject_vcpu(dst_vcpu, &irq);
  61         if (!rc)
  62                 VCPU_EVENT(vcpu, 4, "sent sigp emerg to cpu %x",
  63                            dst_vcpu->vcpu_id);
  64
  65         return rc ? rc : SIGP_CC_ORDER_CODE_ACCEPTED;
  66 }
  67
  68 static int __sigp_emergency(struct kvm_vcpu *vcpu, struct kvm_vcpu *dst_vcpu)
  69 {
  70         return __inject_sigp_emergency(vcpu, dst_vcpu);
  71 }
  72
  73 static int __sigp_conditional_emergency(struct kvm_vcpu *vcpu,
  74                                         struct kvm_vcpu *dst_vcpu,
  75                                         u16 asn, u64 *reg)
  76 {
  77         const u64 psw_int_mask = PSW_MASK_IO | PSW_MASK_EXT;
  78         u16 p_asn, s_asn;
  79         psw_t *psw;
  80         u32 flags;
  81
  82         flags = atomic_read(&dst_vcpu->arch.sie_block->cpuflags);
  83         psw = &dst_vcpu->arch.sie_block->gpsw;
  84         p_asn = dst_vcpu->arch.sie_block->gcr[4] & 0xffff;  /* Primary ASN */
  85         s_asn = dst_vcpu->arch.sie_block->gcr[3] & 0xffff;  /* Secondary ASN */
  86
  87         /* Inject the emergency signal? */
  88         if (!(flags & CPUSTAT_STOPPED)
  89             || (psw->mask & psw_int_mask) != psw_int_mask
  90             || ((flags & CPUSTAT_WAIT) && psw->addr != 0)
  91             || (!(flags & CPUSTAT_WAIT) && (asn == p_asn || asn == s_asn))) {
  92                 return __inject_sigp_emergency(vcpu, dst_vcpu);
  93         } else {
  94                 *reg &= 0xffffffff00000000UL;
  95                 *reg |= SIGP_STATUS_INCORRECT_STATE;
  96                 return SIGP_CC_STATUS_STORED;
  97         }
  98 }
  99
 100 static int __sigp_external_call(struct kvm_vcpu *vcpu,
 101                                 struct kvm_vcpu *dst_vcpu, u64 *reg)
 102 {
 103         struct kvm_s390_irq irq = {
 104                 .type = KVM_S390_INT_EXTERNAL_CALL,
 105                 .u.extcall.code = vcpu->vcpu_id,
 106         };
 107         int rc;
 108
 109         rc = kvm_s390_inject_vcpu(dst_vcpu, &irq);
 110         if (rc == -EBUSY) {
 111                 *reg &= 0xffffffff00000000UL;
 112                 *reg |= SIGP_STATUS_EXT_CALL_PENDING;
 113                 return SIGP_CC_STATUS_STORED;
 114         } else if (rc == 0) {
 115                 VCPU_EVENT(vcpu, 4, "sent sigp ext call to cpu %x",
 116                            dst_vcpu->vcpu_id);
 117         }
 118
 119         return rc ? rc : SIGP_CC_ORDER_CODE_ACCEPTED;
 120 }
 121
 122 static int __sigp_stop(struct kvm_vcpu *vcpu, struct kvm_vcpu *dst_vcpu)
 123 {
 124         struct kvm_s390_irq irq = {
 125                 .type = KVM_S390_SIGP_STOP,
 126         };
 127         int rc;
 128
 129         rc = kvm_s390_inject_vcpu(dst_vcpu, &irq);
 130         if (rc == -EBUSY)
 131                 rc = SIGP_CC_BUSY;
 132         else if (rc == 0)
 133                 VCPU_EVENT(vcpu, 4, "sent sigp stop to cpu %x",
 134                            dst_vcpu->vcpu_id);
 135
 136         return rc;
 137 }
 138
 139 static int __sigp_stop_and_store_status(struct kvm_vcpu *vcpu,
 140                                         struct kvm_vcpu *dst_vcpu, u64 *reg)
 141 {
 142         struct kvm_s390_irq irq = {
 143                 .type = KVM_S390_SIGP_STOP,
 144                 .u.stop.flags = KVM_S390_STOP_FLAG_STORE_STATUS,
 145         };
 146         int rc;
 147
 148         rc = kvm_s390_inject_vcpu(dst_vcpu, &irq);
 149         if (rc == -EBUSY)
 150                 rc = SIGP_CC_BUSY;
 151         else if (rc == 0)
 152                 VCPU_EVENT(vcpu, 4, "sent sigp stop and store status to cpu %x",
 153                            dst_vcpu->vcpu_id);
 154
 155         return rc;
 156 }
 157
 158 static int __sigp_set_arch(struct kvm_vcpu *vcpu, u32 parameter)
 159 {
 160         int rc;
 161         unsigned int i;
 162         struct kvm_vcpu *v;
 163
 164         switch (parameter & 0xff) {
 165         case 0:
 166                 rc = SIGP_CC_NOT_OPERATIONAL;
 167                 break;
 168         case 1:
 169         case 2:
 170                 kvm_for_each_vcpu(i, v, vcpu->kvm) {
 171                         v->arch.pfault_token = KVM_S390_PFAULT_TOKEN_INVALID;
 172                         kvm_clear_async_pf_completion_queue(v);
 173                 }
 174
 175                 rc = SIGP_CC_ORDER_CODE_ACCEPTED;
 176                 break;
 177         default:
 178                 rc = -EOPNOTSUPP;
 179         }
 180         return rc;
 181 }
 182
 183 static int __sigp_set_prefix(struct kvm_vcpu *vcpu, struct kvm_vcpu *dst_vcpu,
 184                              u32 address, u64 *reg)
 185 {
 186         struct kvm_s390_irq irq = {
 187                 .type = KVM_S390_SIGP_SET_PREFIX,
 188                 .u.prefix.address = address & 0x7fffe000u,
 189         };
 190         int rc;
 191
 192         /*
 193          * Make sure the new value is valid memory. We only need to check the
 194          * first page, since address is 8k aligned and memory pieces are always
 195          * at least 1MB aligned and have at least a size of 1MB.
 196          */
 197         if (kvm_is_error_gpa(vcpu->kvm, irq.u.prefix.address)) {
 198                 *reg &= 0xffffffff00000000UL;
 199                 *reg |= SIGP_STATUS_INVALID_PARAMETER;
 200                 return SIGP_CC_STATUS_STORED;
 201         }
 202
 203         rc = kvm_s390_inject_vcpu(dst_vcpu, &irq);
 204         if (rc == -EBUSY) {
 205                 *reg &= 0xffffffff00000000UL;
 206                 *reg |= SIGP_STATUS_INCORRECT_STATE;
 207                 return SIGP_CC_STATUS_STORED;
 208         } else if (rc == 0) {
 209                 VCPU_EVENT(vcpu, 4, "set prefix of cpu %02x to %x",
 210                            dst_vcpu->vcpu_id, irq.u.prefix.address);
 211         }
 212
 213         return rc;
 214 }
 215
 216 static int __sigp_store_status_at_addr(struct kvm_vcpu *vcpu,
 217                                        struct kvm_vcpu *dst_vcpu,
 218                                        u32 addr, u64 *reg)
 219 {
 220         int flags;
 221         int rc;
 222
 223         flags = atomic_read(dst_vcpu->arch.local_int.cpuflags);
 224         if (!(flags & CPUSTAT_STOPPED)) {
 225                 *reg &= 0xffffffff00000000UL;
 226                 *reg |= SIGP_STATUS_INCORRECT_STATE;
 227                 return SIGP_CC_STATUS_STORED;
 228         }
 229
 230         addr &= 0x7ffffe00;
 231         rc = kvm_s390_store_status_unloaded(dst_vcpu, addr);
 232         if (rc == -EFAULT) {
 233                 *reg &= 0xffffffff00000000UL;
 234                 *reg |= SIGP_STATUS_INVALID_PARAMETER;
 235                 rc = SIGP_CC_STATUS_STORED;
 236         }
 237         return rc;
 238 }
 239
 240 static int __sigp_sense_running(struct kvm_vcpu *vcpu,
 241                                 struct kvm_vcpu *dst_vcpu, u64 *reg)
 242 {
 243         struct kvm_s390_local_interrupt *li;
 244         int rc;
 245
 246         li = &dst_vcpu->arch.local_int;
 247         if (atomic_read(li->cpuflags) & CPUSTAT_RUNNING) {
 248                 /* running */
 249                 rc = SIGP_CC_ORDER_CODE_ACCEPTED;
 250         } else {
 251                 /* not running */
 252                 *reg &= 0xffffffff00000000UL;
 253                 *reg |= SIGP_STATUS_NOT_RUNNING;
 254                 rc = SIGP_CC_STATUS_STORED;
 255         }
 256
 257         VCPU_EVENT(vcpu, 4, "sensed running status of cpu %x rc %x",
 258                    dst_vcpu->vcpu_id, rc);
 259
 260         return rc;
 261 }
 262
 263 static int __prepare_sigp_re_start(struct kvm_vcpu *vcpu,
 264                                    struct kvm_vcpu *dst_vcpu, u8 order_code)
 265 {
 266         struct kvm_s390_local_interrupt *li = &dst_vcpu->arch.local_int;
 267         /* handle (RE)START in user space */
 268         int rc = -EOPNOTSUPP;
 269
 270         /* make sure we don't race with STOP irq injection */
 271         spin_lock(&li->lock);
 272         if (kvm_s390_is_stop_irq_pending(dst_vcpu))
 273                 rc = SIGP_CC_BUSY;
 274         spin_unlock(&li->lock);
 275
 276         return rc;
 277 }
 278
 279 static int __prepare_sigp_cpu_reset(struct kvm_vcpu *vcpu,
 280                                     struct kvm_vcpu *dst_vcpu, u8 order_code)
 281 {
 282         /* handle (INITIAL) CPU RESET in user space */
 283         return -EOPNOTSUPP;
 284 }
 285
 286 static int __prepare_sigp_unknown(struct kvm_vcpu *vcpu,
 287                                   struct kvm_vcpu *dst_vcpu)
 288 {
 289         /* handle unknown orders in user space */
 290         return -EOPNOTSUPP;
 291 }
 292
 293 static int handle_sigp_dst(struct kvm_vcpu *vcpu, u8 order_code,
 294                            u16 cpu_addr, u32 parameter, u64 *status_reg)
 295 {
 296         int rc;
 297         struct kvm_vcpu *dst_vcpu;
 298
 299         if (cpu_addr >= KVM_MAX_VCPUS)
 300                 return SIGP_CC_NOT_OPERATIONAL;
 301
 302         dst_vcpu = kvm_get_vcpu(vcpu->kvm, cpu_addr);
 303         if (!dst_vcpu)
 304                 return SIGP_CC_NOT_OPERATIONAL;
 305
 306         switch (order_code) {
 307         case SIGP_SENSE:
 308                 vcpu->stat.instruction_sigp_sense++;
 309                 rc = __sigp_sense(vcpu, dst_vcpu, status_reg);
 310                 break;
 311         case SIGP_EXTERNAL_CALL:
 312                 vcpu->stat.instruction_sigp_external_call++;
 313                 rc = __sigp_external_call(vcpu, dst_vcpu, status_reg);
 314                 break;
 315         case SIGP_EMERGENCY_SIGNAL:
 316                 vcpu->stat.instruction_sigp_emergency++;
 317                 rc = __sigp_emergency(vcpu, dst_vcpu);
 318                 break;
 319         case SIGP_STOP:
 320                 vcpu->stat.instruction_sigp_stop++;
 321                 rc = __sigp_stop(vcpu, dst_vcpu);
 322                 break;
 323         case SIGP_STOP_AND_STORE_STATUS:
 324                 vcpu->stat.instruction_sigp_stop_store_status++;
 325                 rc = __sigp_stop_and_store_status(vcpu, dst_vcpu, status_reg);
 326                 break;
 327         case SIGP_STORE_STATUS_AT_ADDRESS:
 328                 vcpu->stat.instruction_sigp_store_status++;
 329                 rc = __sigp_store_status_at_addr(vcpu, dst_vcpu, parameter,
 330                                                  status_reg);
 331                 break;
 332         case SIGP_SET_PREFIX:
 333                 vcpu->stat.instruction_sigp_prefix++;
 334                 rc = __sigp_set_prefix(vcpu, dst_vcpu, parameter, status_reg);
 335                 break;
 336         case SIGP_COND_EMERGENCY_SIGNAL:
 337                 vcpu->stat.instruction_sigp_cond_emergency++;
 338                 rc = __sigp_conditional_emergency(vcpu, dst_vcpu, parameter,
 339                                                   status_reg);
 340                 break;
 341         case SIGP_SENSE_RUNNING:
 342                 vcpu->stat.instruction_sigp_sense_running++;
 343                 rc = __sigp_sense_running(vcpu, dst_vcpu, status_reg);
 344                 break;
 345         case SIGP_START:
 346                 vcpu->stat.instruction_sigp_start++;
 347                 rc = __prepare_sigp_re_start(vcpu, dst_vcpu, order_code);
 348                 break;
 349         case SIGP_RESTART:
 350                 vcpu->stat.instruction_sigp_restart++;
 351                 rc = __prepare_sigp_re_start(vcpu, dst_vcpu, order_code);
 352                 break;
 353         case SIGP_INITIAL_CPU_RESET:
 354                 vcpu->stat.instruction_sigp_init_cpu_reset++;
 355                 rc = __prepare_sigp_cpu_reset(vcpu, dst_vcpu, order_code);
 356                 break;
 357         case SIGP_CPU_RESET:
 358                 vcpu->stat.instruction_sigp_cpu_reset++;
 359                 rc = __prepare_sigp_cpu_reset(vcpu, dst_vcpu, order_code);
 360                 break;
 361         default:
 362                 vcpu->stat.instruction_sigp_unknown++;
 363                 rc = __prepare_sigp_unknown(vcpu, dst_vcpu);
 364         }
 365
 366         if (rc == -EOPNOTSUPP)
 367                 VCPU_EVENT(vcpu, 4,
 368                            "sigp order %u -> cpu %x: handled in user space",
 369                            order_code, dst_vcpu->vcpu_id);
 370
 371         return rc;
 372 }
 373
 374 static int handle_sigp_order_in_user_space(struct kvm_vcpu *vcpu, u8 order_code)
 375 {
 376         if (!vcpu->kvm->arch.user_sigp)
 377                 return 0;
 378
 379         switch (order_code) {
 380         case SIGP_SENSE:
 381         case SIGP_EXTERNAL_CALL:
 382         case SIGP_EMERGENCY_SIGNAL:
 383         case SIGP_COND_EMERGENCY_SIGNAL:
 384         case SIGP_SENSE_RUNNING:
 385                 return 0;
 386         /* update counters as we're directly dropping to user space */
 387         case SIGP_STOP:
 388                 vcpu->stat.instruction_sigp_stop++;
 389                 break;
 390         case SIGP_STOP_AND_STORE_STATUS:
 391                 vcpu->stat.instruction_sigp_stop_store_status++;
 392                 break;
 393         case SIGP_STORE_STATUS_AT_ADDRESS:
 394                 vcpu->stat.instruction_sigp_store_status++;
 395                 break;
 396         case SIGP_STORE_ADDITIONAL_STATUS:
 397                 vcpu->stat.instruction_sigp_store_adtl_status++;
 398                 break;
 399         case SIGP_SET_PREFIX:
 400                 vcpu->stat.instruction_sigp_prefix++;
 401                 break;
 402         case SIGP_START:
 403                 vcpu->stat.instruction_sigp_start++;
 404                 break;
 405         case SIGP_RESTART:
 406                 vcpu->stat.instruction_sigp_restart++;
 407                 break;
 408         case SIGP_INITIAL_CPU_RESET:
 409                 vcpu->stat.instruction_sigp_init_cpu_reset++;
 410                 break;
 411         case SIGP_CPU_RESET:
 412                 vcpu->stat.instruction_sigp_cpu_reset++;
 413                 break;
 414         default:
 415                 vcpu->stat.instruction_sigp_unknown++;
 416         }
 417
 418         VCPU_EVENT(vcpu, 4, "sigp order %u: completely handled in user space",
 419                    order_code);
 420
 421         return 1;
 422 }
 423
 424 int kvm_s390_handle_sigp(struct kvm_vcpu *vcpu)
 425 {
 426         int r1 = (vcpu->arch.sie_block->ipa & 0x00f0) >> 4;
 427         int r3 = vcpu->arch.sie_block->ipa & 0x000f;
 428         u32 parameter;
 429         u16 cpu_addr = vcpu->run->s.regs.gprs[r3];
 430         u8 order_code;
 431         int rc;
 432
 433         /* sigp in userspace can exit */
 434         if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
 435                 return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);
 436
 437         order_code = kvm_s390_get_base_disp_rs(vcpu, NULL);
 438         if (handle_sigp_order_in_user_space(vcpu, order_code))
 439                 return -EOPNOTSUPP;
 440
 441         if (r1 % 2)
 442                 parameter = vcpu->run->s.regs.gprs[r1];
 443         else
 444                 parameter = vcpu->run->s.regs.gprs[r1 + 1];
 445
 446         trace_kvm_s390_handle_sigp(vcpu, order_code, cpu_addr, parameter);
 447         switch (order_code) {
 448         case SIGP_SET_ARCHITECTURE:
 449                 vcpu->stat.instruction_sigp_arch++;
 450                 rc = __sigp_set_arch(vcpu, parameter);
 451                 break;
 452         default:
 453                 rc = handle_sigp_dst(vcpu, order_code, cpu_addr,
 454                                      parameter,
 455                                      &vcpu->run->s.regs.gprs[r1]);
 456         }
 457
 458         if (rc < 0)
 459                 return rc;
 460
 461         kvm_s390_set_psw_cc(vcpu, rc);
 462         return 0;
 463 }
 464
 465 /*
 466  * Handle SIGP partial execution interception.
 467  *
 468  * This interception will occur at the source cpu when a source cpu sends an
 469  * external call to a target cpu and the target cpu has the WAIT bit set in
 470  * its cpuflags. Interception will occurr after the interrupt indicator bits at
 471  * the target cpu have been set. All error cases will lead to instruction
 472  * interception, therefore nothing is to be checked or prepared.
 473  */
 474 int kvm_s390_handle_sigp_pei(struct kvm_vcpu *vcpu)
 475 {
 476         int r3 = vcpu->arch.sie_block->ipa & 0x000f;
 477         u16 cpu_addr = vcpu->run->s.regs.gprs[r3];
 478         struct kvm_vcpu *dest_vcpu;
 479         u8 order_code = kvm_s390_get_base_disp_rs(vcpu, NULL);
 480
 481         trace_kvm_s390_handle_sigp_pei(vcpu, order_code, cpu_addr);
 482
 483         if (order_code == SIGP_EXTERNAL_CALL) {
 484                 dest_vcpu = kvm_get_vcpu(vcpu->kvm, cpu_addr);
 485                 BUG_ON(dest_vcpu == NULL);
 486
 487                 kvm_s390_vcpu_wakeup(dest_vcpu);
 488                 kvm_s390_set_psw_cc(vcpu, SIGP_CC_ORDER_CODE_ACCEPTED);
 489                 return 0;
 490         }
 491
 492         return -EOPNOTSUPP;
 493 }