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         }
 209
 210         return rc;
 211 }
 212
 213 static int __sigp_store_status_at_addr(struct kvm_vcpu *vcpu,
 214                                        struct kvm_vcpu *dst_vcpu,
 215                                        u32 addr, u64 *reg)
 216 {
 217         int flags;
 218         int rc;
 219
 220         flags = atomic_read(dst_vcpu->arch.local_int.cpuflags);
 221         if (!(flags & CPUSTAT_STOPPED)) {
 222                 *reg &= 0xffffffff00000000UL;
 223                 *reg |= SIGP_STATUS_INCORRECT_STATE;
 224                 return SIGP_CC_STATUS_STORED;
 225         }
 226
 227         addr &= 0x7ffffe00;
 228         rc = kvm_s390_store_status_unloaded(dst_vcpu, addr);
 229         if (rc == -EFAULT) {
 230                 *reg &= 0xffffffff00000000UL;
 231                 *reg |= SIGP_STATUS_INVALID_PARAMETER;
 232                 rc = SIGP_CC_STATUS_STORED;
 233         }
 234         return rc;
 235 }
 236
 237 static int __sigp_sense_running(struct kvm_vcpu *vcpu,
 238                                 struct kvm_vcpu *dst_vcpu, u64 *reg)
 239 {
 240         struct kvm_s390_local_interrupt *li;
 241         int rc;
 242
 243         li = &dst_vcpu->arch.local_int;
 244         if (atomic_read(li->cpuflags) & CPUSTAT_RUNNING) {
 245                 /* running */
 246                 rc = SIGP_CC_ORDER_CODE_ACCEPTED;
 247         } else {
 248                 /* not running */
 249                 *reg &= 0xffffffff00000000UL;
 250                 *reg |= SIGP_STATUS_NOT_RUNNING;
 251                 rc = SIGP_CC_STATUS_STORED;
 252         }
 253
 254         VCPU_EVENT(vcpu, 4, "sensed running status of cpu %x rc %x",
 255                    dst_vcpu->vcpu_id, rc);
 256
 257         return rc;
 258 }
 259
 260 static int __prepare_sigp_re_start(struct kvm_vcpu *vcpu,
 261                                    struct kvm_vcpu *dst_vcpu, u8 order_code)
 262 {
 263         struct kvm_s390_local_interrupt *li = &dst_vcpu->arch.local_int;
 264         /* handle (RE)START in user space */
 265         int rc = -EOPNOTSUPP;
 266
 267         /* make sure we don't race with STOP irq injection */
 268         spin_lock(&li->lock);
 269         if (kvm_s390_is_stop_irq_pending(dst_vcpu))
 270                 rc = SIGP_CC_BUSY;
 271         spin_unlock(&li->lock);
 272
 273         return rc;
 274 }
 275
 276 static int __prepare_sigp_cpu_reset(struct kvm_vcpu *vcpu,
 277                                     struct kvm_vcpu *dst_vcpu, u8 order_code)
 278 {
 279         /* handle (INITIAL) CPU RESET in user space */
 280         return -EOPNOTSUPP;
 281 }
 282
 283 static int __prepare_sigp_unknown(struct kvm_vcpu *vcpu,
 284                                   struct kvm_vcpu *dst_vcpu)
 285 {
 286         /* handle unknown orders in user space */
 287         return -EOPNOTSUPP;
 288 }
 289
 290 static int handle_sigp_dst(struct kvm_vcpu *vcpu, u8 order_code,
 291                            u16 cpu_addr, u32 parameter, u64 *status_reg)
 292 {
 293         int rc;
 294         struct kvm_vcpu *dst_vcpu;
 295
 296         if (cpu_addr >= KVM_MAX_VCPUS)
 297                 return SIGP_CC_NOT_OPERATIONAL;
 298
 299         dst_vcpu = kvm_get_vcpu(vcpu->kvm, cpu_addr);
 300         if (!dst_vcpu)
 301                 return SIGP_CC_NOT_OPERATIONAL;
 302
 303         switch (order_code) {
 304         case SIGP_SENSE:
 305                 vcpu->stat.instruction_sigp_sense++;
 306                 rc = __sigp_sense(vcpu, dst_vcpu, status_reg);
 307                 break;
 308         case SIGP_EXTERNAL_CALL:
 309                 vcpu->stat.instruction_sigp_external_call++;
 310                 rc = __sigp_external_call(vcpu, dst_vcpu, status_reg);
 311                 break;
 312         case SIGP_EMERGENCY_SIGNAL:
 313                 vcpu->stat.instruction_sigp_emergency++;
 314                 rc = __sigp_emergency(vcpu, dst_vcpu);
 315                 break;
 316         case SIGP_STOP:
 317                 vcpu->stat.instruction_sigp_stop++;
 318                 rc = __sigp_stop(vcpu, dst_vcpu);
 319                 break;
 320         case SIGP_STOP_AND_STORE_STATUS:
 321                 vcpu->stat.instruction_sigp_stop_store_status++;
 322                 rc = __sigp_stop_and_store_status(vcpu, dst_vcpu, status_reg);
 323                 break;
 324         case SIGP_STORE_STATUS_AT_ADDRESS:
 325                 vcpu->stat.instruction_sigp_store_status++;
 326                 rc = __sigp_store_status_at_addr(vcpu, dst_vcpu, parameter,
 327                                                  status_reg);
 328                 break;
 329         case SIGP_SET_PREFIX:
 330                 vcpu->stat.instruction_sigp_prefix++;
 331                 rc = __sigp_set_prefix(vcpu, dst_vcpu, parameter, status_reg);
 332                 break;
 333         case SIGP_COND_EMERGENCY_SIGNAL:
 334                 vcpu->stat.instruction_sigp_cond_emergency++;
 335                 rc = __sigp_conditional_emergency(vcpu, dst_vcpu, parameter,
 336                                                   status_reg);
 337                 break;
 338         case SIGP_SENSE_RUNNING:
 339                 vcpu->stat.instruction_sigp_sense_running++;
 340                 rc = __sigp_sense_running(vcpu, dst_vcpu, status_reg);
 341                 break;
 342         case SIGP_START:
 343                 vcpu->stat.instruction_sigp_start++;
 344                 rc = __prepare_sigp_re_start(vcpu, dst_vcpu, order_code);
 345                 break;
 346         case SIGP_RESTART:
 347                 vcpu->stat.instruction_sigp_restart++;
 348                 rc = __prepare_sigp_re_start(vcpu, dst_vcpu, order_code);
 349                 break;
 350         case SIGP_INITIAL_CPU_RESET:
 351                 vcpu->stat.instruction_sigp_init_cpu_reset++;
 352                 rc = __prepare_sigp_cpu_reset(vcpu, dst_vcpu, order_code);
 353                 break;
 354         case SIGP_CPU_RESET:
 355                 vcpu->stat.instruction_sigp_cpu_reset++;
 356                 rc = __prepare_sigp_cpu_reset(vcpu, dst_vcpu, order_code);
 357                 break;
 358         default:
 359                 vcpu->stat.instruction_sigp_unknown++;
 360                 rc = __prepare_sigp_unknown(vcpu, dst_vcpu);
 361         }
 362
 363         if (rc == -EOPNOTSUPP)
 364                 VCPU_EVENT(vcpu, 4,
 365                            "sigp order %u -> cpu %x: handled in user space",
 366                            order_code, dst_vcpu->vcpu_id);
 367
 368         return rc;
 369 }
 370
 371 static int handle_sigp_order_in_user_space(struct kvm_vcpu *vcpu, u8 order_code,
 372                                            u16 cpu_addr)
 373 {
 374         if (!vcpu->kvm->arch.user_sigp)
 375                 return 0;
 376
 377         switch (order_code) {
 378         case SIGP_SENSE:
 379         case SIGP_EXTERNAL_CALL:
 380         case SIGP_EMERGENCY_SIGNAL:
 381         case SIGP_COND_EMERGENCY_SIGNAL:
 382         case SIGP_SENSE_RUNNING:
 383                 return 0;
 384         /* update counters as we're directly dropping to user space */
 385         case SIGP_STOP:
 386                 vcpu->stat.instruction_sigp_stop++;
 387                 break;
 388         case SIGP_STOP_AND_STORE_STATUS:
 389                 vcpu->stat.instruction_sigp_stop_store_status++;
 390                 break;
 391         case SIGP_STORE_STATUS_AT_ADDRESS:
 392                 vcpu->stat.instruction_sigp_store_status++;
 393                 break;
 394         case SIGP_STORE_ADDITIONAL_STATUS:
 395                 vcpu->stat.instruction_sigp_store_adtl_status++;
 396                 break;
 397         case SIGP_SET_PREFIX:
 398                 vcpu->stat.instruction_sigp_prefix++;
 399                 break;
 400         case SIGP_START:
 401                 vcpu->stat.instruction_sigp_start++;
 402                 break;
 403         case SIGP_RESTART:
 404                 vcpu->stat.instruction_sigp_restart++;
 405                 break;
 406         case SIGP_INITIAL_CPU_RESET:
 407                 vcpu->stat.instruction_sigp_init_cpu_reset++;
 408                 break;
 409         case SIGP_CPU_RESET:
 410                 vcpu->stat.instruction_sigp_cpu_reset++;
 411                 break;
 412         default:
 413                 vcpu->stat.instruction_sigp_unknown++;
 414         }
 415         VCPU_EVENT(vcpu, 3, "SIGP: order %u for CPU %d handled in userspace",
 416                    order_code, cpu_addr);
 417
 418         return 1;
 419 }
 420
 421 int kvm_s390_handle_sigp(struct kvm_vcpu *vcpu)
 422 {
 423         int r1 = (vcpu->arch.sie_block->ipa & 0x00f0) >> 4;
 424         int r3 = vcpu->arch.sie_block->ipa & 0x000f;
 425         u32 parameter;
 426         u16 cpu_addr = vcpu->run->s.regs.gprs[r3];
 427         u8 order_code;
 428         int rc;
 429
 430         /* sigp in userspace can exit */
 431         if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
 432                 return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);
 433
 434         order_code = kvm_s390_get_base_disp_rs(vcpu, NULL);
 435         if (handle_sigp_order_in_user_space(vcpu, order_code, cpu_addr))
 436                 return -EOPNOTSUPP;
 437
 438         if (r1 % 2)
 439                 parameter = vcpu->run->s.regs.gprs[r1];
 440         else
 441                 parameter = vcpu->run->s.regs.gprs[r1 + 1];
 442
 443         trace_kvm_s390_handle_sigp(vcpu, order_code, cpu_addr, parameter);
 444         switch (order_code) {
 445         case SIGP_SET_ARCHITECTURE:
 446                 vcpu->stat.instruction_sigp_arch++;
 447                 rc = __sigp_set_arch(vcpu, parameter);
 448                 break;
 449         default:
 450                 rc = handle_sigp_dst(vcpu, order_code, cpu_addr,
 451                                      parameter,
 452                                      &vcpu->run->s.regs.gprs[r1]);
 453         }
 454
 455         if (rc < 0)
 456                 return rc;
 457
 458         kvm_s390_set_psw_cc(vcpu, rc);
 459         return 0;
 460 }
 461
 462 /*
 463  * Handle SIGP partial execution interception.
 464  *
 465  * This interception will occur at the source cpu when a source cpu sends an
 466  * external call to a target cpu and the target cpu has the WAIT bit set in
 467  * its cpuflags. Interception will occurr after the interrupt indicator bits at
 468  * the target cpu have been set. All error cases will lead to instruction
 469  * interception, therefore nothing is to be checked or prepared.
 470  */
 471 int kvm_s390_handle_sigp_pei(struct kvm_vcpu *vcpu)
 472 {
 473         int r3 = vcpu->arch.sie_block->ipa & 0x000f;
 474         u16 cpu_addr = vcpu->run->s.regs.gprs[r3];
 475         struct kvm_vcpu *dest_vcpu;
 476         u8 order_code = kvm_s390_get_base_disp_rs(vcpu, NULL);
 477
 478         trace_kvm_s390_handle_sigp_pei(vcpu, order_code, cpu_addr);
 479
 480         if (order_code == SIGP_EXTERNAL_CALL) {
 481                 dest_vcpu = kvm_get_vcpu(vcpu->kvm, cpu_addr);
 482                 BUG_ON(dest_vcpu == NULL);
 483
 484                 kvm_s390_vcpu_wakeup(dest_vcpu);
 485                 kvm_s390_set_psw_cc(vcpu, SIGP_CC_ORDER_CODE_ACCEPTED);
 486                 return 0;
 487         }
 488
 489         return -EOPNOTSUPP;
 490 }