arch/s390/kvm/sigp.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * handling interprocessor communication
   4  *
   5  * Copyright IBM Corp. 2008, 2013
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License (version 2 only)
   9  * as published by the Free Software Foundation.
  10  *
  11  *    Author(s): Carsten Otte <cotte@de.ibm.com>
  12  *               Christian Borntraeger <borntraeger@de.ibm.com>
  13  *               Christian Ehrhardt <ehrhardt@de.ibm.com>
  14  */
  15
  16 #include <linux/kvm.h>
  17 #include <linux/kvm_host.h>
  18 #include <linux/slab.h>
  19 #include <asm/sigp.h>
  20 #include "gaccess.h"
  21 #include "kvm-s390.h"
  22 #include "trace.h"
  23
  24 static int __sigp_sense(struct kvm_vcpu *vcpu, struct kvm_vcpu *dst_vcpu,
  25                         u64 *reg)
  26 {
  27         struct kvm_s390_local_interrupt *li;
  28         int cpuflags;
  29         int rc;
  30         int ext_call_pending;
  31
  32         li = &dst_vcpu->arch.local_int;
  33
  34         cpuflags = atomic_read(li->cpuflags);
  35         ext_call_pending = kvm_s390_ext_call_pending(dst_vcpu);
  36         if (!(cpuflags & CPUSTAT_STOPPED) && !ext_call_pending)
  37                 rc = SIGP_CC_ORDER_CODE_ACCEPTED;
  38         else {
  39                 *reg &= 0xffffffff00000000UL;
  40                 if (ext_call_pending)
  41                         *reg |= SIGP_STATUS_EXT_CALL_PENDING;
  42                 if (cpuflags & CPUSTAT_STOPPED)
  43                         *reg |= SIGP_STATUS_STOPPED;
  44                 rc = SIGP_CC_STATUS_STORED;
  45         }
  46
  47         VCPU_EVENT(vcpu, 4, "sensed status of cpu %x rc %x", dst_vcpu->vcpu_id,
  48                    rc);
  49         return rc;
  50 }
  51
  52 static int __inject_sigp_emergency(struct kvm_vcpu *vcpu,
  53                                     struct kvm_vcpu *dst_vcpu)
  54 {
  55         struct kvm_s390_irq irq = {
  56                 .type = KVM_S390_INT_EMERGENCY,
  57                 .u.emerg.code = vcpu->vcpu_id,
  58         };
  59         int rc = 0;
  60
  61         rc = kvm_s390_inject_vcpu(dst_vcpu, &irq);
  62         if (!rc)
  63                 VCPU_EVENT(vcpu, 4, "sent sigp emerg to cpu %x",
  64                            dst_vcpu->vcpu_id);
  65
  66         return rc ? rc : SIGP_CC_ORDER_CODE_ACCEPTED;
  67 }
  68
  69 static int __sigp_emergency(struct kvm_vcpu *vcpu, struct kvm_vcpu *dst_vcpu)
  70 {
  71         return __inject_sigp_emergency(vcpu, dst_vcpu);
  72 }
  73
  74 static int __sigp_conditional_emergency(struct kvm_vcpu *vcpu,
  75                                         struct kvm_vcpu *dst_vcpu,
  76                                         u16 asn, u64 *reg)
  77 {
  78         const u64 psw_int_mask = PSW_MASK_IO | PSW_MASK_EXT;
  79         u16 p_asn, s_asn;
  80         psw_t *psw;
  81         bool idle;
  82
  83         idle = is_vcpu_idle(vcpu);
  84         psw = &dst_vcpu->arch.sie_block->gpsw;
  85         p_asn = dst_vcpu->arch.sie_block->gcr[4] & 0xffff;  /* Primary ASN */
  86         s_asn = dst_vcpu->arch.sie_block->gcr[3] & 0xffff;  /* Secondary ASN */
  87
  88         /* Inject the emergency signal? */
  89         if (!is_vcpu_stopped(vcpu)
  90             || (psw->mask & psw_int_mask) != psw_int_mask
  91             || (idle && psw->addr != 0)
  92             || (!idle && (asn == p_asn || asn == s_asn))) {
  93                 return __inject_sigp_emergency(vcpu, dst_vcpu);
  94         } else {
  95                 *reg &= 0xffffffff00000000UL;
  96                 *reg |= SIGP_STATUS_INCORRECT_STATE;
  97                 return SIGP_CC_STATUS_STORED;
  98         }
  99 }
 100
 101 static int __sigp_external_call(struct kvm_vcpu *vcpu,
 102                                 struct kvm_vcpu *dst_vcpu, u64 *reg)
 103 {
 104         struct kvm_s390_irq irq = {
 105                 .type = KVM_S390_INT_EXTERNAL_CALL,
 106                 .u.extcall.code = vcpu->vcpu_id,
 107         };
 108         int rc;
 109
 110         rc = kvm_s390_inject_vcpu(dst_vcpu, &irq);
 111         if (rc == -EBUSY) {
 112                 *reg &= 0xffffffff00000000UL;
 113                 *reg |= SIGP_STATUS_EXT_CALL_PENDING;
 114                 return SIGP_CC_STATUS_STORED;
 115         } else if (rc == 0) {
 116                 VCPU_EVENT(vcpu, 4, "sent sigp ext call to cpu %x",
 117                            dst_vcpu->vcpu_id);
 118         }
 119
 120         return rc ? rc : SIGP_CC_ORDER_CODE_ACCEPTED;
 121 }
 122
 123 static int __sigp_stop(struct kvm_vcpu *vcpu, struct kvm_vcpu *dst_vcpu)
 124 {
 125         struct kvm_s390_irq irq = {
 126                 .type = KVM_S390_SIGP_STOP,
 127         };
 128         int rc;
 129
 130         rc = kvm_s390_inject_vcpu(dst_vcpu, &irq);
 131         if (rc == -EBUSY)
 132                 rc = SIGP_CC_BUSY;
 133         else if (rc == 0)
 134                 VCPU_EVENT(vcpu, 4, "sent sigp stop to cpu %x",
 135                            dst_vcpu->vcpu_id);
 136
 137         return rc;
 138 }
 139
 140 static int __sigp_stop_and_store_status(struct kvm_vcpu *vcpu,
 141                                         struct kvm_vcpu *dst_vcpu, u64 *reg)
 142 {
 143         struct kvm_s390_irq irq = {
 144                 .type = KVM_S390_SIGP_STOP,
 145                 .u.stop.flags = KVM_S390_STOP_FLAG_STORE_STATUS,
 146         };
 147         int rc;
 148
 149         rc = kvm_s390_inject_vcpu(dst_vcpu, &irq);
 150         if (rc == -EBUSY)
 151                 rc = SIGP_CC_BUSY;
 152         else if (rc == 0)
 153                 VCPU_EVENT(vcpu, 4, "sent sigp stop and store status to cpu %x",
 154                            dst_vcpu->vcpu_id);
 155
 156         return rc;
 157 }
 158
 159 static int __sigp_set_arch(struct kvm_vcpu *vcpu, u32 parameter,
 160                            u64 *status_reg)
 161 {
 162         unsigned int i;
 163         struct kvm_vcpu *v;
 164         bool all_stopped = true;
 165
 166         kvm_for_each_vcpu(i, v, vcpu->kvm) {
 167                 if (v == vcpu)
 168                         continue;
 169                 if (!is_vcpu_stopped(v))
 170                         all_stopped = false;
 171         }
 172
 173         *status_reg &= 0xffffffff00000000UL;
 174
 175         /* Reject set arch order, with czam we're always in z/Arch mode. */
 176         *status_reg |= (all_stopped ? SIGP_STATUS_INVALID_PARAMETER :
 177                                         SIGP_STATUS_INCORRECT_STATE);
 178         return SIGP_CC_STATUS_STORED;
 179 }
 180
 181 static int __sigp_set_prefix(struct kvm_vcpu *vcpu, struct kvm_vcpu *dst_vcpu,
 182                              u32 address, u64 *reg)
 183 {
 184         struct kvm_s390_irq irq = {
 185                 .type = KVM_S390_SIGP_SET_PREFIX,
 186                 .u.prefix.address = address & 0x7fffe000u,
 187         };
 188         int rc;
 189
 190         /*
 191          * Make sure the new value is valid memory. We only need to check the
 192          * first page, since address is 8k aligned and memory pieces are always
 193          * at least 1MB aligned and have at least a size of 1MB.
 194          */
 195         if (kvm_is_error_gpa(vcpu->kvm, irq.u.prefix.address)) {
 196                 *reg &= 0xffffffff00000000UL;
 197                 *reg |= SIGP_STATUS_INVALID_PARAMETER;
 198                 return SIGP_CC_STATUS_STORED;
 199         }
 200
 201         rc = kvm_s390_inject_vcpu(dst_vcpu, &irq);
 202         if (rc == -EBUSY) {
 203                 *reg &= 0xffffffff00000000UL;
 204                 *reg |= SIGP_STATUS_INCORRECT_STATE;
 205                 return SIGP_CC_STATUS_STORED;
 206         }
 207
 208         return rc;
 209 }
 210
 211 static int __sigp_store_status_at_addr(struct kvm_vcpu *vcpu,
 212                                        struct kvm_vcpu *dst_vcpu,
 213                                        u32 addr, u64 *reg)
 214 {
 215         int flags;
 216         int rc;
 217
 218         flags = atomic_read(dst_vcpu->arch.local_int.cpuflags);
 219         if (!(flags & CPUSTAT_STOPPED)) {
 220                 *reg &= 0xffffffff00000000UL;
 221                 *reg |= SIGP_STATUS_INCORRECT_STATE;
 222                 return SIGP_CC_STATUS_STORED;
 223         }
 224
 225         addr &= 0x7ffffe00;
 226         rc = kvm_s390_store_status_unloaded(dst_vcpu, addr);
 227         if (rc == -EFAULT) {
 228                 *reg &= 0xffffffff00000000UL;
 229                 *reg |= SIGP_STATUS_INVALID_PARAMETER;
 230                 rc = SIGP_CC_STATUS_STORED;
 231         }
 232         return rc;
 233 }
 234
 235 static int __sigp_sense_running(struct kvm_vcpu *vcpu,
 236                                 struct kvm_vcpu *dst_vcpu, u64 *reg)
 237 {
 238         struct kvm_s390_local_interrupt *li;
 239         int rc;
 240
 241         if (!test_kvm_facility(vcpu->kvm, 9)) {
 242                 *reg &= 0xffffffff00000000UL;
 243                 *reg |= SIGP_STATUS_INVALID_ORDER;
 244                 return SIGP_CC_STATUS_STORED;
 245         }
 246
 247         li = &dst_vcpu->arch.local_int;
 248         if (atomic_read(li->cpuflags) & CPUSTAT_RUNNING) {
 249                 /* running */
 250                 rc = SIGP_CC_ORDER_CODE_ACCEPTED;
 251         } else {
 252                 /* not running */
 253                 *reg &= 0xffffffff00000000UL;
 254                 *reg |= SIGP_STATUS_NOT_RUNNING;
 255                 rc = SIGP_CC_STATUS_STORED;
 256         }
 257
 258         VCPU_EVENT(vcpu, 4, "sensed running status of cpu %x rc %x",
 259                    dst_vcpu->vcpu_id, rc);
 260
 261         return rc;
 262 }
 263
 264 static int __prepare_sigp_re_start(struct kvm_vcpu *vcpu,
 265                                    struct kvm_vcpu *dst_vcpu, u8 order_code)
 266 {
 267         struct kvm_s390_local_interrupt *li = &dst_vcpu->arch.local_int;
 268         /* handle (RE)START in user space */
 269         int rc = -EOPNOTSUPP;
 270
 271         /* make sure we don't race with STOP irq injection */
 272         spin_lock(&li->lock);
 273         if (kvm_s390_is_stop_irq_pending(dst_vcpu))
 274                 rc = SIGP_CC_BUSY;
 275         spin_unlock(&li->lock);
 276
 277         return rc;
 278 }
 279
 280 static int __prepare_sigp_cpu_reset(struct kvm_vcpu *vcpu,
 281                                     struct kvm_vcpu *dst_vcpu, u8 order_code)
 282 {
 283         /* handle (INITIAL) CPU RESET in user space */
 284         return -EOPNOTSUPP;
 285 }
 286
 287 static int __prepare_sigp_unknown(struct kvm_vcpu *vcpu,
 288                                   struct kvm_vcpu *dst_vcpu)
 289 {
 290         /* handle unknown orders in user space */
 291         return -EOPNOTSUPP;
 292 }
 293
 294 static int handle_sigp_dst(struct kvm_vcpu *vcpu, u8 order_code,
 295                            u16 cpu_addr, u32 parameter, u64 *status_reg)
 296 {
 297         int rc;
 298         struct kvm_vcpu *dst_vcpu = kvm_get_vcpu_by_id(vcpu->kvm, cpu_addr);
 299
 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                                      &vcpu->run->s.regs.gprs[r1]);
 449                 break;
 450         default:
 451                 rc = handle_sigp_dst(vcpu, order_code, cpu_addr,
 452                                      parameter,
 453                                      &vcpu->run->s.regs.gprs[r1]);
 454         }
 455
 456         if (rc < 0)
 457                 return rc;
 458
 459         kvm_s390_set_psw_cc(vcpu, rc);
 460         return 0;
 461 }
 462
 463 /*
 464  * Handle SIGP partial execution interception.
 465  *
 466  * This interception will occur at the source cpu when a source cpu sends an
 467  * external call to a target cpu and the target cpu has the WAIT bit set in
 468  * its cpuflags. Interception will occurr after the interrupt indicator bits at
 469  * the target cpu have been set. All error cases will lead to instruction
 470  * interception, therefore nothing is to be checked or prepared.
 471  */
 472 int kvm_s390_handle_sigp_pei(struct kvm_vcpu *vcpu)
 473 {
 474         int r3 = vcpu->arch.sie_block->ipa & 0x000f;
 475         u16 cpu_addr = vcpu->run->s.regs.gprs[r3];
 476         struct kvm_vcpu *dest_vcpu;
 477         u8 order_code = kvm_s390_get_base_disp_rs(vcpu, NULL);
 478
 479         trace_kvm_s390_handle_sigp_pei(vcpu, order_code, cpu_addr);
 480
 481         if (order_code == SIGP_EXTERNAL_CALL) {
 482                 dest_vcpu = kvm_get_vcpu_by_id(vcpu->kvm, cpu_addr);
 483                 BUG_ON(dest_vcpu == NULL);
 484
 485                 kvm_s390_vcpu_wakeup(dest_vcpu);
 486                 kvm_s390_set_psw_cc(vcpu, SIGP_CC_ORDER_CODE_ACCEPTED);
 487                 return 0;
 488         }
 489
 490         return -EOPNOTSUPP;
 491 }