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  *    Author(s): Carsten Otte <cotte@de.ibm.com>
   8  *               Christian Borntraeger <borntraeger@de.ibm.com>
   9  *               Christian Ehrhardt <ehrhardt@de.ibm.com>
  10  */
  11
  12 #include <linux/kvm.h>
  13 #include <linux/kvm_host.h>
  14 #include <linux/slab.h>
  15 #include <asm/sigp.h>
  16 #include "gaccess.h"
  17 #include "kvm-s390.h"
  18 #include "trace.h"
  19
  20 static int __sigp_sense(struct kvm_vcpu *vcpu, struct kvm_vcpu *dst_vcpu,
  21                         u64 *reg)
  22 {
  23         struct kvm_s390_local_interrupt *li;
  24         int cpuflags;
  25         int rc;
  26         int ext_call_pending;
  27
  28         li = &dst_vcpu->arch.local_int;
  29
  30         cpuflags = atomic_read(li->cpuflags);
  31         ext_call_pending = kvm_s390_ext_call_pending(dst_vcpu);
  32         if (!(cpuflags & CPUSTAT_STOPPED) && !ext_call_pending)
  33                 rc = SIGP_CC_ORDER_CODE_ACCEPTED;
  34         else {
  35                 *reg &= 0xffffffff00000000UL;
  36                 if (ext_call_pending)
  37                         *reg |= SIGP_STATUS_EXT_CALL_PENDING;
  38                 if (cpuflags & CPUSTAT_STOPPED)
  39                         *reg |= SIGP_STATUS_STOPPED;
  40                 rc = SIGP_CC_STATUS_STORED;
  41         }
  42
  43         VCPU_EVENT(vcpu, 4, "sensed status of cpu %x rc %x", dst_vcpu->vcpu_id,
  44                    rc);
  45         return rc;
  46 }
  47
  48 static int __inject_sigp_emergency(struct kvm_vcpu *vcpu,
  49                                     struct kvm_vcpu *dst_vcpu)
  50 {
  51         struct kvm_s390_irq irq = {
  52                 .type = KVM_S390_INT_EMERGENCY,
  53                 .u.emerg.code = vcpu->vcpu_id,
  54         };
  55         int rc = 0;
  56
  57         rc = kvm_s390_inject_vcpu(dst_vcpu, &irq);
  58         if (!rc)
  59                 VCPU_EVENT(vcpu, 4, "sent sigp emerg to cpu %x",
  60                            dst_vcpu->vcpu_id);
  61
  62         return rc ? rc : SIGP_CC_ORDER_CODE_ACCEPTED;
  63 }
  64
  65 static int __sigp_emergency(struct kvm_vcpu *vcpu, struct kvm_vcpu *dst_vcpu)
  66 {
  67         return __inject_sigp_emergency(vcpu, dst_vcpu);
  68 }
  69
  70 static int __sigp_conditional_emergency(struct kvm_vcpu *vcpu,
  71                                         struct kvm_vcpu *dst_vcpu,
  72                                         u16 asn, u64 *reg)
  73 {
  74         const u64 psw_int_mask = PSW_MASK_IO | PSW_MASK_EXT;
  75         u16 p_asn, s_asn;
  76         psw_t *psw;
  77         bool idle;
  78
  79         idle = is_vcpu_idle(vcpu);
  80         psw = &dst_vcpu->arch.sie_block->gpsw;
  81         p_asn = dst_vcpu->arch.sie_block->gcr[4] & 0xffff;  /* Primary ASN */
  82         s_asn = dst_vcpu->arch.sie_block->gcr[3] & 0xffff;  /* Secondary ASN */
  83
  84         /* Inject the emergency signal? */
  85         if (!is_vcpu_stopped(vcpu)
  86             || (psw->mask & psw_int_mask) != psw_int_mask
  87             || (idle && psw->addr != 0)
  88             || (!idle && (asn == p_asn || asn == s_asn))) {
  89                 return __inject_sigp_emergency(vcpu, dst_vcpu);
  90         } else {
  91                 *reg &= 0xffffffff00000000UL;
  92                 *reg |= SIGP_STATUS_INCORRECT_STATE;
  93                 return SIGP_CC_STATUS_STORED;
  94         }
  95 }
  96
  97 static int __sigp_external_call(struct kvm_vcpu *vcpu,
  98                                 struct kvm_vcpu *dst_vcpu, u64 *reg)
  99 {
 100         struct kvm_s390_irq irq = {
 101                 .type = KVM_S390_INT_EXTERNAL_CALL,
 102                 .u.extcall.code = vcpu->vcpu_id,
 103         };
 104         int rc;
 105
 106         rc = kvm_s390_inject_vcpu(dst_vcpu, &irq);
 107         if (rc == -EBUSY) {
 108                 *reg &= 0xffffffff00000000UL;
 109                 *reg |= SIGP_STATUS_EXT_CALL_PENDING;
 110                 return SIGP_CC_STATUS_STORED;
 111         } else if (rc == 0) {
 112                 VCPU_EVENT(vcpu, 4, "sent sigp ext call to cpu %x",
 113                            dst_vcpu->vcpu_id);
 114         }
 115
 116         return rc ? rc : SIGP_CC_ORDER_CODE_ACCEPTED;
 117 }
 118
 119 static int __sigp_stop(struct kvm_vcpu *vcpu, struct kvm_vcpu *dst_vcpu)
 120 {
 121         struct kvm_s390_irq irq = {
 122                 .type = KVM_S390_SIGP_STOP,
 123         };
 124         int rc;
 125
 126         rc = kvm_s390_inject_vcpu(dst_vcpu, &irq);
 127         if (rc == -EBUSY)
 128                 rc = SIGP_CC_BUSY;
 129         else if (rc == 0)
 130                 VCPU_EVENT(vcpu, 4, "sent sigp stop to cpu %x",
 131                            dst_vcpu->vcpu_id);
 132
 133         return rc;
 134 }
 135
 136 static int __sigp_stop_and_store_status(struct kvm_vcpu *vcpu,
 137                                         struct kvm_vcpu *dst_vcpu, u64 *reg)
 138 {
 139         struct kvm_s390_irq irq = {
 140                 .type = KVM_S390_SIGP_STOP,
 141                 .u.stop.flags = KVM_S390_STOP_FLAG_STORE_STATUS,
 142         };
 143         int rc;
 144
 145         rc = kvm_s390_inject_vcpu(dst_vcpu, &irq);
 146         if (rc == -EBUSY)
 147                 rc = SIGP_CC_BUSY;
 148         else if (rc == 0)
 149                 VCPU_EVENT(vcpu, 4, "sent sigp stop and store status to cpu %x",
 150                            dst_vcpu->vcpu_id);
 151
 152         return rc;
 153 }
 154
 155 static int __sigp_set_arch(struct kvm_vcpu *vcpu, u32 parameter,
 156                            u64 *status_reg)
 157 {
 158         unsigned int i;
 159         struct kvm_vcpu *v;
 160         bool all_stopped = true;
 161
 162         kvm_for_each_vcpu(i, v, vcpu->kvm) {
 163                 if (v == vcpu)
 164                         continue;
 165                 if (!is_vcpu_stopped(v))
 166                         all_stopped = false;
 167         }
 168
 169         *status_reg &= 0xffffffff00000000UL;
 170
 171         /* Reject set arch order, with czam we're always in z/Arch mode. */
 172         *status_reg |= (all_stopped ? SIGP_STATUS_INVALID_PARAMETER :
 173                                         SIGP_STATUS_INCORRECT_STATE);
 174         return SIGP_CC_STATUS_STORED;
 175 }
 176
 177 static int __sigp_set_prefix(struct kvm_vcpu *vcpu, struct kvm_vcpu *dst_vcpu,
 178                              u32 address, u64 *reg)
 179 {
 180         struct kvm_s390_irq irq = {
 181                 .type = KVM_S390_SIGP_SET_PREFIX,
 182                 .u.prefix.address = address & 0x7fffe000u,
 183         };
 184         int rc;
 185
 186         /*
 187          * Make sure the new value is valid memory. We only need to check the
 188          * first page, since address is 8k aligned and memory pieces are always
 189          * at least 1MB aligned and have at least a size of 1MB.
 190          */
 191         if (kvm_is_error_gpa(vcpu->kvm, irq.u.prefix.address)) {
 192                 *reg &= 0xffffffff00000000UL;
 193                 *reg |= SIGP_STATUS_INVALID_PARAMETER;
 194                 return SIGP_CC_STATUS_STORED;
 195         }
 196
 197         rc = kvm_s390_inject_vcpu(dst_vcpu, &irq);
 198         if (rc == -EBUSY) {
 199                 *reg &= 0xffffffff00000000UL;
 200                 *reg |= SIGP_STATUS_INCORRECT_STATE;
 201                 return SIGP_CC_STATUS_STORED;
 202         }
 203
 204         return rc;
 205 }
 206
 207 static int __sigp_store_status_at_addr(struct kvm_vcpu *vcpu,
 208                                        struct kvm_vcpu *dst_vcpu,
 209                                        u32 addr, u64 *reg)
 210 {
 211         int flags;
 212         int rc;
 213
 214         flags = atomic_read(dst_vcpu->arch.local_int.cpuflags);
 215         if (!(flags & CPUSTAT_STOPPED)) {
 216                 *reg &= 0xffffffff00000000UL;
 217                 *reg |= SIGP_STATUS_INCORRECT_STATE;
 218                 return SIGP_CC_STATUS_STORED;
 219         }
 220
 221         addr &= 0x7ffffe00;
 222         rc = kvm_s390_store_status_unloaded(dst_vcpu, addr);
 223         if (rc == -EFAULT) {
 224                 *reg &= 0xffffffff00000000UL;
 225                 *reg |= SIGP_STATUS_INVALID_PARAMETER;
 226                 rc = SIGP_CC_STATUS_STORED;
 227         }
 228         return rc;
 229 }
 230
 231 static int __sigp_sense_running(struct kvm_vcpu *vcpu,
 232                                 struct kvm_vcpu *dst_vcpu, u64 *reg)
 233 {
 234         struct kvm_s390_local_interrupt *li;
 235         int rc;
 236
 237         if (!test_kvm_facility(vcpu->kvm, 9)) {
 238                 *reg &= 0xffffffff00000000UL;
 239                 *reg |= SIGP_STATUS_INVALID_ORDER;
 240                 return SIGP_CC_STATUS_STORED;
 241         }
 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 = kvm_get_vcpu_by_id(vcpu->kvm, cpu_addr);
 295
 296         if (!dst_vcpu)
 297                 return SIGP_CC_NOT_OPERATIONAL;
 298
 299         switch (order_code) {
 300         case SIGP_SENSE:
 301                 vcpu->stat.instruction_sigp_sense++;
 302                 rc = __sigp_sense(vcpu, dst_vcpu, status_reg);
 303                 break;
 304         case SIGP_EXTERNAL_CALL:
 305                 vcpu->stat.instruction_sigp_external_call++;
 306                 rc = __sigp_external_call(vcpu, dst_vcpu, status_reg);
 307                 break;
 308         case SIGP_EMERGENCY_SIGNAL:
 309                 vcpu->stat.instruction_sigp_emergency++;
 310                 rc = __sigp_emergency(vcpu, dst_vcpu);
 311                 break;
 312         case SIGP_STOP:
 313                 vcpu->stat.instruction_sigp_stop++;
 314                 rc = __sigp_stop(vcpu, dst_vcpu);
 315                 break;
 316         case SIGP_STOP_AND_STORE_STATUS:
 317                 vcpu->stat.instruction_sigp_stop_store_status++;
 318                 rc = __sigp_stop_and_store_status(vcpu, dst_vcpu, status_reg);
 319                 break;
 320         case SIGP_STORE_STATUS_AT_ADDRESS:
 321                 vcpu->stat.instruction_sigp_store_status++;
 322                 rc = __sigp_store_status_at_addr(vcpu, dst_vcpu, parameter,
 323                                                  status_reg);
 324                 break;
 325         case SIGP_SET_PREFIX:
 326                 vcpu->stat.instruction_sigp_prefix++;
 327                 rc = __sigp_set_prefix(vcpu, dst_vcpu, parameter, status_reg);
 328                 break;
 329         case SIGP_COND_EMERGENCY_SIGNAL:
 330                 vcpu->stat.instruction_sigp_cond_emergency++;
 331                 rc = __sigp_conditional_emergency(vcpu, dst_vcpu, parameter,
 332                                                   status_reg);
 333                 break;
 334         case SIGP_SENSE_RUNNING:
 335                 vcpu->stat.instruction_sigp_sense_running++;
 336                 rc = __sigp_sense_running(vcpu, dst_vcpu, status_reg);
 337                 break;
 338         case SIGP_START:
 339                 vcpu->stat.instruction_sigp_start++;
 340                 rc = __prepare_sigp_re_start(vcpu, dst_vcpu, order_code);
 341                 break;
 342         case SIGP_RESTART:
 343                 vcpu->stat.instruction_sigp_restart++;
 344                 rc = __prepare_sigp_re_start(vcpu, dst_vcpu, order_code);
 345                 break;
 346         case SIGP_INITIAL_CPU_RESET:
 347                 vcpu->stat.instruction_sigp_init_cpu_reset++;
 348                 rc = __prepare_sigp_cpu_reset(vcpu, dst_vcpu, order_code);
 349                 break;
 350         case SIGP_CPU_RESET:
 351                 vcpu->stat.instruction_sigp_cpu_reset++;
 352                 rc = __prepare_sigp_cpu_reset(vcpu, dst_vcpu, order_code);
 353                 break;
 354         default:
 355                 vcpu->stat.instruction_sigp_unknown++;
 356                 rc = __prepare_sigp_unknown(vcpu, dst_vcpu);
 357         }
 358
 359         if (rc == -EOPNOTSUPP)
 360                 VCPU_EVENT(vcpu, 4,
 361                            "sigp order %u -> cpu %x: handled in user space",
 362                            order_code, dst_vcpu->vcpu_id);
 363
 364         return rc;
 365 }
 366
 367 static int handle_sigp_order_in_user_space(struct kvm_vcpu *vcpu, u8 order_code,
 368                                            u16 cpu_addr)
 369 {
 370         if (!vcpu->kvm->arch.user_sigp)
 371                 return 0;
 372
 373         switch (order_code) {
 374         case SIGP_SENSE:
 375         case SIGP_EXTERNAL_CALL:
 376         case SIGP_EMERGENCY_SIGNAL:
 377         case SIGP_COND_EMERGENCY_SIGNAL:
 378         case SIGP_SENSE_RUNNING:
 379                 return 0;
 380         /* update counters as we're directly dropping to user space */
 381         case SIGP_STOP:
 382                 vcpu->stat.instruction_sigp_stop++;
 383                 break;
 384         case SIGP_STOP_AND_STORE_STATUS:
 385                 vcpu->stat.instruction_sigp_stop_store_status++;
 386                 break;
 387         case SIGP_STORE_STATUS_AT_ADDRESS:
 388                 vcpu->stat.instruction_sigp_store_status++;
 389                 break;
 390         case SIGP_STORE_ADDITIONAL_STATUS:
 391                 vcpu->stat.instruction_sigp_store_adtl_status++;
 392                 break;
 393         case SIGP_SET_PREFIX:
 394                 vcpu->stat.instruction_sigp_prefix++;
 395                 break;
 396         case SIGP_START:
 397                 vcpu->stat.instruction_sigp_start++;
 398                 break;
 399         case SIGP_RESTART:
 400                 vcpu->stat.instruction_sigp_restart++;
 401                 break;
 402         case SIGP_INITIAL_CPU_RESET:
 403                 vcpu->stat.instruction_sigp_init_cpu_reset++;
 404                 break;
 405         case SIGP_CPU_RESET:
 406                 vcpu->stat.instruction_sigp_cpu_reset++;
 407                 break;
 408         default:
 409                 vcpu->stat.instruction_sigp_unknown++;
 410         }
 411         VCPU_EVENT(vcpu, 3, "SIGP: order %u for CPU %d handled in userspace",
 412                    order_code, cpu_addr);
 413
 414         return 1;
 415 }
 416
 417 int kvm_s390_handle_sigp(struct kvm_vcpu *vcpu)
 418 {
 419         int r1 = (vcpu->arch.sie_block->ipa & 0x00f0) >> 4;
 420         int r3 = vcpu->arch.sie_block->ipa & 0x000f;
 421         u32 parameter;
 422         u16 cpu_addr = vcpu->run->s.regs.gprs[r3];
 423         u8 order_code;
 424         int rc;
 425
 426         /* sigp in userspace can exit */
 427         if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
 428                 return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);
 429
 430         order_code = kvm_s390_get_base_disp_rs(vcpu, NULL);
 431         if (handle_sigp_order_in_user_space(vcpu, order_code, cpu_addr))
 432                 return -EOPNOTSUPP;
 433
 434         if (r1 % 2)
 435                 parameter = vcpu->run->s.regs.gprs[r1];
 436         else
 437                 parameter = vcpu->run->s.regs.gprs[r1 + 1];
 438
 439         trace_kvm_s390_handle_sigp(vcpu, order_code, cpu_addr, parameter);
 440         switch (order_code) {
 441         case SIGP_SET_ARCHITECTURE:
 442                 vcpu->stat.instruction_sigp_arch++;
 443                 rc = __sigp_set_arch(vcpu, parameter,
 444                                      &vcpu->run->s.regs.gprs[r1]);
 445                 break;
 446         default:
 447                 rc = handle_sigp_dst(vcpu, order_code, cpu_addr,
 448                                      parameter,
 449                                      &vcpu->run->s.regs.gprs[r1]);
 450         }
 451
 452         if (rc < 0)
 453                 return rc;
 454
 455         kvm_s390_set_psw_cc(vcpu, rc);
 456         return 0;
 457 }
 458
 459 /*
 460  * Handle SIGP partial execution interception.
 461  *
 462  * This interception will occur at the source cpu when a source cpu sends an
 463  * external call to a target cpu and the target cpu has the WAIT bit set in
 464  * its cpuflags. Interception will occurr after the interrupt indicator bits at
 465  * the target cpu have been set. All error cases will lead to instruction
 466  * interception, therefore nothing is to be checked or prepared.
 467  */
 468 int kvm_s390_handle_sigp_pei(struct kvm_vcpu *vcpu)
 469 {
 470         int r3 = vcpu->arch.sie_block->ipa & 0x000f;
 471         u16 cpu_addr = vcpu->run->s.regs.gprs[r3];
 472         struct kvm_vcpu *dest_vcpu;
 473         u8 order_code = kvm_s390_get_base_disp_rs(vcpu, NULL);
 474
 475         trace_kvm_s390_handle_sigp_pei(vcpu, order_code, cpu_addr);
 476
 477         if (order_code == SIGP_EXTERNAL_CALL) {
 478                 dest_vcpu = kvm_get_vcpu_by_id(vcpu->kvm, cpu_addr);
 479                 BUG_ON(dest_vcpu == NULL);
 480
 481                 kvm_s390_vcpu_wakeup(dest_vcpu);
 482                 kvm_s390_set_psw_cc(vcpu, SIGP_CC_ORDER_CODE_ACCEPTED);
 483                 return 0;
 484         }
 485
 486         return -EOPNOTSUPP;
 487 }