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 <[email protected]>
   8  *               Christian Borntraeger <[email protected]>
   9  *               Christian Ehrhardt <[email protected]>
  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         const bool stopped = kvm_s390_test_cpuflags(dst_vcpu, CPUSTAT_STOPPED);
  24         int rc;
  25         int ext_call_pending;
  26
  27         ext_call_pending = kvm_s390_ext_call_pending(dst_vcpu);
  28         if (!stopped && !ext_call_pending)
  29                 rc = SIGP_CC_ORDER_CODE_ACCEPTED;
  30         else {
  31                 *reg &= 0xffffffff00000000UL;
  32                 if (ext_call_pending)
  33                         *reg |= SIGP_STATUS_EXT_CALL_PENDING;
  34                 if (stopped)
  35                         *reg |= SIGP_STATUS_STOPPED;
  36                 rc = SIGP_CC_STATUS_STORED;
  37         }
  38
  39         VCPU_EVENT(vcpu, 4, "sensed status of cpu %x rc %x", dst_vcpu->vcpu_id,
  40                    rc);
  41         return rc;
  42 }
  43
  44 static int __inject_sigp_emergency(struct kvm_vcpu *vcpu,
  45                                     struct kvm_vcpu *dst_vcpu)
  46 {
  47         struct kvm_s390_irq irq = {
  48                 .type = KVM_S390_INT_EMERGENCY,
  49                 .u.emerg.code = vcpu->vcpu_id,
  50         };
  51         int rc = 0;
  52
  53         rc = kvm_s390_inject_vcpu(dst_vcpu, &irq);
  54         if (!rc)
  55                 VCPU_EVENT(vcpu, 4, "sent sigp emerg to cpu %x",
  56                            dst_vcpu->vcpu_id);
  57
  58         return rc ? rc : SIGP_CC_ORDER_CODE_ACCEPTED;
  59 }
  60
  61 static int __sigp_emergency(struct kvm_vcpu *vcpu, struct kvm_vcpu *dst_vcpu)
  62 {
  63         return __inject_sigp_emergency(vcpu, dst_vcpu);
  64 }
  65
  66 static int __sigp_conditional_emergency(struct kvm_vcpu *vcpu,
  67                                         struct kvm_vcpu *dst_vcpu,
  68                                         u16 asn, u64 *reg)
  69 {
  70         const u64 psw_int_mask = PSW_MASK_IO | PSW_MASK_EXT;
  71         u16 p_asn, s_asn;
  72         psw_t *psw;
  73         bool idle;
  74
  75         idle = is_vcpu_idle(vcpu);
  76         psw = &dst_vcpu->arch.sie_block->gpsw;
  77         p_asn = dst_vcpu->arch.sie_block->gcr[4] & 0xffff;  /* Primary ASN */
  78         s_asn = dst_vcpu->arch.sie_block->gcr[3] & 0xffff;  /* Secondary ASN */
  79
  80         /* Inject the emergency signal? */
  81         if (!is_vcpu_stopped(vcpu)
  82             || (psw->mask & psw_int_mask) != psw_int_mask
  83             || (idle && psw->addr != 0)
  84             || (!idle && (asn == p_asn || asn == s_asn))) {
  85                 return __inject_sigp_emergency(vcpu, dst_vcpu);
  86         } else {
  87                 *reg &= 0xffffffff00000000UL;
  88                 *reg |= SIGP_STATUS_INCORRECT_STATE;
  89                 return SIGP_CC_STATUS_STORED;
  90         }
  91 }
  92
  93 static int __sigp_external_call(struct kvm_vcpu *vcpu,
  94                                 struct kvm_vcpu *dst_vcpu, u64 *reg)
  95 {
  96         struct kvm_s390_irq irq = {
  97                 .type = KVM_S390_INT_EXTERNAL_CALL,
  98                 .u.extcall.code = vcpu->vcpu_id,
  99         };
 100         int rc;
 101
 102         rc = kvm_s390_inject_vcpu(dst_vcpu, &irq);
 103         if (rc == -EBUSY) {
 104                 *reg &= 0xffffffff00000000UL;
 105                 *reg |= SIGP_STATUS_EXT_CALL_PENDING;
 106                 return SIGP_CC_STATUS_STORED;
 107         } else if (rc == 0) {
 108                 VCPU_EVENT(vcpu, 4, "sent sigp ext call to cpu %x",
 109                            dst_vcpu->vcpu_id);
 110         }
 111
 112         return rc ? rc : SIGP_CC_ORDER_CODE_ACCEPTED;
 113 }
 114
 115 static int __sigp_stop(struct kvm_vcpu *vcpu, struct kvm_vcpu *dst_vcpu)
 116 {
 117         struct kvm_s390_irq irq = {
 118                 .type = KVM_S390_SIGP_STOP,
 119         };
 120         int rc;
 121
 122         rc = kvm_s390_inject_vcpu(dst_vcpu, &irq);
 123         if (rc == -EBUSY)
 124                 rc = SIGP_CC_BUSY;
 125         else if (rc == 0)
 126                 VCPU_EVENT(vcpu, 4, "sent sigp stop to cpu %x",
 127                            dst_vcpu->vcpu_id);
 128
 129         return rc;
 130 }
 131
 132 static int __sigp_stop_and_store_status(struct kvm_vcpu *vcpu,
 133                                         struct kvm_vcpu *dst_vcpu, u64 *reg)
 134 {
 135         struct kvm_s390_irq irq = {
 136                 .type = KVM_S390_SIGP_STOP,
 137                 .u.stop.flags = KVM_S390_STOP_FLAG_STORE_STATUS,
 138         };
 139         int rc;
 140
 141         rc = kvm_s390_inject_vcpu(dst_vcpu, &irq);
 142         if (rc == -EBUSY)
 143                 rc = SIGP_CC_BUSY;
 144         else if (rc == 0)
 145                 VCPU_EVENT(vcpu, 4, "sent sigp stop and store status to cpu %x",
 146                            dst_vcpu->vcpu_id);
 147
 148         return rc;
 149 }
 150
 151 static int __sigp_set_arch(struct kvm_vcpu *vcpu, u32 parameter,
 152                            u64 *status_reg)
 153 {
 154         *status_reg &= 0xffffffff00000000UL;
 155
 156         /* Reject set arch order, with czam we're always in z/Arch mode. */
 157         *status_reg |= SIGP_STATUS_INVALID_PARAMETER;
 158         return SIGP_CC_STATUS_STORED;
 159 }
 160
 161 static int __sigp_set_prefix(struct kvm_vcpu *vcpu, struct kvm_vcpu *dst_vcpu,
 162                              u32 address, u64 *reg)
 163 {
 164         struct kvm_s390_irq irq = {
 165                 .type = KVM_S390_SIGP_SET_PREFIX,
 166                 .u.prefix.address = address & 0x7fffe000u,
 167         };
 168         int rc;
 169
 170         /*
 171          * Make sure the new value is valid memory. We only need to check the
 172          * first page, since address is 8k aligned and memory pieces are always
 173          * at least 1MB aligned and have at least a size of 1MB.
 174          */
 175         if (kvm_is_error_gpa(vcpu->kvm, irq.u.prefix.address)) {
 176                 *reg &= 0xffffffff00000000UL;
 177                 *reg |= SIGP_STATUS_INVALID_PARAMETER;
 178                 return SIGP_CC_STATUS_STORED;
 179         }
 180
 181         rc = kvm_s390_inject_vcpu(dst_vcpu, &irq);
 182         if (rc == -EBUSY) {
 183                 *reg &= 0xffffffff00000000UL;
 184                 *reg |= SIGP_STATUS_INCORRECT_STATE;
 185                 return SIGP_CC_STATUS_STORED;
 186         }
 187
 188         return rc;
 189 }
 190
 191 static int __sigp_store_status_at_addr(struct kvm_vcpu *vcpu,
 192                                        struct kvm_vcpu *dst_vcpu,
 193                                        u32 addr, u64 *reg)
 194 {
 195         int rc;
 196
 197         if (!kvm_s390_test_cpuflags(dst_vcpu, CPUSTAT_STOPPED)) {
 198                 *reg &= 0xffffffff00000000UL;
 199                 *reg |= SIGP_STATUS_INCORRECT_STATE;
 200                 return SIGP_CC_STATUS_STORED;
 201         }
 202
 203         addr &= 0x7ffffe00;
 204         rc = kvm_s390_store_status_unloaded(dst_vcpu, addr);
 205         if (rc == -EFAULT) {
 206                 *reg &= 0xffffffff00000000UL;
 207                 *reg |= SIGP_STATUS_INVALID_PARAMETER;
 208                 rc = SIGP_CC_STATUS_STORED;
 209         }
 210         return rc;
 211 }
 212
 213 static int __sigp_sense_running(struct kvm_vcpu *vcpu,
 214                                 struct kvm_vcpu *dst_vcpu, u64 *reg)
 215 {
 216         int rc;
 217
 218         if (!test_kvm_facility(vcpu->kvm, 9)) {
 219                 *reg &= 0xffffffff00000000UL;
 220                 *reg |= SIGP_STATUS_INVALID_ORDER;
 221                 return SIGP_CC_STATUS_STORED;
 222         }
 223
 224         if (kvm_s390_test_cpuflags(dst_vcpu, CPUSTAT_RUNNING)) {
 225                 /* running */
 226                 rc = SIGP_CC_ORDER_CODE_ACCEPTED;
 227         } else {
 228                 /* not running */
 229                 *reg &= 0xffffffff00000000UL;
 230                 *reg |= SIGP_STATUS_NOT_RUNNING;
 231                 rc = SIGP_CC_STATUS_STORED;
 232         }
 233
 234         VCPU_EVENT(vcpu, 4, "sensed running status of cpu %x rc %x",
 235                    dst_vcpu->vcpu_id, rc);
 236
 237         return rc;
 238 }
 239
 240 static int __prepare_sigp_re_start(struct kvm_vcpu *vcpu,
 241                                    struct kvm_vcpu *dst_vcpu, u8 order_code)
 242 {
 243         struct kvm_s390_local_interrupt *li = &dst_vcpu->arch.local_int;
 244         /* handle (RE)START in user space */
 245         int rc = -EOPNOTSUPP;
 246
 247         /* make sure we don't race with STOP irq injection */
 248         spin_lock(&li->lock);
 249         if (kvm_s390_is_stop_irq_pending(dst_vcpu))
 250                 rc = SIGP_CC_BUSY;
 251         spin_unlock(&li->lock);
 252
 253         return rc;
 254 }
 255
 256 static int __prepare_sigp_cpu_reset(struct kvm_vcpu *vcpu,
 257                                     struct kvm_vcpu *dst_vcpu, u8 order_code)
 258 {
 259         /* handle (INITIAL) CPU RESET in user space */
 260         return -EOPNOTSUPP;
 261 }
 262
 263 static int __prepare_sigp_unknown(struct kvm_vcpu *vcpu,
 264                                   struct kvm_vcpu *dst_vcpu)
 265 {
 266         /* handle unknown orders in user space */
 267         return -EOPNOTSUPP;
 268 }
 269
 270 static int handle_sigp_dst(struct kvm_vcpu *vcpu, u8 order_code,
 271                            u16 cpu_addr, u32 parameter, u64 *status_reg)
 272 {
 273         int rc;
 274         struct kvm_vcpu *dst_vcpu = kvm_get_vcpu_by_id(vcpu->kvm, cpu_addr);
 275
 276         if (!dst_vcpu)
 277                 return SIGP_CC_NOT_OPERATIONAL;
 278
 279         /*
 280          * SIGP RESTART, SIGP STOP, and SIGP STOP AND STORE STATUS orders
 281          * are processed asynchronously. Until the affected VCPU finishes
 282          * its work and calls back into KVM to clear the (RESTART or STOP)
 283          * interrupt, we need to return any new non-reset orders "busy".
 284          *
 285          * This is important because a single VCPU could issue:
 286          *  1) SIGP STOP $DESTINATION
 287          *  2) SIGP SENSE $DESTINATION
 288          *
 289          * If the SIGP SENSE would not be rejected as "busy", it could
 290          * return an incorrect answer as to whether the VCPU is STOPPED
 291          * or OPERATING.
 292          */
 293         if (order_code != SIGP_INITIAL_CPU_RESET &&
 294             order_code != SIGP_CPU_RESET) {
 295                 /*
 296                  * Lockless check. Both SIGP STOP and SIGP (RE)START
 297                  * properly synchronize everything while processing
 298                  * their orders, while the guest cannot observe a
 299                  * difference when issuing other orders from two
 300                  * different VCPUs.
 301                  */
 302                 if (kvm_s390_is_stop_irq_pending(dst_vcpu) ||
 303                     kvm_s390_is_restart_irq_pending(dst_vcpu))
 304                         return SIGP_CC_BUSY;
 305         }
 306
 307         switch (order_code) {
 308         case SIGP_SENSE:
 309                 vcpu->stat.instruction_sigp_sense++;
 310                 rc = __sigp_sense(vcpu, dst_vcpu, status_reg);
 311                 break;
 312         case SIGP_EXTERNAL_CALL:
 313                 vcpu->stat.instruction_sigp_external_call++;
 314                 rc = __sigp_external_call(vcpu, dst_vcpu, status_reg);
 315                 break;
 316         case SIGP_EMERGENCY_SIGNAL:
 317                 vcpu->stat.instruction_sigp_emergency++;
 318                 rc = __sigp_emergency(vcpu, dst_vcpu);
 319                 break;
 320         case SIGP_STOP:
 321                 vcpu->stat.instruction_sigp_stop++;
 322                 rc = __sigp_stop(vcpu, dst_vcpu);
 323                 break;
 324         case SIGP_STOP_AND_STORE_STATUS:
 325                 vcpu->stat.instruction_sigp_stop_store_status++;
 326                 rc = __sigp_stop_and_store_status(vcpu, dst_vcpu, status_reg);
 327                 break;
 328         case SIGP_STORE_STATUS_AT_ADDRESS:
 329                 vcpu->stat.instruction_sigp_store_status++;
 330                 rc = __sigp_store_status_at_addr(vcpu, dst_vcpu, parameter,
 331                                                  status_reg);
 332                 break;
 333         case SIGP_SET_PREFIX:
 334                 vcpu->stat.instruction_sigp_prefix++;
 335                 rc = __sigp_set_prefix(vcpu, dst_vcpu, parameter, status_reg);
 336                 break;
 337         case SIGP_COND_EMERGENCY_SIGNAL:
 338                 vcpu->stat.instruction_sigp_cond_emergency++;
 339                 rc = __sigp_conditional_emergency(vcpu, dst_vcpu, parameter,
 340                                                   status_reg);
 341                 break;
 342         case SIGP_SENSE_RUNNING:
 343                 vcpu->stat.instruction_sigp_sense_running++;
 344                 rc = __sigp_sense_running(vcpu, dst_vcpu, status_reg);
 345                 break;
 346         case SIGP_START:
 347                 vcpu->stat.instruction_sigp_start++;
 348                 rc = __prepare_sigp_re_start(vcpu, dst_vcpu, order_code);
 349                 break;
 350         case SIGP_RESTART:
 351                 vcpu->stat.instruction_sigp_restart++;
 352                 rc = __prepare_sigp_re_start(vcpu, dst_vcpu, order_code);
 353                 break;
 354         case SIGP_INITIAL_CPU_RESET:
 355                 vcpu->stat.instruction_sigp_init_cpu_reset++;
 356                 rc = __prepare_sigp_cpu_reset(vcpu, dst_vcpu, order_code);
 357                 break;
 358         case SIGP_CPU_RESET:
 359                 vcpu->stat.instruction_sigp_cpu_reset++;
 360                 rc = __prepare_sigp_cpu_reset(vcpu, dst_vcpu, order_code);
 361                 break;
 362         default:
 363                 vcpu->stat.instruction_sigp_unknown++;
 364                 rc = __prepare_sigp_unknown(vcpu, dst_vcpu);
 365         }
 366
 367         if (rc == -EOPNOTSUPP)
 368                 VCPU_EVENT(vcpu, 4,
 369                            "sigp order %u -> cpu %x: handled in user space",
 370                            order_code, dst_vcpu->vcpu_id);
 371
 372         return rc;
 373 }
 374
 375 static int handle_sigp_order_in_user_space(struct kvm_vcpu *vcpu, u8 order_code,
 376                                            u16 cpu_addr)
 377 {
 378         if (!vcpu->kvm->arch.user_sigp)
 379                 return 0;
 380
 381         switch (order_code) {
 382         case SIGP_SENSE:
 383         case SIGP_EXTERNAL_CALL:
 384         case SIGP_EMERGENCY_SIGNAL:
 385         case SIGP_COND_EMERGENCY_SIGNAL:
 386         case SIGP_SENSE_RUNNING:
 387                 return 0;
 388         /* update counters as we're directly dropping to user space */
 389         case SIGP_STOP:
 390                 vcpu->stat.instruction_sigp_stop++;
 391                 break;
 392         case SIGP_STOP_AND_STORE_STATUS:
 393                 vcpu->stat.instruction_sigp_stop_store_status++;
 394                 break;
 395         case SIGP_STORE_STATUS_AT_ADDRESS:
 396                 vcpu->stat.instruction_sigp_store_status++;
 397                 break;
 398         case SIGP_STORE_ADDITIONAL_STATUS:
 399                 vcpu->stat.instruction_sigp_store_adtl_status++;
 400                 break;
 401         case SIGP_SET_PREFIX:
 402                 vcpu->stat.instruction_sigp_prefix++;
 403                 break;
 404         case SIGP_START:
 405                 vcpu->stat.instruction_sigp_start++;
 406                 break;
 407         case SIGP_RESTART:
 408                 vcpu->stat.instruction_sigp_restart++;
 409                 break;
 410         case SIGP_INITIAL_CPU_RESET:
 411                 vcpu->stat.instruction_sigp_init_cpu_reset++;
 412                 break;
 413         case SIGP_CPU_RESET:
 414                 vcpu->stat.instruction_sigp_cpu_reset++;
 415                 break;
 416         default:
 417                 vcpu->stat.instruction_sigp_unknown++;
 418         }
 419         VCPU_EVENT(vcpu, 3, "SIGP: order %u for CPU %d handled in userspace",
 420                    order_code, cpu_addr);
 421
 422         return 1;
 423 }
 424
 425 int kvm_s390_handle_sigp(struct kvm_vcpu *vcpu)
 426 {
 427         int r1 = (vcpu->arch.sie_block->ipa & 0x00f0) >> 4;
 428         int r3 = vcpu->arch.sie_block->ipa & 0x000f;
 429         u32 parameter;
 430         u16 cpu_addr = vcpu->run->s.regs.gprs[r3];
 431         u8 order_code;
 432         int rc;
 433
 434         /* sigp in userspace can exit */
 435         if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
 436                 return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);
 437
 438         order_code = kvm_s390_get_base_disp_rs(vcpu, NULL);
 439         if (handle_sigp_order_in_user_space(vcpu, order_code, cpu_addr))
 440                 return -EOPNOTSUPP;
 441
 442         if (r1 % 2)
 443                 parameter = vcpu->run->s.regs.gprs[r1];
 444         else
 445                 parameter = vcpu->run->s.regs.gprs[r1 + 1];
 446
 447         trace_kvm_s390_handle_sigp(vcpu, order_code, cpu_addr, parameter);
 448         switch (order_code) {
 449         case SIGP_SET_ARCHITECTURE:
 450                 vcpu->stat.instruction_sigp_arch++;
 451                 rc = __sigp_set_arch(vcpu, parameter,
 452                                      &vcpu->run->s.regs.gprs[r1]);
 453                 break;
 454         default:
 455                 rc = handle_sigp_dst(vcpu, order_code, cpu_addr,
 456                                      parameter,
 457                                      &vcpu->run->s.regs.gprs[r1]);
 458         }
 459
 460         if (rc < 0)
 461                 return rc;
 462
 463         kvm_s390_set_psw_cc(vcpu, rc);
 464         return 0;
 465 }
 466
 467 /*
 468  * Handle SIGP partial execution interception.
 469  *
 470  * This interception will occur at the source cpu when a source cpu sends an
 471  * external call to a target cpu and the target cpu has the WAIT bit set in
 472  * its cpuflags. Interception will occurr after the interrupt indicator bits at
 473  * the target cpu have been set. All error cases will lead to instruction
 474  * interception, therefore nothing is to be checked or prepared.
 475  */
 476 int kvm_s390_handle_sigp_pei(struct kvm_vcpu *vcpu)
 477 {
 478         int r3 = vcpu->arch.sie_block->ipa & 0x000f;
 479         u16 cpu_addr = vcpu->run->s.regs.gprs[r3];
 480         struct kvm_vcpu *dest_vcpu;
 481         u8 order_code = kvm_s390_get_base_disp_rs(vcpu, NULL);
 482
 483         if (order_code == SIGP_EXTERNAL_CALL) {
 484                 trace_kvm_s390_handle_sigp_pei(vcpu, order_code, cpu_addr);
 485
 486                 dest_vcpu = kvm_get_vcpu_by_id(vcpu->kvm, cpu_addr);
 487                 BUG_ON(dest_vcpu == NULL);
 488
 489                 kvm_s390_vcpu_wakeup(dest_vcpu);
 490                 kvm_s390_set_psw_cc(vcpu, SIGP_CC_ORDER_CODE_ACCEPTED);
 491                 return 0;
 492         }
 493
 494         return -EOPNOTSUPP;
 495 }