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         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         unsigned int i;
 155         struct kvm_vcpu *v;
 156         bool all_stopped = true;
 157
 158         kvm_for_each_vcpu(i, v, vcpu->kvm) {
 159                 if (v == vcpu)
 160                         continue;
 161                 if (!is_vcpu_stopped(v))
 162                         all_stopped = false;
 163         }
 164
 165         *status_reg &= 0xffffffff00000000UL;
 166
 167         /* Reject set arch order, with czam we're always in z/Arch mode. */
 168         *status_reg |= (all_stopped ? SIGP_STATUS_INVALID_PARAMETER :
 169                                         SIGP_STATUS_INCORRECT_STATE);
 170         return SIGP_CC_STATUS_STORED;
 171 }
 172
 173 static int __sigp_set_prefix(struct kvm_vcpu *vcpu, struct kvm_vcpu *dst_vcpu,
 174                              u32 address, u64 *reg)
 175 {
 176         struct kvm_s390_irq irq = {
 177                 .type = KVM_S390_SIGP_SET_PREFIX,
 178                 .u.prefix.address = address & 0x7fffe000u,
 179         };
 180         int rc;
 181
 182         /*
 183          * Make sure the new value is valid memory. We only need to check the
 184          * first page, since address is 8k aligned and memory pieces are always
 185          * at least 1MB aligned and have at least a size of 1MB.
 186          */
 187         if (kvm_is_error_gpa(vcpu->kvm, irq.u.prefix.address)) {
 188                 *reg &= 0xffffffff00000000UL;
 189                 *reg |= SIGP_STATUS_INVALID_PARAMETER;
 190                 return SIGP_CC_STATUS_STORED;
 191         }
 192
 193         rc = kvm_s390_inject_vcpu(dst_vcpu, &irq);
 194         if (rc == -EBUSY) {
 195                 *reg &= 0xffffffff00000000UL;
 196                 *reg |= SIGP_STATUS_INCORRECT_STATE;
 197                 return SIGP_CC_STATUS_STORED;
 198         }
 199
 200         return rc;
 201 }
 202
 203 static int __sigp_store_status_at_addr(struct kvm_vcpu *vcpu,
 204                                        struct kvm_vcpu *dst_vcpu,
 205                                        u32 addr, u64 *reg)
 206 {
 207         int rc;
 208
 209         if (!kvm_s390_test_cpuflags(dst_vcpu, CPUSTAT_STOPPED)) {
 210                 *reg &= 0xffffffff00000000UL;
 211                 *reg |= SIGP_STATUS_INCORRECT_STATE;
 212                 return SIGP_CC_STATUS_STORED;
 213         }
 214
 215         addr &= 0x7ffffe00;
 216         rc = kvm_s390_store_status_unloaded(dst_vcpu, addr);
 217         if (rc == -EFAULT) {
 218                 *reg &= 0xffffffff00000000UL;
 219                 *reg |= SIGP_STATUS_INVALID_PARAMETER;
 220                 rc = SIGP_CC_STATUS_STORED;
 221         }
 222         return rc;
 223 }
 224
 225 static int __sigp_sense_running(struct kvm_vcpu *vcpu,
 226                                 struct kvm_vcpu *dst_vcpu, u64 *reg)
 227 {
 228         int rc;
 229
 230         if (!test_kvm_facility(vcpu->kvm, 9)) {
 231                 *reg &= 0xffffffff00000000UL;
 232                 *reg |= SIGP_STATUS_INVALID_ORDER;
 233                 return SIGP_CC_STATUS_STORED;
 234         }
 235
 236         if (kvm_s390_test_cpuflags(dst_vcpu, CPUSTAT_RUNNING)) {
 237                 /* running */
 238                 rc = SIGP_CC_ORDER_CODE_ACCEPTED;
 239         } else {
 240                 /* not running */
 241                 *reg &= 0xffffffff00000000UL;
 242                 *reg |= SIGP_STATUS_NOT_RUNNING;
 243                 rc = SIGP_CC_STATUS_STORED;
 244         }
 245
 246         VCPU_EVENT(vcpu, 4, "sensed running status of cpu %x rc %x",
 247                    dst_vcpu->vcpu_id, rc);
 248
 249         return rc;
 250 }
 251
 252 static int __prepare_sigp_re_start(struct kvm_vcpu *vcpu,
 253                                    struct kvm_vcpu *dst_vcpu, u8 order_code)
 254 {
 255         struct kvm_s390_local_interrupt *li = &dst_vcpu->arch.local_int;
 256         /* handle (RE)START in user space */
 257         int rc = -EOPNOTSUPP;
 258
 259         /* make sure we don't race with STOP irq injection */
 260         spin_lock(&li->lock);
 261         if (kvm_s390_is_stop_irq_pending(dst_vcpu))
 262                 rc = SIGP_CC_BUSY;
 263         spin_unlock(&li->lock);
 264
 265         return rc;
 266 }
 267
 268 static int __prepare_sigp_cpu_reset(struct kvm_vcpu *vcpu,
 269                                     struct kvm_vcpu *dst_vcpu, u8 order_code)
 270 {
 271         /* handle (INITIAL) CPU RESET in user space */
 272         return -EOPNOTSUPP;
 273 }
 274
 275 static int __prepare_sigp_unknown(struct kvm_vcpu *vcpu,
 276                                   struct kvm_vcpu *dst_vcpu)
 277 {
 278         /* handle unknown orders in user space */
 279         return -EOPNOTSUPP;
 280 }
 281
 282 static int handle_sigp_dst(struct kvm_vcpu *vcpu, u8 order_code,
 283                            u16 cpu_addr, u32 parameter, u64 *status_reg)
 284 {
 285         int rc;
 286         struct kvm_vcpu *dst_vcpu = kvm_get_vcpu_by_id(vcpu->kvm, cpu_addr);
 287
 288         if (!dst_vcpu)
 289                 return SIGP_CC_NOT_OPERATIONAL;
 290
 291         /*
 292          * SIGP RESTART, SIGP STOP, and SIGP STOP AND STORE STATUS orders
 293          * are processed asynchronously. Until the affected VCPU finishes
 294          * its work and calls back into KVM to clear the (RESTART or STOP)
 295          * interrupt, we need to return any new non-reset orders "busy".
 296          *
 297          * This is important because a single VCPU could issue:
 298          *  1) SIGP STOP $DESTINATION
 299          *  2) SIGP SENSE $DESTINATION
 300          *
 301          * If the SIGP SENSE would not be rejected as "busy", it could
 302          * return an incorrect answer as to whether the VCPU is STOPPED
 303          * or OPERATING.
 304          */
 305         if (order_code != SIGP_INITIAL_CPU_RESET &&
 306             order_code != SIGP_CPU_RESET) {
 307                 /*
 308                  * Lockless check. Both SIGP STOP and SIGP (RE)START
 309                  * properly synchronize everything while processing
 310                  * their orders, while the guest cannot observe a
 311                  * difference when issuing other orders from two
 312                  * different VCPUs.
 313                  */
 314                 if (kvm_s390_is_stop_irq_pending(dst_vcpu) ||
 315                     kvm_s390_is_restart_irq_pending(dst_vcpu))
 316                         return SIGP_CC_BUSY;
 317         }
 318
 319         switch (order_code) {
 320         case SIGP_SENSE:
 321                 vcpu->stat.instruction_sigp_sense++;
 322                 rc = __sigp_sense(vcpu, dst_vcpu, status_reg);
 323                 break;
 324         case SIGP_EXTERNAL_CALL:
 325                 vcpu->stat.instruction_sigp_external_call++;
 326                 rc = __sigp_external_call(vcpu, dst_vcpu, status_reg);
 327                 break;
 328         case SIGP_EMERGENCY_SIGNAL:
 329                 vcpu->stat.instruction_sigp_emergency++;
 330                 rc = __sigp_emergency(vcpu, dst_vcpu);
 331                 break;
 332         case SIGP_STOP:
 333                 vcpu->stat.instruction_sigp_stop++;
 334                 rc = __sigp_stop(vcpu, dst_vcpu);
 335                 break;
 336         case SIGP_STOP_AND_STORE_STATUS:
 337                 vcpu->stat.instruction_sigp_stop_store_status++;
 338                 rc = __sigp_stop_and_store_status(vcpu, dst_vcpu, status_reg);
 339                 break;
 340         case SIGP_STORE_STATUS_AT_ADDRESS:
 341                 vcpu->stat.instruction_sigp_store_status++;
 342                 rc = __sigp_store_status_at_addr(vcpu, dst_vcpu, parameter,
 343                                                  status_reg);
 344                 break;
 345         case SIGP_SET_PREFIX:
 346                 vcpu->stat.instruction_sigp_prefix++;
 347                 rc = __sigp_set_prefix(vcpu, dst_vcpu, parameter, status_reg);
 348                 break;
 349         case SIGP_COND_EMERGENCY_SIGNAL:
 350                 vcpu->stat.instruction_sigp_cond_emergency++;
 351                 rc = __sigp_conditional_emergency(vcpu, dst_vcpu, parameter,
 352                                                   status_reg);
 353                 break;
 354         case SIGP_SENSE_RUNNING:
 355                 vcpu->stat.instruction_sigp_sense_running++;
 356                 rc = __sigp_sense_running(vcpu, dst_vcpu, status_reg);
 357                 break;
 358         case SIGP_START:
 359                 vcpu->stat.instruction_sigp_start++;
 360                 rc = __prepare_sigp_re_start(vcpu, dst_vcpu, order_code);
 361                 break;
 362         case SIGP_RESTART:
 363                 vcpu->stat.instruction_sigp_restart++;
 364                 rc = __prepare_sigp_re_start(vcpu, dst_vcpu, order_code);
 365                 break;
 366         case SIGP_INITIAL_CPU_RESET:
 367                 vcpu->stat.instruction_sigp_init_cpu_reset++;
 368                 rc = __prepare_sigp_cpu_reset(vcpu, dst_vcpu, order_code);
 369                 break;
 370         case SIGP_CPU_RESET:
 371                 vcpu->stat.instruction_sigp_cpu_reset++;
 372                 rc = __prepare_sigp_cpu_reset(vcpu, dst_vcpu, order_code);
 373                 break;
 374         default:
 375                 vcpu->stat.instruction_sigp_unknown++;
 376                 rc = __prepare_sigp_unknown(vcpu, dst_vcpu);
 377         }
 378
 379         if (rc == -EOPNOTSUPP)
 380                 VCPU_EVENT(vcpu, 4,
 381                            "sigp order %u -> cpu %x: handled in user space",
 382                            order_code, dst_vcpu->vcpu_id);
 383
 384         return rc;
 385 }
 386
 387 static int handle_sigp_order_in_user_space(struct kvm_vcpu *vcpu, u8 order_code,
 388                                            u16 cpu_addr)
 389 {
 390         if (!vcpu->kvm->arch.user_sigp)
 391                 return 0;
 392
 393         switch (order_code) {
 394         case SIGP_SENSE:
 395         case SIGP_EXTERNAL_CALL:
 396         case SIGP_EMERGENCY_SIGNAL:
 397         case SIGP_COND_EMERGENCY_SIGNAL:
 398         case SIGP_SENSE_RUNNING:
 399                 return 0;
 400         /* update counters as we're directly dropping to user space */
 401         case SIGP_STOP:
 402                 vcpu->stat.instruction_sigp_stop++;
 403                 break;
 404         case SIGP_STOP_AND_STORE_STATUS:
 405                 vcpu->stat.instruction_sigp_stop_store_status++;
 406                 break;
 407         case SIGP_STORE_STATUS_AT_ADDRESS:
 408                 vcpu->stat.instruction_sigp_store_status++;
 409                 break;
 410         case SIGP_STORE_ADDITIONAL_STATUS:
 411                 vcpu->stat.instruction_sigp_store_adtl_status++;
 412                 break;
 413         case SIGP_SET_PREFIX:
 414                 vcpu->stat.instruction_sigp_prefix++;
 415                 break;
 416         case SIGP_START:
 417                 vcpu->stat.instruction_sigp_start++;
 418                 break;
 419         case SIGP_RESTART:
 420                 vcpu->stat.instruction_sigp_restart++;
 421                 break;
 422         case SIGP_INITIAL_CPU_RESET:
 423                 vcpu->stat.instruction_sigp_init_cpu_reset++;
 424                 break;
 425         case SIGP_CPU_RESET:
 426                 vcpu->stat.instruction_sigp_cpu_reset++;
 427                 break;
 428         default:
 429                 vcpu->stat.instruction_sigp_unknown++;
 430         }
 431         VCPU_EVENT(vcpu, 3, "SIGP: order %u for CPU %d handled in userspace",
 432                    order_code, cpu_addr);
 433
 434         return 1;
 435 }
 436
 437 int kvm_s390_handle_sigp(struct kvm_vcpu *vcpu)
 438 {
 439         int r1 = (vcpu->arch.sie_block->ipa & 0x00f0) >> 4;
 440         int r3 = vcpu->arch.sie_block->ipa & 0x000f;
 441         u32 parameter;
 442         u16 cpu_addr = vcpu->run->s.regs.gprs[r3];
 443         u8 order_code;
 444         int rc;
 445
 446         /* sigp in userspace can exit */
 447         if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
 448                 return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);
 449
 450         order_code = kvm_s390_get_base_disp_rs(vcpu, NULL);
 451         if (handle_sigp_order_in_user_space(vcpu, order_code, cpu_addr))
 452                 return -EOPNOTSUPP;
 453
 454         if (r1 % 2)
 455                 parameter = vcpu->run->s.regs.gprs[r1];
 456         else
 457                 parameter = vcpu->run->s.regs.gprs[r1 + 1];
 458
 459         trace_kvm_s390_handle_sigp(vcpu, order_code, cpu_addr, parameter);
 460         switch (order_code) {
 461         case SIGP_SET_ARCHITECTURE:
 462                 vcpu->stat.instruction_sigp_arch++;
 463                 rc = __sigp_set_arch(vcpu, parameter,
 464                                      &vcpu->run->s.regs.gprs[r1]);
 465                 break;
 466         default:
 467                 rc = handle_sigp_dst(vcpu, order_code, cpu_addr,
 468                                      parameter,
 469                                      &vcpu->run->s.regs.gprs[r1]);
 470         }
 471
 472         if (rc < 0)
 473                 return rc;
 474
 475         kvm_s390_set_psw_cc(vcpu, rc);
 476         return 0;
 477 }
 478
 479 /*
 480  * Handle SIGP partial execution interception.
 481  *
 482  * This interception will occur at the source cpu when a source cpu sends an
 483  * external call to a target cpu and the target cpu has the WAIT bit set in
 484  * its cpuflags. Interception will occurr after the interrupt indicator bits at
 485  * the target cpu have been set. All error cases will lead to instruction
 486  * interception, therefore nothing is to be checked or prepared.
 487  */
 488 int kvm_s390_handle_sigp_pei(struct kvm_vcpu *vcpu)
 489 {
 490         int r3 = vcpu->arch.sie_block->ipa & 0x000f;
 491         u16 cpu_addr = vcpu->run->s.regs.gprs[r3];
 492         struct kvm_vcpu *dest_vcpu;
 493         u8 order_code = kvm_s390_get_base_disp_rs(vcpu, NULL);
 494
 495         trace_kvm_s390_handle_sigp_pei(vcpu, order_code, cpu_addr);
 496
 497         if (order_code == SIGP_EXTERNAL_CALL) {
 498                 dest_vcpu = kvm_get_vcpu_by_id(vcpu->kvm, cpu_addr);
 499                 BUG_ON(dest_vcpu == NULL);
 500
 501                 kvm_s390_vcpu_wakeup(dest_vcpu);
 502                 kvm_s390_set_psw_cc(vcpu, SIGP_CC_ORDER_CODE_ACCEPTED);
 503                 return 0;
 504         }
 505
 506         return -EOPNOTSUPP;
 507 }