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
  30         li = &dst_vcpu->arch.local_int;
  31
  32         cpuflags = atomic_read(li->cpuflags);
  33         if (!(cpuflags & (CPUSTAT_ECALL_PEND | CPUSTAT_STOPPED)))
  34                 rc = SIGP_CC_ORDER_CODE_ACCEPTED;
  35         else {
  36                 *reg &= 0xffffffff00000000UL;
  37                 if (cpuflags & CPUSTAT_ECALL_PEND)
  38                         *reg |= SIGP_STATUS_EXT_CALL_PENDING;
  39                 if (cpuflags & CPUSTAT_STOPPED)
  40                         *reg |= SIGP_STATUS_STOPPED;
  41                 rc = SIGP_CC_STATUS_STORED;
  42         }
  43
  44         VCPU_EVENT(vcpu, 4, "sensed status of cpu %x rc %x", dst_vcpu->vcpu_id,
  45                    rc);
  46         return rc;
  47 }
  48
  49 static int __inject_sigp_emergency(struct kvm_vcpu *vcpu,
  50                                     struct kvm_vcpu *dst_vcpu)
  51 {
  52         struct kvm_s390_irq irq = {
  53                 .type = KVM_S390_INT_EMERGENCY,
  54                 .u.emerg.code = vcpu->vcpu_id,
  55         };
  56         int rc = 0;
  57
  58         rc = kvm_s390_inject_vcpu(dst_vcpu, &irq);
  59         if (!rc)
  60                 VCPU_EVENT(vcpu, 4, "sent sigp emerg to cpu %x",
  61                            dst_vcpu->vcpu_id);
  62
  63         return rc ? rc : SIGP_CC_ORDER_CODE_ACCEPTED;
  64 }
  65
  66 static int __sigp_emergency(struct kvm_vcpu *vcpu, struct kvm_vcpu *dst_vcpu)
  67 {
  68         return __inject_sigp_emergency(vcpu, dst_vcpu);
  69 }
  70
  71 static int __sigp_conditional_emergency(struct kvm_vcpu *vcpu,
  72                                         struct kvm_vcpu *dst_vcpu,
  73                                         u16 asn, u64 *reg)
  74 {
  75         const u64 psw_int_mask = PSW_MASK_IO | PSW_MASK_EXT;
  76         u16 p_asn, s_asn;
  77         psw_t *psw;
  78         u32 flags;
  79
  80         flags = atomic_read(&dst_vcpu->arch.sie_block->cpuflags);
  81         psw = &dst_vcpu->arch.sie_block->gpsw;
  82         p_asn = dst_vcpu->arch.sie_block->gcr[4] & 0xffff;  /* Primary ASN */
  83         s_asn = dst_vcpu->arch.sie_block->gcr[3] & 0xffff;  /* Secondary ASN */
  84
  85         /* Inject the emergency signal? */
  86         if (!(flags & CPUSTAT_STOPPED)
  87             || (psw->mask & psw_int_mask) != psw_int_mask
  88             || ((flags & CPUSTAT_WAIT) && psw->addr != 0)
  89             || (!(flags & CPUSTAT_WAIT) && (asn == p_asn || asn == s_asn))) {
  90                 return __inject_sigp_emergency(vcpu, dst_vcpu);
  91         } else {
  92                 *reg &= 0xffffffff00000000UL;
  93                 *reg |= SIGP_STATUS_INCORRECT_STATE;
  94                 return SIGP_CC_STATUS_STORED;
  95         }
  96 }
  97
  98 static int __sigp_external_call(struct kvm_vcpu *vcpu,
  99                                 struct kvm_vcpu *dst_vcpu)
 100 {
 101         struct kvm_s390_irq irq = {
 102                 .type = KVM_S390_INT_EXTERNAL_CALL,
 103                 .u.extcall.code = vcpu->vcpu_id,
 104         };
 105         int rc;
 106
 107         rc = kvm_s390_inject_vcpu(dst_vcpu, &irq);
 108         if (!rc)
 109                 VCPU_EVENT(vcpu, 4, "sent sigp ext call to cpu %x",
 110                            dst_vcpu->vcpu_id);
 111
 112         return rc ? rc : SIGP_CC_ORDER_CODE_ACCEPTED;
 113 }
 114
 115 static int __inject_sigp_stop(struct kvm_vcpu *dst_vcpu, int action)
 116 {
 117         struct kvm_s390_local_interrupt *li = &dst_vcpu->arch.local_int;
 118         int rc = SIGP_CC_ORDER_CODE_ACCEPTED;
 119
 120         spin_lock(&li->lock);
 121         if (li->action_bits & ACTION_STOP_ON_STOP) {
 122                 /* another SIGP STOP is pending */
 123                 rc = SIGP_CC_BUSY;
 124                 goto out;
 125         }
 126         if ((atomic_read(li->cpuflags) & CPUSTAT_STOPPED)) {
 127                 if ((action & ACTION_STORE_ON_STOP) != 0)
 128                         rc = -ESHUTDOWN;
 129                 goto out;
 130         }
 131         set_bit(IRQ_PEND_SIGP_STOP, &li->pending_irqs);
 132         li->action_bits |= action;
 133         atomic_set_mask(CPUSTAT_STOP_INT, li->cpuflags);
 134         kvm_s390_vcpu_wakeup(dst_vcpu);
 135 out:
 136         spin_unlock(&li->lock);
 137
 138         return rc;
 139 }
 140
 141 static int __sigp_stop(struct kvm_vcpu *vcpu, struct kvm_vcpu *dst_vcpu)
 142 {
 143         int rc;
 144
 145         rc = __inject_sigp_stop(dst_vcpu, ACTION_STOP_ON_STOP);
 146         VCPU_EVENT(vcpu, 4, "sent sigp stop to cpu %x", dst_vcpu->vcpu_id);
 147
 148         return rc;
 149 }
 150
 151 static int __sigp_stop_and_store_status(struct kvm_vcpu *vcpu,
 152                                         struct kvm_vcpu *dst_vcpu, u64 *reg)
 153 {
 154         int rc;
 155
 156         rc = __inject_sigp_stop(dst_vcpu, ACTION_STOP_ON_STOP |
 157                                               ACTION_STORE_ON_STOP);
 158         VCPU_EVENT(vcpu, 4, "sent sigp stop and store status to cpu %x",
 159                    dst_vcpu->vcpu_id);
 160
 161         if (rc == -ESHUTDOWN) {
 162                 /* If the CPU has already been stopped, we still have
 163                  * to save the status when doing stop-and-store. This
 164                  * has to be done after unlocking all spinlocks. */
 165                 rc = kvm_s390_store_status_unloaded(dst_vcpu,
 166                                                 KVM_S390_STORE_STATUS_NOADDR);
 167         }
 168
 169         return rc;
 170 }
 171
 172 static int __sigp_set_arch(struct kvm_vcpu *vcpu, u32 parameter)
 173 {
 174         int rc;
 175         unsigned int i;
 176         struct kvm_vcpu *v;
 177
 178         switch (parameter & 0xff) {
 179         case 0:
 180                 rc = SIGP_CC_NOT_OPERATIONAL;
 181                 break;
 182         case 1:
 183         case 2:
 184                 kvm_for_each_vcpu(i, v, vcpu->kvm) {
 185                         v->arch.pfault_token = KVM_S390_PFAULT_TOKEN_INVALID;
 186                         kvm_clear_async_pf_completion_queue(v);
 187                 }
 188
 189                 rc = SIGP_CC_ORDER_CODE_ACCEPTED;
 190                 break;
 191         default:
 192                 rc = -EOPNOTSUPP;
 193         }
 194         return rc;
 195 }
 196
 197 static int __sigp_set_prefix(struct kvm_vcpu *vcpu, struct kvm_vcpu *dst_vcpu,
 198                              u32 address, u64 *reg)
 199 {
 200         struct kvm_s390_local_interrupt *li;
 201         int rc;
 202
 203         li = &dst_vcpu->arch.local_int;
 204
 205         /*
 206          * Make sure the new value is valid memory. We only need to check the
 207          * first page, since address is 8k aligned and memory pieces are always
 208          * at least 1MB aligned and have at least a size of 1MB.
 209          */
 210         address &= 0x7fffe000u;
 211         if (kvm_is_error_gpa(vcpu->kvm, address)) {
 212                 *reg &= 0xffffffff00000000UL;
 213                 *reg |= SIGP_STATUS_INVALID_PARAMETER;
 214                 return SIGP_CC_STATUS_STORED;
 215         }
 216
 217         spin_lock(&li->lock);
 218         /* cpu must be in stopped state */
 219         if (!(atomic_read(li->cpuflags) & CPUSTAT_STOPPED)) {
 220                 *reg &= 0xffffffff00000000UL;
 221                 *reg |= SIGP_STATUS_INCORRECT_STATE;
 222                 rc = SIGP_CC_STATUS_STORED;
 223                 goto out_li;
 224         }
 225
 226         li->irq.prefix.address = address;
 227         set_bit(IRQ_PEND_SET_PREFIX, &li->pending_irqs);
 228         kvm_s390_vcpu_wakeup(dst_vcpu);
 229         rc = SIGP_CC_ORDER_CODE_ACCEPTED;
 230
 231         VCPU_EVENT(vcpu, 4, "set prefix of cpu %02x to %x", dst_vcpu->vcpu_id,
 232                    address);
 233 out_li:
 234         spin_unlock(&li->lock);
 235         return rc;
 236 }
 237
 238 static int __sigp_store_status_at_addr(struct kvm_vcpu *vcpu,
 239                                        struct kvm_vcpu *dst_vcpu,
 240                                        u32 addr, u64 *reg)
 241 {
 242         int flags;
 243         int rc;
 244
 245         spin_lock(&dst_vcpu->arch.local_int.lock);
 246         flags = atomic_read(dst_vcpu->arch.local_int.cpuflags);
 247         spin_unlock(&dst_vcpu->arch.local_int.lock);
 248         if (!(flags & CPUSTAT_STOPPED)) {
 249                 *reg &= 0xffffffff00000000UL;
 250                 *reg |= SIGP_STATUS_INCORRECT_STATE;
 251                 return SIGP_CC_STATUS_STORED;
 252         }
 253
 254         addr &= 0x7ffffe00;
 255         rc = kvm_s390_store_status_unloaded(dst_vcpu, addr);
 256         if (rc == -EFAULT) {
 257                 *reg &= 0xffffffff00000000UL;
 258                 *reg |= SIGP_STATUS_INVALID_PARAMETER;
 259                 rc = SIGP_CC_STATUS_STORED;
 260         }
 261         return rc;
 262 }
 263
 264 static int __sigp_sense_running(struct kvm_vcpu *vcpu,
 265                                 struct kvm_vcpu *dst_vcpu, u64 *reg)
 266 {
 267         struct kvm_s390_local_interrupt *li;
 268         int rc;
 269
 270         li = &dst_vcpu->arch.local_int;
 271         if (atomic_read(li->cpuflags) & CPUSTAT_RUNNING) {
 272                 /* running */
 273                 rc = SIGP_CC_ORDER_CODE_ACCEPTED;
 274         } else {
 275                 /* not running */
 276                 *reg &= 0xffffffff00000000UL;
 277                 *reg |= SIGP_STATUS_NOT_RUNNING;
 278                 rc = SIGP_CC_STATUS_STORED;
 279         }
 280
 281         VCPU_EVENT(vcpu, 4, "sensed running status of cpu %x rc %x",
 282                    dst_vcpu->vcpu_id, rc);
 283
 284         return rc;
 285 }
 286
 287 static int __prepare_sigp_re_start(struct kvm_vcpu *vcpu,
 288                                    struct kvm_vcpu *dst_vcpu, u8 order_code)
 289 {
 290         struct kvm_s390_local_interrupt *li = &dst_vcpu->arch.local_int;
 291         /* handle (RE)START in user space */
 292         int rc = -EOPNOTSUPP;
 293
 294         spin_lock(&li->lock);
 295         if (li->action_bits & ACTION_STOP_ON_STOP)
 296                 rc = SIGP_CC_BUSY;
 297         spin_unlock(&li->lock);
 298
 299         return rc;
 300 }
 301
 302 static int __prepare_sigp_cpu_reset(struct kvm_vcpu *vcpu,
 303                                     struct kvm_vcpu *dst_vcpu, u8 order_code)
 304 {
 305         /* handle (INITIAL) CPU RESET in user space */
 306         return -EOPNOTSUPP;
 307 }
 308
 309 static int __prepare_sigp_unknown(struct kvm_vcpu *vcpu,
 310                                   struct kvm_vcpu *dst_vcpu)
 311 {
 312         /* handle unknown orders in user space */
 313         return -EOPNOTSUPP;
 314 }
 315
 316 static int handle_sigp_dst(struct kvm_vcpu *vcpu, u8 order_code,
 317                            u16 cpu_addr, u32 parameter, u64 *status_reg)
 318 {
 319         int rc;
 320         struct kvm_vcpu *dst_vcpu;
 321
 322         if (cpu_addr >= KVM_MAX_VCPUS)
 323                 return SIGP_CC_NOT_OPERATIONAL;
 324
 325         dst_vcpu = kvm_get_vcpu(vcpu->kvm, cpu_addr);
 326         if (!dst_vcpu)
 327                 return SIGP_CC_NOT_OPERATIONAL;
 328
 329         switch (order_code) {
 330         case SIGP_SENSE:
 331                 vcpu->stat.instruction_sigp_sense++;
 332                 rc = __sigp_sense(vcpu, dst_vcpu, status_reg);
 333                 break;
 334         case SIGP_EXTERNAL_CALL:
 335                 vcpu->stat.instruction_sigp_external_call++;
 336                 rc = __sigp_external_call(vcpu, dst_vcpu);
 337                 break;
 338         case SIGP_EMERGENCY_SIGNAL:
 339                 vcpu->stat.instruction_sigp_emergency++;
 340                 rc = __sigp_emergency(vcpu, dst_vcpu);
 341                 break;
 342         case SIGP_STOP:
 343                 vcpu->stat.instruction_sigp_stop++;
 344                 rc = __sigp_stop(vcpu, dst_vcpu);
 345                 break;
 346         case SIGP_STOP_AND_STORE_STATUS:
 347                 vcpu->stat.instruction_sigp_stop_store_status++;
 348                 rc = __sigp_stop_and_store_status(vcpu, dst_vcpu, status_reg);
 349                 break;
 350         case SIGP_STORE_STATUS_AT_ADDRESS:
 351                 vcpu->stat.instruction_sigp_store_status++;
 352                 rc = __sigp_store_status_at_addr(vcpu, dst_vcpu, parameter,
 353                                                  status_reg);
 354                 break;
 355         case SIGP_SET_PREFIX:
 356                 vcpu->stat.instruction_sigp_prefix++;
 357                 rc = __sigp_set_prefix(vcpu, dst_vcpu, parameter, status_reg);
 358                 break;
 359         case SIGP_COND_EMERGENCY_SIGNAL:
 360                 vcpu->stat.instruction_sigp_cond_emergency++;
 361                 rc = __sigp_conditional_emergency(vcpu, dst_vcpu, parameter,
 362                                                   status_reg);
 363                 break;
 364         case SIGP_SENSE_RUNNING:
 365                 vcpu->stat.instruction_sigp_sense_running++;
 366                 rc = __sigp_sense_running(vcpu, dst_vcpu, status_reg);
 367                 break;
 368         case SIGP_START:
 369                 vcpu->stat.instruction_sigp_start++;
 370                 rc = __prepare_sigp_re_start(vcpu, dst_vcpu, order_code);
 371                 break;
 372         case SIGP_RESTART:
 373                 vcpu->stat.instruction_sigp_restart++;
 374                 rc = __prepare_sigp_re_start(vcpu, dst_vcpu, order_code);
 375                 break;
 376         case SIGP_INITIAL_CPU_RESET:
 377                 vcpu->stat.instruction_sigp_init_cpu_reset++;
 378                 rc = __prepare_sigp_cpu_reset(vcpu, dst_vcpu, order_code);
 379                 break;
 380         case SIGP_CPU_RESET:
 381                 vcpu->stat.instruction_sigp_cpu_reset++;
 382                 rc = __prepare_sigp_cpu_reset(vcpu, dst_vcpu, order_code);
 383                 break;
 384         default:
 385                 vcpu->stat.instruction_sigp_unknown++;
 386                 rc = __prepare_sigp_unknown(vcpu, dst_vcpu);
 387         }
 388
 389         if (rc == -EOPNOTSUPP)
 390                 VCPU_EVENT(vcpu, 4,
 391                            "sigp order %u -> cpu %x: handled in user space",
 392                            order_code, dst_vcpu->vcpu_id);
 393
 394         return rc;
 395 }
 396
 397 int kvm_s390_handle_sigp(struct kvm_vcpu *vcpu)
 398 {
 399         int r1 = (vcpu->arch.sie_block->ipa & 0x00f0) >> 4;
 400         int r3 = vcpu->arch.sie_block->ipa & 0x000f;
 401         u32 parameter;
 402         u16 cpu_addr = vcpu->run->s.regs.gprs[r3];
 403         u8 order_code;
 404         int rc;
 405
 406         /* sigp in userspace can exit */
 407         if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
 408                 return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);
 409
 410         order_code = kvm_s390_get_base_disp_rs(vcpu);
 411
 412         if (r1 % 2)
 413                 parameter = vcpu->run->s.regs.gprs[r1];
 414         else
 415                 parameter = vcpu->run->s.regs.gprs[r1 + 1];
 416
 417         trace_kvm_s390_handle_sigp(vcpu, order_code, cpu_addr, parameter);
 418         switch (order_code) {
 419         case SIGP_SET_ARCHITECTURE:
 420                 vcpu->stat.instruction_sigp_arch++;
 421                 rc = __sigp_set_arch(vcpu, parameter);
 422                 break;
 423         default:
 424                 rc = handle_sigp_dst(vcpu, order_code, cpu_addr,
 425                                      parameter,
 426                                      &vcpu->run->s.regs.gprs[r1]);
 427         }
 428
 429         if (rc < 0)
 430                 return rc;
 431
 432         kvm_s390_set_psw_cc(vcpu, rc);
 433         return 0;
 434 }
 435
 436 /*
 437  * Handle SIGP partial execution interception.
 438  *
 439  * This interception will occur at the source cpu when a source cpu sends an
 440  * external call to a target cpu and the target cpu has the WAIT bit set in
 441  * its cpuflags. Interception will occurr after the interrupt indicator bits at
 442  * the target cpu have been set. All error cases will lead to instruction
 443  * interception, therefore nothing is to be checked or prepared.
 444  */
 445 int kvm_s390_handle_sigp_pei(struct kvm_vcpu *vcpu)
 446 {
 447         int r3 = vcpu->arch.sie_block->ipa & 0x000f;
 448         u16 cpu_addr = vcpu->run->s.regs.gprs[r3];
 449         struct kvm_vcpu *dest_vcpu;
 450         u8 order_code = kvm_s390_get_base_disp_rs(vcpu);
 451
 452         trace_kvm_s390_handle_sigp_pei(vcpu, order_code, cpu_addr);
 453
 454         if (order_code == SIGP_EXTERNAL_CALL) {
 455                 dest_vcpu = kvm_get_vcpu(vcpu->kvm, cpu_addr);
 456                 BUG_ON(dest_vcpu == NULL);
 457
 458                 kvm_s390_vcpu_wakeup(dest_vcpu);
 459                 kvm_s390_set_psw_cc(vcpu, SIGP_CC_ORDER_CODE_ACCEPTED);
 460                 return 0;
 461         }
 462
 463         return -EOPNOTSUPP;
 464 }