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, u16 cpu_addr,
  24                         u64 *reg)
  25 {
  26         struct kvm_s390_local_interrupt *li;
  27         struct kvm_vcpu *dst_vcpu = NULL;
  28         int cpuflags;
  29         int rc;
  30
  31         if (cpu_addr >= KVM_MAX_VCPUS)
  32                 return SIGP_CC_NOT_OPERATIONAL;
  33
  34         dst_vcpu = kvm_get_vcpu(vcpu->kvm, cpu_addr);
  35         if (!dst_vcpu)
  36                 return SIGP_CC_NOT_OPERATIONAL;
  37         li = &dst_vcpu->arch.local_int;
  38
  39         cpuflags = atomic_read(li->cpuflags);
  40         if (!(cpuflags & (CPUSTAT_ECALL_PEND | CPUSTAT_STOPPED)))
  41                 rc = SIGP_CC_ORDER_CODE_ACCEPTED;
  42         else {
  43                 *reg &= 0xffffffff00000000UL;
  44                 if (cpuflags & CPUSTAT_ECALL_PEND)
  45                         *reg |= SIGP_STATUS_EXT_CALL_PENDING;
  46                 if (cpuflags & CPUSTAT_STOPPED)
  47                         *reg |= SIGP_STATUS_STOPPED;
  48                 rc = SIGP_CC_STATUS_STORED;
  49         }
  50
  51         VCPU_EVENT(vcpu, 4, "sensed status of cpu %x rc %x", cpu_addr, rc);
  52         return rc;
  53 }
  54
  55 static int __sigp_emergency(struct kvm_vcpu *vcpu, u16 cpu_addr)
  56 {
  57         struct kvm_s390_local_interrupt *li;
  58         struct kvm_s390_interrupt_info *inti;
  59         struct kvm_vcpu *dst_vcpu = NULL;
  60
  61         if (cpu_addr < KVM_MAX_VCPUS)
  62                 dst_vcpu = kvm_get_vcpu(vcpu->kvm, cpu_addr);
  63         if (!dst_vcpu)
  64                 return SIGP_CC_NOT_OPERATIONAL;
  65
  66         inti = kzalloc(sizeof(*inti), GFP_KERNEL);
  67         if (!inti)
  68                 return -ENOMEM;
  69
  70         inti->type = KVM_S390_INT_EMERGENCY;
  71         inti->emerg.code = vcpu->vcpu_id;
  72
  73         li = &dst_vcpu->arch.local_int;
  74         spin_lock_bh(&li->lock);
  75         list_add_tail(&inti->list, &li->list);
  76         atomic_set(&li->active, 1);
  77         atomic_set_mask(CPUSTAT_EXT_INT, li->cpuflags);
  78         if (waitqueue_active(li->wq))
  79                 wake_up_interruptible(li->wq);
  80         spin_unlock_bh(&li->lock);
  81         VCPU_EVENT(vcpu, 4, "sent sigp emerg to cpu %x", cpu_addr);
  82
  83         return SIGP_CC_ORDER_CODE_ACCEPTED;
  84 }
  85
  86 static int __sigp_conditional_emergency(struct kvm_vcpu *vcpu, u16 cpu_addr,
  87                                         u16 asn, u64 *reg)
  88 {
  89         struct kvm_vcpu *dst_vcpu = NULL;
  90         const u64 psw_int_mask = PSW_MASK_IO | PSW_MASK_EXT;
  91         u16 p_asn, s_asn;
  92         psw_t *psw;
  93         u32 flags;
  94
  95         if (cpu_addr < KVM_MAX_VCPUS)
  96                 dst_vcpu = kvm_get_vcpu(vcpu->kvm, cpu_addr);
  97         if (!dst_vcpu)
  98                 return SIGP_CC_NOT_OPERATIONAL;
  99         flags = atomic_read(&dst_vcpu->arch.sie_block->cpuflags);
 100         psw = &dst_vcpu->arch.sie_block->gpsw;
 101         p_asn = dst_vcpu->arch.sie_block->gcr[4] & 0xffff;  /* Primary ASN */
 102         s_asn = dst_vcpu->arch.sie_block->gcr[3] & 0xffff;  /* Secondary ASN */
 103
 104         /* Deliver the emergency signal? */
 105         if (!(flags & CPUSTAT_STOPPED)
 106             || (psw->mask & psw_int_mask) != psw_int_mask
 107             || ((flags & CPUSTAT_WAIT) && psw->addr != 0)
 108             || (!(flags & CPUSTAT_WAIT) && (asn == p_asn || asn == s_asn))) {
 109                 return __sigp_emergency(vcpu, cpu_addr);
 110         } else {
 111                 *reg &= 0xffffffff00000000UL;
 112                 *reg |= SIGP_STATUS_INCORRECT_STATE;
 113                 return SIGP_CC_STATUS_STORED;
 114         }
 115 }
 116
 117 static int __sigp_external_call(struct kvm_vcpu *vcpu, u16 cpu_addr)
 118 {
 119         struct kvm_s390_local_interrupt *li;
 120         struct kvm_s390_interrupt_info *inti;
 121         struct kvm_vcpu *dst_vcpu = NULL;
 122
 123         if (cpu_addr < KVM_MAX_VCPUS)
 124                 dst_vcpu = kvm_get_vcpu(vcpu->kvm, cpu_addr);
 125         if (!dst_vcpu)
 126                 return SIGP_CC_NOT_OPERATIONAL;
 127
 128         inti = kzalloc(sizeof(*inti), GFP_KERNEL);
 129         if (!inti)
 130                 return -ENOMEM;
 131
 132         inti->type = KVM_S390_INT_EXTERNAL_CALL;
 133         inti->extcall.code = vcpu->vcpu_id;
 134
 135         li = &dst_vcpu->arch.local_int;
 136         spin_lock_bh(&li->lock);
 137         list_add_tail(&inti->list, &li->list);
 138         atomic_set(&li->active, 1);
 139         atomic_set_mask(CPUSTAT_EXT_INT, li->cpuflags);
 140         if (waitqueue_active(li->wq))
 141                 wake_up_interruptible(li->wq);
 142         spin_unlock_bh(&li->lock);
 143         VCPU_EVENT(vcpu, 4, "sent sigp ext call to cpu %x", cpu_addr);
 144
 145         return SIGP_CC_ORDER_CODE_ACCEPTED;
 146 }
 147
 148 static int __inject_sigp_stop(struct kvm_s390_local_interrupt *li, int action)
 149 {
 150         struct kvm_s390_interrupt_info *inti;
 151         int rc = SIGP_CC_ORDER_CODE_ACCEPTED;
 152
 153         inti = kzalloc(sizeof(*inti), GFP_ATOMIC);
 154         if (!inti)
 155                 return -ENOMEM;
 156         inti->type = KVM_S390_SIGP_STOP;
 157
 158         spin_lock_bh(&li->lock);
 159         if ((atomic_read(li->cpuflags) & CPUSTAT_STOPPED)) {
 160                 kfree(inti);
 161                 if ((action & ACTION_STORE_ON_STOP) != 0)
 162                         rc = -ESHUTDOWN;
 163                 goto out;
 164         }
 165         list_add_tail(&inti->list, &li->list);
 166         atomic_set(&li->active, 1);
 167         atomic_set_mask(CPUSTAT_STOP_INT, li->cpuflags);
 168         li->action_bits |= action;
 169         if (waitqueue_active(li->wq))
 170                 wake_up_interruptible(li->wq);
 171 out:
 172         spin_unlock_bh(&li->lock);
 173
 174         return rc;
 175 }
 176
 177 static int __sigp_stop(struct kvm_vcpu *vcpu, u16 cpu_addr, int action)
 178 {
 179         struct kvm_s390_local_interrupt *li;
 180         struct kvm_vcpu *dst_vcpu = NULL;
 181         int rc;
 182
 183         if (cpu_addr >= KVM_MAX_VCPUS)
 184                 return SIGP_CC_NOT_OPERATIONAL;
 185
 186         dst_vcpu = kvm_get_vcpu(vcpu->kvm, cpu_addr);
 187         if (!dst_vcpu)
 188                 return SIGP_CC_NOT_OPERATIONAL;
 189         li = &dst_vcpu->arch.local_int;
 190
 191         rc = __inject_sigp_stop(li, action);
 192
 193         VCPU_EVENT(vcpu, 4, "sent sigp stop to cpu %x", cpu_addr);
 194
 195         if ((action & ACTION_STORE_ON_STOP) != 0 && rc == -ESHUTDOWN) {
 196                 /* If the CPU has already been stopped, we still have
 197                  * to save the status when doing stop-and-store. This
 198                  * has to be done after unlocking all spinlocks. */
 199                 rc = kvm_s390_store_status_unloaded(dst_vcpu,
 200                                                 KVM_S390_STORE_STATUS_NOADDR);
 201         }
 202
 203         return rc;
 204 }
 205
 206 static int __sigp_set_arch(struct kvm_vcpu *vcpu, u32 parameter)
 207 {
 208         int rc;
 209         unsigned int i;
 210         struct kvm_vcpu *v;
 211
 212         switch (parameter & 0xff) {
 213         case 0:
 214                 rc = SIGP_CC_NOT_OPERATIONAL;
 215                 break;
 216         case 1:
 217         case 2:
 218                 kvm_for_each_vcpu(i, v, vcpu->kvm) {
 219                         v->arch.pfault_token = KVM_S390_PFAULT_TOKEN_INVALID;
 220                         kvm_clear_async_pf_completion_queue(v);
 221                 }
 222
 223                 rc = SIGP_CC_ORDER_CODE_ACCEPTED;
 224                 break;
 225         default:
 226                 rc = -EOPNOTSUPP;
 227         }
 228         return rc;
 229 }
 230
 231 static int __sigp_set_prefix(struct kvm_vcpu *vcpu, u16 cpu_addr, u32 address,
 232                              u64 *reg)
 233 {
 234         struct kvm_s390_local_interrupt *li;
 235         struct kvm_vcpu *dst_vcpu = NULL;
 236         struct kvm_s390_interrupt_info *inti;
 237         int rc;
 238
 239         if (cpu_addr < KVM_MAX_VCPUS)
 240                 dst_vcpu = kvm_get_vcpu(vcpu->kvm, cpu_addr);
 241         if (!dst_vcpu)
 242                 return SIGP_CC_NOT_OPERATIONAL;
 243         li = &dst_vcpu->arch.local_int;
 244
 245         /*
 246          * Make sure the new value is valid memory. We only need to check the
 247          * first page, since address is 8k aligned and memory pieces are always
 248          * at least 1MB aligned and have at least a size of 1MB.
 249          */
 250         address &= 0x7fffe000u;
 251         if (kvm_is_error_gpa(vcpu->kvm, address)) {
 252                 *reg &= 0xffffffff00000000UL;
 253                 *reg |= SIGP_STATUS_INVALID_PARAMETER;
 254                 return SIGP_CC_STATUS_STORED;
 255         }
 256
 257         inti = kzalloc(sizeof(*inti), GFP_KERNEL);
 258         if (!inti)
 259                 return SIGP_CC_BUSY;
 260
 261         spin_lock_bh(&li->lock);
 262         /* cpu must be in stopped state */
 263         if (!(atomic_read(li->cpuflags) & CPUSTAT_STOPPED)) {
 264                 *reg &= 0xffffffff00000000UL;
 265                 *reg |= SIGP_STATUS_INCORRECT_STATE;
 266                 rc = SIGP_CC_STATUS_STORED;
 267                 kfree(inti);
 268                 goto out_li;
 269         }
 270
 271         inti->type = KVM_S390_SIGP_SET_PREFIX;
 272         inti->prefix.address = address;
 273
 274         list_add_tail(&inti->list, &li->list);
 275         atomic_set(&li->active, 1);
 276         if (waitqueue_active(li->wq))
 277                 wake_up_interruptible(li->wq);
 278         rc = SIGP_CC_ORDER_CODE_ACCEPTED;
 279
 280         VCPU_EVENT(vcpu, 4, "set prefix of cpu %02x to %x", cpu_addr, address);
 281 out_li:
 282         spin_unlock_bh(&li->lock);
 283         return rc;
 284 }
 285
 286 static int __sigp_store_status_at_addr(struct kvm_vcpu *vcpu, u16 cpu_id,
 287                                         u32 addr, u64 *reg)
 288 {
 289         struct kvm_vcpu *dst_vcpu = NULL;
 290         int flags;
 291         int rc;
 292
 293         if (cpu_id < KVM_MAX_VCPUS)
 294                 dst_vcpu = kvm_get_vcpu(vcpu->kvm, cpu_id);
 295         if (!dst_vcpu)
 296                 return SIGP_CC_NOT_OPERATIONAL;
 297
 298         spin_lock_bh(&dst_vcpu->arch.local_int.lock);
 299         flags = atomic_read(dst_vcpu->arch.local_int.cpuflags);
 300         spin_unlock_bh(&dst_vcpu->arch.local_int.lock);
 301         if (!(flags & CPUSTAT_STOPPED)) {
 302                 *reg &= 0xffffffff00000000UL;
 303                 *reg |= SIGP_STATUS_INCORRECT_STATE;
 304                 return SIGP_CC_STATUS_STORED;
 305         }
 306
 307         addr &= 0x7ffffe00;
 308         rc = kvm_s390_store_status_unloaded(dst_vcpu, addr);
 309         if (rc == -EFAULT) {
 310                 *reg &= 0xffffffff00000000UL;
 311                 *reg |= SIGP_STATUS_INVALID_PARAMETER;
 312                 rc = SIGP_CC_STATUS_STORED;
 313         }
 314         return rc;
 315 }
 316
 317 static int __sigp_sense_running(struct kvm_vcpu *vcpu, u16 cpu_addr,
 318                                 u64 *reg)
 319 {
 320         struct kvm_s390_local_interrupt *li;
 321         struct kvm_vcpu *dst_vcpu = NULL;
 322         int rc;
 323
 324         if (cpu_addr >= KVM_MAX_VCPUS)
 325                 return SIGP_CC_NOT_OPERATIONAL;
 326
 327         dst_vcpu = kvm_get_vcpu(vcpu->kvm, cpu_addr);
 328         if (!dst_vcpu)
 329                 return SIGP_CC_NOT_OPERATIONAL;
 330         li = &dst_vcpu->arch.local_int;
 331         if (atomic_read(li->cpuflags) & CPUSTAT_RUNNING) {
 332                 /* running */
 333                 rc = SIGP_CC_ORDER_CODE_ACCEPTED;
 334         } else {
 335                 /* not running */
 336                 *reg &= 0xffffffff00000000UL;
 337                 *reg |= SIGP_STATUS_NOT_RUNNING;
 338                 rc = SIGP_CC_STATUS_STORED;
 339         }
 340
 341         VCPU_EVENT(vcpu, 4, "sensed running status of cpu %x rc %x", cpu_addr,
 342                    rc);
 343
 344         return rc;
 345 }
 346
 347 /* Test whether the destination CPU is available and not busy */
 348 static int sigp_check_callable(struct kvm_vcpu *vcpu, u16 cpu_addr)
 349 {
 350         struct kvm_s390_local_interrupt *li;
 351         int rc = SIGP_CC_ORDER_CODE_ACCEPTED;
 352         struct kvm_vcpu *dst_vcpu = NULL;
 353
 354         if (cpu_addr >= KVM_MAX_VCPUS)
 355                 return SIGP_CC_NOT_OPERATIONAL;
 356
 357         dst_vcpu = kvm_get_vcpu(vcpu->kvm, cpu_addr);
 358         if (!dst_vcpu)
 359                 return SIGP_CC_NOT_OPERATIONAL;
 360         li = &dst_vcpu->arch.local_int;
 361         spin_lock_bh(&li->lock);
 362         if (li->action_bits & ACTION_STOP_ON_STOP)
 363                 rc = SIGP_CC_BUSY;
 364         spin_unlock_bh(&li->lock);
 365
 366         return rc;
 367 }
 368
 369 int kvm_s390_handle_sigp(struct kvm_vcpu *vcpu)
 370 {
 371         int r1 = (vcpu->arch.sie_block->ipa & 0x00f0) >> 4;
 372         int r3 = vcpu->arch.sie_block->ipa & 0x000f;
 373         u32 parameter;
 374         u16 cpu_addr = vcpu->run->s.regs.gprs[r3];
 375         u8 order_code;
 376         int rc;
 377
 378         /* sigp in userspace can exit */
 379         if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
 380                 return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);
 381
 382         order_code = kvm_s390_get_base_disp_rs(vcpu);
 383
 384         if (r1 % 2)
 385                 parameter = vcpu->run->s.regs.gprs[r1];
 386         else
 387                 parameter = vcpu->run->s.regs.gprs[r1 + 1];
 388
 389         trace_kvm_s390_handle_sigp(vcpu, order_code, cpu_addr, parameter);
 390         switch (order_code) {
 391         case SIGP_SENSE:
 392                 vcpu->stat.instruction_sigp_sense++;
 393                 rc = __sigp_sense(vcpu, cpu_addr,
 394                                   &vcpu->run->s.regs.gprs[r1]);
 395                 break;
 396         case SIGP_EXTERNAL_CALL:
 397                 vcpu->stat.instruction_sigp_external_call++;
 398                 rc = __sigp_external_call(vcpu, cpu_addr);
 399                 break;
 400         case SIGP_EMERGENCY_SIGNAL:
 401                 vcpu->stat.instruction_sigp_emergency++;
 402                 rc = __sigp_emergency(vcpu, cpu_addr);
 403                 break;
 404         case SIGP_STOP:
 405                 vcpu->stat.instruction_sigp_stop++;
 406                 rc = __sigp_stop(vcpu, cpu_addr, ACTION_STOP_ON_STOP);
 407                 break;
 408         case SIGP_STOP_AND_STORE_STATUS:
 409                 vcpu->stat.instruction_sigp_stop++;
 410                 rc = __sigp_stop(vcpu, cpu_addr, ACTION_STORE_ON_STOP |
 411                                                  ACTION_STOP_ON_STOP);
 412                 break;
 413         case SIGP_STORE_STATUS_AT_ADDRESS:
 414                 rc = __sigp_store_status_at_addr(vcpu, cpu_addr, parameter,
 415                                                  &vcpu->run->s.regs.gprs[r1]);
 416                 break;
 417         case SIGP_SET_ARCHITECTURE:
 418                 vcpu->stat.instruction_sigp_arch++;
 419                 rc = __sigp_set_arch(vcpu, parameter);
 420                 break;
 421         case SIGP_SET_PREFIX:
 422                 vcpu->stat.instruction_sigp_prefix++;
 423                 rc = __sigp_set_prefix(vcpu, cpu_addr, parameter,
 424                                        &vcpu->run->s.regs.gprs[r1]);
 425                 break;
 426         case SIGP_COND_EMERGENCY_SIGNAL:
 427                 rc = __sigp_conditional_emergency(vcpu, cpu_addr, parameter,
 428                                                   &vcpu->run->s.regs.gprs[r1]);
 429                 break;
 430         case SIGP_SENSE_RUNNING:
 431                 vcpu->stat.instruction_sigp_sense_running++;
 432                 rc = __sigp_sense_running(vcpu, cpu_addr,
 433                                           &vcpu->run->s.regs.gprs[r1]);
 434                 break;
 435         case SIGP_START:
 436                 rc = sigp_check_callable(vcpu, cpu_addr);
 437                 if (rc == SIGP_CC_ORDER_CODE_ACCEPTED)
 438                         rc = -EOPNOTSUPP;    /* Handle START in user space */
 439                 break;
 440         case SIGP_RESTART:
 441                 vcpu->stat.instruction_sigp_restart++;
 442                 rc = sigp_check_callable(vcpu, cpu_addr);
 443                 if (rc == SIGP_CC_ORDER_CODE_ACCEPTED) {
 444                         VCPU_EVENT(vcpu, 4,
 445                                    "sigp restart %x to handle userspace",
 446                                    cpu_addr);
 447                         /* user space must know about restart */
 448                         rc = -EOPNOTSUPP;
 449                 }
 450                 break;
 451         default:
 452                 return -EOPNOTSUPP;
 453         }
 454
 455         if (rc < 0)
 456                 return rc;
 457
 458         kvm_s390_set_psw_cc(vcpu, rc);
 459         return 0;
 460 }