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_interrupt s390int = {
  58                 .type = KVM_S390_INT_EMERGENCY,
  59                 .parm = vcpu->vcpu_id,
  60         };
  61         struct kvm_vcpu *dst_vcpu = NULL;
  62         int rc = 0;
  63
  64         if (cpu_addr < KVM_MAX_VCPUS)
  65                 dst_vcpu = kvm_get_vcpu(vcpu->kvm, cpu_addr);
  66         if (!dst_vcpu)
  67                 return SIGP_CC_NOT_OPERATIONAL;
  68
  69         rc = kvm_s390_inject_vcpu(dst_vcpu, &s390int);
  70         if (!rc)
  71                 VCPU_EVENT(vcpu, 4, "sent sigp emerg to cpu %x", cpu_addr);
  72
  73         return rc ? rc : SIGP_CC_ORDER_CODE_ACCEPTED;
  74 }
  75
  76 static int __sigp_conditional_emergency(struct kvm_vcpu *vcpu, u16 cpu_addr,
  77                                         u16 asn, u64 *reg)
  78 {
  79         struct kvm_vcpu *dst_vcpu = NULL;
  80         const u64 psw_int_mask = PSW_MASK_IO | PSW_MASK_EXT;
  81         u16 p_asn, s_asn;
  82         psw_t *psw;
  83         u32 flags;
  84
  85         if (cpu_addr < KVM_MAX_VCPUS)
  86                 dst_vcpu = kvm_get_vcpu(vcpu->kvm, cpu_addr);
  87         if (!dst_vcpu)
  88                 return SIGP_CC_NOT_OPERATIONAL;
  89         flags = atomic_read(&dst_vcpu->arch.sie_block->cpuflags);
  90         psw = &dst_vcpu->arch.sie_block->gpsw;
  91         p_asn = dst_vcpu->arch.sie_block->gcr[4] & 0xffff;  /* Primary ASN */
  92         s_asn = dst_vcpu->arch.sie_block->gcr[3] & 0xffff;  /* Secondary ASN */
  93
  94         /* Deliver the emergency signal? */
  95         if (!(flags & CPUSTAT_STOPPED)
  96             || (psw->mask & psw_int_mask) != psw_int_mask
  97             || ((flags & CPUSTAT_WAIT) && psw->addr != 0)
  98             || (!(flags & CPUSTAT_WAIT) && (asn == p_asn || asn == s_asn))) {
  99                 return __sigp_emergency(vcpu, cpu_addr);
 100         } else {
 101                 *reg &= 0xffffffff00000000UL;
 102                 *reg |= SIGP_STATUS_INCORRECT_STATE;
 103                 return SIGP_CC_STATUS_STORED;
 104         }
 105 }
 106
 107 static int __sigp_external_call(struct kvm_vcpu *vcpu, u16 cpu_addr)
 108 {
 109         struct kvm_s390_interrupt s390int = {
 110                 .type = KVM_S390_INT_EXTERNAL_CALL,
 111                 .parm = vcpu->vcpu_id,
 112         };
 113         struct kvm_vcpu *dst_vcpu = NULL;
 114         int rc;
 115
 116         if (cpu_addr < KVM_MAX_VCPUS)
 117                 dst_vcpu = kvm_get_vcpu(vcpu->kvm, cpu_addr);
 118         if (!dst_vcpu)
 119                 return SIGP_CC_NOT_OPERATIONAL;
 120
 121         rc = kvm_s390_inject_vcpu(dst_vcpu, &s390int);
 122         if (!rc)
 123                 VCPU_EVENT(vcpu, 4, "sent sigp ext call to cpu %x", cpu_addr);
 124
 125         return rc ? rc : SIGP_CC_ORDER_CODE_ACCEPTED;
 126 }
 127
 128 static int __inject_sigp_stop(struct kvm_s390_local_interrupt *li, int action)
 129 {
 130         struct kvm_s390_interrupt_info *inti;
 131         int rc = SIGP_CC_ORDER_CODE_ACCEPTED;
 132
 133         inti = kzalloc(sizeof(*inti), GFP_ATOMIC);
 134         if (!inti)
 135                 return -ENOMEM;
 136         inti->type = KVM_S390_SIGP_STOP;
 137
 138         spin_lock_bh(&li->lock);
 139         if ((atomic_read(li->cpuflags) & CPUSTAT_STOPPED)) {
 140                 kfree(inti);
 141                 if ((action & ACTION_STORE_ON_STOP) != 0)
 142                         rc = -ESHUTDOWN;
 143                 goto out;
 144         }
 145         list_add_tail(&inti->list, &li->list);
 146         atomic_set(&li->active, 1);
 147         atomic_set_mask(CPUSTAT_STOP_INT, li->cpuflags);
 148         li->action_bits |= action;
 149         if (waitqueue_active(li->wq))
 150                 wake_up_interruptible(li->wq);
 151 out:
 152         spin_unlock_bh(&li->lock);
 153
 154         return rc;
 155 }
 156
 157 static int __sigp_stop(struct kvm_vcpu *vcpu, u16 cpu_addr, int action)
 158 {
 159         struct kvm_s390_local_interrupt *li;
 160         struct kvm_vcpu *dst_vcpu = NULL;
 161         int rc;
 162
 163         if (cpu_addr >= KVM_MAX_VCPUS)
 164                 return SIGP_CC_NOT_OPERATIONAL;
 165
 166         dst_vcpu = kvm_get_vcpu(vcpu->kvm, cpu_addr);
 167         if (!dst_vcpu)
 168                 return SIGP_CC_NOT_OPERATIONAL;
 169         li = &dst_vcpu->arch.local_int;
 170
 171         rc = __inject_sigp_stop(li, action);
 172
 173         VCPU_EVENT(vcpu, 4, "sent sigp stop to cpu %x", cpu_addr);
 174
 175         if ((action & ACTION_STORE_ON_STOP) != 0 && rc == -ESHUTDOWN) {
 176                 /* If the CPU has already been stopped, we still have
 177                  * to save the status when doing stop-and-store. This
 178                  * has to be done after unlocking all spinlocks. */
 179                 rc = kvm_s390_store_status_unloaded(dst_vcpu,
 180                                                 KVM_S390_STORE_STATUS_NOADDR);
 181         }
 182
 183         return rc;
 184 }
 185
 186 static int __sigp_set_arch(struct kvm_vcpu *vcpu, u32 parameter)
 187 {
 188         int rc;
 189         unsigned int i;
 190         struct kvm_vcpu *v;
 191
 192         switch (parameter & 0xff) {
 193         case 0:
 194                 rc = SIGP_CC_NOT_OPERATIONAL;
 195                 break;
 196         case 1:
 197         case 2:
 198                 kvm_for_each_vcpu(i, v, vcpu->kvm) {
 199                         v->arch.pfault_token = KVM_S390_PFAULT_TOKEN_INVALID;
 200                         kvm_clear_async_pf_completion_queue(v);
 201                 }
 202
 203                 rc = SIGP_CC_ORDER_CODE_ACCEPTED;
 204                 break;
 205         default:
 206                 rc = -EOPNOTSUPP;
 207         }
 208         return rc;
 209 }
 210
 211 static int __sigp_set_prefix(struct kvm_vcpu *vcpu, u16 cpu_addr, u32 address,
 212                              u64 *reg)
 213 {
 214         struct kvm_s390_local_interrupt *li;
 215         struct kvm_vcpu *dst_vcpu = NULL;
 216         struct kvm_s390_interrupt_info *inti;
 217         int rc;
 218
 219         if (cpu_addr < KVM_MAX_VCPUS)
 220                 dst_vcpu = kvm_get_vcpu(vcpu->kvm, cpu_addr);
 221         if (!dst_vcpu)
 222                 return SIGP_CC_NOT_OPERATIONAL;
 223         li = &dst_vcpu->arch.local_int;
 224
 225         /*
 226          * Make sure the new value is valid memory. We only need to check the
 227          * first page, since address is 8k aligned and memory pieces are always
 228          * at least 1MB aligned and have at least a size of 1MB.
 229          */
 230         address &= 0x7fffe000u;
 231         if (kvm_is_error_gpa(vcpu->kvm, address)) {
 232                 *reg &= 0xffffffff00000000UL;
 233                 *reg |= SIGP_STATUS_INVALID_PARAMETER;
 234                 return SIGP_CC_STATUS_STORED;
 235         }
 236
 237         inti = kzalloc(sizeof(*inti), GFP_KERNEL);
 238         if (!inti)
 239                 return SIGP_CC_BUSY;
 240
 241         spin_lock_bh(&li->lock);
 242         /* cpu must be in stopped state */
 243         if (!(atomic_read(li->cpuflags) & CPUSTAT_STOPPED)) {
 244                 *reg &= 0xffffffff00000000UL;
 245                 *reg |= SIGP_STATUS_INCORRECT_STATE;
 246                 rc = SIGP_CC_STATUS_STORED;
 247                 kfree(inti);
 248                 goto out_li;
 249         }
 250
 251         inti->type = KVM_S390_SIGP_SET_PREFIX;
 252         inti->prefix.address = address;
 253
 254         list_add_tail(&inti->list, &li->list);
 255         atomic_set(&li->active, 1);
 256         if (waitqueue_active(li->wq))
 257                 wake_up_interruptible(li->wq);
 258         rc = SIGP_CC_ORDER_CODE_ACCEPTED;
 259
 260         VCPU_EVENT(vcpu, 4, "set prefix of cpu %02x to %x", cpu_addr, address);
 261 out_li:
 262         spin_unlock_bh(&li->lock);
 263         return rc;
 264 }
 265
 266 static int __sigp_store_status_at_addr(struct kvm_vcpu *vcpu, u16 cpu_id,
 267                                         u32 addr, u64 *reg)
 268 {
 269         struct kvm_vcpu *dst_vcpu = NULL;
 270         int flags;
 271         int rc;
 272
 273         if (cpu_id < KVM_MAX_VCPUS)
 274                 dst_vcpu = kvm_get_vcpu(vcpu->kvm, cpu_id);
 275         if (!dst_vcpu)
 276                 return SIGP_CC_NOT_OPERATIONAL;
 277
 278         spin_lock_bh(&dst_vcpu->arch.local_int.lock);
 279         flags = atomic_read(dst_vcpu->arch.local_int.cpuflags);
 280         spin_unlock_bh(&dst_vcpu->arch.local_int.lock);
 281         if (!(flags & CPUSTAT_STOPPED)) {
 282                 *reg &= 0xffffffff00000000UL;
 283                 *reg |= SIGP_STATUS_INCORRECT_STATE;
 284                 return SIGP_CC_STATUS_STORED;
 285         }
 286
 287         addr &= 0x7ffffe00;
 288         rc = kvm_s390_store_status_unloaded(dst_vcpu, addr);
 289         if (rc == -EFAULT) {
 290                 *reg &= 0xffffffff00000000UL;
 291                 *reg |= SIGP_STATUS_INVALID_PARAMETER;
 292                 rc = SIGP_CC_STATUS_STORED;
 293         }
 294         return rc;
 295 }
 296
 297 static int __sigp_sense_running(struct kvm_vcpu *vcpu, u16 cpu_addr,
 298                                 u64 *reg)
 299 {
 300         struct kvm_s390_local_interrupt *li;
 301         struct kvm_vcpu *dst_vcpu = NULL;
 302         int rc;
 303
 304         if (cpu_addr >= KVM_MAX_VCPUS)
 305                 return SIGP_CC_NOT_OPERATIONAL;
 306
 307         dst_vcpu = kvm_get_vcpu(vcpu->kvm, cpu_addr);
 308         if (!dst_vcpu)
 309                 return SIGP_CC_NOT_OPERATIONAL;
 310         li = &dst_vcpu->arch.local_int;
 311         if (atomic_read(li->cpuflags) & CPUSTAT_RUNNING) {
 312                 /* running */
 313                 rc = SIGP_CC_ORDER_CODE_ACCEPTED;
 314         } else {
 315                 /* not running */
 316                 *reg &= 0xffffffff00000000UL;
 317                 *reg |= SIGP_STATUS_NOT_RUNNING;
 318                 rc = SIGP_CC_STATUS_STORED;
 319         }
 320
 321         VCPU_EVENT(vcpu, 4, "sensed running status of cpu %x rc %x", cpu_addr,
 322                    rc);
 323
 324         return rc;
 325 }
 326
 327 /* Test whether the destination CPU is available and not busy */
 328 static int sigp_check_callable(struct kvm_vcpu *vcpu, u16 cpu_addr)
 329 {
 330         struct kvm_s390_local_interrupt *li;
 331         int rc = SIGP_CC_ORDER_CODE_ACCEPTED;
 332         struct kvm_vcpu *dst_vcpu = NULL;
 333
 334         if (cpu_addr >= KVM_MAX_VCPUS)
 335                 return SIGP_CC_NOT_OPERATIONAL;
 336
 337         dst_vcpu = kvm_get_vcpu(vcpu->kvm, cpu_addr);
 338         if (!dst_vcpu)
 339                 return SIGP_CC_NOT_OPERATIONAL;
 340         li = &dst_vcpu->arch.local_int;
 341         spin_lock_bh(&li->lock);
 342         if (li->action_bits & ACTION_STOP_ON_STOP)
 343                 rc = SIGP_CC_BUSY;
 344         spin_unlock_bh(&li->lock);
 345
 346         return rc;
 347 }
 348
 349 int kvm_s390_handle_sigp(struct kvm_vcpu *vcpu)
 350 {
 351         int r1 = (vcpu->arch.sie_block->ipa & 0x00f0) >> 4;
 352         int r3 = vcpu->arch.sie_block->ipa & 0x000f;
 353         u32 parameter;
 354         u16 cpu_addr = vcpu->run->s.regs.gprs[r3];
 355         u8 order_code;
 356         int rc;
 357
 358         /* sigp in userspace can exit */
 359         if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
 360                 return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);
 361
 362         order_code = kvm_s390_get_base_disp_rs(vcpu);
 363
 364         if (r1 % 2)
 365                 parameter = vcpu->run->s.regs.gprs[r1];
 366         else
 367                 parameter = vcpu->run->s.regs.gprs[r1 + 1];
 368
 369         trace_kvm_s390_handle_sigp(vcpu, order_code, cpu_addr, parameter);
 370         switch (order_code) {
 371         case SIGP_SENSE:
 372                 vcpu->stat.instruction_sigp_sense++;
 373                 rc = __sigp_sense(vcpu, cpu_addr,
 374                                   &vcpu->run->s.regs.gprs[r1]);
 375                 break;
 376         case SIGP_EXTERNAL_CALL:
 377                 vcpu->stat.instruction_sigp_external_call++;
 378                 rc = __sigp_external_call(vcpu, cpu_addr);
 379                 break;
 380         case SIGP_EMERGENCY_SIGNAL:
 381                 vcpu->stat.instruction_sigp_emergency++;
 382                 rc = __sigp_emergency(vcpu, cpu_addr);
 383                 break;
 384         case SIGP_STOP:
 385                 vcpu->stat.instruction_sigp_stop++;
 386                 rc = __sigp_stop(vcpu, cpu_addr, ACTION_STOP_ON_STOP);
 387                 break;
 388         case SIGP_STOP_AND_STORE_STATUS:
 389                 vcpu->stat.instruction_sigp_stop++;
 390                 rc = __sigp_stop(vcpu, cpu_addr, ACTION_STORE_ON_STOP |
 391                                                  ACTION_STOP_ON_STOP);
 392                 break;
 393         case SIGP_STORE_STATUS_AT_ADDRESS:
 394                 rc = __sigp_store_status_at_addr(vcpu, cpu_addr, parameter,
 395                                                  &vcpu->run->s.regs.gprs[r1]);
 396                 break;
 397         case SIGP_SET_ARCHITECTURE:
 398                 vcpu->stat.instruction_sigp_arch++;
 399                 rc = __sigp_set_arch(vcpu, parameter);
 400                 break;
 401         case SIGP_SET_PREFIX:
 402                 vcpu->stat.instruction_sigp_prefix++;
 403                 rc = __sigp_set_prefix(vcpu, cpu_addr, parameter,
 404                                        &vcpu->run->s.regs.gprs[r1]);
 405                 break;
 406         case SIGP_COND_EMERGENCY_SIGNAL:
 407                 rc = __sigp_conditional_emergency(vcpu, cpu_addr, parameter,
 408                                                   &vcpu->run->s.regs.gprs[r1]);
 409                 break;
 410         case SIGP_SENSE_RUNNING:
 411                 vcpu->stat.instruction_sigp_sense_running++;
 412                 rc = __sigp_sense_running(vcpu, cpu_addr,
 413                                           &vcpu->run->s.regs.gprs[r1]);
 414                 break;
 415         case SIGP_START:
 416                 rc = sigp_check_callable(vcpu, cpu_addr);
 417                 if (rc == SIGP_CC_ORDER_CODE_ACCEPTED)
 418                         rc = -EOPNOTSUPP;    /* Handle START in user space */
 419                 break;
 420         case SIGP_RESTART:
 421                 vcpu->stat.instruction_sigp_restart++;
 422                 rc = sigp_check_callable(vcpu, cpu_addr);
 423                 if (rc == SIGP_CC_ORDER_CODE_ACCEPTED) {
 424                         VCPU_EVENT(vcpu, 4,
 425                                    "sigp restart %x to handle userspace",
 426                                    cpu_addr);
 427                         /* user space must know about restart */
 428                         rc = -EOPNOTSUPP;
 429                 }
 430                 break;
 431         default:
 432                 return -EOPNOTSUPP;
 433         }
 434
 435         if (rc < 0)
 436                 return rc;
 437
 438         kvm_s390_set_psw_cc(vcpu, rc);
 439         return 0;
 440 }
 441
 442 /*
 443  * Handle SIGP partial execution interception.
 444  *
 445  * This interception will occur at the source cpu when a source cpu sends an
 446  * external call to a target cpu and the target cpu has the WAIT bit set in
 447  * its cpuflags. Interception will occurr after the interrupt indicator bits at
 448  * the target cpu have been set. All error cases will lead to instruction
 449  * interception, therefore nothing is to be checked or prepared.
 450  */
 451 int kvm_s390_handle_sigp_pei(struct kvm_vcpu *vcpu)
 452 {
 453         int r3 = vcpu->arch.sie_block->ipa & 0x000f;
 454         u16 cpu_addr = vcpu->run->s.regs.gprs[r3];
 455         struct kvm_vcpu *dest_vcpu;
 456         u8 order_code = kvm_s390_get_base_disp_rs(vcpu);
 457
 458         trace_kvm_s390_handle_sigp_pei(vcpu, order_code, cpu_addr);
 459
 460         if (order_code == SIGP_EXTERNAL_CALL) {
 461                 dest_vcpu = kvm_get_vcpu(vcpu->kvm, cpu_addr);
 462                 BUG_ON(dest_vcpu == NULL);
 463
 464                 spin_lock_bh(&dest_vcpu->arch.local_int.lock);
 465                 if (waitqueue_active(&dest_vcpu->wq))
 466                         wake_up_interruptible(&dest_vcpu->wq);
 467                 dest_vcpu->preempted = true;
 468                 spin_unlock_bh(&dest_vcpu->arch.local_int.lock);
 469
 470                 kvm_s390_set_psw_cc(vcpu, SIGP_CC_ORDER_CODE_ACCEPTED);
 471                 return 0;
 472         }
 473
 474         return -EOPNOTSUPP;
 475 }