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 (li->action_bits & ACTION_STOP_ON_STOP) {
 140                 /* another SIGP STOP is pending */
 141                 rc = SIGP_CC_BUSY;
 142                 goto out;
 143         }
 144         if ((atomic_read(li->cpuflags) & CPUSTAT_STOPPED)) {
 145                 kfree(inti);
 146                 if ((action & ACTION_STORE_ON_STOP) != 0)
 147                         rc = -ESHUTDOWN;
 148                 goto out;
 149         }
 150         list_add_tail(&inti->list, &li->list);
 151         atomic_set(&li->active, 1);
 152         li->action_bits |= action;
 153         atomic_set_mask(CPUSTAT_STOP_INT, li->cpuflags);
 154         if (waitqueue_active(li->wq))
 155                 wake_up_interruptible(li->wq);
 156 out:
 157         spin_unlock_bh(&li->lock);
 158
 159         return rc;
 160 }
 161
 162 static int __sigp_stop(struct kvm_vcpu *vcpu, u16 cpu_addr, int action)
 163 {
 164         struct kvm_s390_local_interrupt *li;
 165         struct kvm_vcpu *dst_vcpu = NULL;
 166         int rc;
 167
 168         if (cpu_addr >= KVM_MAX_VCPUS)
 169                 return SIGP_CC_NOT_OPERATIONAL;
 170
 171         dst_vcpu = kvm_get_vcpu(vcpu->kvm, cpu_addr);
 172         if (!dst_vcpu)
 173                 return SIGP_CC_NOT_OPERATIONAL;
 174         li = &dst_vcpu->arch.local_int;
 175
 176         rc = __inject_sigp_stop(li, action);
 177
 178         VCPU_EVENT(vcpu, 4, "sent sigp stop to cpu %x", cpu_addr);
 179
 180         if ((action & ACTION_STORE_ON_STOP) != 0 && rc == -ESHUTDOWN) {
 181                 /* If the CPU has already been stopped, we still have
 182                  * to save the status when doing stop-and-store. This
 183                  * has to be done after unlocking all spinlocks. */
 184                 rc = kvm_s390_store_status_unloaded(dst_vcpu,
 185                                                 KVM_S390_STORE_STATUS_NOADDR);
 186         }
 187
 188         return rc;
 189 }
 190
 191 static int __sigp_set_arch(struct kvm_vcpu *vcpu, u32 parameter)
 192 {
 193         int rc;
 194         unsigned int i;
 195         struct kvm_vcpu *v;
 196
 197         switch (parameter & 0xff) {
 198         case 0:
 199                 rc = SIGP_CC_NOT_OPERATIONAL;
 200                 break;
 201         case 1:
 202         case 2:
 203                 kvm_for_each_vcpu(i, v, vcpu->kvm) {
 204                         v->arch.pfault_token = KVM_S390_PFAULT_TOKEN_INVALID;
 205                         kvm_clear_async_pf_completion_queue(v);
 206                 }
 207
 208                 rc = SIGP_CC_ORDER_CODE_ACCEPTED;
 209                 break;
 210         default:
 211                 rc = -EOPNOTSUPP;
 212         }
 213         return rc;
 214 }
 215
 216 static int __sigp_set_prefix(struct kvm_vcpu *vcpu, u16 cpu_addr, u32 address,
 217                              u64 *reg)
 218 {
 219         struct kvm_s390_local_interrupt *li;
 220         struct kvm_vcpu *dst_vcpu = NULL;
 221         struct kvm_s390_interrupt_info *inti;
 222         int rc;
 223
 224         if (cpu_addr < KVM_MAX_VCPUS)
 225                 dst_vcpu = kvm_get_vcpu(vcpu->kvm, cpu_addr);
 226         if (!dst_vcpu)
 227                 return SIGP_CC_NOT_OPERATIONAL;
 228         li = &dst_vcpu->arch.local_int;
 229
 230         /*
 231          * Make sure the new value is valid memory. We only need to check the
 232          * first page, since address is 8k aligned and memory pieces are always
 233          * at least 1MB aligned and have at least a size of 1MB.
 234          */
 235         address &= 0x7fffe000u;
 236         if (kvm_is_error_gpa(vcpu->kvm, address)) {
 237                 *reg &= 0xffffffff00000000UL;
 238                 *reg |= SIGP_STATUS_INVALID_PARAMETER;
 239                 return SIGP_CC_STATUS_STORED;
 240         }
 241
 242         inti = kzalloc(sizeof(*inti), GFP_KERNEL);
 243         if (!inti)
 244                 return SIGP_CC_BUSY;
 245
 246         spin_lock_bh(&li->lock);
 247         /* cpu must be in stopped state */
 248         if (!(atomic_read(li->cpuflags) & CPUSTAT_STOPPED)) {
 249                 *reg &= 0xffffffff00000000UL;
 250                 *reg |= SIGP_STATUS_INCORRECT_STATE;
 251                 rc = SIGP_CC_STATUS_STORED;
 252                 kfree(inti);
 253                 goto out_li;
 254         }
 255
 256         inti->type = KVM_S390_SIGP_SET_PREFIX;
 257         inti->prefix.address = address;
 258
 259         list_add_tail(&inti->list, &li->list);
 260         atomic_set(&li->active, 1);
 261         if (waitqueue_active(li->wq))
 262                 wake_up_interruptible(li->wq);
 263         rc = SIGP_CC_ORDER_CODE_ACCEPTED;
 264
 265         VCPU_EVENT(vcpu, 4, "set prefix of cpu %02x to %x", cpu_addr, address);
 266 out_li:
 267         spin_unlock_bh(&li->lock);
 268         return rc;
 269 }
 270
 271 static int __sigp_store_status_at_addr(struct kvm_vcpu *vcpu, u16 cpu_id,
 272                                         u32 addr, u64 *reg)
 273 {
 274         struct kvm_vcpu *dst_vcpu = NULL;
 275         int flags;
 276         int rc;
 277
 278         if (cpu_id < KVM_MAX_VCPUS)
 279                 dst_vcpu = kvm_get_vcpu(vcpu->kvm, cpu_id);
 280         if (!dst_vcpu)
 281                 return SIGP_CC_NOT_OPERATIONAL;
 282
 283         spin_lock_bh(&dst_vcpu->arch.local_int.lock);
 284         flags = atomic_read(dst_vcpu->arch.local_int.cpuflags);
 285         spin_unlock_bh(&dst_vcpu->arch.local_int.lock);
 286         if (!(flags & CPUSTAT_STOPPED)) {
 287                 *reg &= 0xffffffff00000000UL;
 288                 *reg |= SIGP_STATUS_INCORRECT_STATE;
 289                 return SIGP_CC_STATUS_STORED;
 290         }
 291
 292         addr &= 0x7ffffe00;
 293         rc = kvm_s390_store_status_unloaded(dst_vcpu, addr);
 294         if (rc == -EFAULT) {
 295                 *reg &= 0xffffffff00000000UL;
 296                 *reg |= SIGP_STATUS_INVALID_PARAMETER;
 297                 rc = SIGP_CC_STATUS_STORED;
 298         }
 299         return rc;
 300 }
 301
 302 static int __sigp_sense_running(struct kvm_vcpu *vcpu, u16 cpu_addr,
 303                                 u64 *reg)
 304 {
 305         struct kvm_s390_local_interrupt *li;
 306         struct kvm_vcpu *dst_vcpu = NULL;
 307         int rc;
 308
 309         if (cpu_addr >= KVM_MAX_VCPUS)
 310                 return SIGP_CC_NOT_OPERATIONAL;
 311
 312         dst_vcpu = kvm_get_vcpu(vcpu->kvm, cpu_addr);
 313         if (!dst_vcpu)
 314                 return SIGP_CC_NOT_OPERATIONAL;
 315         li = &dst_vcpu->arch.local_int;
 316         if (atomic_read(li->cpuflags) & CPUSTAT_RUNNING) {
 317                 /* running */
 318                 rc = SIGP_CC_ORDER_CODE_ACCEPTED;
 319         } else {
 320                 /* not running */
 321                 *reg &= 0xffffffff00000000UL;
 322                 *reg |= SIGP_STATUS_NOT_RUNNING;
 323                 rc = SIGP_CC_STATUS_STORED;
 324         }
 325
 326         VCPU_EVENT(vcpu, 4, "sensed running status of cpu %x rc %x", cpu_addr,
 327                    rc);
 328
 329         return rc;
 330 }
 331
 332 /* Test whether the destination CPU is available and not busy */
 333 static int sigp_check_callable(struct kvm_vcpu *vcpu, u16 cpu_addr)
 334 {
 335         struct kvm_s390_local_interrupt *li;
 336         int rc = SIGP_CC_ORDER_CODE_ACCEPTED;
 337         struct kvm_vcpu *dst_vcpu = NULL;
 338
 339         if (cpu_addr >= KVM_MAX_VCPUS)
 340                 return SIGP_CC_NOT_OPERATIONAL;
 341
 342         dst_vcpu = kvm_get_vcpu(vcpu->kvm, cpu_addr);
 343         if (!dst_vcpu)
 344                 return SIGP_CC_NOT_OPERATIONAL;
 345         li = &dst_vcpu->arch.local_int;
 346         spin_lock_bh(&li->lock);
 347         if (li->action_bits & ACTION_STOP_ON_STOP)
 348                 rc = SIGP_CC_BUSY;
 349         spin_unlock_bh(&li->lock);
 350
 351         return rc;
 352 }
 353
 354 int kvm_s390_handle_sigp(struct kvm_vcpu *vcpu)
 355 {
 356         int r1 = (vcpu->arch.sie_block->ipa & 0x00f0) >> 4;
 357         int r3 = vcpu->arch.sie_block->ipa & 0x000f;
 358         u32 parameter;
 359         u16 cpu_addr = vcpu->run->s.regs.gprs[r3];
 360         u8 order_code;
 361         int rc;
 362
 363         /* sigp in userspace can exit */
 364         if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
 365                 return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);
 366
 367         order_code = kvm_s390_get_base_disp_rs(vcpu);
 368
 369         if (r1 % 2)
 370                 parameter = vcpu->run->s.regs.gprs[r1];
 371         else
 372                 parameter = vcpu->run->s.regs.gprs[r1 + 1];
 373
 374         trace_kvm_s390_handle_sigp(vcpu, order_code, cpu_addr, parameter);
 375         switch (order_code) {
 376         case SIGP_SENSE:
 377                 vcpu->stat.instruction_sigp_sense++;
 378                 rc = __sigp_sense(vcpu, cpu_addr,
 379                                   &vcpu->run->s.regs.gprs[r1]);
 380                 break;
 381         case SIGP_EXTERNAL_CALL:
 382                 vcpu->stat.instruction_sigp_external_call++;
 383                 rc = __sigp_external_call(vcpu, cpu_addr);
 384                 break;
 385         case SIGP_EMERGENCY_SIGNAL:
 386                 vcpu->stat.instruction_sigp_emergency++;
 387                 rc = __sigp_emergency(vcpu, cpu_addr);
 388                 break;
 389         case SIGP_STOP:
 390                 vcpu->stat.instruction_sigp_stop++;
 391                 rc = __sigp_stop(vcpu, cpu_addr, ACTION_STOP_ON_STOP);
 392                 break;
 393         case SIGP_STOP_AND_STORE_STATUS:
 394                 vcpu->stat.instruction_sigp_stop++;
 395                 rc = __sigp_stop(vcpu, cpu_addr, ACTION_STORE_ON_STOP |
 396                                                  ACTION_STOP_ON_STOP);
 397                 break;
 398         case SIGP_STORE_STATUS_AT_ADDRESS:
 399                 rc = __sigp_store_status_at_addr(vcpu, cpu_addr, parameter,
 400                                                  &vcpu->run->s.regs.gprs[r1]);
 401                 break;
 402         case SIGP_SET_ARCHITECTURE:
 403                 vcpu->stat.instruction_sigp_arch++;
 404                 rc = __sigp_set_arch(vcpu, parameter);
 405                 break;
 406         case SIGP_SET_PREFIX:
 407                 vcpu->stat.instruction_sigp_prefix++;
 408                 rc = __sigp_set_prefix(vcpu, cpu_addr, parameter,
 409                                        &vcpu->run->s.regs.gprs[r1]);
 410                 break;
 411         case SIGP_COND_EMERGENCY_SIGNAL:
 412                 rc = __sigp_conditional_emergency(vcpu, cpu_addr, parameter,
 413                                                   &vcpu->run->s.regs.gprs[r1]);
 414                 break;
 415         case SIGP_SENSE_RUNNING:
 416                 vcpu->stat.instruction_sigp_sense_running++;
 417                 rc = __sigp_sense_running(vcpu, cpu_addr,
 418                                           &vcpu->run->s.regs.gprs[r1]);
 419                 break;
 420         case SIGP_START:
 421                 rc = sigp_check_callable(vcpu, cpu_addr);
 422                 if (rc == SIGP_CC_ORDER_CODE_ACCEPTED)
 423                         rc = -EOPNOTSUPP;    /* Handle START in user space */
 424                 break;
 425         case SIGP_RESTART:
 426                 vcpu->stat.instruction_sigp_restart++;
 427                 rc = sigp_check_callable(vcpu, cpu_addr);
 428                 if (rc == SIGP_CC_ORDER_CODE_ACCEPTED) {
 429                         VCPU_EVENT(vcpu, 4,
 430                                    "sigp restart %x to handle userspace",
 431                                    cpu_addr);
 432                         /* user space must know about restart */
 433                         rc = -EOPNOTSUPP;
 434                 }
 435                 break;
 436         default:
 437                 return -EOPNOTSUPP;
 438         }
 439
 440         if (rc < 0)
 441                 return rc;
 442
 443         kvm_s390_set_psw_cc(vcpu, rc);
 444         return 0;
 445 }
 446
 447 /*
 448  * Handle SIGP partial execution interception.
 449  *
 450  * This interception will occur at the source cpu when a source cpu sends an
 451  * external call to a target cpu and the target cpu has the WAIT bit set in
 452  * its cpuflags. Interception will occurr after the interrupt indicator bits at
 453  * the target cpu have been set. All error cases will lead to instruction
 454  * interception, therefore nothing is to be checked or prepared.
 455  */
 456 int kvm_s390_handle_sigp_pei(struct kvm_vcpu *vcpu)
 457 {
 458         int r3 = vcpu->arch.sie_block->ipa & 0x000f;
 459         u16 cpu_addr = vcpu->run->s.regs.gprs[r3];
 460         struct kvm_vcpu *dest_vcpu;
 461         u8 order_code = kvm_s390_get_base_disp_rs(vcpu);
 462
 463         trace_kvm_s390_handle_sigp_pei(vcpu, order_code, cpu_addr);
 464
 465         if (order_code == SIGP_EXTERNAL_CALL) {
 466                 dest_vcpu = kvm_get_vcpu(vcpu->kvm, cpu_addr);
 467                 BUG_ON(dest_vcpu == NULL);
 468
 469                 spin_lock_bh(&dest_vcpu->arch.local_int.lock);
 470                 if (waitqueue_active(&dest_vcpu->wq))
 471                         wake_up_interruptible(&dest_vcpu->wq);
 472                 dest_vcpu->preempted = true;
 473                 spin_unlock_bh(&dest_vcpu->arch.local_int.lock);
 474
 475                 kvm_s390_set_psw_cc(vcpu, SIGP_CC_ORDER_CODE_ACCEPTED);
 476                 return 0;
 477         }
 478
 479         return -EOPNOTSUPP;
 480 }