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 __sigp_emergency(struct kvm_vcpu *vcpu, struct kvm_vcpu *dst_vcpu)
  50 {
  51         struct kvm_s390_interrupt s390int = {
  52                 .type = KVM_S390_INT_EMERGENCY,
  53                 .parm = vcpu->vcpu_id,
  54         };
  55         int rc = 0;
  56
  57         rc = kvm_s390_inject_vcpu(dst_vcpu, &s390int);
  58         if (!rc)
  59                 VCPU_EVENT(vcpu, 4, "sent sigp emerg to cpu %x",
  60                            dst_vcpu->vcpu_id);
  61
  62         return rc ? rc : SIGP_CC_ORDER_CODE_ACCEPTED;
  63 }
  64
  65 static int __sigp_conditional_emergency(struct kvm_vcpu *vcpu,
  66                                         struct kvm_vcpu *dst_vcpu,
  67                                         u16 asn, u64 *reg)
  68 {
  69         const u64 psw_int_mask = PSW_MASK_IO | PSW_MASK_EXT;
  70         u16 p_asn, s_asn;
  71         psw_t *psw;
  72         u32 flags;
  73
  74         flags = atomic_read(&dst_vcpu->arch.sie_block->cpuflags);
  75         psw = &dst_vcpu->arch.sie_block->gpsw;
  76         p_asn = dst_vcpu->arch.sie_block->gcr[4] & 0xffff;  /* Primary ASN */
  77         s_asn = dst_vcpu->arch.sie_block->gcr[3] & 0xffff;  /* Secondary ASN */
  78
  79         /* Deliver the emergency signal? */
  80         if (!(flags & CPUSTAT_STOPPED)
  81             || (psw->mask & psw_int_mask) != psw_int_mask
  82             || ((flags & CPUSTAT_WAIT) && psw->addr != 0)
  83             || (!(flags & CPUSTAT_WAIT) && (asn == p_asn || asn == s_asn))) {
  84                 return __sigp_emergency(vcpu, dst_vcpu);
  85         } else {
  86                 *reg &= 0xffffffff00000000UL;
  87                 *reg |= SIGP_STATUS_INCORRECT_STATE;
  88                 return SIGP_CC_STATUS_STORED;
  89         }
  90 }
  91
  92 static int __sigp_external_call(struct kvm_vcpu *vcpu,
  93                                 struct kvm_vcpu *dst_vcpu)
  94 {
  95         struct kvm_s390_interrupt s390int = {
  96                 .type = KVM_S390_INT_EXTERNAL_CALL,
  97                 .parm = vcpu->vcpu_id,
  98         };
  99         int rc;
 100
 101         rc = kvm_s390_inject_vcpu(dst_vcpu, &s390int);
 102         if (!rc)
 103                 VCPU_EVENT(vcpu, 4, "sent sigp ext call to cpu %x",
 104                            dst_vcpu->vcpu_id);
 105
 106         return rc ? rc : SIGP_CC_ORDER_CODE_ACCEPTED;
 107 }
 108
 109 static int __inject_sigp_stop(struct kvm_vcpu *dst_vcpu, int action)
 110 {
 111         struct kvm_s390_local_interrupt *li = &dst_vcpu->arch.local_int;
 112         struct kvm_s390_interrupt_info *inti;
 113         int rc = SIGP_CC_ORDER_CODE_ACCEPTED;
 114
 115         inti = kzalloc(sizeof(*inti), GFP_ATOMIC);
 116         if (!inti)
 117                 return -ENOMEM;
 118         inti->type = KVM_S390_SIGP_STOP;
 119
 120         spin_lock(&li->lock);
 121         if (li->action_bits & ACTION_STOP_ON_STOP) {
 122                 /* another SIGP STOP is pending */
 123                 kfree(inti);
 124                 rc = SIGP_CC_BUSY;
 125                 goto out;
 126         }
 127         if ((atomic_read(li->cpuflags) & CPUSTAT_STOPPED)) {
 128                 kfree(inti);
 129                 if ((action & ACTION_STORE_ON_STOP) != 0)
 130                         rc = -ESHUTDOWN;
 131                 goto out;
 132         }
 133         list_add_tail(&inti->list, &li->list);
 134         atomic_set(&li->active, 1);
 135         li->action_bits |= action;
 136         atomic_set_mask(CPUSTAT_STOP_INT, li->cpuflags);
 137         kvm_s390_vcpu_wakeup(dst_vcpu);
 138 out:
 139         spin_unlock(&li->lock);
 140
 141         return rc;
 142 }
 143
 144 static int __sigp_stop(struct kvm_vcpu *vcpu, struct kvm_vcpu *dst_vcpu,
 145                        int action)
 146 {
 147         int rc;
 148
 149         rc = __inject_sigp_stop(dst_vcpu, action);
 150         VCPU_EVENT(vcpu, 4, "sent sigp stop to cpu %x", dst_vcpu->vcpu_id);
 151
 152         if ((action & ACTION_STORE_ON_STOP) != 0 && rc == -ESHUTDOWN) {
 153                 /* If the CPU has already been stopped, we still have
 154                  * to save the status when doing stop-and-store. This
 155                  * has to be done after unlocking all spinlocks. */
 156                 rc = kvm_s390_store_status_unloaded(dst_vcpu,
 157                                                 KVM_S390_STORE_STATUS_NOADDR);
 158         }
 159
 160         return rc;
 161 }
 162
 163 static int __sigp_set_arch(struct kvm_vcpu *vcpu, u32 parameter)
 164 {
 165         int rc;
 166         unsigned int i;
 167         struct kvm_vcpu *v;
 168
 169         switch (parameter & 0xff) {
 170         case 0:
 171                 rc = SIGP_CC_NOT_OPERATIONAL;
 172                 break;
 173         case 1:
 174         case 2:
 175                 kvm_for_each_vcpu(i, v, vcpu->kvm) {
 176                         v->arch.pfault_token = KVM_S390_PFAULT_TOKEN_INVALID;
 177                         kvm_clear_async_pf_completion_queue(v);
 178                 }
 179
 180                 rc = SIGP_CC_ORDER_CODE_ACCEPTED;
 181                 break;
 182         default:
 183                 rc = -EOPNOTSUPP;
 184         }
 185         return rc;
 186 }
 187
 188 static int __sigp_set_prefix(struct kvm_vcpu *vcpu, struct kvm_vcpu *dst_vcpu,
 189                              u32 address, u64 *reg)
 190 {
 191         struct kvm_s390_local_interrupt *li;
 192         struct kvm_s390_interrupt_info *inti;
 193         int rc;
 194
 195         li = &dst_vcpu->arch.local_int;
 196
 197         /*
 198          * Make sure the new value is valid memory. We only need to check the
 199          * first page, since address is 8k aligned and memory pieces are always
 200          * at least 1MB aligned and have at least a size of 1MB.
 201          */
 202         address &= 0x7fffe000u;
 203         if (kvm_is_error_gpa(vcpu->kvm, address)) {
 204                 *reg &= 0xffffffff00000000UL;
 205                 *reg |= SIGP_STATUS_INVALID_PARAMETER;
 206                 return SIGP_CC_STATUS_STORED;
 207         }
 208
 209         inti = kzalloc(sizeof(*inti), GFP_KERNEL);
 210         if (!inti)
 211                 return SIGP_CC_BUSY;
 212
 213         spin_lock(&li->lock);
 214         /* cpu must be in stopped state */
 215         if (!(atomic_read(li->cpuflags) & CPUSTAT_STOPPED)) {
 216                 *reg &= 0xffffffff00000000UL;
 217                 *reg |= SIGP_STATUS_INCORRECT_STATE;
 218                 rc = SIGP_CC_STATUS_STORED;
 219                 kfree(inti);
 220                 goto out_li;
 221         }
 222
 223         inti->type = KVM_S390_SIGP_SET_PREFIX;
 224         inti->prefix.address = address;
 225
 226         list_add_tail(&inti->list, &li->list);
 227         atomic_set(&li->active, 1);
 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 /* Test whether the destination CPU is available and not busy */
 288 static int sigp_check_callable(struct kvm_vcpu *vcpu, struct kvm_vcpu *dst_vcpu)
 289 {
 290         struct kvm_s390_local_interrupt *li = &dst_vcpu->arch.local_int;
 291         int rc = SIGP_CC_ORDER_CODE_ACCEPTED;
 292
 293         spin_lock(&li->lock);
 294         if (li->action_bits & ACTION_STOP_ON_STOP)
 295                 rc = SIGP_CC_BUSY;
 296         spin_unlock(&li->lock);
 297
 298         return rc;
 299 }
 300
 301 static int handle_sigp_dst(struct kvm_vcpu *vcpu, u8 order_code,
 302                            u16 cpu_addr, u32 parameter, u64 *status_reg)
 303 {
 304         int rc;
 305         struct kvm_vcpu *dst_vcpu;
 306
 307         if (cpu_addr >= KVM_MAX_VCPUS)
 308                 return SIGP_CC_NOT_OPERATIONAL;
 309
 310         dst_vcpu = kvm_get_vcpu(vcpu->kvm, cpu_addr);
 311         if (!dst_vcpu)
 312                 return SIGP_CC_NOT_OPERATIONAL;
 313
 314         switch (order_code) {
 315         case SIGP_SENSE:
 316                 vcpu->stat.instruction_sigp_sense++;
 317                 rc = __sigp_sense(vcpu, dst_vcpu, status_reg);
 318                 break;
 319         case SIGP_EXTERNAL_CALL:
 320                 vcpu->stat.instruction_sigp_external_call++;
 321                 rc = __sigp_external_call(vcpu, dst_vcpu);
 322                 break;
 323         case SIGP_EMERGENCY_SIGNAL:
 324                 vcpu->stat.instruction_sigp_emergency++;
 325                 rc = __sigp_emergency(vcpu, dst_vcpu);
 326                 break;
 327         case SIGP_STOP:
 328                 vcpu->stat.instruction_sigp_stop++;
 329                 rc = __sigp_stop(vcpu, dst_vcpu, ACTION_STOP_ON_STOP);
 330                 break;
 331         case SIGP_STOP_AND_STORE_STATUS:
 332                 vcpu->stat.instruction_sigp_stop++;
 333                 rc = __sigp_stop(vcpu, dst_vcpu, ACTION_STORE_ON_STOP |
 334                                                  ACTION_STOP_ON_STOP);
 335                 break;
 336         case SIGP_STORE_STATUS_AT_ADDRESS:
 337                 rc = __sigp_store_status_at_addr(vcpu, dst_vcpu, parameter,
 338                                                  status_reg);
 339                 break;
 340         case SIGP_SET_PREFIX:
 341                 vcpu->stat.instruction_sigp_prefix++;
 342                 rc = __sigp_set_prefix(vcpu, dst_vcpu, parameter, status_reg);
 343                 break;
 344         case SIGP_COND_EMERGENCY_SIGNAL:
 345                 rc = __sigp_conditional_emergency(vcpu, dst_vcpu, parameter,
 346                                                   status_reg);
 347                 break;
 348         case SIGP_SENSE_RUNNING:
 349                 vcpu->stat.instruction_sigp_sense_running++;
 350                 rc = __sigp_sense_running(vcpu, dst_vcpu, status_reg);
 351                 break;
 352         case SIGP_START:
 353                 rc = sigp_check_callable(vcpu, dst_vcpu);
 354                 if (rc == SIGP_CC_ORDER_CODE_ACCEPTED)
 355                         rc = -EOPNOTSUPP;    /* Handle START in user space */
 356                 break;
 357         case SIGP_RESTART:
 358                 vcpu->stat.instruction_sigp_restart++;
 359                 rc = sigp_check_callable(vcpu, dst_vcpu);
 360                 if (rc == SIGP_CC_ORDER_CODE_ACCEPTED) {
 361                         VCPU_EVENT(vcpu, 4,
 362                                    "sigp restart %x to handle userspace",
 363                                    cpu_addr);
 364                         /* user space must know about restart */
 365                         rc = -EOPNOTSUPP;
 366                 }
 367                 break;
 368         default:
 369                 rc = -EOPNOTSUPP;
 370         }
 371
 372         return rc;
 373 }
 374
 375 int kvm_s390_handle_sigp(struct kvm_vcpu *vcpu)
 376 {
 377         int r1 = (vcpu->arch.sie_block->ipa & 0x00f0) >> 4;
 378         int r3 = vcpu->arch.sie_block->ipa & 0x000f;
 379         u32 parameter;
 380         u16 cpu_addr = vcpu->run->s.regs.gprs[r3];
 381         u8 order_code;
 382         int rc;
 383
 384         /* sigp in userspace can exit */
 385         if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
 386                 return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);
 387
 388         order_code = kvm_s390_get_base_disp_rs(vcpu);
 389
 390         if (r1 % 2)
 391                 parameter = vcpu->run->s.regs.gprs[r1];
 392         else
 393                 parameter = vcpu->run->s.regs.gprs[r1 + 1];
 394
 395         trace_kvm_s390_handle_sigp(vcpu, order_code, cpu_addr, parameter);
 396         switch (order_code) {
 397         case SIGP_SET_ARCHITECTURE:
 398                 vcpu->stat.instruction_sigp_arch++;
 399                 rc = __sigp_set_arch(vcpu, parameter);
 400                 break;
 401         default:
 402                 rc = handle_sigp_dst(vcpu, order_code, cpu_addr,
 403                                      parameter,
 404                                      &vcpu->run->s.regs.gprs[r1]);
 405         }
 406
 407         if (rc < 0)
 408                 return rc;
 409
 410         kvm_s390_set_psw_cc(vcpu, rc);
 411         return 0;
 412 }
 413
 414 /*
 415  * Handle SIGP partial execution interception.
 416  *
 417  * This interception will occur at the source cpu when a source cpu sends an
 418  * external call to a target cpu and the target cpu has the WAIT bit set in
 419  * its cpuflags. Interception will occurr after the interrupt indicator bits at
 420  * the target cpu have been set. All error cases will lead to instruction
 421  * interception, therefore nothing is to be checked or prepared.
 422  */
 423 int kvm_s390_handle_sigp_pei(struct kvm_vcpu *vcpu)
 424 {
 425         int r3 = vcpu->arch.sie_block->ipa & 0x000f;
 426         u16 cpu_addr = vcpu->run->s.regs.gprs[r3];
 427         struct kvm_vcpu *dest_vcpu;
 428         u8 order_code = kvm_s390_get_base_disp_rs(vcpu);
 429
 430         trace_kvm_s390_handle_sigp_pei(vcpu, order_code, cpu_addr);
 431
 432         if (order_code == SIGP_EXTERNAL_CALL) {
 433                 dest_vcpu = kvm_get_vcpu(vcpu->kvm, cpu_addr);
 434                 BUG_ON(dest_vcpu == NULL);
 435
 436                 kvm_s390_vcpu_wakeup(dest_vcpu);
 437                 kvm_s390_set_psw_cc(vcpu, SIGP_CC_ORDER_CODE_ACCEPTED);
 438                 return 0;
 439         }
 440
 441         return -EOPNOTSUPP;
 442 }