LXR linux/arch/s390/kvm/sigp.c

   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * handling interprocessor communication
   4 *
   5 * Copyright IBM Corp. 2008, 2013
   6 *
   7 *    Author(s): Carsten Otte <cotte@de.ibm.com>
   8 *               Christian Borntraeger <borntraeger@de.ibm.com>
   9 *               Christian Ehrhardt <ehrhardt@de.ibm.com>
  10 */
  11
  12#include <linux/kvm.h>
  13#include <linux/kvm_host.h>
  14#include <linux/slab.h>
  15#include <asm/sigp.h>
  16#include "gaccess.h"
  17#include "kvm-s390.h"
  18#include "trace.h"
  19
  20static int __sigp_sense(struct kvm_vcpu *vcpu, struct kvm_vcpu *dst_vcpu,
  21                        u64 *reg)
  22{
  23        const bool stopped = kvm_s390_test_cpuflags(dst_vcpu, CPUSTAT_STOPPED);
  24        int rc;
  25        int ext_call_pending;
  26
  27        ext_call_pending = kvm_s390_ext_call_pending(dst_vcpu);
  28        if (!stopped && !ext_call_pending)
  29                rc = SIGP_CC_ORDER_CODE_ACCEPTED;
  30        else {
  31                *reg &= 0xffffffff00000000UL;
  32                if (ext_call_pending)
  33                        *reg |= SIGP_STATUS_EXT_CALL_PENDING;
  34                if (stopped)
  35                        *reg |= SIGP_STATUS_STOPPED;
  36                rc = SIGP_CC_STATUS_STORED;
  37        }
  38
  39        VCPU_EVENT(vcpu, 4, "sensed status of cpu %x rc %x", dst_vcpu->vcpu_id,
  40                   rc);
  41        return rc;
  42}
  43
  44static int __inject_sigp_emergency(struct kvm_vcpu *vcpu,
  45                                    struct kvm_vcpu *dst_vcpu)
  46{
  47        struct kvm_s390_irq irq = {
  48                .type = KVM_S390_INT_EMERGENCY,
  49                .u.emerg.code = vcpu->vcpu_id,
  50        };
  51        int rc = 0;
  52
  53        rc = kvm_s390_inject_vcpu(dst_vcpu, &irq);
  54        if (!rc)
  55                VCPU_EVENT(vcpu, 4, "sent sigp emerg to cpu %x",
  56                           dst_vcpu->vcpu_id);
  57
  58        return rc ? rc : SIGP_CC_ORDER_CODE_ACCEPTED;
  59}
  60
  61static int __sigp_emergency(struct kvm_vcpu *vcpu, struct kvm_vcpu *dst_vcpu)
  62{
  63        return __inject_sigp_emergency(vcpu, dst_vcpu);
  64}
  65
  66static int __sigp_conditional_emergency(struct kvm_vcpu *vcpu,
  67                                        struct kvm_vcpu *dst_vcpu,
  68                                        u16 asn, u64 *reg)
  69{
  70        const u64 psw_int_mask = PSW_MASK_IO | PSW_MASK_EXT;
  71        u16 p_asn, s_asn;
  72        psw_t *psw;
  73        bool idle;
  74
  75        idle = is_vcpu_idle(vcpu);
  76        psw = &dst_vcpu->arch.sie_block->gpsw;
  77        p_asn = dst_vcpu->arch.sie_block->gcr[4] & 0xffff;  /* Primary ASN */
  78        s_asn = dst_vcpu->arch.sie_block->gcr[3] & 0xffff;  /* Secondary ASN */
  79
  80        /* Inject the emergency signal? */
  81        if (!is_vcpu_stopped(vcpu)
  82            || (psw->mask & psw_int_mask) != psw_int_mask
  83            || (idle && psw->addr != 0)
  84            || (!idle && (asn == p_asn || asn == s_asn))) {
  85                return __inject_sigp_emergency(vcpu, dst_vcpu);
  86        } else {
  87                *reg &= 0xffffffff00000000UL;
  88                *reg |= SIGP_STATUS_INCORRECT_STATE;
  89                return SIGP_CC_STATUS_STORED;
  90        }
  91}
  92
  93static int __sigp_external_call(struct kvm_vcpu *vcpu,
  94                                struct kvm_vcpu *dst_vcpu, u64 *reg)
  95{
  96        struct kvm_s390_irq irq = {
  97                .type = KVM_S390_INT_EXTERNAL_CALL,
  98                .u.extcall.code = vcpu->vcpu_id,
  99        };
 100        int rc;
 101
 102        rc = kvm_s390_inject_vcpu(dst_vcpu, &irq);
 103        if (rc == -EBUSY) {
 104                *reg &= 0xffffffff00000000UL;
 105                *reg |= SIGP_STATUS_EXT_CALL_PENDING;
 106                return SIGP_CC_STATUS_STORED;
 107        } else if (rc == 0) {
 108                VCPU_EVENT(vcpu, 4, "sent sigp ext call to cpu %x",
 109                           dst_vcpu->vcpu_id);
 110        }
 111
 112        return rc ? rc : SIGP_CC_ORDER_CODE_ACCEPTED;
 113}
 114
 115static int __sigp_stop(struct kvm_vcpu *vcpu, struct kvm_vcpu *dst_vcpu)
 116{
 117        struct kvm_s390_irq irq = {
 118                .type = KVM_S390_SIGP_STOP,
 119        };
 120        int rc;
 121
 122        rc = kvm_s390_inject_vcpu(dst_vcpu, &irq);
 123        if (rc == -EBUSY)
 124                rc = SIGP_CC_BUSY;
 125        else if (rc == 0)
 126                VCPU_EVENT(vcpu, 4, "sent sigp stop to cpu %x",
 127                           dst_vcpu->vcpu_id);
 128
 129        return rc;
 130}
 131
 132static int __sigp_stop_and_store_status(struct kvm_vcpu *vcpu,
 133                                        struct kvm_vcpu *dst_vcpu, u64 *reg)
 134{
 135        struct kvm_s390_irq irq = {
 136                .type = KVM_S390_SIGP_STOP,
 137                .u.stop.flags = KVM_S390_STOP_FLAG_STORE_STATUS,
 138        };
 139        int rc;
 140
 141        rc = kvm_s390_inject_vcpu(dst_vcpu, &irq);
 142        if (rc == -EBUSY)
 143                rc = SIGP_CC_BUSY;
 144        else if (rc == 0)
 145                VCPU_EVENT(vcpu, 4, "sent sigp stop and store status to cpu %x",
 146                           dst_vcpu->vcpu_id);
 147
 148        return rc;
 149}
 150
 151static int __sigp_set_arch(struct kvm_vcpu *vcpu, u32 parameter,
 152                           u64 *status_reg)
 153{
 154        unsigned int i;
 155        struct kvm_vcpu *v;
 156        bool all_stopped = true;
 157
 158        kvm_for_each_vcpu(i, v, vcpu->kvm) {
 159                if (v == vcpu)
 160                        continue;
 161                if (!is_vcpu_stopped(v))
 162                        all_stopped = false;
 163        }
 164
 165        *status_reg &= 0xffffffff00000000UL;
 166
 167        /* Reject set arch order, with czam we're always in z/Arch mode. */
 168        *status_reg |= (all_stopped ? SIGP_STATUS_INVALID_PARAMETER :
 169                                        SIGP_STATUS_INCORRECT_STATE);
 170        return SIGP_CC_STATUS_STORED;
 171}
 172
 173static int __sigp_set_prefix(struct kvm_vcpu *vcpu, struct kvm_vcpu *dst_vcpu,
 174                             u32 address, u64 *reg)
 175{
 176        struct kvm_s390_irq irq = {
 177                .type = KVM_S390_SIGP_SET_PREFIX,
 178                .u.prefix.address = address & 0x7fffe000u,
 179        };
 180        int rc;
 181
 182        /*
 183         * Make sure the new value is valid memory. We only need to check the
 184         * first page, since address is 8k aligned and memory pieces are always
 185         * at least 1MB aligned and have at least a size of 1MB.
 186         */
 187        if (kvm_is_error_gpa(vcpu->kvm, irq.u.prefix.address)) {
 188                *reg &= 0xffffffff00000000UL;
 189                *reg |= SIGP_STATUS_INVALID_PARAMETER;
 190                return SIGP_CC_STATUS_STORED;
 191        }
 192
 193        rc = kvm_s390_inject_vcpu(dst_vcpu, &irq);
 194        if (rc == -EBUSY) {
 195                *reg &= 0xffffffff00000000UL;
 196                *reg |= SIGP_STATUS_INCORRECT_STATE;
 197                return SIGP_CC_STATUS_STORED;
 198        }
 199
 200        return rc;
 201}
 202
 203static int __sigp_store_status_at_addr(struct kvm_vcpu *vcpu,
 204                                       struct kvm_vcpu *dst_vcpu,
 205                                       u32 addr, u64 *reg)
 206{
 207        int rc;
 208
 209        if (!kvm_s390_test_cpuflags(dst_vcpu, CPUSTAT_STOPPED)) {
 210                *reg &= 0xffffffff00000000UL;
 211                *reg |= SIGP_STATUS_INCORRECT_STATE;
 212                return SIGP_CC_STATUS_STORED;
 213        }
 214
 215        addr &= 0x7ffffe00;
 216        rc = kvm_s390_store_status_unloaded(dst_vcpu, addr);
 217        if (rc == -EFAULT) {
 218                *reg &= 0xffffffff00000000UL;
 219                *reg |= SIGP_STATUS_INVALID_PARAMETER;
 220                rc = SIGP_CC_STATUS_STORED;
 221        }
 222        return rc;
 223}
 224
 225static int __sigp_sense_running(struct kvm_vcpu *vcpu,
 226                                struct kvm_vcpu *dst_vcpu, u64 *reg)
 227{
 228        int rc;
 229
 230        if (!test_kvm_facility(vcpu->kvm, 9)) {
 231                *reg &= 0xffffffff00000000UL;
 232                *reg |= SIGP_STATUS_INVALID_ORDER;
 233                return SIGP_CC_STATUS_STORED;
 234        }
 235
 236        if (kvm_s390_test_cpuflags(dst_vcpu, CPUSTAT_RUNNING)) {
 237                /* running */
 238                rc = SIGP_CC_ORDER_CODE_ACCEPTED;
 239        } else {
 240                /* not running */
 241                *reg &= 0xffffffff00000000UL;
 242                *reg |= SIGP_STATUS_NOT_RUNNING;
 243                rc = SIGP_CC_STATUS_STORED;
 244        }
 245
 246        VCPU_EVENT(vcpu, 4, "sensed running status of cpu %x rc %x",
 247                   dst_vcpu->vcpu_id, rc);
 248
 249        return rc;
 250}
 251
 252static int __prepare_sigp_re_start(struct kvm_vcpu *vcpu,
 253                                   struct kvm_vcpu *dst_vcpu, u8 order_code)
 254{
 255        struct kvm_s390_local_interrupt *li = &dst_vcpu->arch.local_int;
 256        /* handle (RE)START in user space */
 257        int rc = -EOPNOTSUPP;
 258
 259        /* make sure we don't race with STOP irq injection */
 260        spin_lock(&li->lock);
 261        if (kvm_s390_is_stop_irq_pending(dst_vcpu))
 262                rc = SIGP_CC_BUSY;
 263        spin_unlock(&li->lock);
 264
 265        return rc;
 266}
 267
 268static int __prepare_sigp_cpu_reset(struct kvm_vcpu *vcpu,
 269                                    struct kvm_vcpu *dst_vcpu, u8 order_code)
 270{
 271        /* handle (INITIAL) CPU RESET in user space */
 272        return -EOPNOTSUPP;
 273}
 274
 275static int __prepare_sigp_unknown(struct kvm_vcpu *vcpu,
 276                                  struct kvm_vcpu *dst_vcpu)
 277{
 278        /* handle unknown orders in user space */
 279        return -EOPNOTSUPP;
 280}
 281
 282static int handle_sigp_dst(struct kvm_vcpu *vcpu, u8 order_code,
 283                           u16 cpu_addr, u32 parameter, u64 *status_reg)
 284{
 285        int rc;
 286        struct kvm_vcpu *dst_vcpu = kvm_get_vcpu_by_id(vcpu->kvm, cpu_addr);
 287
 288        if (!dst_vcpu)
 289                return SIGP_CC_NOT_OPERATIONAL;
 290
 291        switch (order_code) {
 292        case SIGP_SENSE:
 293                vcpu->stat.instruction_sigp_sense++;
 294                rc = __sigp_sense(vcpu, dst_vcpu, status_reg);
 295                break;
 296        case SIGP_EXTERNAL_CALL:
 297                vcpu->stat.instruction_sigp_external_call++;
 298                rc = __sigp_external_call(vcpu, dst_vcpu, status_reg);
 299                break;
 300        case SIGP_EMERGENCY_SIGNAL:
 301                vcpu->stat.instruction_sigp_emergency++;
 302                rc = __sigp_emergency(vcpu, dst_vcpu);
 303                break;
 304        case SIGP_STOP:
 305                vcpu->stat.instruction_sigp_stop++;
 306                rc = __sigp_stop(vcpu, dst_vcpu);
 307                break;
 308        case SIGP_STOP_AND_STORE_STATUS:
 309                vcpu->stat.instruction_sigp_stop_store_status++;
 310                rc = __sigp_stop_and_store_status(vcpu, dst_vcpu, status_reg);
 311                break;
 312        case SIGP_STORE_STATUS_AT_ADDRESS:
 313                vcpu->stat.instruction_sigp_store_status++;
 314                rc = __sigp_store_status_at_addr(vcpu, dst_vcpu, parameter,
 315                                                 status_reg);
 316                break;
 317        case SIGP_SET_PREFIX:
 318                vcpu->stat.instruction_sigp_prefix++;
 319                rc = __sigp_set_prefix(vcpu, dst_vcpu, parameter, status_reg);
 320                break;
 321        case SIGP_COND_EMERGENCY_SIGNAL:
 322                vcpu->stat.instruction_sigp_cond_emergency++;
 323                rc = __sigp_conditional_emergency(vcpu, dst_vcpu, parameter,
 324                                                  status_reg);
 325                break;
 326        case SIGP_SENSE_RUNNING:
 327                vcpu->stat.instruction_sigp_sense_running++;
 328                rc = __sigp_sense_running(vcpu, dst_vcpu, status_reg);
 329                break;
 330        case SIGP_START:
 331                vcpu->stat.instruction_sigp_start++;
 332                rc = __prepare_sigp_re_start(vcpu, dst_vcpu, order_code);
 333                break;
 334        case SIGP_RESTART:
 335                vcpu->stat.instruction_sigp_restart++;
 336                rc = __prepare_sigp_re_start(vcpu, dst_vcpu, order_code);
 337                break;
 338        case SIGP_INITIAL_CPU_RESET:
 339                vcpu->stat.instruction_sigp_init_cpu_reset++;
 340                rc = __prepare_sigp_cpu_reset(vcpu, dst_vcpu, order_code);
 341                break;
 342        case SIGP_CPU_RESET:
 343                vcpu->stat.instruction_sigp_cpu_reset++;
 344                rc = __prepare_sigp_cpu_reset(vcpu, dst_vcpu, order_code);
 345                break;
 346        default:
 347                vcpu->stat.instruction_sigp_unknown++;
 348                rc = __prepare_sigp_unknown(vcpu, dst_vcpu);
 349        }
 350
 351        if (rc == -EOPNOTSUPP)
 352                VCPU_EVENT(vcpu, 4,
 353                           "sigp order %u -> cpu %x: handled in user space",
 354                           order_code, dst_vcpu->vcpu_id);
 355
 356        return rc;
 357}
 358
 359static int handle_sigp_order_in_user_space(struct kvm_vcpu *vcpu, u8 order_code,
 360                                           u16 cpu_addr)
 361{
 362        if (!vcpu->kvm->arch.user_sigp)
 363                return 0;
 364
 365        switch (order_code) {
 366        case SIGP_SENSE:
 367        case SIGP_EXTERNAL_CALL:
 368        case SIGP_EMERGENCY_SIGNAL:
 369        case SIGP_COND_EMERGENCY_SIGNAL:
 370        case SIGP_SENSE_RUNNING:
 371                return 0;
 372        /* update counters as we're directly dropping to user space */
 373        case SIGP_STOP:
 374                vcpu->stat.instruction_sigp_stop++;
 375                break;
 376        case SIGP_STOP_AND_STORE_STATUS:
 377                vcpu->stat.instruction_sigp_stop_store_status++;
 378                break;
 379        case SIGP_STORE_STATUS_AT_ADDRESS:
 380                vcpu->stat.instruction_sigp_store_status++;
 381                break;
 382        case SIGP_STORE_ADDITIONAL_STATUS:
 383                vcpu->stat.instruction_sigp_store_adtl_status++;
 384                break;
 385        case SIGP_SET_PREFIX:
 386                vcpu->stat.instruction_sigp_prefix++;
 387                break;
 388        case SIGP_START:
 389                vcpu->stat.instruction_sigp_start++;
 390                break;
 391        case SIGP_RESTART:
 392                vcpu->stat.instruction_sigp_restart++;
 393                break;
 394        case SIGP_INITIAL_CPU_RESET:
 395                vcpu->stat.instruction_sigp_init_cpu_reset++;
 396                break;
 397        case SIGP_CPU_RESET:
 398                vcpu->stat.instruction_sigp_cpu_reset++;
 399                break;
 400        default:
 401                vcpu->stat.instruction_sigp_unknown++;
 402        }
 403        VCPU_EVENT(vcpu, 3, "SIGP: order %u for CPU %d handled in userspace",
 404                   order_code, cpu_addr);
 405
 406        return 1;
 407}
 408
 409int kvm_s390_handle_sigp(struct kvm_vcpu *vcpu)
 410{
 411        int r1 = (vcpu->arch.sie_block->ipa & 0x00f0) >> 4;
 412        int r3 = vcpu->arch.sie_block->ipa & 0x000f;
 413        u32 parameter;
 414        u16 cpu_addr = vcpu->run->s.regs.gprs[r3];
 415        u8 order_code;
 416        int rc;
 417
 418        /* sigp in userspace can exit */
 419        if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
 420                return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);
 421
 422        order_code = kvm_s390_get_base_disp_rs(vcpu, NULL);
 423        if (handle_sigp_order_in_user_space(vcpu, order_code, cpu_addr))
 424                return -EOPNOTSUPP;
 425
 426        if (r1 % 2)
 427                parameter = vcpu->run->s.regs.gprs[r1];
 428        else
 429                parameter = vcpu->run->s.regs.gprs[r1 + 1];
 430
 431        trace_kvm_s390_handle_sigp(vcpu, order_code, cpu_addr, parameter);
 432        switch (order_code) {
 433        case SIGP_SET_ARCHITECTURE:
 434                vcpu->stat.instruction_sigp_arch++;
 435                rc = __sigp_set_arch(vcpu, parameter,
 436                                     &vcpu->run->s.regs.gprs[r1]);
 437                break;
 438        default:
 439                rc = handle_sigp_dst(vcpu, order_code, cpu_addr,
 440                                     parameter,
 441                                     &vcpu->run->s.regs.gprs[r1]);
 442        }
 443
 444        if (rc < 0)
 445                return rc;
 446
 447        kvm_s390_set_psw_cc(vcpu, rc);
 448        return 0;
 449}
 450
 451/*
 452 * Handle SIGP partial execution interception.
 453 *
 454 * This interception will occur at the source cpu when a source cpu sends an
 455 * external call to a target cpu and the target cpu has the WAIT bit set in
 456 * its cpuflags. Interception will occurr after the interrupt indicator bits at
 457 * the target cpu have been set. All error cases will lead to instruction
 458 * interception, therefore nothing is to be checked or prepared.
 459 */
 460int kvm_s390_handle_sigp_pei(struct kvm_vcpu *vcpu)
 461{
 462        int r3 = vcpu->arch.sie_block->ipa & 0x000f;
 463        u16 cpu_addr = vcpu->run->s.regs.gprs[r3];
 464        struct kvm_vcpu *dest_vcpu;
 465        u8 order_code = kvm_s390_get_base_disp_rs(vcpu, NULL);
 466
 467        trace_kvm_s390_handle_sigp_pei(vcpu, order_code, cpu_addr);
 468
 469        if (order_code == SIGP_EXTERNAL_CALL) {
 470                dest_vcpu = kvm_get_vcpu_by_id(vcpu->kvm, cpu_addr);
 471                BUG_ON(dest_vcpu == NULL);
 472
 473                kvm_s390_vcpu_wakeup(dest_vcpu);
 474                kvm_s390_set_psw_cc(vcpu, SIGP_CC_ORDER_CODE_ACCEPTED);
 475                return 0;
 476        }
 477
 478        return -EOPNOTSUPP;
 479}
 480