arch/s390/kvm/kvm-s390.c

   1 /*
   2  * hosting zSeries kernel virtual machines
   3  *
   4  * Copyright IBM Corp. 2008, 2009
   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  *               Heiko Carstens <heiko.carstens@de.ibm.com>
  13  *               Christian Ehrhardt <ehrhardt@de.ibm.com>
  14  */
  15
  16 #include <linux/compiler.h>
  17 #include <linux/err.h>
  18 #include <linux/fs.h>
  19 #include <linux/hrtimer.h>
  20 #include <linux/init.h>
  21 #include <linux/kvm.h>
  22 #include <linux/kvm_host.h>
  23 #include <linux/module.h>
  24 #include <linux/slab.h>
  25 #include <linux/timer.h>
  26 #include <asm/asm-offsets.h>
  27 #include <asm/lowcore.h>
  28 #include <asm/pgtable.h>
  29 #include <asm/nmi.h>
  30 #include <asm/switch_to.h>
  31 #include <asm/facility.h>
  32 #include <asm/sclp.h>
  33 #include "kvm-s390.h"
  34 #include "gaccess.h"
  35
  36 #define CREATE_TRACE_POINTS
  37 #include "trace.h"
  38 #include "trace-s390.h"
  39
  40 #define VCPU_STAT(x) offsetof(struct kvm_vcpu, stat.x), KVM_STAT_VCPU
  41
  42 struct kvm_stats_debugfs_item debugfs_entries[] = {
  43         { "userspace_handled", VCPU_STAT(exit_userspace) },
  44         { "exit_null", VCPU_STAT(exit_null) },
  45         { "exit_validity", VCPU_STAT(exit_validity) },
  46         { "exit_stop_request", VCPU_STAT(exit_stop_request) },
  47         { "exit_external_request", VCPU_STAT(exit_external_request) },
  48         { "exit_external_interrupt", VCPU_STAT(exit_external_interrupt) },
  49         { "exit_instruction", VCPU_STAT(exit_instruction) },
  50         { "exit_program_interruption", VCPU_STAT(exit_program_interruption) },
  51         { "exit_instr_and_program_int", VCPU_STAT(exit_instr_and_program) },
  52         { "instruction_lctlg", VCPU_STAT(instruction_lctlg) },
  53         { "instruction_lctl", VCPU_STAT(instruction_lctl) },
  54         { "deliver_emergency_signal", VCPU_STAT(deliver_emergency_signal) },
  55         { "deliver_external_call", VCPU_STAT(deliver_external_call) },
  56         { "deliver_service_signal", VCPU_STAT(deliver_service_signal) },
  57         { "deliver_virtio_interrupt", VCPU_STAT(deliver_virtio_interrupt) },
  58         { "deliver_stop_signal", VCPU_STAT(deliver_stop_signal) },
  59         { "deliver_prefix_signal", VCPU_STAT(deliver_prefix_signal) },
  60         { "deliver_restart_signal", VCPU_STAT(deliver_restart_signal) },
  61         { "deliver_program_interruption", VCPU_STAT(deliver_program_int) },
  62         { "exit_wait_state", VCPU_STAT(exit_wait_state) },
  63         { "instruction_pfmf", VCPU_STAT(instruction_pfmf) },
  64         { "instruction_stidp", VCPU_STAT(instruction_stidp) },
  65         { "instruction_spx", VCPU_STAT(instruction_spx) },
  66         { "instruction_stpx", VCPU_STAT(instruction_stpx) },
  67         { "instruction_stap", VCPU_STAT(instruction_stap) },
  68         { "instruction_storage_key", VCPU_STAT(instruction_storage_key) },
  69         { "instruction_stsch", VCPU_STAT(instruction_stsch) },
  70         { "instruction_chsc", VCPU_STAT(instruction_chsc) },
  71         { "instruction_stsi", VCPU_STAT(instruction_stsi) },
  72         { "instruction_stfl", VCPU_STAT(instruction_stfl) },
  73         { "instruction_tprot", VCPU_STAT(instruction_tprot) },
  74         { "instruction_sigp_sense", VCPU_STAT(instruction_sigp_sense) },
  75         { "instruction_sigp_sense_running", VCPU_STAT(instruction_sigp_sense_running) },
  76         { "instruction_sigp_external_call", VCPU_STAT(instruction_sigp_external_call) },
  77         { "instruction_sigp_emergency", VCPU_STAT(instruction_sigp_emergency) },
  78         { "instruction_sigp_stop", VCPU_STAT(instruction_sigp_stop) },
  79         { "instruction_sigp_set_arch", VCPU_STAT(instruction_sigp_arch) },
  80         { "instruction_sigp_set_prefix", VCPU_STAT(instruction_sigp_prefix) },
  81         { "instruction_sigp_restart", VCPU_STAT(instruction_sigp_restart) },
  82         { "diagnose_10", VCPU_STAT(diagnose_10) },
  83         { "diagnose_44", VCPU_STAT(diagnose_44) },
  84         { "diagnose_9c", VCPU_STAT(diagnose_9c) },
  85         { NULL }
  86 };
  87
  88 unsigned long *vfacilities;
  89 static struct gmap_notifier gmap_notifier;
  90
  91 /* test availability of vfacility */
  92 static inline int test_vfacility(unsigned long nr)
  93 {
  94         return __test_facility(nr, (void *) vfacilities);
  95 }
  96
  97 /* Section: not file related */
  98 int kvm_arch_hardware_enable(void *garbage)
  99 {
 100         /* every s390 is virtualization enabled ;-) */
 101         return 0;
 102 }
 103
 104 void kvm_arch_hardware_disable(void *garbage)
 105 {
 106 }
 107
 108 static void kvm_gmap_notifier(struct gmap *gmap, unsigned long address);
 109
 110 int kvm_arch_hardware_setup(void)
 111 {
 112         gmap_notifier.notifier_call = kvm_gmap_notifier;
 113         gmap_register_ipte_notifier(&gmap_notifier);
 114         return 0;
 115 }
 116
 117 void kvm_arch_hardware_unsetup(void)
 118 {
 119         gmap_unregister_ipte_notifier(&gmap_notifier);
 120 }
 121
 122 void kvm_arch_check_processor_compat(void *rtn)
 123 {
 124 }
 125
 126 int kvm_arch_init(void *opaque)
 127 {
 128         return 0;
 129 }
 130
 131 void kvm_arch_exit(void)
 132 {
 133 }
 134
 135 /* Section: device related */
 136 long kvm_arch_dev_ioctl(struct file *filp,
 137                         unsigned int ioctl, unsigned long arg)
 138 {
 139         if (ioctl == KVM_S390_ENABLE_SIE)
 140                 return s390_enable_sie();
 141         return -EINVAL;
 142 }
 143
 144 int kvm_dev_ioctl_check_extension(long ext)
 145 {
 146         int r;
 147
 148         switch (ext) {
 149         case KVM_CAP_S390_PSW:
 150         case KVM_CAP_S390_GMAP:
 151         case KVM_CAP_SYNC_MMU:
 152 #ifdef CONFIG_KVM_S390_UCONTROL
 153         case KVM_CAP_S390_UCONTROL:
 154 #endif
 155         case KVM_CAP_SYNC_REGS:
 156         case KVM_CAP_ONE_REG:
 157         case KVM_CAP_ENABLE_CAP:
 158         case KVM_CAP_S390_CSS_SUPPORT:
 159         case KVM_CAP_IOEVENTFD:
 160                 r = 1;
 161                 break;
 162         case KVM_CAP_NR_VCPUS:
 163         case KVM_CAP_MAX_VCPUS:
 164                 r = KVM_MAX_VCPUS;
 165                 break;
 166         case KVM_CAP_NR_MEMSLOTS:
 167                 r = KVM_USER_MEM_SLOTS;
 168                 break;
 169         case KVM_CAP_S390_COW:
 170                 r = MACHINE_HAS_ESOP;
 171                 break;
 172         default:
 173                 r = 0;
 174         }
 175         return r;
 176 }
 177
 178 /* Section: vm related */
 179 /*
 180  * Get (and clear) the dirty memory log for a memory slot.
 181  */
 182 int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
 183                                struct kvm_dirty_log *log)
 184 {
 185         return 0;
 186 }
 187
 188 long kvm_arch_vm_ioctl(struct file *filp,
 189                        unsigned int ioctl, unsigned long arg)
 190 {
 191         struct kvm *kvm = filp->private_data;
 192         void __user *argp = (void __user *)arg;
 193         int r;
 194
 195         switch (ioctl) {
 196         case KVM_S390_INTERRUPT: {
 197                 struct kvm_s390_interrupt s390int;
 198
 199                 r = -EFAULT;
 200                 if (copy_from_user(&s390int, argp, sizeof(s390int)))
 201                         break;
 202                 r = kvm_s390_inject_vm(kvm, &s390int);
 203                 break;
 204         }
 205         default:
 206                 r = -ENOTTY;
 207         }
 208
 209         return r;
 210 }
 211
 212 int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
 213 {
 214         int rc;
 215         char debug_name[16];
 216
 217         rc = -EINVAL;
 218 #ifdef CONFIG_KVM_S390_UCONTROL
 219         if (type & ~KVM_VM_S390_UCONTROL)
 220                 goto out_err;
 221         if ((type & KVM_VM_S390_UCONTROL) && (!capable(CAP_SYS_ADMIN)))
 222                 goto out_err;
 223 #else
 224         if (type)
 225                 goto out_err;
 226 #endif
 227
 228         rc = s390_enable_sie();
 229         if (rc)
 230                 goto out_err;
 231
 232         rc = -ENOMEM;
 233
 234         kvm->arch.sca = (struct sca_block *) get_zeroed_page(GFP_KERNEL);
 235         if (!kvm->arch.sca)
 236                 goto out_err;
 237
 238         sprintf(debug_name, "kvm-%u", current->pid);
 239
 240         kvm->arch.dbf = debug_register(debug_name, 8, 2, 8 * sizeof(long));
 241         if (!kvm->arch.dbf)
 242                 goto out_nodbf;
 243
 244         spin_lock_init(&kvm->arch.float_int.lock);
 245         INIT_LIST_HEAD(&kvm->arch.float_int.list);
 246
 247         debug_register_view(kvm->arch.dbf, &debug_sprintf_view);
 248         VM_EVENT(kvm, 3, "%s", "vm created");
 249
 250         if (type & KVM_VM_S390_UCONTROL) {
 251                 kvm->arch.gmap = NULL;
 252         } else {
 253                 kvm->arch.gmap = gmap_alloc(current->mm);
 254                 if (!kvm->arch.gmap)
 255                         goto out_nogmap;
 256                 kvm->arch.gmap->private = kvm;
 257         }
 258
 259         kvm->arch.css_support = 0;
 260
 261         return 0;
 262 out_nogmap:
 263         debug_unregister(kvm->arch.dbf);
 264 out_nodbf:
 265         free_page((unsigned long)(kvm->arch.sca));
 266 out_err:
 267         return rc;
 268 }
 269
 270 void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu)
 271 {
 272         VCPU_EVENT(vcpu, 3, "%s", "free cpu");
 273         trace_kvm_s390_destroy_vcpu(vcpu->vcpu_id);
 274         if (!kvm_is_ucontrol(vcpu->kvm)) {
 275                 clear_bit(63 - vcpu->vcpu_id,
 276                           (unsigned long *) &vcpu->kvm->arch.sca->mcn);
 277                 if (vcpu->kvm->arch.sca->cpu[vcpu->vcpu_id].sda ==
 278                     (__u64) vcpu->arch.sie_block)
 279                         vcpu->kvm->arch.sca->cpu[vcpu->vcpu_id].sda = 0;
 280         }
 281         smp_mb();
 282
 283         if (kvm_is_ucontrol(vcpu->kvm))
 284                 gmap_free(vcpu->arch.gmap);
 285
 286         free_page((unsigned long)(vcpu->arch.sie_block));
 287         kvm_vcpu_uninit(vcpu);
 288         kmem_cache_free(kvm_vcpu_cache, vcpu);
 289 }
 290
 291 static void kvm_free_vcpus(struct kvm *kvm)
 292 {
 293         unsigned int i;
 294         struct kvm_vcpu *vcpu;
 295
 296         kvm_for_each_vcpu(i, vcpu, kvm)
 297                 kvm_arch_vcpu_destroy(vcpu);
 298
 299         mutex_lock(&kvm->lock);
 300         for (i = 0; i < atomic_read(&kvm->online_vcpus); i++)
 301                 kvm->vcpus[i] = NULL;
 302
 303         atomic_set(&kvm->online_vcpus, 0);
 304         mutex_unlock(&kvm->lock);
 305 }
 306
 307 void kvm_arch_sync_events(struct kvm *kvm)
 308 {
 309 }
 310
 311 void kvm_arch_destroy_vm(struct kvm *kvm)
 312 {
 313         kvm_free_vcpus(kvm);
 314         free_page((unsigned long)(kvm->arch.sca));
 315         debug_unregister(kvm->arch.dbf);
 316         if (!kvm_is_ucontrol(kvm))
 317                 gmap_free(kvm->arch.gmap);
 318 }
 319
 320 /* Section: vcpu related */
 321 int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
 322 {
 323         if (kvm_is_ucontrol(vcpu->kvm)) {
 324                 vcpu->arch.gmap = gmap_alloc(current->mm);
 325                 if (!vcpu->arch.gmap)
 326                         return -ENOMEM;
 327                 vcpu->arch.gmap->private = vcpu->kvm;
 328                 return 0;
 329         }
 330
 331         vcpu->arch.gmap = vcpu->kvm->arch.gmap;
 332         vcpu->run->kvm_valid_regs = KVM_SYNC_PREFIX |
 333                                     KVM_SYNC_GPRS |
 334                                     KVM_SYNC_ACRS |
 335                                     KVM_SYNC_CRS;
 336         return 0;
 337 }
 338
 339 void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu)
 340 {
 341         /* Nothing todo */
 342 }
 343
 344 void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
 345 {
 346         save_fp_ctl(&vcpu->arch.host_fpregs.fpc);
 347         save_fp_regs(vcpu->arch.host_fpregs.fprs);
 348         save_access_regs(vcpu->arch.host_acrs);
 349         restore_fp_ctl(&vcpu->arch.guest_fpregs.fpc);
 350         restore_fp_regs(vcpu->arch.guest_fpregs.fprs);
 351         restore_access_regs(vcpu->run->s.regs.acrs);
 352         gmap_enable(vcpu->arch.gmap);
 353         atomic_set_mask(CPUSTAT_RUNNING, &vcpu->arch.sie_block->cpuflags);
 354 }
 355
 356 void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
 357 {
 358         atomic_clear_mask(CPUSTAT_RUNNING, &vcpu->arch.sie_block->cpuflags);
 359         gmap_disable(vcpu->arch.gmap);
 360         save_fp_ctl(&vcpu->arch.guest_fpregs.fpc);
 361         save_fp_regs(vcpu->arch.guest_fpregs.fprs);
 362         save_access_regs(vcpu->run->s.regs.acrs);
 363         restore_fp_ctl(&vcpu->arch.host_fpregs.fpc);
 364         restore_fp_regs(vcpu->arch.host_fpregs.fprs);
 365         restore_access_regs(vcpu->arch.host_acrs);
 366 }
 367
 368 static void kvm_s390_vcpu_initial_reset(struct kvm_vcpu *vcpu)
 369 {
 370         /* this equals initial cpu reset in pop, but we don't switch to ESA */
 371         vcpu->arch.sie_block->gpsw.mask = 0UL;
 372         vcpu->arch.sie_block->gpsw.addr = 0UL;
 373         kvm_s390_set_prefix(vcpu, 0);
 374         vcpu->arch.sie_block->cputm     = 0UL;
 375         vcpu->arch.sie_block->ckc       = 0UL;
 376         vcpu->arch.sie_block->todpr     = 0;
 377         memset(vcpu->arch.sie_block->gcr, 0, 16 * sizeof(__u64));
 378         vcpu->arch.sie_block->gcr[0]  = 0xE0UL;
 379         vcpu->arch.sie_block->gcr[14] = 0xC2000000UL;
 380         vcpu->arch.guest_fpregs.fpc = 0;
 381         asm volatile("lfpc %0" : : "Q" (vcpu->arch.guest_fpregs.fpc));
 382         vcpu->arch.sie_block->gbea = 1;
 383         atomic_set_mask(CPUSTAT_STOPPED, &vcpu->arch.sie_block->cpuflags);
 384 }
 385
 386 int kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu)
 387 {
 388         return 0;
 389 }
 390
 391 int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu)
 392 {
 393         atomic_set(&vcpu->arch.sie_block->cpuflags, CPUSTAT_ZARCH |
 394                                                     CPUSTAT_SM |
 395                                                     CPUSTAT_STOPPED |
 396                                                     CPUSTAT_GED);
 397         vcpu->arch.sie_block->ecb   = 6;
 398         if (test_vfacility(50) && test_vfacility(73))
 399                 vcpu->arch.sie_block->ecb |= 0x10;
 400
 401         vcpu->arch.sie_block->ecb2  = 8;
 402         vcpu->arch.sie_block->eca   = 0xC1002001U;
 403         vcpu->arch.sie_block->fac   = (int) (long) vfacilities;
 404         hrtimer_init(&vcpu->arch.ckc_timer, CLOCK_REALTIME, HRTIMER_MODE_ABS);
 405         tasklet_init(&vcpu->arch.tasklet, kvm_s390_tasklet,
 406                      (unsigned long) vcpu);
 407         vcpu->arch.ckc_timer.function = kvm_s390_idle_wakeup;
 408         get_cpu_id(&vcpu->arch.cpu_id);
 409         vcpu->arch.cpu_id.version = 0xff;
 410         return 0;
 411 }
 412
 413 struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm,
 414                                       unsigned int id)
 415 {
 416         struct kvm_vcpu *vcpu;
 417         struct sie_page *sie_page;
 418         int rc = -EINVAL;
 419
 420         if (id >= KVM_MAX_VCPUS)
 421                 goto out;
 422
 423         rc = -ENOMEM;
 424
 425         vcpu = kmem_cache_zalloc(kvm_vcpu_cache, GFP_KERNEL);
 426         if (!vcpu)
 427                 goto out;
 428
 429         sie_page = (struct sie_page *) get_zeroed_page(GFP_KERNEL);
 430         if (!sie_page)
 431                 goto out_free_cpu;
 432
 433         vcpu->arch.sie_block = &sie_page->sie_block;
 434         vcpu->arch.sie_block->itdba = (unsigned long) &sie_page->itdb;
 435
 436         vcpu->arch.sie_block->icpua = id;
 437         if (!kvm_is_ucontrol(kvm)) {
 438                 if (!kvm->arch.sca) {
 439                         WARN_ON_ONCE(1);
 440                         goto out_free_cpu;
 441                 }
 442                 if (!kvm->arch.sca->cpu[id].sda)
 443                         kvm->arch.sca->cpu[id].sda =
 444                                 (__u64) vcpu->arch.sie_block;
 445                 vcpu->arch.sie_block->scaoh =
 446                         (__u32)(((__u64)kvm->arch.sca) >> 32);
 447                 vcpu->arch.sie_block->scaol = (__u32)(__u64)kvm->arch.sca;
 448                 set_bit(63 - id, (unsigned long *) &kvm->arch.sca->mcn);
 449         }
 450
 451         spin_lock_init(&vcpu->arch.local_int.lock);
 452         INIT_LIST_HEAD(&vcpu->arch.local_int.list);
 453         vcpu->arch.local_int.float_int = &kvm->arch.float_int;
 454         spin_lock(&kvm->arch.float_int.lock);
 455         kvm->arch.float_int.local_int[id] = &vcpu->arch.local_int;
 456         vcpu->arch.local_int.wq = &vcpu->wq;
 457         vcpu->arch.local_int.cpuflags = &vcpu->arch.sie_block->cpuflags;
 458         spin_unlock(&kvm->arch.float_int.lock);
 459
 460         rc = kvm_vcpu_init(vcpu, kvm, id);
 461         if (rc)
 462                 goto out_free_sie_block;
 463         VM_EVENT(kvm, 3, "create cpu %d at %p, sie block at %p", id, vcpu,
 464                  vcpu->arch.sie_block);
 465         trace_kvm_s390_create_vcpu(id, vcpu, vcpu->arch.sie_block);
 466
 467         return vcpu;
 468 out_free_sie_block:
 469         free_page((unsigned long)(vcpu->arch.sie_block));
 470 out_free_cpu:
 471         kmem_cache_free(kvm_vcpu_cache, vcpu);
 472 out:
 473         return ERR_PTR(rc);
 474 }
 475
 476 int kvm_arch_vcpu_runnable(struct kvm_vcpu *vcpu)
 477 {
 478         /* kvm common code refers to this, but never calls it */
 479         BUG();
 480         return 0;
 481 }
 482
 483 void s390_vcpu_block(struct kvm_vcpu *vcpu)
 484 {
 485         atomic_set_mask(PROG_BLOCK_SIE, &vcpu->arch.sie_block->prog20);
 486 }
 487
 488 void s390_vcpu_unblock(struct kvm_vcpu *vcpu)
 489 {
 490         atomic_clear_mask(PROG_BLOCK_SIE, &vcpu->arch.sie_block->prog20);
 491 }
 492
 493 /*
 494  * Kick a guest cpu out of SIE and wait until SIE is not running.
 495  * If the CPU is not running (e.g. waiting as idle) the function will
 496  * return immediately. */
 497 void exit_sie(struct kvm_vcpu *vcpu)
 498 {
 499         atomic_set_mask(CPUSTAT_STOP_INT, &vcpu->arch.sie_block->cpuflags);
 500         while (vcpu->arch.sie_block->prog0c & PROG_IN_SIE)
 501                 cpu_relax();
 502 }
 503
 504 /* Kick a guest cpu out of SIE and prevent SIE-reentry */
 505 void exit_sie_sync(struct kvm_vcpu *vcpu)
 506 {
 507         s390_vcpu_block(vcpu);
 508         exit_sie(vcpu);
 509 }
 510
 511 static void kvm_gmap_notifier(struct gmap *gmap, unsigned long address)
 512 {
 513         int i;
 514         struct kvm *kvm = gmap->private;
 515         struct kvm_vcpu *vcpu;
 516
 517         kvm_for_each_vcpu(i, vcpu, kvm) {
 518                 /* match against both prefix pages */
 519                 if (vcpu->arch.sie_block->prefix == (address & ~0x1000UL)) {
 520                         VCPU_EVENT(vcpu, 2, "gmap notifier for %lx", address);
 521                         kvm_make_request(KVM_REQ_MMU_RELOAD, vcpu);
 522                         exit_sie_sync(vcpu);
 523                 }
 524         }
 525 }
 526
 527 int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu)
 528 {
 529         /* kvm common code refers to this, but never calls it */
 530         BUG();
 531         return 0;
 532 }
 533
 534 static int kvm_arch_vcpu_ioctl_get_one_reg(struct kvm_vcpu *vcpu,
 535                                            struct kvm_one_reg *reg)
 536 {
 537         int r = -EINVAL;
 538
 539         switch (reg->id) {
 540         case KVM_REG_S390_TODPR:
 541                 r = put_user(vcpu->arch.sie_block->todpr,
 542                              (u32 __user *)reg->addr);
 543                 break;
 544         case KVM_REG_S390_EPOCHDIFF:
 545                 r = put_user(vcpu->arch.sie_block->epoch,
 546                              (u64 __user *)reg->addr);
 547                 break;
 548         case KVM_REG_S390_CPU_TIMER:
 549                 r = put_user(vcpu->arch.sie_block->cputm,
 550                              (u64 __user *)reg->addr);
 551                 break;
 552         case KVM_REG_S390_CLOCK_COMP:
 553                 r = put_user(vcpu->arch.sie_block->ckc,
 554                              (u64 __user *)reg->addr);
 555                 break;
 556         default:
 557                 break;
 558         }
 559
 560         return r;
 561 }
 562
 563 static int kvm_arch_vcpu_ioctl_set_one_reg(struct kvm_vcpu *vcpu,
 564                                            struct kvm_one_reg *reg)
 565 {
 566         int r = -EINVAL;
 567
 568         switch (reg->id) {
 569         case KVM_REG_S390_TODPR:
 570                 r = get_user(vcpu->arch.sie_block->todpr,
 571                              (u32 __user *)reg->addr);
 572                 break;
 573         case KVM_REG_S390_EPOCHDIFF:
 574                 r = get_user(vcpu->arch.sie_block->epoch,
 575                              (u64 __user *)reg->addr);
 576                 break;
 577         case KVM_REG_S390_CPU_TIMER:
 578                 r = get_user(vcpu->arch.sie_block->cputm,
 579                              (u64 __user *)reg->addr);
 580                 break;
 581         case KVM_REG_S390_CLOCK_COMP:
 582                 r = get_user(vcpu->arch.sie_block->ckc,
 583                              (u64 __user *)reg->addr);
 584                 break;
 585         default:
 586                 break;
 587         }
 588
 589         return r;
 590 }
 591
 592 static int kvm_arch_vcpu_ioctl_initial_reset(struct kvm_vcpu *vcpu)
 593 {
 594         kvm_s390_vcpu_initial_reset(vcpu);
 595         return 0;
 596 }
 597
 598 int kvm_arch_vcpu_ioctl_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
 599 {
 600         memcpy(&vcpu->run->s.regs.gprs, &regs->gprs, sizeof(regs->gprs));
 601         return 0;
 602 }
 603
 604 int kvm_arch_vcpu_ioctl_get_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
 605 {
 606         memcpy(&regs->gprs, &vcpu->run->s.regs.gprs, sizeof(regs->gprs));
 607         return 0;
 608 }
 609
 610 int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
 611                                   struct kvm_sregs *sregs)
 612 {
 613         memcpy(&vcpu->run->s.regs.acrs, &sregs->acrs, sizeof(sregs->acrs));
 614         memcpy(&vcpu->arch.sie_block->gcr, &sregs->crs, sizeof(sregs->crs));
 615         restore_access_regs(vcpu->run->s.regs.acrs);
 616         return 0;
 617 }
 618
 619 int kvm_arch_vcpu_ioctl_get_sregs(struct kvm_vcpu *vcpu,
 620                                   struct kvm_sregs *sregs)
 621 {
 622         memcpy(&sregs->acrs, &vcpu->run->s.regs.acrs, sizeof(sregs->acrs));
 623         memcpy(&sregs->crs, &vcpu->arch.sie_block->gcr, sizeof(sregs->crs));
 624         return 0;
 625 }
 626
 627 int kvm_arch_vcpu_ioctl_set_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
 628 {
 629         if (test_fp_ctl(fpu->fpc))
 630                 return -EINVAL;
 631         memcpy(&vcpu->arch.guest_fpregs.fprs, &fpu->fprs, sizeof(fpu->fprs));
 632         vcpu->arch.guest_fpregs.fpc = fpu->fpc;
 633         restore_fp_ctl(&vcpu->arch.guest_fpregs.fpc);
 634         restore_fp_regs(vcpu->arch.guest_fpregs.fprs);
 635         return 0;
 636 }
 637
 638 int kvm_arch_vcpu_ioctl_get_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
 639 {
 640         memcpy(&fpu->fprs, &vcpu->arch.guest_fpregs.fprs, sizeof(fpu->fprs));
 641         fpu->fpc = vcpu->arch.guest_fpregs.fpc;
 642         return 0;
 643 }
 644
 645 static int kvm_arch_vcpu_ioctl_set_initial_psw(struct kvm_vcpu *vcpu, psw_t psw)
 646 {
 647         int rc = 0;
 648
 649         if (!(atomic_read(&vcpu->arch.sie_block->cpuflags) & CPUSTAT_STOPPED))
 650                 rc = -EBUSY;
 651         else {
 652                 vcpu->run->psw_mask = psw.mask;
 653                 vcpu->run->psw_addr = psw.addr;
 654         }
 655         return rc;
 656 }
 657
 658 int kvm_arch_vcpu_ioctl_translate(struct kvm_vcpu *vcpu,
 659                                   struct kvm_translation *tr)
 660 {
 661         return -EINVAL; /* not implemented yet */
 662 }
 663
 664 int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu,
 665                                         struct kvm_guest_debug *dbg)
 666 {
 667         return -EINVAL; /* not implemented yet */
 668 }
 669
 670 int kvm_arch_vcpu_ioctl_get_mpstate(struct kvm_vcpu *vcpu,
 671                                     struct kvm_mp_state *mp_state)
 672 {
 673         return -EINVAL; /* not implemented yet */
 674 }
 675
 676 int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu,
 677                                     struct kvm_mp_state *mp_state)
 678 {
 679         return -EINVAL; /* not implemented yet */
 680 }
 681
 682 static int kvm_s390_handle_requests(struct kvm_vcpu *vcpu)
 683 {
 684         /*
 685          * We use MMU_RELOAD just to re-arm the ipte notifier for the
 686          * guest prefix page. gmap_ipte_notify will wait on the ptl lock.
 687          * This ensures that the ipte instruction for this request has
 688          * already finished. We might race against a second unmapper that
 689          * wants to set the blocking bit. Lets just retry the request loop.
 690          */
 691         while (kvm_check_request(KVM_REQ_MMU_RELOAD, vcpu)) {
 692                 int rc;
 693                 rc = gmap_ipte_notify(vcpu->arch.gmap,
 694                                       vcpu->arch.sie_block->prefix,
 695                                       PAGE_SIZE * 2);
 696                 if (rc)
 697                         return rc;
 698                 s390_vcpu_unblock(vcpu);
 699         }
 700         return 0;
 701 }
 702
 703 static int vcpu_pre_run(struct kvm_vcpu *vcpu)
 704 {
 705         int rc, cpuflags;
 706
 707         memcpy(&vcpu->arch.sie_block->gg14, &vcpu->run->s.regs.gprs[14], 16);
 708
 709         if (need_resched())
 710                 schedule();
 711
 712         if (test_thread_flag(TIF_MCCK_PENDING))
 713                 s390_handle_mcck();
 714
 715         if (!kvm_is_ucontrol(vcpu->kvm))
 716                 kvm_s390_deliver_pending_interrupts(vcpu);
 717
 718         rc = kvm_s390_handle_requests(vcpu);
 719         if (rc)
 720                 return rc;
 721
 722         vcpu->arch.sie_block->icptcode = 0;
 723         cpuflags = atomic_read(&vcpu->arch.sie_block->cpuflags);
 724         VCPU_EVENT(vcpu, 6, "entering sie flags %x", cpuflags);
 725         trace_kvm_s390_sie_enter(vcpu, cpuflags);
 726
 727         return 0;
 728 }
 729
 730 static int vcpu_post_run(struct kvm_vcpu *vcpu, int exit_reason)
 731 {
 732         int rc;
 733
 734         VCPU_EVENT(vcpu, 6, "exit sie icptcode %d",
 735                    vcpu->arch.sie_block->icptcode);
 736         trace_kvm_s390_sie_exit(vcpu, vcpu->arch.sie_block->icptcode);
 737
 738         if (exit_reason >= 0) {
 739                 rc = 0;
 740         } else if (kvm_is_ucontrol(vcpu->kvm)) {
 741                 vcpu->run->exit_reason = KVM_EXIT_S390_UCONTROL;
 742                 vcpu->run->s390_ucontrol.trans_exc_code =
 743                                                 current->thread.gmap_addr;
 744                 vcpu->run->s390_ucontrol.pgm_code = 0x10;
 745                 rc = -EREMOTE;
 746         }
 747
 748         memcpy(&vcpu->run->s.regs.gprs[14], &vcpu->arch.sie_block->gg14, 16);
 749
 750         if (rc == 0) {
 751                 if (kvm_is_ucontrol(vcpu->kvm))
 752                         rc = -EOPNOTSUPP;
 753                 else
 754                         rc = kvm_handle_sie_intercept(vcpu);
 755         }
 756
 757         return rc;
 758 }
 759
 760 static int __vcpu_run(struct kvm_vcpu *vcpu)
 761 {
 762         int rc, exit_reason;
 763
 764         /*
 765          * We try to hold kvm->srcu during most of vcpu_run (except when run-
 766          * ning the guest), so that memslots (and other stuff) are protected
 767          */
 768         vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
 769
 770         do {
 771                 rc = vcpu_pre_run(vcpu);
 772                 if (rc)
 773                         break;
 774
 775                 srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx);
 776                 /*
 777                  * As PF_VCPU will be used in fault handler, between
 778                  * guest_enter and guest_exit should be no uaccess.
 779                  */
 780                 preempt_disable();
 781                 kvm_guest_enter();
 782                 preempt_enable();
 783                 exit_reason = sie64a(vcpu->arch.sie_block,
 784                                      vcpu->run->s.regs.gprs);
 785                 kvm_guest_exit();
 786                 vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
 787
 788                 rc = vcpu_post_run(vcpu, exit_reason);
 789         } while (!signal_pending(current) && !rc);
 790
 791         srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx);
 792         return rc;
 793 }
 794
 795 int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
 796 {
 797         int rc;
 798         sigset_t sigsaved;
 799
 800         if (vcpu->sigset_active)
 801                 sigprocmask(SIG_SETMASK, &vcpu->sigset, &sigsaved);
 802
 803         atomic_clear_mask(CPUSTAT_STOPPED, &vcpu->arch.sie_block->cpuflags);
 804
 805         BUG_ON(vcpu->kvm->arch.float_int.local_int[vcpu->vcpu_id] == NULL);
 806
 807         switch (kvm_run->exit_reason) {
 808         case KVM_EXIT_S390_SIEIC:
 809         case KVM_EXIT_UNKNOWN:
 810         case KVM_EXIT_INTR:
 811         case KVM_EXIT_S390_RESET:
 812         case KVM_EXIT_S390_UCONTROL:
 813         case KVM_EXIT_S390_TSCH:
 814                 break;
 815         default:
 816                 BUG();
 817         }
 818
 819         vcpu->arch.sie_block->gpsw.mask = kvm_run->psw_mask;
 820         vcpu->arch.sie_block->gpsw.addr = kvm_run->psw_addr;
 821         if (kvm_run->kvm_dirty_regs & KVM_SYNC_PREFIX) {
 822                 kvm_run->kvm_dirty_regs &= ~KVM_SYNC_PREFIX;
 823                 kvm_s390_set_prefix(vcpu, kvm_run->s.regs.prefix);
 824         }
 825         if (kvm_run->kvm_dirty_regs & KVM_SYNC_CRS) {
 826                 kvm_run->kvm_dirty_regs &= ~KVM_SYNC_CRS;
 827                 memcpy(&vcpu->arch.sie_block->gcr, &kvm_run->s.regs.crs, 128);
 828                 kvm_s390_set_prefix(vcpu, kvm_run->s.regs.prefix);
 829         }
 830
 831         might_fault();
 832         rc = __vcpu_run(vcpu);
 833
 834         if (signal_pending(current) && !rc) {
 835                 kvm_run->exit_reason = KVM_EXIT_INTR;
 836                 rc = -EINTR;
 837         }
 838
 839         if (rc == -EOPNOTSUPP) {
 840                 /* intercept cannot be handled in-kernel, prepare kvm-run */
 841                 kvm_run->exit_reason         = KVM_EXIT_S390_SIEIC;
 842                 kvm_run->s390_sieic.icptcode = vcpu->arch.sie_block->icptcode;
 843                 kvm_run->s390_sieic.ipa      = vcpu->arch.sie_block->ipa;
 844                 kvm_run->s390_sieic.ipb      = vcpu->arch.sie_block->ipb;
 845                 rc = 0;
 846         }
 847
 848         if (rc == -EREMOTE) {
 849                 /* intercept was handled, but userspace support is needed
 850                  * kvm_run has been prepared by the handler */
 851                 rc = 0;
 852         }
 853
 854         kvm_run->psw_mask     = vcpu->arch.sie_block->gpsw.mask;
 855         kvm_run->psw_addr     = vcpu->arch.sie_block->gpsw.addr;
 856         kvm_run->s.regs.prefix = vcpu->arch.sie_block->prefix;
 857         memcpy(&kvm_run->s.regs.crs, &vcpu->arch.sie_block->gcr, 128);
 858
 859         if (vcpu->sigset_active)
 860                 sigprocmask(SIG_SETMASK, &sigsaved, NULL);
 861
 862         vcpu->stat.exit_userspace++;
 863         return rc;
 864 }
 865
 866 static int __guestcopy(struct kvm_vcpu *vcpu, u64 guestdest, void *from,
 867                        unsigned long n, int prefix)
 868 {
 869         if (prefix)
 870                 return copy_to_guest(vcpu, guestdest, from, n);
 871         else
 872                 return copy_to_guest_absolute(vcpu, guestdest, from, n);
 873 }
 874
 875 /*
 876  * store status at address
 877  * we use have two special cases:
 878  * KVM_S390_STORE_STATUS_NOADDR: -> 0x1200 on 64 bit
 879  * KVM_S390_STORE_STATUS_PREFIXED: -> prefix
 880  */
 881 int kvm_s390_store_status_unloaded(struct kvm_vcpu *vcpu, unsigned long addr)
 882 {
 883         unsigned char archmode = 1;
 884         int prefix;
 885         u64 clkcomp;
 886
 887         if (addr == KVM_S390_STORE_STATUS_NOADDR) {
 888                 if (copy_to_guest_absolute(vcpu, 163ul, &archmode, 1))
 889                         return -EFAULT;
 890                 addr = SAVE_AREA_BASE;
 891                 prefix = 0;
 892         } else if (addr == KVM_S390_STORE_STATUS_PREFIXED) {
 893                 if (copy_to_guest(vcpu, 163ul, &archmode, 1))
 894                         return -EFAULT;
 895                 addr = SAVE_AREA_BASE;
 896                 prefix = 1;
 897         } else
 898                 prefix = 0;
 899
 900         if (__guestcopy(vcpu, addr + offsetof(struct save_area, fp_regs),
 901                         vcpu->arch.guest_fpregs.fprs, 128, prefix))
 902                 return -EFAULT;
 903
 904         if (__guestcopy(vcpu, addr + offsetof(struct save_area, gp_regs),
 905                         vcpu->run->s.regs.gprs, 128, prefix))
 906                 return -EFAULT;
 907
 908         if (__guestcopy(vcpu, addr + offsetof(struct save_area, psw),
 909                         &vcpu->arch.sie_block->gpsw, 16, prefix))
 910                 return -EFAULT;
 911
 912         if (__guestcopy(vcpu, addr + offsetof(struct save_area, pref_reg),
 913                         &vcpu->arch.sie_block->prefix, 4, prefix))
 914                 return -EFAULT;
 915
 916         if (__guestcopy(vcpu,
 917                         addr + offsetof(struct save_area, fp_ctrl_reg),
 918                         &vcpu->arch.guest_fpregs.fpc, 4, prefix))
 919                 return -EFAULT;
 920
 921         if (__guestcopy(vcpu, addr + offsetof(struct save_area, tod_reg),
 922                         &vcpu->arch.sie_block->todpr, 4, prefix))
 923                 return -EFAULT;
 924
 925         if (__guestcopy(vcpu, addr + offsetof(struct save_area, timer),
 926                         &vcpu->arch.sie_block->cputm, 8, prefix))
 927                 return -EFAULT;
 928
 929         clkcomp = vcpu->arch.sie_block->ckc >> 8;
 930         if (__guestcopy(vcpu, addr + offsetof(struct save_area, clk_cmp),
 931                         &clkcomp, 8, prefix))
 932                 return -EFAULT;
 933
 934         if (__guestcopy(vcpu, addr + offsetof(struct save_area, acc_regs),
 935                         &vcpu->run->s.regs.acrs, 64, prefix))
 936                 return -EFAULT;
 937
 938         if (__guestcopy(vcpu,
 939                         addr + offsetof(struct save_area, ctrl_regs),
 940                         &vcpu->arch.sie_block->gcr, 128, prefix))
 941                 return -EFAULT;
 942         return 0;
 943 }
 944
 945 int kvm_s390_vcpu_store_status(struct kvm_vcpu *vcpu, unsigned long addr)
 946 {
 947         /*
 948          * The guest FPRS and ACRS are in the host FPRS/ACRS due to the lazy
 949          * copying in vcpu load/put. Lets update our copies before we save
 950          * it into the save area
 951          */
 952         save_fp_ctl(&vcpu->arch.guest_fpregs.fpc);
 953         save_fp_regs(vcpu->arch.guest_fpregs.fprs);
 954         save_access_regs(vcpu->run->s.regs.acrs);
 955
 956         return kvm_s390_store_status_unloaded(vcpu, addr);
 957 }
 958
 959 static int kvm_vcpu_ioctl_enable_cap(struct kvm_vcpu *vcpu,
 960                                      struct kvm_enable_cap *cap)
 961 {
 962         int r;
 963
 964         if (cap->flags)
 965                 return -EINVAL;
 966
 967         switch (cap->cap) {
 968         case KVM_CAP_S390_CSS_SUPPORT:
 969                 if (!vcpu->kvm->arch.css_support) {
 970                         vcpu->kvm->arch.css_support = 1;
 971                         trace_kvm_s390_enable_css(vcpu->kvm);
 972                 }
 973                 r = 0;
 974                 break;
 975         default:
 976                 r = -EINVAL;
 977                 break;
 978         }
 979         return r;
 980 }
 981
 982 long kvm_arch_vcpu_ioctl(struct file *filp,
 983                          unsigned int ioctl, unsigned long arg)
 984 {
 985         struct kvm_vcpu *vcpu = filp->private_data;
 986         void __user *argp = (void __user *)arg;
 987         int idx;
 988         long r;
 989
 990         switch (ioctl) {
 991         case KVM_S390_INTERRUPT: {
 992                 struct kvm_s390_interrupt s390int;
 993
 994                 r = -EFAULT;
 995                 if (copy_from_user(&s390int, argp, sizeof(s390int)))
 996                         break;
 997                 r = kvm_s390_inject_vcpu(vcpu, &s390int);
 998                 break;
 999         }
1000         case KVM_S390_STORE_STATUS:
1001                 idx = srcu_read_lock(&vcpu->kvm->srcu);
1002                 r = kvm_s390_vcpu_store_status(vcpu, arg);
1003                 srcu_read_unlock(&vcpu->kvm->srcu, idx);
1004                 break;
1005         case KVM_S390_SET_INITIAL_PSW: {
1006                 psw_t psw;
1007
1008                 r = -EFAULT;
1009                 if (copy_from_user(&psw, argp, sizeof(psw)))
1010                         break;
1011                 r = kvm_arch_vcpu_ioctl_set_initial_psw(vcpu, psw);
1012                 break;
1013         }
1014         case KVM_S390_INITIAL_RESET:
1015                 r = kvm_arch_vcpu_ioctl_initial_reset(vcpu);
1016                 break;
1017         case KVM_SET_ONE_REG:
1018         case KVM_GET_ONE_REG: {
1019                 struct kvm_one_reg reg;
1020                 r = -EFAULT;
1021                 if (copy_from_user(&reg, argp, sizeof(reg)))
1022                         break;
1023                 if (ioctl == KVM_SET_ONE_REG)
1024                         r = kvm_arch_vcpu_ioctl_set_one_reg(vcpu, &reg);
1025                 else
1026                         r = kvm_arch_vcpu_ioctl_get_one_reg(vcpu, &reg);
1027                 break;
1028         }
1029 #ifdef CONFIG_KVM_S390_UCONTROL
1030         case KVM_S390_UCAS_MAP: {
1031                 struct kvm_s390_ucas_mapping ucasmap;
1032
1033                 if (copy_from_user(&ucasmap, argp, sizeof(ucasmap))) {
1034                         r = -EFAULT;
1035                         break;
1036                 }
1037
1038                 if (!kvm_is_ucontrol(vcpu->kvm)) {
1039                         r = -EINVAL;
1040                         break;
1041                 }
1042
1043                 r = gmap_map_segment(vcpu->arch.gmap, ucasmap.user_addr,
1044                                      ucasmap.vcpu_addr, ucasmap.length);
1045                 break;
1046         }
1047         case KVM_S390_UCAS_UNMAP: {
1048                 struct kvm_s390_ucas_mapping ucasmap;
1049
1050                 if (copy_from_user(&ucasmap, argp, sizeof(ucasmap))) {
1051                         r = -EFAULT;
1052                         break;
1053                 }
1054
1055                 if (!kvm_is_ucontrol(vcpu->kvm)) {
1056                         r = -EINVAL;
1057                         break;
1058                 }
1059
1060                 r = gmap_unmap_segment(vcpu->arch.gmap, ucasmap.vcpu_addr,
1061                         ucasmap.length);
1062                 break;
1063         }
1064 #endif
1065         case KVM_S390_VCPU_FAULT: {
1066                 r = gmap_fault(arg, vcpu->arch.gmap);
1067                 if (!IS_ERR_VALUE(r))
1068                         r = 0;
1069                 break;
1070         }
1071         case KVM_ENABLE_CAP:
1072         {
1073                 struct kvm_enable_cap cap;
1074                 r = -EFAULT;
1075                 if (copy_from_user(&cap, argp, sizeof(cap)))
1076                         break;
1077                 r = kvm_vcpu_ioctl_enable_cap(vcpu, &cap);
1078                 break;
1079         }
1080         default:
1081                 r = -ENOTTY;
1082         }
1083         return r;
1084 }
1085
1086 int kvm_arch_vcpu_fault(struct kvm_vcpu *vcpu, struct vm_fault *vmf)
1087 {
1088 #ifdef CONFIG_KVM_S390_UCONTROL
1089         if ((vmf->pgoff == KVM_S390_SIE_PAGE_OFFSET)
1090                  && (kvm_is_ucontrol(vcpu->kvm))) {
1091                 vmf->page = virt_to_page(vcpu->arch.sie_block);
1092                 get_page(vmf->page);
1093                 return 0;
1094         }
1095 #endif
1096         return VM_FAULT_SIGBUS;
1097 }
1098
1099 void kvm_arch_free_memslot(struct kvm *kvm, struct kvm_memory_slot *free,
1100                            struct kvm_memory_slot *dont)
1101 {
1102 }
1103
1104 int kvm_arch_create_memslot(struct kvm *kvm, struct kvm_memory_slot *slot,
1105                             unsigned long npages)
1106 {
1107         return 0;
1108 }
1109
1110 void kvm_arch_memslots_updated(struct kvm *kvm)
1111 {
1112 }
1113
1114 /* Section: memory related */
1115 int kvm_arch_prepare_memory_region(struct kvm *kvm,
1116                                    struct kvm_memory_slot *memslot,
1117                                    struct kvm_userspace_memory_region *mem,
1118                                    enum kvm_mr_change change)
1119 {
1120         /* A few sanity checks. We can have memory slots which have to be
1121            located/ended at a segment boundary (1MB). The memory in userland is
1122            ok to be fragmented into various different vmas. It is okay to mmap()
1123            and munmap() stuff in this slot after doing this call at any time */
1124
1125         if (mem->userspace_addr & 0xffffful)
1126                 return -EINVAL;
1127
1128         if (mem->memory_size & 0xffffful)
1129                 return -EINVAL;
1130
1131         return 0;
1132 }
1133
1134 void kvm_arch_commit_memory_region(struct kvm *kvm,
1135                                 struct kvm_userspace_memory_region *mem,
1136                                 const struct kvm_memory_slot *old,
1137                                 enum kvm_mr_change change)
1138 {
1139         int rc;
1140
1141         /* If the basics of the memslot do not change, we do not want
1142          * to update the gmap. Every update causes several unnecessary
1143          * segment translation exceptions. This is usually handled just
1144          * fine by the normal fault handler + gmap, but it will also
1145          * cause faults on the prefix page of running guest CPUs.
1146          */
1147         if (old->userspace_addr == mem->userspace_addr &&
1148             old->base_gfn * PAGE_SIZE == mem->guest_phys_addr &&
1149             old->npages * PAGE_SIZE == mem->memory_size)
1150                 return;
1151
1152         rc = gmap_map_segment(kvm->arch.gmap, mem->userspace_addr,
1153                 mem->guest_phys_addr, mem->memory_size);
1154         if (rc)
1155                 printk(KERN_WARNING "kvm-s390: failed to commit memory region\n");
1156         return;
1157 }
1158
1159 void kvm_arch_flush_shadow_all(struct kvm *kvm)
1160 {
1161 }
1162
1163 void kvm_arch_flush_shadow_memslot(struct kvm *kvm,
1164                                    struct kvm_memory_slot *slot)
1165 {
1166 }
1167
1168 static int __init kvm_s390_init(void)
1169 {
1170         int ret;
1171         ret = kvm_init(NULL, sizeof(struct kvm_vcpu), 0, THIS_MODULE);
1172         if (ret)
1173                 return ret;
1174
1175         /*
1176          * guests can ask for up to 255+1 double words, we need a full page
1177          * to hold the maximum amount of facilities. On the other hand, we
1178          * only set facilities that are known to work in KVM.
1179          */
1180         vfacilities = (unsigned long *) get_zeroed_page(GFP_KERNEL|GFP_DMA);
1181         if (!vfacilities) {
1182                 kvm_exit();
1183                 return -ENOMEM;
1184         }
1185         memcpy(vfacilities, S390_lowcore.stfle_fac_list, 16);
1186         vfacilities[0] &= 0xff82fff3f4fc2000UL;
1187         vfacilities[1] &= 0x005c000000000000UL;
1188         return 0;
1189 }
1190
1191 static void __exit kvm_s390_exit(void)
1192 {
1193         free_page((unsigned long) vfacilities);
1194         kvm_exit();
1195 }
1196
1197 module_init(kvm_s390_init);
1198 module_exit(kvm_s390_exit);
1199
1200 /*
1201  * Enable autoloading of the kvm module.
1202  * Note that we add the module alias here instead of virt/kvm/kvm_main.c
1203  * since x86 takes a different approach.
1204  */
1205 #include <linux/miscdevice.h>
1206 MODULE_ALIAS_MISCDEV(KVM_MINOR);
1207 MODULE_ALIAS("devname:kvm");