sys/amd64/vmm/vmm_dev.c

   1 /*-
   2  * Copyright (c) 2011 NetApp, Inc.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY NETAPP, INC ``AS IS'' AND
  15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  17  * ARE DISCLAIMED.  IN NO EVENT SHALL NETAPP, INC OR CONTRIBUTORS BE LIABLE
  18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  24  * SUCH DAMAGE.
  25  *
  26  * $FreeBSD$
  27  */
  28
  29 #include <sys/cdefs.h>
  30 __FBSDID("$FreeBSD$");
  31
  32 #include <sys/param.h>
  33 #include <sys/kernel.h>
  34 #include <sys/queue.h>
  35 #include <sys/lock.h>
  36 #include <sys/mutex.h>
  37 #include <sys/malloc.h>
  38 #include <sys/conf.h>
  39 #include <sys/sysctl.h>
  40 #include <sys/libkern.h>
  41 #include <sys/ioccom.h>
  42 #include <sys/mman.h>
  43 #include <sys/uio.h>
  44
  45 #include <vm/vm.h>
  46 #include <vm/pmap.h>
  47 #include <vm/vm_map.h>
  48
  49 #include <machine/vmparam.h>
  50 #include <machine/vmm.h>
  51 #include <machine/vmm_dev.h>
  52
  53 #include "vmm_lapic.h"
  54 #include "vmm_stat.h"
  55 #include "vmm_mem.h"
  56 #include "io/ppt.h"
  57 #include "io/vatpic.h"
  58 #include "io/vioapic.h"
  59 #include "io/vhpet.h"
  60
  61 struct vmmdev_softc {
  62         struct vm       *vm;            /* vm instance cookie */
  63         struct cdev     *cdev;
  64         SLIST_ENTRY(vmmdev_softc) link;
  65         int             flags;
  66 };
  67 #define VSC_LINKED              0x01
  68
  69 static SLIST_HEAD(, vmmdev_softc) head;
  70
  71 static struct mtx vmmdev_mtx;
  72
  73 static MALLOC_DEFINE(M_VMMDEV, "vmmdev", "vmmdev");
  74
  75 SYSCTL_DECL(_hw_vmm);
  76
  77 static struct vmmdev_softc *
  78 vmmdev_lookup(const char *name)
  79 {
  80         struct vmmdev_softc *sc;
  81
  82 #ifdef notyet   /* XXX kernel is not compiled with invariants */
  83         mtx_assert(&vmmdev_mtx, MA_OWNED);
  84 #endif
  85
  86         SLIST_FOREACH(sc, &head, link) {
  87                 if (strcmp(name, vm_name(sc->vm)) == 0)
  88                         break;
  89         }
  90
  91         return (sc);
  92 }
  93
  94 static struct vmmdev_softc *
  95 vmmdev_lookup2(struct cdev *cdev)
  96 {
  97
  98         return (cdev->si_drv1);
  99 }
 100
 101 static int
 102 vmmdev_rw(struct cdev *cdev, struct uio *uio, int flags)
 103 {
 104         int error, off, c, prot;
 105         vm_paddr_t gpa;
 106         void *hpa, *cookie;
 107         struct vmmdev_softc *sc;
 108
 109         static char zerobuf[PAGE_SIZE];
 110
 111         error = 0;
 112         sc = vmmdev_lookup2(cdev);
 113         if (sc == NULL)
 114                 error = ENXIO;
 115
 116         prot = (uio->uio_rw == UIO_WRITE ? VM_PROT_WRITE : VM_PROT_READ);
 117         while (uio->uio_resid > 0 && error == 0) {
 118                 gpa = uio->uio_offset;
 119                 off = gpa & PAGE_MASK;
 120                 c = min(uio->uio_resid, PAGE_SIZE - off);
 121
 122                 /*
 123                  * The VM has a hole in its physical memory map. If we want to
 124                  * use 'dd' to inspect memory beyond the hole we need to
 125                  * provide bogus data for memory that lies in the hole.
 126                  *
 127                  * Since this device does not support lseek(2), dd(1) will
 128                  * read(2) blocks of data to simulate the lseek(2).
 129                  */
 130                 hpa = vm_gpa_hold(sc->vm, gpa, c, prot, &cookie);
 131                 if (hpa == NULL) {
 132                         if (uio->uio_rw == UIO_READ)
 133                                 error = uiomove(zerobuf, c, uio);
 134                         else
 135                                 error = EFAULT;
 136                 } else {
 137                         error = uiomove(hpa, c, uio);
 138                         vm_gpa_release(cookie);
 139                 }
 140         }
 141         return (error);
 142 }
 143
 144 static int
 145 vmmdev_ioctl(struct cdev *cdev, u_long cmd, caddr_t data, int fflag,
 146              struct thread *td)
 147 {
 148         int error, vcpu, state_changed;
 149         struct vmmdev_softc *sc;
 150         struct vm_memory_segment *seg;
 151         struct vm_register *vmreg;
 152         struct vm_seg_desc *vmsegdesc;
 153         struct vm_run *vmrun;
 154         struct vm_exception *vmexc;
 155         struct vm_lapic_irq *vmirq;
 156         struct vm_lapic_msi *vmmsi;
 157         struct vm_ioapic_irq *ioapic_irq;
 158         struct vm_isa_irq *isa_irq;
 159         struct vm_capability *vmcap;
 160         struct vm_pptdev *pptdev;
 161         struct vm_pptdev_mmio *pptmmio;
 162         struct vm_pptdev_msi *pptmsi;
 163         struct vm_pptdev_msix *pptmsix;
 164         struct vm_nmi *vmnmi;
 165         struct vm_stats *vmstats;
 166         struct vm_stat_desc *statdesc;
 167         struct vm_x2apic *x2apic;
 168         struct vm_gpa_pte *gpapte;
 169
 170         sc = vmmdev_lookup2(cdev);
 171         if (sc == NULL)
 172                 return (ENXIO);
 173
 174         error = 0;
 175         vcpu = -1;
 176         state_changed = 0;
 177
 178         /*
 179          * Some VMM ioctls can operate only on vcpus that are not running.
 180          */
 181         switch (cmd) {
 182         case VM_RUN:
 183         case VM_GET_REGISTER:
 184         case VM_SET_REGISTER:
 185         case VM_GET_SEGMENT_DESCRIPTOR:
 186         case VM_SET_SEGMENT_DESCRIPTOR:
 187         case VM_INJECT_EXCEPTION:
 188         case VM_GET_CAPABILITY:
 189         case VM_SET_CAPABILITY:
 190         case VM_PPTDEV_MSI:
 191         case VM_PPTDEV_MSIX:
 192         case VM_SET_X2APIC_STATE:
 193                 /*
 194                  * XXX fragile, handle with care
 195                  * Assumes that the first field of the ioctl data is the vcpu.
 196                  */
 197                 vcpu = *(int *)data;
 198                 if (vcpu < 0 || vcpu >= VM_MAXCPU) {
 199                         error = EINVAL;
 200                         goto done;
 201                 }
 202
 203                 error = vcpu_set_state(sc->vm, vcpu, VCPU_FROZEN, true);
 204                 if (error)
 205                         goto done;
 206
 207                 state_changed = 1;
 208                 break;
 209
 210         case VM_MAP_PPTDEV_MMIO:
 211         case VM_BIND_PPTDEV:
 212         case VM_UNBIND_PPTDEV:
 213         case VM_MAP_MEMORY:
 214                 /*
 215                  * ioctls that operate on the entire virtual machine must
 216                  * prevent all vcpus from running.
 217                  */
 218                 error = 0;
 219                 for (vcpu = 0; vcpu < VM_MAXCPU; vcpu++) {
 220                         error = vcpu_set_state(sc->vm, vcpu, VCPU_FROZEN, true);
 221                         if (error)
 222                                 break;
 223                 }
 224
 225                 if (error) {
 226                         while (--vcpu >= 0)
 227                                 vcpu_set_state(sc->vm, vcpu, VCPU_IDLE, false);
 228                         goto done;
 229                 }
 230
 231                 state_changed = 2;
 232                 break;
 233
 234         default:
 235                 break;
 236         }
 237
 238         switch(cmd) {
 239         case VM_RUN:
 240                 vmrun = (struct vm_run *)data;
 241                 error = vm_run(sc->vm, vmrun);
 242                 break;
 243         case VM_SUSPEND:
 244                 error = vm_suspend(sc->vm);
 245                 break;
 246         case VM_STAT_DESC: {
 247                 statdesc = (struct vm_stat_desc *)data;
 248                 error = vmm_stat_desc_copy(statdesc->index,
 249                                         statdesc->desc, sizeof(statdesc->desc));
 250                 break;
 251         }
 252         case VM_STATS: {
 253                 CTASSERT(MAX_VM_STATS >= MAX_VMM_STAT_ELEMS);
 254                 vmstats = (struct vm_stats *)data;
 255                 getmicrotime(&vmstats->tv);
 256                 error = vmm_stat_copy(sc->vm, vmstats->cpuid,
 257                                       &vmstats->num_entries, vmstats->statbuf);
 258                 break;
 259         }
 260         case VM_PPTDEV_MSI:
 261                 pptmsi = (struct vm_pptdev_msi *)data;
 262                 error = ppt_setup_msi(sc->vm, pptmsi->vcpu,
 263                                       pptmsi->bus, pptmsi->slot, pptmsi->func,
 264                                       pptmsi->addr, pptmsi->msg,
 265                                       pptmsi->numvec);
 266                 break;
 267         case VM_PPTDEV_MSIX:
 268                 pptmsix = (struct vm_pptdev_msix *)data;
 269                 error = ppt_setup_msix(sc->vm, pptmsix->vcpu,
 270                                        pptmsix->bus, pptmsix->slot,
 271                                        pptmsix->func, pptmsix->idx,
 272                                        pptmsix->addr, pptmsix->msg,
 273                                        pptmsix->vector_control);
 274                 break;
 275         case VM_MAP_PPTDEV_MMIO:
 276                 pptmmio = (struct vm_pptdev_mmio *)data;
 277                 error = ppt_map_mmio(sc->vm, pptmmio->bus, pptmmio->slot,
 278                                      pptmmio->func, pptmmio->gpa, pptmmio->len,
 279                                      pptmmio->hpa);
 280                 break;
 281         case VM_BIND_PPTDEV:
 282                 pptdev = (struct vm_pptdev *)data;
 283                 error = vm_assign_pptdev(sc->vm, pptdev->bus, pptdev->slot,
 284                                          pptdev->func);
 285                 break;
 286         case VM_UNBIND_PPTDEV:
 287                 pptdev = (struct vm_pptdev *)data;
 288                 error = vm_unassign_pptdev(sc->vm, pptdev->bus, pptdev->slot,
 289                                            pptdev->func);
 290                 break;
 291         case VM_INJECT_EXCEPTION:
 292                 vmexc = (struct vm_exception *)data;
 293                 error = vm_inject_exception(sc->vm, vmexc->cpuid, vmexc);
 294                 break;
 295         case VM_INJECT_NMI:
 296                 vmnmi = (struct vm_nmi *)data;
 297                 error = vm_inject_nmi(sc->vm, vmnmi->cpuid);
 298                 break;
 299         case VM_LAPIC_IRQ:
 300                 vmirq = (struct vm_lapic_irq *)data;
 301                 error = lapic_intr_edge(sc->vm, vmirq->cpuid, vmirq->vector);
 302                 break;
 303         case VM_LAPIC_LOCAL_IRQ:
 304                 vmirq = (struct vm_lapic_irq *)data;
 305                 error = lapic_set_local_intr(sc->vm, vmirq->cpuid,
 306                     vmirq->vector);
 307                 break;
 308         case VM_LAPIC_MSI:
 309                 vmmsi = (struct vm_lapic_msi *)data;
 310                 error = lapic_intr_msi(sc->vm, vmmsi->addr, vmmsi->msg);
 311                 break;
 312         case VM_IOAPIC_ASSERT_IRQ:
 313                 ioapic_irq = (struct vm_ioapic_irq *)data;
 314                 error = vioapic_assert_irq(sc->vm, ioapic_irq->irq);
 315                 break;
 316         case VM_IOAPIC_DEASSERT_IRQ:
 317                 ioapic_irq = (struct vm_ioapic_irq *)data;
 318                 error = vioapic_deassert_irq(sc->vm, ioapic_irq->irq);
 319                 break;
 320         case VM_IOAPIC_PULSE_IRQ:
 321                 ioapic_irq = (struct vm_ioapic_irq *)data;
 322                 error = vioapic_pulse_irq(sc->vm, ioapic_irq->irq);
 323                 break;
 324         case VM_IOAPIC_PINCOUNT:
 325                 *(int *)data = vioapic_pincount(sc->vm);
 326                 break;
 327         case VM_ISA_ASSERT_IRQ:
 328                 isa_irq = (struct vm_isa_irq *)data;
 329                 error = vatpic_assert_irq(sc->vm, isa_irq->atpic_irq);
 330                 if (error == 0 && isa_irq->ioapic_irq != -1)
 331                         error = vioapic_assert_irq(sc->vm,
 332                             isa_irq->ioapic_irq);
 333                 break;
 334         case VM_ISA_DEASSERT_IRQ:
 335                 isa_irq = (struct vm_isa_irq *)data;
 336                 error = vatpic_deassert_irq(sc->vm, isa_irq->atpic_irq);
 337                 if (error == 0 && isa_irq->ioapic_irq != -1)
 338                         error = vioapic_deassert_irq(sc->vm,
 339                             isa_irq->ioapic_irq);
 340                 break;
 341         case VM_ISA_PULSE_IRQ:
 342                 isa_irq = (struct vm_isa_irq *)data;
 343                 error = vatpic_pulse_irq(sc->vm, isa_irq->atpic_irq);
 344                 if (error == 0 && isa_irq->ioapic_irq != -1)
 345                         error = vioapic_pulse_irq(sc->vm, isa_irq->ioapic_irq);
 346                 break;
 347         case VM_MAP_MEMORY:
 348                 seg = (struct vm_memory_segment *)data;
 349                 error = vm_malloc(sc->vm, seg->gpa, seg->len);
 350                 break;
 351         case VM_GET_MEMORY_SEG:
 352                 seg = (struct vm_memory_segment *)data;
 353                 seg->len = 0;
 354                 (void)vm_gpabase2memseg(sc->vm, seg->gpa, seg);
 355                 error = 0;
 356                 break;
 357         case VM_GET_REGISTER:
 358                 vmreg = (struct vm_register *)data;
 359                 error = vm_get_register(sc->vm, vmreg->cpuid, vmreg->regnum,
 360                                         &vmreg->regval);
 361                 break;
 362         case VM_SET_REGISTER:
 363                 vmreg = (struct vm_register *)data;
 364                 error = vm_set_register(sc->vm, vmreg->cpuid, vmreg->regnum,
 365                                         vmreg->regval);
 366                 break;
 367         case VM_SET_SEGMENT_DESCRIPTOR:
 368                 vmsegdesc = (struct vm_seg_desc *)data;
 369                 error = vm_set_seg_desc(sc->vm, vmsegdesc->cpuid,
 370                                         vmsegdesc->regnum,
 371                                         &vmsegdesc->desc);
 372                 break;
 373         case VM_GET_SEGMENT_DESCRIPTOR:
 374                 vmsegdesc = (struct vm_seg_desc *)data;
 375                 error = vm_get_seg_desc(sc->vm, vmsegdesc->cpuid,
 376                                         vmsegdesc->regnum,
 377                                         &vmsegdesc->desc);
 378                 break;
 379         case VM_GET_CAPABILITY:
 380                 vmcap = (struct vm_capability *)data;
 381                 error = vm_get_capability(sc->vm, vmcap->cpuid,
 382                                           vmcap->captype,
 383                                           &vmcap->capval);
 384                 break;
 385         case VM_SET_CAPABILITY:
 386                 vmcap = (struct vm_capability *)data;
 387                 error = vm_set_capability(sc->vm, vmcap->cpuid,
 388                                           vmcap->captype,
 389                                           vmcap->capval);
 390                 break;
 391         case VM_SET_X2APIC_STATE:
 392                 x2apic = (struct vm_x2apic *)data;
 393                 error = vm_set_x2apic_state(sc->vm,
 394                                             x2apic->cpuid, x2apic->state);
 395                 break;
 396         case VM_GET_X2APIC_STATE:
 397                 x2apic = (struct vm_x2apic *)data;
 398                 error = vm_get_x2apic_state(sc->vm,
 399                                             x2apic->cpuid, &x2apic->state);
 400                 break;
 401         case VM_GET_GPA_PMAP:
 402                 gpapte = (struct vm_gpa_pte *)data;
 403                 pmap_get_mapping(vmspace_pmap(vm_get_vmspace(sc->vm)),
 404                                  gpapte->gpa, gpapte->pte, &gpapte->ptenum);
 405                 error = 0;
 406                 break;
 407         case VM_GET_HPET_CAPABILITIES:
 408                 error = vhpet_getcap((struct vm_hpet_cap *)data);
 409                 break;
 410         default:
 411                 error = ENOTTY;
 412                 break;
 413         }
 414
 415         if (state_changed == 1) {
 416                 vcpu_set_state(sc->vm, vcpu, VCPU_IDLE, false);
 417         } else if (state_changed == 2) {
 418                 for (vcpu = 0; vcpu < VM_MAXCPU; vcpu++)
 419                         vcpu_set_state(sc->vm, vcpu, VCPU_IDLE, false);
 420         }
 421
 422 done:
 423         /* Make sure that no handler returns a bogus value like ERESTART */
 424         KASSERT(error >= 0, ("vmmdev_ioctl: invalid error return %d", error));
 425         return (error);
 426 }
 427
 428 static int
 429 vmmdev_mmap_single(struct cdev *cdev, vm_ooffset_t *offset,
 430                    vm_size_t size, struct vm_object **object, int nprot)
 431 {
 432         int error;
 433         struct vmmdev_softc *sc;
 434
 435         sc = vmmdev_lookup2(cdev);
 436         if (sc != NULL && (nprot & PROT_EXEC) == 0)
 437                 error = vm_get_memobj(sc->vm, *offset, size, offset, object);
 438         else
 439                 error = EINVAL;
 440
 441         return (error);
 442 }
 443
 444 static void
 445 vmmdev_destroy(void *arg)
 446 {
 447
 448         struct vmmdev_softc *sc = arg;
 449
 450         if (sc->cdev != NULL)
 451                 destroy_dev(sc->cdev);
 452
 453         if (sc->vm != NULL)
 454                 vm_destroy(sc->vm);
 455
 456         if ((sc->flags & VSC_LINKED) != 0) {
 457                 mtx_lock(&vmmdev_mtx);
 458                 SLIST_REMOVE(&head, sc, vmmdev_softc, link);
 459                 mtx_unlock(&vmmdev_mtx);
 460         }
 461
 462         free(sc, M_VMMDEV);
 463 }
 464
 465 static int
 466 sysctl_vmm_destroy(SYSCTL_HANDLER_ARGS)
 467 {
 468         int error;
 469         char buf[VM_MAX_NAMELEN];
 470         struct vmmdev_softc *sc;
 471         struct cdev *cdev;
 472
 473         strlcpy(buf, "beavis", sizeof(buf));
 474         error = sysctl_handle_string(oidp, buf, sizeof(buf), req);
 475         if (error != 0 || req->newptr == NULL)
 476                 return (error);
 477
 478         mtx_lock(&vmmdev_mtx);
 479         sc = vmmdev_lookup(buf);
 480         if (sc == NULL || sc->cdev == NULL) {
 481                 mtx_unlock(&vmmdev_mtx);
 482                 return (EINVAL);
 483         }
 484
 485         /*
 486          * The 'cdev' will be destroyed asynchronously when 'si_threadcount'
 487          * goes down to 0 so we should not do it again in the callback.
 488          */
 489         cdev = sc->cdev;
 490         sc->cdev = NULL;
 491         mtx_unlock(&vmmdev_mtx);
 492
 493         /*
 494          * Schedule the 'cdev' to be destroyed:
 495          *
 496          * - any new operations on this 'cdev' will return an error (ENXIO).
 497          *
 498          * - when the 'si_threadcount' dwindles down to zero the 'cdev' will
 499          *   be destroyed and the callback will be invoked in a taskqueue
 500          *   context.
 501          */
 502         destroy_dev_sched_cb(cdev, vmmdev_destroy, sc);
 503
 504         return (0);
 505 }
 506 SYSCTL_PROC(_hw_vmm, OID_AUTO, destroy, CTLTYPE_STRING | CTLFLAG_RW,
 507             NULL, 0, sysctl_vmm_destroy, "A", NULL);
 508
 509 static struct cdevsw vmmdevsw = {
 510         .d_name         = "vmmdev",
 511         .d_version      = D_VERSION,
 512         .d_ioctl        = vmmdev_ioctl,
 513         .d_mmap_single  = vmmdev_mmap_single,
 514         .d_read         = vmmdev_rw,
 515         .d_write        = vmmdev_rw,
 516 };
 517
 518 static int
 519 sysctl_vmm_create(SYSCTL_HANDLER_ARGS)
 520 {
 521         int error;
 522         struct vm *vm;
 523         struct cdev *cdev;
 524         struct vmmdev_softc *sc, *sc2;
 525         char buf[VM_MAX_NAMELEN];
 526
 527         strlcpy(buf, "beavis", sizeof(buf));
 528         error = sysctl_handle_string(oidp, buf, sizeof(buf), req);
 529         if (error != 0 || req->newptr == NULL)
 530                 return (error);
 531
 532         mtx_lock(&vmmdev_mtx);
 533         sc = vmmdev_lookup(buf);
 534         mtx_unlock(&vmmdev_mtx);
 535         if (sc != NULL)
 536                 return (EEXIST);
 537
 538         error = vm_create(buf, &vm);
 539         if (error != 0)
 540                 return (error);
 541
 542         sc = malloc(sizeof(struct vmmdev_softc), M_VMMDEV, M_WAITOK | M_ZERO);
 543         sc->vm = vm;
 544
 545         /*
 546          * Lookup the name again just in case somebody sneaked in when we
 547          * dropped the lock.
 548          */
 549         mtx_lock(&vmmdev_mtx);
 550         sc2 = vmmdev_lookup(buf);
 551         if (sc2 == NULL) {
 552                 SLIST_INSERT_HEAD(&head, sc, link);
 553                 sc->flags |= VSC_LINKED;
 554         }
 555         mtx_unlock(&vmmdev_mtx);
 556
 557         if (sc2 != NULL) {
 558                 vmmdev_destroy(sc);
 559                 return (EEXIST);
 560         }
 561
 562         error = make_dev_p(MAKEDEV_CHECKNAME, &cdev, &vmmdevsw, NULL,
 563                            UID_ROOT, GID_WHEEL, 0600, "vmm/%s", buf);
 564         if (error != 0) {
 565                 vmmdev_destroy(sc);
 566                 return (error);
 567         }
 568
 569         mtx_lock(&vmmdev_mtx);
 570         sc->cdev = cdev;
 571         sc->cdev->si_drv1 = sc;
 572         mtx_unlock(&vmmdev_mtx);
 573
 574         return (0);
 575 }
 576 SYSCTL_PROC(_hw_vmm, OID_AUTO, create, CTLTYPE_STRING | CTLFLAG_RW,
 577             NULL, 0, sysctl_vmm_create, "A", NULL);
 578
 579 void
 580 vmmdev_init(void)
 581 {
 582         mtx_init(&vmmdev_mtx, "vmm device mutex", NULL, MTX_DEF);
 583 }
 584
 585 int
 586 vmmdev_cleanup(void)
 587 {
 588         int error;
 589
 590         if (SLIST_EMPTY(&head))
 591                 error = 0;
 592         else
 593                 error = EBUSY;
 594
 595         return (error);
 596 }