xref: /f-stack/freebsd/amd64/vmm/vmm_dev.c (revision 22ce4aff)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2011 NetApp, Inc.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY NETAPP, INC ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL NETAPP, INC OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  *
28  * $FreeBSD$
29  */
30 
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
33 
34 #include "opt_bhyve_snapshot.h"
35 
36 #include <sys/param.h>
37 #include <sys/kernel.h>
38 #include <sys/jail.h>
39 #include <sys/queue.h>
40 #include <sys/lock.h>
41 #include <sys/mutex.h>
42 #include <sys/malloc.h>
43 #include <sys/conf.h>
44 #include <sys/sysctl.h>
45 #include <sys/libkern.h>
46 #include <sys/ioccom.h>
47 #include <sys/mman.h>
48 #include <sys/uio.h>
49 #include <sys/proc.h>
50 
51 #include <vm/vm.h>
52 #include <vm/pmap.h>
53 #include <vm/vm_map.h>
54 #include <vm/vm_object.h>
55 
56 #include <machine/vmparam.h>
57 #include <machine/vmm.h>
58 #include <machine/vmm_dev.h>
59 #include <machine/vmm_instruction_emul.h>
60 #include <machine/vmm_snapshot.h>
61 #include <x86/apicreg.h>
62 
63 #include "vmm_lapic.h"
64 #include "vmm_stat.h"
65 #include "vmm_mem.h"
66 #include "io/ppt.h"
67 #include "io/vatpic.h"
68 #include "io/vioapic.h"
69 #include "io/vhpet.h"
70 #include "io/vrtc.h"
71 
72 struct devmem_softc {
73 	int	segid;
74 	char	*name;
75 	struct cdev *cdev;
76 	struct vmmdev_softc *sc;
77 	SLIST_ENTRY(devmem_softc) link;
78 };
79 
80 struct vmmdev_softc {
81 	struct vm	*vm;		/* vm instance cookie */
82 	struct cdev	*cdev;
83 	SLIST_ENTRY(vmmdev_softc) link;
84 	SLIST_HEAD(, devmem_softc) devmem;
85 	int		flags;
86 };
87 #define	VSC_LINKED		0x01
88 
89 static SLIST_HEAD(, vmmdev_softc) head;
90 
91 static unsigned pr_allow_flag;
92 static struct mtx vmmdev_mtx;
93 
94 static MALLOC_DEFINE(M_VMMDEV, "vmmdev", "vmmdev");
95 
96 SYSCTL_DECL(_hw_vmm);
97 
98 static int vmm_priv_check(struct ucred *ucred);
99 static int devmem_create_cdev(const char *vmname, int id, char *devmem);
100 static void devmem_destroy(void *arg);
101 
102 static int
vmm_priv_check(struct ucred * ucred)103 vmm_priv_check(struct ucred *ucred)
104 {
105 
106 	if (jailed(ucred) &&
107 	    !(ucred->cr_prison->pr_allow & pr_allow_flag))
108 		return (EPERM);
109 
110 	return (0);
111 }
112 
113 static int
vcpu_lock_one(struct vmmdev_softc * sc,int vcpu)114 vcpu_lock_one(struct vmmdev_softc *sc, int vcpu)
115 {
116 	int error;
117 
118 	if (vcpu < 0 || vcpu >= vm_get_maxcpus(sc->vm))
119 		return (EINVAL);
120 
121 	error = vcpu_set_state(sc->vm, vcpu, VCPU_FROZEN, true);
122 	return (error);
123 }
124 
125 static void
vcpu_unlock_one(struct vmmdev_softc * sc,int vcpu)126 vcpu_unlock_one(struct vmmdev_softc *sc, int vcpu)
127 {
128 	enum vcpu_state state;
129 
130 	state = vcpu_get_state(sc->vm, vcpu, NULL);
131 	if (state != VCPU_FROZEN) {
132 		panic("vcpu %s(%d) has invalid state %d", vm_name(sc->vm),
133 		    vcpu, state);
134 	}
135 
136 	vcpu_set_state(sc->vm, vcpu, VCPU_IDLE, false);
137 }
138 
139 static int
vcpu_lock_all(struct vmmdev_softc * sc)140 vcpu_lock_all(struct vmmdev_softc *sc)
141 {
142 	int error, vcpu;
143 	uint16_t maxcpus;
144 
145 	maxcpus = vm_get_maxcpus(sc->vm);
146 	for (vcpu = 0; vcpu < maxcpus; vcpu++) {
147 		error = vcpu_lock_one(sc, vcpu);
148 		if (error)
149 			break;
150 	}
151 
152 	if (error) {
153 		while (--vcpu >= 0)
154 			vcpu_unlock_one(sc, vcpu);
155 	}
156 
157 	return (error);
158 }
159 
160 static void
vcpu_unlock_all(struct vmmdev_softc * sc)161 vcpu_unlock_all(struct vmmdev_softc *sc)
162 {
163 	int vcpu;
164 	uint16_t maxcpus;
165 
166 	maxcpus = vm_get_maxcpus(sc->vm);
167 	for (vcpu = 0; vcpu < maxcpus; vcpu++)
168 		vcpu_unlock_one(sc, vcpu);
169 }
170 
171 static struct vmmdev_softc *
vmmdev_lookup(const char * name)172 vmmdev_lookup(const char *name)
173 {
174 	struct vmmdev_softc *sc;
175 
176 #ifdef notyet	/* XXX kernel is not compiled with invariants */
177 	mtx_assert(&vmmdev_mtx, MA_OWNED);
178 #endif
179 
180 	SLIST_FOREACH(sc, &head, link) {
181 		if (strcmp(name, vm_name(sc->vm)) == 0)
182 			break;
183 	}
184 
185 	return (sc);
186 }
187 
188 static struct vmmdev_softc *
vmmdev_lookup2(struct cdev * cdev)189 vmmdev_lookup2(struct cdev *cdev)
190 {
191 
192 	return (cdev->si_drv1);
193 }
194 
195 static int
vmmdev_rw(struct cdev * cdev,struct uio * uio,int flags)196 vmmdev_rw(struct cdev *cdev, struct uio *uio, int flags)
197 {
198 	int error, off, c, prot;
199 	vm_paddr_t gpa, maxaddr;
200 	void *hpa, *cookie;
201 	struct vmmdev_softc *sc;
202 	uint16_t lastcpu;
203 
204 	error = vmm_priv_check(curthread->td_ucred);
205 	if (error)
206 		return (error);
207 
208 	sc = vmmdev_lookup2(cdev);
209 	if (sc == NULL)
210 		return (ENXIO);
211 
212 	/*
213 	 * Get a read lock on the guest memory map by freezing any vcpu.
214 	 */
215 	lastcpu = vm_get_maxcpus(sc->vm) - 1;
216 	error = vcpu_lock_one(sc, lastcpu);
217 	if (error)
218 		return (error);
219 
220 	prot = (uio->uio_rw == UIO_WRITE ? VM_PROT_WRITE : VM_PROT_READ);
221 	maxaddr = vmm_sysmem_maxaddr(sc->vm);
222 	while (uio->uio_resid > 0 && error == 0) {
223 		gpa = uio->uio_offset;
224 		off = gpa & PAGE_MASK;
225 		c = min(uio->uio_resid, PAGE_SIZE - off);
226 
227 		/*
228 		 * The VM has a hole in its physical memory map. If we want to
229 		 * use 'dd' to inspect memory beyond the hole we need to
230 		 * provide bogus data for memory that lies in the hole.
231 		 *
232 		 * Since this device does not support lseek(2), dd(1) will
233 		 * read(2) blocks of data to simulate the lseek(2).
234 		 */
235 		hpa = vm_gpa_hold(sc->vm, lastcpu, gpa, c,
236 		    prot, &cookie);
237 		if (hpa == NULL) {
238 			if (uio->uio_rw == UIO_READ && gpa < maxaddr)
239 				error = uiomove(__DECONST(void *, zero_region),
240 				    c, uio);
241 			else
242 				error = EFAULT;
243 		} else {
244 			error = uiomove(hpa, c, uio);
245 			vm_gpa_release(cookie);
246 		}
247 	}
248 	vcpu_unlock_one(sc, lastcpu);
249 	return (error);
250 }
251 
252 CTASSERT(sizeof(((struct vm_memseg *)0)->name) >= VM_MAX_SUFFIXLEN + 1);
253 
254 static int
get_memseg(struct vmmdev_softc * sc,struct vm_memseg * mseg,size_t len)255 get_memseg(struct vmmdev_softc *sc, struct vm_memseg *mseg, size_t len)
256 {
257 	struct devmem_softc *dsc;
258 	int error;
259 	bool sysmem;
260 
261 	error = vm_get_memseg(sc->vm, mseg->segid, &mseg->len, &sysmem, NULL);
262 	if (error || mseg->len == 0)
263 		return (error);
264 
265 	if (!sysmem) {
266 		SLIST_FOREACH(dsc, &sc->devmem, link) {
267 			if (dsc->segid == mseg->segid)
268 				break;
269 		}
270 		KASSERT(dsc != NULL, ("%s: devmem segment %d not found",
271 		    __func__, mseg->segid));
272 		error = copystr(dsc->name, mseg->name, len, NULL);
273 	} else {
274 		bzero(mseg->name, len);
275 	}
276 
277 	return (error);
278 }
279 
280 static int
alloc_memseg(struct vmmdev_softc * sc,struct vm_memseg * mseg,size_t len)281 alloc_memseg(struct vmmdev_softc *sc, struct vm_memseg *mseg, size_t len)
282 {
283 	char *name;
284 	int error;
285 	bool sysmem;
286 
287 	error = 0;
288 	name = NULL;
289 	sysmem = true;
290 
291 	/*
292 	 * The allocation is lengthened by 1 to hold a terminating NUL.  It'll
293 	 * by stripped off when devfs processes the full string.
294 	 */
295 	if (VM_MEMSEG_NAME(mseg)) {
296 		sysmem = false;
297 		name = malloc(len, M_VMMDEV, M_WAITOK);
298 		error = copystr(mseg->name, name, len, NULL);
299 		if (error)
300 			goto done;
301 	}
302 
303 	error = vm_alloc_memseg(sc->vm, mseg->segid, mseg->len, sysmem);
304 	if (error)
305 		goto done;
306 
307 	if (VM_MEMSEG_NAME(mseg)) {
308 		error = devmem_create_cdev(vm_name(sc->vm), mseg->segid, name);
309 		if (error)
310 			vm_free_memseg(sc->vm, mseg->segid);
311 		else
312 			name = NULL;	/* freed when 'cdev' is destroyed */
313 	}
314 done:
315 	free(name, M_VMMDEV);
316 	return (error);
317 }
318 
319 static int
vm_get_register_set(struct vm * vm,int vcpu,unsigned int count,int * regnum,uint64_t * regval)320 vm_get_register_set(struct vm *vm, int vcpu, unsigned int count, int *regnum,
321     uint64_t *regval)
322 {
323 	int error, i;
324 
325 	error = 0;
326 	for (i = 0; i < count; i++) {
327 		error = vm_get_register(vm, vcpu, regnum[i], &regval[i]);
328 		if (error)
329 			break;
330 	}
331 	return (error);
332 }
333 
334 static int
vm_set_register_set(struct vm * vm,int vcpu,unsigned int count,int * regnum,uint64_t * regval)335 vm_set_register_set(struct vm *vm, int vcpu, unsigned int count, int *regnum,
336     uint64_t *regval)
337 {
338 	int error, i;
339 
340 	error = 0;
341 	for (i = 0; i < count; i++) {
342 		error = vm_set_register(vm, vcpu, regnum[i], regval[i]);
343 		if (error)
344 			break;
345 	}
346 	return (error);
347 }
348 
349 static int
vmmdev_ioctl(struct cdev * cdev,u_long cmd,caddr_t data,int fflag,struct thread * td)350 vmmdev_ioctl(struct cdev *cdev, u_long cmd, caddr_t data, int fflag,
351 	     struct thread *td)
352 {
353 	int error, vcpu, state_changed, size;
354 	cpuset_t *cpuset;
355 	struct vmmdev_softc *sc;
356 	struct vm_register *vmreg;
357 	struct vm_seg_desc *vmsegdesc;
358 	struct vm_register_set *vmregset;
359 	struct vm_run *vmrun;
360 	struct vm_exception *vmexc;
361 	struct vm_lapic_irq *vmirq;
362 	struct vm_lapic_msi *vmmsi;
363 	struct vm_ioapic_irq *ioapic_irq;
364 	struct vm_isa_irq *isa_irq;
365 	struct vm_isa_irq_trigger *isa_irq_trigger;
366 	struct vm_capability *vmcap;
367 	struct vm_pptdev *pptdev;
368 	struct vm_pptdev_mmio *pptmmio;
369 	struct vm_pptdev_msi *pptmsi;
370 	struct vm_pptdev_msix *pptmsix;
371 	struct vm_nmi *vmnmi;
372 	struct vm_stats *vmstats;
373 	struct vm_stat_desc *statdesc;
374 	struct vm_x2apic *x2apic;
375 	struct vm_gpa_pte *gpapte;
376 	struct vm_suspend *vmsuspend;
377 	struct vm_gla2gpa *gg;
378 	struct vm_activate_cpu *vac;
379 	struct vm_cpuset *vm_cpuset;
380 	struct vm_intinfo *vmii;
381 	struct vm_rtc_time *rtctime;
382 	struct vm_rtc_data *rtcdata;
383 	struct vm_memmap *mm;
384 	struct vm_cpu_topology *topology;
385 	struct vm_readwrite_kernemu_device *kernemu;
386 	uint64_t *regvals;
387 	int *regnums;
388 #ifdef BHYVE_SNAPSHOT
389 	struct vm_snapshot_meta *snapshot_meta;
390 #endif
391 
392 	error = vmm_priv_check(curthread->td_ucred);
393 	if (error)
394 		return (error);
395 
396 	sc = vmmdev_lookup2(cdev);
397 	if (sc == NULL)
398 		return (ENXIO);
399 
400 	vcpu = -1;
401 	state_changed = 0;
402 
403 	/*
404 	 * Some VMM ioctls can operate only on vcpus that are not running.
405 	 */
406 	switch (cmd) {
407 	case VM_RUN:
408 	case VM_GET_REGISTER:
409 	case VM_SET_REGISTER:
410 	case VM_GET_SEGMENT_DESCRIPTOR:
411 	case VM_SET_SEGMENT_DESCRIPTOR:
412 	case VM_GET_REGISTER_SET:
413 	case VM_SET_REGISTER_SET:
414 	case VM_INJECT_EXCEPTION:
415 	case VM_GET_CAPABILITY:
416 	case VM_SET_CAPABILITY:
417 	case VM_PPTDEV_MSI:
418 	case VM_PPTDEV_MSIX:
419 	case VM_SET_X2APIC_STATE:
420 	case VM_GLA2GPA:
421 	case VM_GLA2GPA_NOFAULT:
422 	case VM_ACTIVATE_CPU:
423 	case VM_SET_INTINFO:
424 	case VM_GET_INTINFO:
425 	case VM_RESTART_INSTRUCTION:
426 		/*
427 		 * XXX fragile, handle with care
428 		 * Assumes that the first field of the ioctl data is the vcpu.
429 		 */
430 		vcpu = *(int *)data;
431 		error = vcpu_lock_one(sc, vcpu);
432 		if (error)
433 			goto done;
434 		state_changed = 1;
435 		break;
436 
437 	case VM_MAP_PPTDEV_MMIO:
438 	case VM_BIND_PPTDEV:
439 	case VM_UNBIND_PPTDEV:
440 #ifdef COMPAT_FREEBSD12
441 	case VM_ALLOC_MEMSEG_FBSD12:
442 #endif
443 	case VM_ALLOC_MEMSEG:
444 	case VM_MMAP_MEMSEG:
445 	case VM_REINIT:
446 		/*
447 		 * ioctls that operate on the entire virtual machine must
448 		 * prevent all vcpus from running.
449 		 */
450 		error = vcpu_lock_all(sc);
451 		if (error)
452 			goto done;
453 		state_changed = 2;
454 		break;
455 
456 #ifdef COMPAT_FREEBSD12
457 	case VM_GET_MEMSEG_FBSD12:
458 #endif
459 	case VM_GET_MEMSEG:
460 	case VM_MMAP_GETNEXT:
461 		/*
462 		 * Lock a vcpu to make sure that the memory map cannot be
463 		 * modified while it is being inspected.
464 		 */
465 		vcpu = vm_get_maxcpus(sc->vm) - 1;
466 		error = vcpu_lock_one(sc, vcpu);
467 		if (error)
468 			goto done;
469 		state_changed = 1;
470 		break;
471 
472 	default:
473 		break;
474 	}
475 
476 	switch(cmd) {
477 	case VM_RUN:
478 		vmrun = (struct vm_run *)data;
479 		error = vm_run(sc->vm, vmrun);
480 		break;
481 	case VM_SUSPEND:
482 		vmsuspend = (struct vm_suspend *)data;
483 		error = vm_suspend(sc->vm, vmsuspend->how);
484 		break;
485 	case VM_REINIT:
486 		error = vm_reinit(sc->vm);
487 		break;
488 	case VM_STAT_DESC: {
489 		statdesc = (struct vm_stat_desc *)data;
490 		error = vmm_stat_desc_copy(statdesc->index,
491 					statdesc->desc, sizeof(statdesc->desc));
492 		break;
493 	}
494 	case VM_STATS: {
495 		CTASSERT(MAX_VM_STATS >= MAX_VMM_STAT_ELEMS);
496 		vmstats = (struct vm_stats *)data;
497 		getmicrotime(&vmstats->tv);
498 		error = vmm_stat_copy(sc->vm, vmstats->cpuid,
499 				      &vmstats->num_entries, vmstats->statbuf);
500 		break;
501 	}
502 	case VM_PPTDEV_MSI:
503 		pptmsi = (struct vm_pptdev_msi *)data;
504 		error = ppt_setup_msi(sc->vm, pptmsi->vcpu,
505 				      pptmsi->bus, pptmsi->slot, pptmsi->func,
506 				      pptmsi->addr, pptmsi->msg,
507 				      pptmsi->numvec);
508 		break;
509 	case VM_PPTDEV_MSIX:
510 		pptmsix = (struct vm_pptdev_msix *)data;
511 		error = ppt_setup_msix(sc->vm, pptmsix->vcpu,
512 				       pptmsix->bus, pptmsix->slot,
513 				       pptmsix->func, pptmsix->idx,
514 				       pptmsix->addr, pptmsix->msg,
515 				       pptmsix->vector_control);
516 		break;
517 	case VM_PPTDEV_DISABLE_MSIX:
518 		pptdev = (struct vm_pptdev *)data;
519 		error = ppt_disable_msix(sc->vm, pptdev->bus, pptdev->slot,
520 					 pptdev->func);
521 		break;
522 	case VM_MAP_PPTDEV_MMIO:
523 		pptmmio = (struct vm_pptdev_mmio *)data;
524 		error = ppt_map_mmio(sc->vm, pptmmio->bus, pptmmio->slot,
525 				     pptmmio->func, pptmmio->gpa, pptmmio->len,
526 				     pptmmio->hpa);
527 		break;
528 	case VM_BIND_PPTDEV:
529 		pptdev = (struct vm_pptdev *)data;
530 		error = vm_assign_pptdev(sc->vm, pptdev->bus, pptdev->slot,
531 					 pptdev->func);
532 		break;
533 	case VM_UNBIND_PPTDEV:
534 		pptdev = (struct vm_pptdev *)data;
535 		error = vm_unassign_pptdev(sc->vm, pptdev->bus, pptdev->slot,
536 					   pptdev->func);
537 		break;
538 	case VM_INJECT_EXCEPTION:
539 		vmexc = (struct vm_exception *)data;
540 		error = vm_inject_exception(sc->vm, vmexc->cpuid,
541 		    vmexc->vector, vmexc->error_code_valid, vmexc->error_code,
542 		    vmexc->restart_instruction);
543 		break;
544 	case VM_INJECT_NMI:
545 		vmnmi = (struct vm_nmi *)data;
546 		error = vm_inject_nmi(sc->vm, vmnmi->cpuid);
547 		break;
548 	case VM_LAPIC_IRQ:
549 		vmirq = (struct vm_lapic_irq *)data;
550 		error = lapic_intr_edge(sc->vm, vmirq->cpuid, vmirq->vector);
551 		break;
552 	case VM_LAPIC_LOCAL_IRQ:
553 		vmirq = (struct vm_lapic_irq *)data;
554 		error = lapic_set_local_intr(sc->vm, vmirq->cpuid,
555 		    vmirq->vector);
556 		break;
557 	case VM_LAPIC_MSI:
558 		vmmsi = (struct vm_lapic_msi *)data;
559 		error = lapic_intr_msi(sc->vm, vmmsi->addr, vmmsi->msg);
560 		break;
561 	case VM_IOAPIC_ASSERT_IRQ:
562 		ioapic_irq = (struct vm_ioapic_irq *)data;
563 		error = vioapic_assert_irq(sc->vm, ioapic_irq->irq);
564 		break;
565 	case VM_IOAPIC_DEASSERT_IRQ:
566 		ioapic_irq = (struct vm_ioapic_irq *)data;
567 		error = vioapic_deassert_irq(sc->vm, ioapic_irq->irq);
568 		break;
569 	case VM_IOAPIC_PULSE_IRQ:
570 		ioapic_irq = (struct vm_ioapic_irq *)data;
571 		error = vioapic_pulse_irq(sc->vm, ioapic_irq->irq);
572 		break;
573 	case VM_IOAPIC_PINCOUNT:
574 		*(int *)data = vioapic_pincount(sc->vm);
575 		break;
576 	case VM_SET_KERNEMU_DEV:
577 	case VM_GET_KERNEMU_DEV: {
578 		mem_region_write_t mwrite;
579 		mem_region_read_t mread;
580 		bool arg;
581 
582 		kernemu = (void *)data;
583 
584 		if (kernemu->access_width > 0)
585 			size = (1u << kernemu->access_width);
586 		else
587 			size = 1;
588 
589 		if (kernemu->gpa >= DEFAULT_APIC_BASE && kernemu->gpa < DEFAULT_APIC_BASE + PAGE_SIZE) {
590 			mread = lapic_mmio_read;
591 			mwrite = lapic_mmio_write;
592 		} else if (kernemu->gpa >= VIOAPIC_BASE && kernemu->gpa < VIOAPIC_BASE + VIOAPIC_SIZE) {
593 			mread = vioapic_mmio_read;
594 			mwrite = vioapic_mmio_write;
595 		} else if (kernemu->gpa >= VHPET_BASE && kernemu->gpa < VHPET_BASE + VHPET_SIZE) {
596 			mread = vhpet_mmio_read;
597 			mwrite = vhpet_mmio_write;
598 		} else {
599 			error = EINVAL;
600 			break;
601 		}
602 
603 		if (cmd == VM_SET_KERNEMU_DEV)
604 			error = mwrite(sc->vm, kernemu->vcpuid, kernemu->gpa,
605 			    kernemu->value, size, &arg);
606 		else
607 			error = mread(sc->vm, kernemu->vcpuid, kernemu->gpa,
608 			    &kernemu->value, size, &arg);
609 		break;
610 		}
611 	case VM_ISA_ASSERT_IRQ:
612 		isa_irq = (struct vm_isa_irq *)data;
613 		error = vatpic_assert_irq(sc->vm, isa_irq->atpic_irq);
614 		if (error == 0 && isa_irq->ioapic_irq != -1)
615 			error = vioapic_assert_irq(sc->vm,
616 			    isa_irq->ioapic_irq);
617 		break;
618 	case VM_ISA_DEASSERT_IRQ:
619 		isa_irq = (struct vm_isa_irq *)data;
620 		error = vatpic_deassert_irq(sc->vm, isa_irq->atpic_irq);
621 		if (error == 0 && isa_irq->ioapic_irq != -1)
622 			error = vioapic_deassert_irq(sc->vm,
623 			    isa_irq->ioapic_irq);
624 		break;
625 	case VM_ISA_PULSE_IRQ:
626 		isa_irq = (struct vm_isa_irq *)data;
627 		error = vatpic_pulse_irq(sc->vm, isa_irq->atpic_irq);
628 		if (error == 0 && isa_irq->ioapic_irq != -1)
629 			error = vioapic_pulse_irq(sc->vm, isa_irq->ioapic_irq);
630 		break;
631 	case VM_ISA_SET_IRQ_TRIGGER:
632 		isa_irq_trigger = (struct vm_isa_irq_trigger *)data;
633 		error = vatpic_set_irq_trigger(sc->vm,
634 		    isa_irq_trigger->atpic_irq, isa_irq_trigger->trigger);
635 		break;
636 	case VM_MMAP_GETNEXT:
637 		mm = (struct vm_memmap *)data;
638 		error = vm_mmap_getnext(sc->vm, &mm->gpa, &mm->segid,
639 		    &mm->segoff, &mm->len, &mm->prot, &mm->flags);
640 		break;
641 	case VM_MMAP_MEMSEG:
642 		mm = (struct vm_memmap *)data;
643 		error = vm_mmap_memseg(sc->vm, mm->gpa, mm->segid, mm->segoff,
644 		    mm->len, mm->prot, mm->flags);
645 		break;
646 #ifdef COMPAT_FREEBSD12
647 	case VM_ALLOC_MEMSEG_FBSD12:
648 		error = alloc_memseg(sc, (struct vm_memseg *)data,
649 		    sizeof(((struct vm_memseg_fbsd12 *)0)->name));
650 		break;
651 #endif
652 	case VM_ALLOC_MEMSEG:
653 		error = alloc_memseg(sc, (struct vm_memseg *)data,
654 		    sizeof(((struct vm_memseg *)0)->name));
655 		break;
656 #ifdef COMPAT_FREEBSD12
657 	case VM_GET_MEMSEG_FBSD12:
658 		error = get_memseg(sc, (struct vm_memseg *)data,
659 		    sizeof(((struct vm_memseg_fbsd12 *)0)->name));
660 		break;
661 #endif
662 	case VM_GET_MEMSEG:
663 		error = get_memseg(sc, (struct vm_memseg *)data,
664 		    sizeof(((struct vm_memseg *)0)->name));
665 		break;
666 	case VM_GET_REGISTER:
667 		vmreg = (struct vm_register *)data;
668 		error = vm_get_register(sc->vm, vmreg->cpuid, vmreg->regnum,
669 					&vmreg->regval);
670 		break;
671 	case VM_SET_REGISTER:
672 		vmreg = (struct vm_register *)data;
673 		error = vm_set_register(sc->vm, vmreg->cpuid, vmreg->regnum,
674 					vmreg->regval);
675 		break;
676 	case VM_SET_SEGMENT_DESCRIPTOR:
677 		vmsegdesc = (struct vm_seg_desc *)data;
678 		error = vm_set_seg_desc(sc->vm, vmsegdesc->cpuid,
679 					vmsegdesc->regnum,
680 					&vmsegdesc->desc);
681 		break;
682 	case VM_GET_SEGMENT_DESCRIPTOR:
683 		vmsegdesc = (struct vm_seg_desc *)data;
684 		error = vm_get_seg_desc(sc->vm, vmsegdesc->cpuid,
685 					vmsegdesc->regnum,
686 					&vmsegdesc->desc);
687 		break;
688 	case VM_GET_REGISTER_SET:
689 		vmregset = (struct vm_register_set *)data;
690 		if (vmregset->count > VM_REG_LAST) {
691 			error = EINVAL;
692 			break;
693 		}
694 		regvals = malloc(sizeof(regvals[0]) * vmregset->count, M_VMMDEV,
695 		    M_WAITOK);
696 		regnums = malloc(sizeof(regnums[0]) * vmregset->count, M_VMMDEV,
697 		    M_WAITOK);
698 		error = copyin(vmregset->regnums, regnums, sizeof(regnums[0]) *
699 		    vmregset->count);
700 		if (error == 0)
701 			error = vm_get_register_set(sc->vm, vmregset->cpuid,
702 			    vmregset->count, regnums, regvals);
703 		if (error == 0)
704 			error = copyout(regvals, vmregset->regvals,
705 			    sizeof(regvals[0]) * vmregset->count);
706 		free(regvals, M_VMMDEV);
707 		free(regnums, M_VMMDEV);
708 		break;
709 	case VM_SET_REGISTER_SET:
710 		vmregset = (struct vm_register_set *)data;
711 		if (vmregset->count > VM_REG_LAST) {
712 			error = EINVAL;
713 			break;
714 		}
715 		regvals = malloc(sizeof(regvals[0]) * vmregset->count, M_VMMDEV,
716 		    M_WAITOK);
717 		regnums = malloc(sizeof(regnums[0]) * vmregset->count, M_VMMDEV,
718 		    M_WAITOK);
719 		error = copyin(vmregset->regnums, regnums, sizeof(regnums[0]) *
720 		    vmregset->count);
721 		if (error == 0)
722 			error = copyin(vmregset->regvals, regvals,
723 			    sizeof(regvals[0]) * vmregset->count);
724 		if (error == 0)
725 			error = vm_set_register_set(sc->vm, vmregset->cpuid,
726 			    vmregset->count, regnums, regvals);
727 		free(regvals, M_VMMDEV);
728 		free(regnums, M_VMMDEV);
729 		break;
730 	case VM_GET_CAPABILITY:
731 		vmcap = (struct vm_capability *)data;
732 		error = vm_get_capability(sc->vm, vmcap->cpuid,
733 					  vmcap->captype,
734 					  &vmcap->capval);
735 		break;
736 	case VM_SET_CAPABILITY:
737 		vmcap = (struct vm_capability *)data;
738 		error = vm_set_capability(sc->vm, vmcap->cpuid,
739 					  vmcap->captype,
740 					  vmcap->capval);
741 		break;
742 	case VM_SET_X2APIC_STATE:
743 		x2apic = (struct vm_x2apic *)data;
744 		error = vm_set_x2apic_state(sc->vm,
745 					    x2apic->cpuid, x2apic->state);
746 		break;
747 	case VM_GET_X2APIC_STATE:
748 		x2apic = (struct vm_x2apic *)data;
749 		error = vm_get_x2apic_state(sc->vm,
750 					    x2apic->cpuid, &x2apic->state);
751 		break;
752 	case VM_GET_GPA_PMAP:
753 		gpapte = (struct vm_gpa_pte *)data;
754 		pmap_get_mapping(vmspace_pmap(vm_get_vmspace(sc->vm)),
755 				 gpapte->gpa, gpapte->pte, &gpapte->ptenum);
756 		error = 0;
757 		break;
758 	case VM_GET_HPET_CAPABILITIES:
759 		error = vhpet_getcap((struct vm_hpet_cap *)data);
760 		break;
761 	case VM_GLA2GPA: {
762 		CTASSERT(PROT_READ == VM_PROT_READ);
763 		CTASSERT(PROT_WRITE == VM_PROT_WRITE);
764 		CTASSERT(PROT_EXEC == VM_PROT_EXECUTE);
765 		gg = (struct vm_gla2gpa *)data;
766 		error = vm_gla2gpa(sc->vm, gg->vcpuid, &gg->paging, gg->gla,
767 		    gg->prot, &gg->gpa, &gg->fault);
768 		KASSERT(error == 0 || error == EFAULT,
769 		    ("%s: vm_gla2gpa unknown error %d", __func__, error));
770 		break;
771 	}
772 	case VM_GLA2GPA_NOFAULT:
773 		gg = (struct vm_gla2gpa *)data;
774 		error = vm_gla2gpa_nofault(sc->vm, gg->vcpuid, &gg->paging,
775 		    gg->gla, gg->prot, &gg->gpa, &gg->fault);
776 		KASSERT(error == 0 || error == EFAULT,
777 		    ("%s: vm_gla2gpa unknown error %d", __func__, error));
778 		break;
779 	case VM_ACTIVATE_CPU:
780 		vac = (struct vm_activate_cpu *)data;
781 		error = vm_activate_cpu(sc->vm, vac->vcpuid);
782 		break;
783 	case VM_GET_CPUS:
784 		error = 0;
785 		vm_cpuset = (struct vm_cpuset *)data;
786 		size = vm_cpuset->cpusetsize;
787 		if (size < sizeof(cpuset_t) || size > CPU_MAXSIZE / NBBY) {
788 			error = ERANGE;
789 			break;
790 		}
791 		cpuset = malloc(size, M_TEMP, M_WAITOK | M_ZERO);
792 		if (vm_cpuset->which == VM_ACTIVE_CPUS)
793 			*cpuset = vm_active_cpus(sc->vm);
794 		else if (vm_cpuset->which == VM_SUSPENDED_CPUS)
795 			*cpuset = vm_suspended_cpus(sc->vm);
796 		else if (vm_cpuset->which == VM_DEBUG_CPUS)
797 			*cpuset = vm_debug_cpus(sc->vm);
798 		else
799 			error = EINVAL;
800 		if (error == 0)
801 			error = copyout(cpuset, vm_cpuset->cpus, size);
802 		free(cpuset, M_TEMP);
803 		break;
804 	case VM_SUSPEND_CPU:
805 		vac = (struct vm_activate_cpu *)data;
806 		error = vm_suspend_cpu(sc->vm, vac->vcpuid);
807 		break;
808 	case VM_RESUME_CPU:
809 		vac = (struct vm_activate_cpu *)data;
810 		error = vm_resume_cpu(sc->vm, vac->vcpuid);
811 		break;
812 	case VM_SET_INTINFO:
813 		vmii = (struct vm_intinfo *)data;
814 		error = vm_exit_intinfo(sc->vm, vmii->vcpuid, vmii->info1);
815 		break;
816 	case VM_GET_INTINFO:
817 		vmii = (struct vm_intinfo *)data;
818 		error = vm_get_intinfo(sc->vm, vmii->vcpuid, &vmii->info1,
819 		    &vmii->info2);
820 		break;
821 	case VM_RTC_WRITE:
822 		rtcdata = (struct vm_rtc_data *)data;
823 		error = vrtc_nvram_write(sc->vm, rtcdata->offset,
824 		    rtcdata->value);
825 		break;
826 	case VM_RTC_READ:
827 		rtcdata = (struct vm_rtc_data *)data;
828 		error = vrtc_nvram_read(sc->vm, rtcdata->offset,
829 		    &rtcdata->value);
830 		break;
831 	case VM_RTC_SETTIME:
832 		rtctime = (struct vm_rtc_time *)data;
833 		error = vrtc_set_time(sc->vm, rtctime->secs);
834 		break;
835 	case VM_RTC_GETTIME:
836 		error = 0;
837 		rtctime = (struct vm_rtc_time *)data;
838 		rtctime->secs = vrtc_get_time(sc->vm);
839 		break;
840 	case VM_RESTART_INSTRUCTION:
841 		error = vm_restart_instruction(sc->vm, vcpu);
842 		break;
843 	case VM_SET_TOPOLOGY:
844 		topology = (struct vm_cpu_topology *)data;
845 		error = vm_set_topology(sc->vm, topology->sockets,
846 		    topology->cores, topology->threads, topology->maxcpus);
847 		break;
848 	case VM_GET_TOPOLOGY:
849 		topology = (struct vm_cpu_topology *)data;
850 		vm_get_topology(sc->vm, &topology->sockets, &topology->cores,
851 		    &topology->threads, &topology->maxcpus);
852 		error = 0;
853 		break;
854 #ifdef BHYVE_SNAPSHOT
855 	case VM_SNAPSHOT_REQ:
856 		snapshot_meta = (struct vm_snapshot_meta *)data;
857 		error = vm_snapshot_req(sc->vm, snapshot_meta);
858 		break;
859 	case VM_RESTORE_TIME:
860 		error = vm_restore_time(sc->vm);
861 		break;
862 #endif
863 	default:
864 		error = ENOTTY;
865 		break;
866 	}
867 
868 	if (state_changed == 1)
869 		vcpu_unlock_one(sc, vcpu);
870 	else if (state_changed == 2)
871 		vcpu_unlock_all(sc);
872 
873 done:
874 	/*
875 	 * Make sure that no handler returns a kernel-internal
876 	 * error value to userspace.
877 	 */
878 	KASSERT(error == ERESTART || error >= 0,
879 	    ("vmmdev_ioctl: invalid error return %d", error));
880 	return (error);
881 }
882 
883 static int
vmmdev_mmap_single(struct cdev * cdev,vm_ooffset_t * offset,vm_size_t mapsize,struct vm_object ** objp,int nprot)884 vmmdev_mmap_single(struct cdev *cdev, vm_ooffset_t *offset, vm_size_t mapsize,
885     struct vm_object **objp, int nprot)
886 {
887 	struct vmmdev_softc *sc;
888 	vm_paddr_t gpa;
889 	size_t len;
890 	vm_ooffset_t segoff, first, last;
891 	int error, found, segid;
892 	uint16_t lastcpu;
893 	bool sysmem;
894 
895 	error = vmm_priv_check(curthread->td_ucred);
896 	if (error)
897 		return (error);
898 
899 	first = *offset;
900 	last = first + mapsize;
901 	if ((nprot & PROT_EXEC) || first < 0 || first >= last)
902 		return (EINVAL);
903 
904 	sc = vmmdev_lookup2(cdev);
905 	if (sc == NULL) {
906 		/* virtual machine is in the process of being created */
907 		return (EINVAL);
908 	}
909 
910 	/*
911 	 * Get a read lock on the guest memory map by freezing any vcpu.
912 	 */
913 	lastcpu = vm_get_maxcpus(sc->vm) - 1;
914 	error = vcpu_lock_one(sc, lastcpu);
915 	if (error)
916 		return (error);
917 
918 	gpa = 0;
919 	found = 0;
920 	while (!found) {
921 		error = vm_mmap_getnext(sc->vm, &gpa, &segid, &segoff, &len,
922 		    NULL, NULL);
923 		if (error)
924 			break;
925 
926 		if (first >= gpa && last <= gpa + len)
927 			found = 1;
928 		else
929 			gpa += len;
930 	}
931 
932 	if (found) {
933 		error = vm_get_memseg(sc->vm, segid, &len, &sysmem, objp);
934 		KASSERT(error == 0 && *objp != NULL,
935 		    ("%s: invalid memory segment %d", __func__, segid));
936 		if (sysmem) {
937 			vm_object_reference(*objp);
938 			*offset = segoff + (first - gpa);
939 		} else {
940 			error = EINVAL;
941 		}
942 	}
943 	vcpu_unlock_one(sc, lastcpu);
944 	return (error);
945 }
946 
947 static void
vmmdev_destroy(void * arg)948 vmmdev_destroy(void *arg)
949 {
950 	struct vmmdev_softc *sc = arg;
951 	struct devmem_softc *dsc;
952 	int error;
953 
954 	error = vcpu_lock_all(sc);
955 	KASSERT(error == 0, ("%s: error %d freezing vcpus", __func__, error));
956 
957 	while ((dsc = SLIST_FIRST(&sc->devmem)) != NULL) {
958 		KASSERT(dsc->cdev == NULL, ("%s: devmem not free", __func__));
959 		SLIST_REMOVE_HEAD(&sc->devmem, link);
960 		free(dsc->name, M_VMMDEV);
961 		free(dsc, M_VMMDEV);
962 	}
963 
964 	if (sc->cdev != NULL)
965 		destroy_dev(sc->cdev);
966 
967 	if (sc->vm != NULL)
968 		vm_destroy(sc->vm);
969 
970 	if ((sc->flags & VSC_LINKED) != 0) {
971 		mtx_lock(&vmmdev_mtx);
972 		SLIST_REMOVE(&head, sc, vmmdev_softc, link);
973 		mtx_unlock(&vmmdev_mtx);
974 	}
975 
976 	free(sc, M_VMMDEV);
977 }
978 
979 static int
sysctl_vmm_destroy(SYSCTL_HANDLER_ARGS)980 sysctl_vmm_destroy(SYSCTL_HANDLER_ARGS)
981 {
982 	struct devmem_softc *dsc;
983 	struct vmmdev_softc *sc;
984 	struct cdev *cdev;
985 	char *buf;
986 	int error, buflen;
987 
988 	error = vmm_priv_check(req->td->td_ucred);
989 	if (error)
990 		return (error);
991 
992 	buflen = VM_MAX_NAMELEN + 1;
993 	buf = malloc(buflen, M_VMMDEV, M_WAITOK | M_ZERO);
994 	strlcpy(buf, "beavis", buflen);
995 	error = sysctl_handle_string(oidp, buf, buflen, req);
996 	if (error != 0 || req->newptr == NULL)
997 		goto out;
998 
999 	mtx_lock(&vmmdev_mtx);
1000 	sc = vmmdev_lookup(buf);
1001 	if (sc == NULL || sc->cdev == NULL) {
1002 		mtx_unlock(&vmmdev_mtx);
1003 		error = EINVAL;
1004 		goto out;
1005 	}
1006 
1007 	/*
1008 	 * The 'cdev' will be destroyed asynchronously when 'si_threadcount'
1009 	 * goes down to 0 so we should not do it again in the callback.
1010 	 *
1011 	 * Setting 'sc->cdev' to NULL is also used to indicate that the VM
1012 	 * is scheduled for destruction.
1013 	 */
1014 	cdev = sc->cdev;
1015 	sc->cdev = NULL;
1016 	mtx_unlock(&vmmdev_mtx);
1017 
1018 	/*
1019 	 * Schedule all cdevs to be destroyed:
1020 	 *
1021 	 * - any new operations on the 'cdev' will return an error (ENXIO).
1022 	 *
1023 	 * - when the 'si_threadcount' dwindles down to zero the 'cdev' will
1024 	 *   be destroyed and the callback will be invoked in a taskqueue
1025 	 *   context.
1026 	 *
1027 	 * - the 'devmem' cdevs are destroyed before the virtual machine 'cdev'
1028 	 */
1029 	SLIST_FOREACH(dsc, &sc->devmem, link) {
1030 		KASSERT(dsc->cdev != NULL, ("devmem cdev already destroyed"));
1031 		destroy_dev_sched_cb(dsc->cdev, devmem_destroy, dsc);
1032 	}
1033 	destroy_dev_sched_cb(cdev, vmmdev_destroy, sc);
1034 	error = 0;
1035 
1036 out:
1037 	free(buf, M_VMMDEV);
1038 	return (error);
1039 }
1040 SYSCTL_PROC(_hw_vmm, OID_AUTO, destroy,
1041     CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_PRISON | CTLFLAG_MPSAFE,
1042     NULL, 0, sysctl_vmm_destroy, "A",
1043     NULL);
1044 
1045 static struct cdevsw vmmdevsw = {
1046 	.d_name		= "vmmdev",
1047 	.d_version	= D_VERSION,
1048 	.d_ioctl	= vmmdev_ioctl,
1049 	.d_mmap_single	= vmmdev_mmap_single,
1050 	.d_read		= vmmdev_rw,
1051 	.d_write	= vmmdev_rw,
1052 };
1053 
1054 static int
sysctl_vmm_create(SYSCTL_HANDLER_ARGS)1055 sysctl_vmm_create(SYSCTL_HANDLER_ARGS)
1056 {
1057 	struct vm *vm;
1058 	struct cdev *cdev;
1059 	struct vmmdev_softc *sc, *sc2;
1060 	char *buf;
1061 	int error, buflen;
1062 
1063 	error = vmm_priv_check(req->td->td_ucred);
1064 	if (error)
1065 		return (error);
1066 
1067 	buflen = VM_MAX_NAMELEN + 1;
1068 	buf = malloc(buflen, M_VMMDEV, M_WAITOK | M_ZERO);
1069 	strlcpy(buf, "beavis", buflen);
1070 	error = sysctl_handle_string(oidp, buf, buflen, req);
1071 	if (error != 0 || req->newptr == NULL)
1072 		goto out;
1073 
1074 	mtx_lock(&vmmdev_mtx);
1075 	sc = vmmdev_lookup(buf);
1076 	mtx_unlock(&vmmdev_mtx);
1077 	if (sc != NULL) {
1078 		error = EEXIST;
1079 		goto out;
1080 	}
1081 
1082 	error = vm_create(buf, &vm);
1083 	if (error != 0)
1084 		goto out;
1085 
1086 	sc = malloc(sizeof(struct vmmdev_softc), M_VMMDEV, M_WAITOK | M_ZERO);
1087 	sc->vm = vm;
1088 	SLIST_INIT(&sc->devmem);
1089 
1090 	/*
1091 	 * Lookup the name again just in case somebody sneaked in when we
1092 	 * dropped the lock.
1093 	 */
1094 	mtx_lock(&vmmdev_mtx);
1095 	sc2 = vmmdev_lookup(buf);
1096 	if (sc2 == NULL) {
1097 		SLIST_INSERT_HEAD(&head, sc, link);
1098 		sc->flags |= VSC_LINKED;
1099 	}
1100 	mtx_unlock(&vmmdev_mtx);
1101 
1102 	if (sc2 != NULL) {
1103 		vmmdev_destroy(sc);
1104 		error = EEXIST;
1105 		goto out;
1106 	}
1107 
1108 	error = make_dev_p(MAKEDEV_CHECKNAME, &cdev, &vmmdevsw, NULL,
1109 			   UID_ROOT, GID_WHEEL, 0600, "vmm/%s", buf);
1110 	if (error != 0) {
1111 		vmmdev_destroy(sc);
1112 		goto out;
1113 	}
1114 
1115 	mtx_lock(&vmmdev_mtx);
1116 	sc->cdev = cdev;
1117 	sc->cdev->si_drv1 = sc;
1118 	mtx_unlock(&vmmdev_mtx);
1119 
1120 out:
1121 	free(buf, M_VMMDEV);
1122 	return (error);
1123 }
1124 SYSCTL_PROC(_hw_vmm, OID_AUTO, create,
1125     CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_PRISON | CTLFLAG_MPSAFE,
1126     NULL, 0, sysctl_vmm_create, "A",
1127     NULL);
1128 
1129 void
vmmdev_init(void)1130 vmmdev_init(void)
1131 {
1132 	mtx_init(&vmmdev_mtx, "vmm device mutex", NULL, MTX_DEF);
1133 	pr_allow_flag = prison_add_allow(NULL, "vmm", NULL,
1134 	    "Allow use of vmm in a jail.");
1135 }
1136 
1137 int
vmmdev_cleanup(void)1138 vmmdev_cleanup(void)
1139 {
1140 	int error;
1141 
1142 	if (SLIST_EMPTY(&head))
1143 		error = 0;
1144 	else
1145 		error = EBUSY;
1146 
1147 	return (error);
1148 }
1149 
1150 static int
devmem_mmap_single(struct cdev * cdev,vm_ooffset_t * offset,vm_size_t len,struct vm_object ** objp,int nprot)1151 devmem_mmap_single(struct cdev *cdev, vm_ooffset_t *offset, vm_size_t len,
1152     struct vm_object **objp, int nprot)
1153 {
1154 	struct devmem_softc *dsc;
1155 	vm_ooffset_t first, last;
1156 	size_t seglen;
1157 	int error;
1158 	uint16_t lastcpu;
1159 	bool sysmem;
1160 
1161 	dsc = cdev->si_drv1;
1162 	if (dsc == NULL) {
1163 		/* 'cdev' has been created but is not ready for use */
1164 		return (ENXIO);
1165 	}
1166 
1167 	first = *offset;
1168 	last = *offset + len;
1169 	if ((nprot & PROT_EXEC) || first < 0 || first >= last)
1170 		return (EINVAL);
1171 
1172 	lastcpu = vm_get_maxcpus(dsc->sc->vm) - 1;
1173 	error = vcpu_lock_one(dsc->sc, lastcpu);
1174 	if (error)
1175 		return (error);
1176 
1177 	error = vm_get_memseg(dsc->sc->vm, dsc->segid, &seglen, &sysmem, objp);
1178 	KASSERT(error == 0 && !sysmem && *objp != NULL,
1179 	    ("%s: invalid devmem segment %d", __func__, dsc->segid));
1180 
1181 	vcpu_unlock_one(dsc->sc, lastcpu);
1182 
1183 	if (seglen >= last) {
1184 		vm_object_reference(*objp);
1185 		return (0);
1186 	} else {
1187 		return (EINVAL);
1188 	}
1189 }
1190 
1191 static struct cdevsw devmemsw = {
1192 	.d_name		= "devmem",
1193 	.d_version	= D_VERSION,
1194 	.d_mmap_single	= devmem_mmap_single,
1195 };
1196 
1197 static int
devmem_create_cdev(const char * vmname,int segid,char * devname)1198 devmem_create_cdev(const char *vmname, int segid, char *devname)
1199 {
1200 	struct devmem_softc *dsc;
1201 	struct vmmdev_softc *sc;
1202 	struct cdev *cdev;
1203 	int error;
1204 
1205 	error = make_dev_p(MAKEDEV_CHECKNAME, &cdev, &devmemsw, NULL,
1206 	    UID_ROOT, GID_WHEEL, 0600, "vmm.io/%s.%s", vmname, devname);
1207 	if (error)
1208 		return (error);
1209 
1210 	dsc = malloc(sizeof(struct devmem_softc), M_VMMDEV, M_WAITOK | M_ZERO);
1211 
1212 	mtx_lock(&vmmdev_mtx);
1213 	sc = vmmdev_lookup(vmname);
1214 	KASSERT(sc != NULL, ("%s: vm %s softc not found", __func__, vmname));
1215 	if (sc->cdev == NULL) {
1216 		/* virtual machine is being created or destroyed */
1217 		mtx_unlock(&vmmdev_mtx);
1218 		free(dsc, M_VMMDEV);
1219 		destroy_dev_sched_cb(cdev, NULL, 0);
1220 		return (ENODEV);
1221 	}
1222 
1223 	dsc->segid = segid;
1224 	dsc->name = devname;
1225 	dsc->cdev = cdev;
1226 	dsc->sc = sc;
1227 	SLIST_INSERT_HEAD(&sc->devmem, dsc, link);
1228 	mtx_unlock(&vmmdev_mtx);
1229 
1230 	/* The 'cdev' is ready for use after 'si_drv1' is initialized */
1231 	cdev->si_drv1 = dsc;
1232 	return (0);
1233 }
1234 
1235 static void
devmem_destroy(void * arg)1236 devmem_destroy(void *arg)
1237 {
1238 	struct devmem_softc *dsc = arg;
1239 
1240 	KASSERT(dsc->cdev, ("%s: devmem cdev already destroyed", __func__));
1241 	dsc->cdev = NULL;
1242 	dsc->sc = NULL;
1243 }
1244