vmm_ioport.c revision 273807 
1/*-
2 * Copyright (c) 2014 Tycho Nightingale <tycho.nightingale@pluribusnetworks.com>
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 THE AUTHOR ``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 THE AUTHOR 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
27#include <sys/cdefs.h>
28__FBSDID("$FreeBSD: stable/10/sys/amd64/vmm/vmm_ioport.c 273807 2014-10-29 01:54:37Z neel $");
29
30#include <sys/param.h>
31#include <sys/types.h>
32#include <sys/queue.h>
33#include <sys/cpuset.h>
34#include <sys/systm.h>
35
36#include <vm/vm.h>
37
38#include <machine/vmm.h>
39#include <machine/vmm_instruction_emul.h>
40#include <x86/psl.h>
41
42#include "vatpic.h"
43#include "vatpit.h"
44#include "vmm_ioport.h"
45#include "vmm_ktr.h"
46
47#define	MAX_IOPORTS		1280
48
49ioport_handler_func_t ioport_handler[MAX_IOPORTS] = {
50	[TIMER_MODE] = vatpit_handler,
51	[TIMER_CNTR0] = vatpit_handler,
52	[TIMER_CNTR1] = vatpit_handler,
53	[TIMER_CNTR2] = vatpit_handler,
54	[NMISC_PORT] = vatpit_nmisc_handler,
55	[IO_ICU1] = vatpic_master_handler,
56	[IO_ICU1 + ICU_IMR_OFFSET] = vatpic_master_handler,
57	[IO_ICU2] = vatpic_slave_handler,
58	[IO_ICU2 + ICU_IMR_OFFSET] = vatpic_slave_handler,
59	[IO_ELCR1] = vatpic_elc_handler,
60	[IO_ELCR2] = vatpic_elc_handler,
61};
62
63#ifdef KTR
64static const char *
65inout_instruction(struct vm_exit *vmexit)
66{
67	int index;
68
69	static const char *iodesc[] = {
70		"outb", "outw", "outl",
71		"inb", "inw", "inl",
72		"outsb", "outsw", "outsd"
73		"insb", "insw", "insd",
74	};
75
76	switch (vmexit->u.inout.bytes) {
77	case 1:
78		index = 0;
79		break;
80	case 2:
81		index = 1;
82		break;
83	default:
84		index = 2;
85		break;
86	}
87
88	if (vmexit->u.inout.in)
89		index += 3;
90
91	if (vmexit->u.inout.string)
92		index += 6;
93
94	KASSERT(index < nitems(iodesc), ("%s: invalid index %d",
95	    __func__, index));
96
97	return (iodesc[index]);
98}
99#endif	/* KTR */
100
101static int
102emulate_inout_port(struct vm *vm, int vcpuid, struct vm_exit *vmexit,
103    bool *retu)
104{
105	ioport_handler_func_t handler;
106	uint32_t mask, val;
107	int error;
108
109	/*
110	 * If there is no handler for the I/O port then punt to userspace.
111	 */
112	if (vmexit->u.inout.port >= MAX_IOPORTS ||
113	    (handler = ioport_handler[vmexit->u.inout.port]) == NULL) {
114		*retu = true;
115		return (0);
116	}
117
118	mask = vie_size2mask(vmexit->u.inout.bytes);
119
120	if (!vmexit->u.inout.in) {
121		val = vmexit->u.inout.eax & mask;
122	}
123
124	error = (*handler)(vm, vcpuid, vmexit->u.inout.in,
125	    vmexit->u.inout.port, vmexit->u.inout.bytes, &val);
126	if (error) {
127		/*
128		 * The value returned by this function is also the return value
129		 * of vm_run(). This needs to be a positive number otherwise it
130		 * can be interpreted as a "pseudo-error" like ERESTART.
131		 *
132		 * Enforce this by mapping all errors to EIO.
133		 */
134		return (EIO);
135	}
136
137	if (vmexit->u.inout.in) {
138		vmexit->u.inout.eax &= ~mask;
139		vmexit->u.inout.eax |= val & mask;
140		error = vm_set_register(vm, vcpuid, VM_REG_GUEST_RAX,
141		    vmexit->u.inout.eax);
142		KASSERT(error == 0, ("emulate_ioport: error %d setting guest "
143		    "rax register", error));
144	}
145	*retu = false;
146	return (0);
147}
148
149static int
150emulate_inout_str(struct vm *vm, int vcpuid, struct vm_exit *vmexit, bool *retu)
151{
152	*retu = true;
153	return (0);	/* Return to userspace to finish emulation */
154}
155
156int
157vm_handle_inout(struct vm *vm, int vcpuid, struct vm_exit *vmexit, bool *retu)
158{
159	int bytes, error;
160
161	bytes = vmexit->u.inout.bytes;
162	KASSERT(bytes == 1 || bytes == 2 || bytes == 4,
163	    ("vm_handle_inout: invalid operand size %d", bytes));
164
165	if (vmexit->u.inout.string)
166		error = emulate_inout_str(vm, vcpuid, vmexit, retu);
167	else
168		error = emulate_inout_port(vm, vcpuid, vmexit, retu);
169
170	VCPU_CTR4(vm, vcpuid, "%s%s 0x%04x: %s",
171	    vmexit->u.inout.rep ? "rep " : "",
172	    inout_instruction(vmexit),
173	    vmexit->u.inout.port,
174	    error ? "error" : (*retu ? "userspace" : "handled"));
175
176	return (error);
177}
178