vmm_ioport.c revision 284900 
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 284900 2015-06-28 03:22:26Z neel $");
29
30#include <sys/param.h>
31#include <sys/systm.h>
32
33#include <machine/vmm.h>
34#include <machine/vmm_instruction_emul.h>
35
36#include "vatpic.h"
37#include "vatpit.h"
38#include "vpmtmr.h"
39#include "vrtc.h"
40#include "vmm_ioport.h"
41#include "vmm_ktr.h"
42
43#define	MAX_IOPORTS		1280
44
45ioport_handler_func_t ioport_handler[MAX_IOPORTS] = {
46	[TIMER_MODE] = vatpit_handler,
47	[TIMER_CNTR0] = vatpit_handler,
48	[TIMER_CNTR1] = vatpit_handler,
49	[TIMER_CNTR2] = vatpit_handler,
50	[NMISC_PORT] = vatpit_nmisc_handler,
51	[IO_ICU1] = vatpic_master_handler,
52	[IO_ICU1 + ICU_IMR_OFFSET] = vatpic_master_handler,
53	[IO_ICU2] = vatpic_slave_handler,
54	[IO_ICU2 + ICU_IMR_OFFSET] = vatpic_slave_handler,
55	[IO_ELCR1] = vatpic_elc_handler,
56	[IO_ELCR2] = vatpic_elc_handler,
57	[IO_PMTMR] = vpmtmr_handler,
58	[IO_RTC] = vrtc_addr_handler,
59	[IO_RTC + 1] = vrtc_data_handler,
60};
61
62#ifdef KTR
63static const char *
64inout_instruction(struct vm_exit *vmexit)
65{
66	int index;
67
68	static const char *iodesc[] = {
69		"outb", "outw", "outl",
70		"inb", "inw", "inl",
71		"outsb", "outsw", "outsd",
72		"insb", "insw", "insd",
73	};
74
75	switch (vmexit->u.inout.bytes) {
76	case 1:
77		index = 0;
78		break;
79	case 2:
80		index = 1;
81		break;
82	default:
83		index = 2;
84		break;
85	}
86
87	if (vmexit->u.inout.in)
88		index += 3;
89
90	if (vmexit->u.inout.string)
91		index += 6;
92
93	KASSERT(index < nitems(iodesc), ("%s: invalid index %d",
94	    __func__, index));
95
96	return (iodesc[index]);
97}
98#endif	/* KTR */
99
100static int
101emulate_inout_port(struct vm *vm, int vcpuid, struct vm_exit *vmexit,
102    bool *retu)
103{
104	ioport_handler_func_t handler;
105	uint32_t mask, val;
106	int error;
107
108	/*
109	 * If there is no handler for the I/O port then punt to userspace.
110	 */
111	if (vmexit->u.inout.port >= MAX_IOPORTS ||
112	    (handler = ioport_handler[vmexit->u.inout.port]) == NULL) {
113		*retu = true;
114		return (0);
115	}
116
117	mask = vie_size2mask(vmexit->u.inout.bytes);
118
119	if (!vmexit->u.inout.in) {
120		val = vmexit->u.inout.eax & mask;
121	}
122
123	error = (*handler)(vm, vcpuid, vmexit->u.inout.in,
124	    vmexit->u.inout.port, vmexit->u.inout.bytes, &val);
125	if (error) {
126		/*
127		 * The value returned by this function is also the return value
128		 * of vm_run(). This needs to be a positive number otherwise it
129		 * can be interpreted as a "pseudo-error" like ERESTART.
130		 *
131		 * Enforce this by mapping all errors to EIO.
132		 */
133		return (EIO);
134	}
135
136	if (vmexit->u.inout.in) {
137		vmexit->u.inout.eax &= ~mask;
138		vmexit->u.inout.eax |= val & mask;
139		error = vm_set_register(vm, vcpuid, VM_REG_GUEST_RAX,
140		    vmexit->u.inout.eax);
141		KASSERT(error == 0, ("emulate_ioport: error %d setting guest "
142		    "rax register", error));
143	}
144	*retu = false;
145	return (0);
146}
147
148static int
149emulate_inout_str(struct vm *vm, int vcpuid, struct vm_exit *vmexit, bool *retu)
150{
151	*retu = true;
152	return (0);	/* Return to userspace to finish emulation */
153}
154
155int
156vm_handle_inout(struct vm *vm, int vcpuid, struct vm_exit *vmexit, bool *retu)
157{
158	int bytes, error;
159
160	bytes = vmexit->u.inout.bytes;
161	KASSERT(bytes == 1 || bytes == 2 || bytes == 4,
162	    ("vm_handle_inout: invalid operand size %d", bytes));
163
164	if (vmexit->u.inout.string)
165		error = emulate_inout_str(vm, vcpuid, vmexit, retu);
166	else
167		error = emulate_inout_port(vm, vcpuid, vmexit, retu);
168
169	VCPU_CTR4(vm, vcpuid, "%s%s 0x%04x: %s",
170	    vmexit->u.inout.rep ? "rep " : "",
171	    inout_instruction(vmexit),
172	    vmexit->u.inout.port,
173	    error ? "error" : (*retu ? "userspace" : "handled"));
174
175	return (error);
176}
177