vmm_ioport.c revision 277168 
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: head/sys/amd64/vmm/vmm_ioport.c 277168 2015-01-14 07:18:51Z 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 "vpmtmr.h"
45#include "vrtc.h"
46#include "vmm_ioport.h"
47#include "vmm_ktr.h"
48
49#define	MAX_IOPORTS		1280
50
51ioport_handler_func_t ioport_handler[MAX_IOPORTS] = {
52	[TIMER_MODE] = vatpit_handler,
53	[TIMER_CNTR0] = vatpit_handler,
54	[TIMER_CNTR1] = vatpit_handler,
55	[TIMER_CNTR2] = vatpit_handler,
56	[NMISC_PORT] = vatpit_nmisc_handler,
57	[IO_ICU1] = vatpic_master_handler,
58	[IO_ICU1 + ICU_IMR_OFFSET] = vatpic_master_handler,
59	[IO_ICU2] = vatpic_slave_handler,
60	[IO_ICU2 + ICU_IMR_OFFSET] = vatpic_slave_handler,
61	[IO_ELCR1] = vatpic_elc_handler,
62	[IO_ELCR2] = vatpic_elc_handler,
63	[IO_PMTMR] = vpmtmr_handler,
64	[IO_RTC] = vrtc_addr_handler,
65	[IO_RTC + 1] = vrtc_data_handler,
66};
67
68#ifdef KTR
69static const char *
70inout_instruction(struct vm_exit *vmexit)
71{
72	int index;
73
74	static const char *iodesc[] = {
75		"outb", "outw", "outl",
76		"inb", "inw", "inl",
77		"outsb", "outsw", "outsd",
78		"insb", "insw", "insd",
79	};
80
81	switch (vmexit->u.inout.bytes) {
82	case 1:
83		index = 0;
84		break;
85	case 2:
86		index = 1;
87		break;
88	default:
89		index = 2;
90		break;
91	}
92
93	if (vmexit->u.inout.in)
94		index += 3;
95
96	if (vmexit->u.inout.string)
97		index += 6;
98
99	KASSERT(index < nitems(iodesc), ("%s: invalid index %d",
100	    __func__, index));
101
102	return (iodesc[index]);
103}
104#endif	/* KTR */
105
106static int
107emulate_inout_port(struct vm *vm, int vcpuid, struct vm_exit *vmexit,
108    bool *retu)
109{
110	ioport_handler_func_t handler;
111	uint32_t mask, val;
112	int error;
113
114	/*
115	 * If there is no handler for the I/O port then punt to userspace.
116	 */
117	if (vmexit->u.inout.port >= MAX_IOPORTS ||
118	    (handler = ioport_handler[vmexit->u.inout.port]) == NULL) {
119		*retu = true;
120		return (0);
121	}
122
123	mask = vie_size2mask(vmexit->u.inout.bytes);
124
125	if (!vmexit->u.inout.in) {
126		val = vmexit->u.inout.eax & mask;
127	}
128
129	error = (*handler)(vm, vcpuid, vmexit->u.inout.in,
130	    vmexit->u.inout.port, vmexit->u.inout.bytes, &val);
131	if (error) {
132		/*
133		 * The value returned by this function is also the return value
134		 * of vm_run(). This needs to be a positive number otherwise it
135		 * can be interpreted as a "pseudo-error" like ERESTART.
136		 *
137		 * Enforce this by mapping all errors to EIO.
138		 */
139		return (EIO);
140	}
141
142	if (vmexit->u.inout.in) {
143		vmexit->u.inout.eax &= ~mask;
144		vmexit->u.inout.eax |= val & mask;
145		error = vm_set_register(vm, vcpuid, VM_REG_GUEST_RAX,
146		    vmexit->u.inout.eax);
147		KASSERT(error == 0, ("emulate_ioport: error %d setting guest "
148		    "rax register", error));
149	}
150	*retu = false;
151	return (0);
152}
153
154static int
155emulate_inout_str(struct vm *vm, int vcpuid, struct vm_exit *vmexit, bool *retu)
156{
157	*retu = true;
158	return (0);	/* Return to userspace to finish emulation */
159}
160
161int
162vm_handle_inout(struct vm *vm, int vcpuid, struct vm_exit *vmexit, bool *retu)
163{
164	int bytes, error;
165
166	bytes = vmexit->u.inout.bytes;
167	KASSERT(bytes == 1 || bytes == 2 || bytes == 4,
168	    ("vm_handle_inout: invalid operand size %d", bytes));
169
170	if (vmexit->u.inout.string)
171		error = emulate_inout_str(vm, vcpuid, vmexit, retu);
172	else
173		error = emulate_inout_port(vm, vcpuid, vmexit, retu);
174
175	VCPU_CTR4(vm, vcpuid, "%s%s 0x%04x: %s",
176	    vmexit->u.inout.rep ? "rep " : "",
177	    inout_instruction(vmexit),
178	    vmexit->u.inout.port,
179	    error ? "error" : (*retu ? "userspace" : "handled"));
180
181	return (error);
182}
183