vmm_ioport.c revision 276429 
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 276429 2014-12-30 22:22:46Z 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 "vmm_ioport.h"
46#include "vmm_ktr.h"
47
48#define	MAX_IOPORTS		1280
49
50ioport_handler_func_t ioport_handler[MAX_IOPORTS] = {
51	[TIMER_MODE] = vatpit_handler,
52	[TIMER_CNTR0] = vatpit_handler,
53	[TIMER_CNTR1] = vatpit_handler,
54	[TIMER_CNTR2] = vatpit_handler,
55	[NMISC_PORT] = vatpit_nmisc_handler,
56	[IO_ICU1] = vatpic_master_handler,
57	[IO_ICU1 + ICU_IMR_OFFSET] = vatpic_master_handler,
58	[IO_ICU2] = vatpic_slave_handler,
59	[IO_ICU2 + ICU_IMR_OFFSET] = vatpic_slave_handler,
60	[IO_ELCR1] = vatpic_elc_handler,
61	[IO_ELCR2] = vatpic_elc_handler,
62	[IO_PMTMR] = vpmtmr_handler,
63};
64
65#ifdef KTR
66static const char *
67inout_instruction(struct vm_exit *vmexit)
68{
69	int index;
70
71	static const char *iodesc[] = {
72		"outb", "outw", "outl",
73		"inb", "inw", "inl",
74		"outsb", "outsw", "outsd"
75		"insb", "insw", "insd",
76	};
77
78	switch (vmexit->u.inout.bytes) {
79	case 1:
80		index = 0;
81		break;
82	case 2:
83		index = 1;
84		break;
85	default:
86		index = 2;
87		break;
88	}
89
90	if (vmexit->u.inout.in)
91		index += 3;
92
93	if (vmexit->u.inout.string)
94		index += 6;
95
96	KASSERT(index < nitems(iodesc), ("%s: invalid index %d",
97	    __func__, index));
98
99	return (iodesc[index]);
100}
101#endif	/* KTR */
102
103static int
104emulate_inout_port(struct vm *vm, int vcpuid, struct vm_exit *vmexit,
105    bool *retu)
106{
107	ioport_handler_func_t handler;
108	uint32_t mask, val;
109	int error;
110
111	/*
112	 * If there is no handler for the I/O port then punt to userspace.
113	 */
114	if (vmexit->u.inout.port >= MAX_IOPORTS ||
115	    (handler = ioport_handler[vmexit->u.inout.port]) == NULL) {
116		*retu = true;
117		return (0);
118	}
119
120	mask = vie_size2mask(vmexit->u.inout.bytes);
121
122	if (!vmexit->u.inout.in) {
123		val = vmexit->u.inout.eax & mask;
124	}
125
126	error = (*handler)(vm, vcpuid, vmexit->u.inout.in,
127	    vmexit->u.inout.port, vmexit->u.inout.bytes, &val);
128	if (error) {
129		/*
130		 * The value returned by this function is also the return value
131		 * of vm_run(). This needs to be a positive number otherwise it
132		 * can be interpreted as a "pseudo-error" like ERESTART.
133		 *
134		 * Enforce this by mapping all errors to EIO.
135		 */
136		return (EIO);
137	}
138
139	if (vmexit->u.inout.in) {
140		vmexit->u.inout.eax &= ~mask;
141		vmexit->u.inout.eax |= val & mask;
142		error = vm_set_register(vm, vcpuid, VM_REG_GUEST_RAX,
143		    vmexit->u.inout.eax);
144		KASSERT(error == 0, ("emulate_ioport: error %d setting guest "
145		    "rax register", error));
146	}
147	*retu = false;
148	return (0);
149}
150
151static int
152emulate_inout_str(struct vm *vm, int vcpuid, struct vm_exit *vmexit, bool *retu)
153{
154	*retu = true;
155	return (0);	/* Return to userspace to finish emulation */
156}
157
158int
159vm_handle_inout(struct vm *vm, int vcpuid, struct vm_exit *vmexit, bool *retu)
160{
161	int bytes, error;
162
163	bytes = vmexit->u.inout.bytes;
164	KASSERT(bytes == 1 || bytes == 2 || bytes == 4,
165	    ("vm_handle_inout: invalid operand size %d", bytes));
166
167	if (vmexit->u.inout.string)
168		error = emulate_inout_str(vm, vcpuid, vmexit, retu);
169	else
170		error = emulate_inout_port(vm, vcpuid, vmexit, retu);
171
172	VCPU_CTR4(vm, vcpuid, "%s%s 0x%04x: %s",
173	    vmexit->u.inout.rep ? "rep " : "",
174	    inout_instruction(vmexit),
175	    vmexit->u.inout.port,
176	    error ? "error" : (*retu ? "userspace" : "handled"));
177
178	return (error);
179}
180