xref: /freebsd/sys/amd64/vmm/vmm_ioport.c (revision ff0ba87247820afbdfdc1b307c803f7923d0e4d3)
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("$FreeBSD$");
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 
50 ioport_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
66 static const char *
67 inout_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 
103 static int
104 emulate_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 
151 static int
152 emulate_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 
158 int
159 vm_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