xref: /freebsd/sys/amd64/vmm/vmm_ioport.c (revision 6ef644f5889afbd0f681b08ed1a2f369524af83e)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2014 Tycho Nightingale <tycho.nightingale@pluribusnetworks.com>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
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 
45 ioport_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
63 static const char *
64 inout_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 
100 static int
101 emulate_inout_port(struct vcpu *vcpu, struct vm_exit *vmexit, bool *retu)
102 {
103 	ioport_handler_func_t handler;
104 	uint32_t mask, val;
105 	int error;
106 
107 	/*
108 	 * If there is no handler for the I/O port then punt to userspace.
109 	 */
110 	if (vmexit->u.inout.port >= MAX_IOPORTS ||
111 	    (handler = ioport_handler[vmexit->u.inout.port]) == NULL) {
112 		*retu = true;
113 		return (0);
114 	}
115 
116 	mask = vie_size2mask(vmexit->u.inout.bytes);
117 
118 	if (!vmexit->u.inout.in) {
119 		val = vmexit->u.inout.eax & mask;
120 	}
121 
122 	error = (*handler)(vcpu_vm(vcpu), vmexit->u.inout.in,
123 	    vmexit->u.inout.port, vmexit->u.inout.bytes, &val);
124 	if (error) {
125 		/*
126 		 * The value returned by this function is also the return value
127 		 * of vm_run(). This needs to be a positive number otherwise it
128 		 * can be interpreted as a "pseudo-error" like ERESTART.
129 		 *
130 		 * Enforce this by mapping all errors to EIO.
131 		 */
132 		return (EIO);
133 	}
134 
135 	if (vmexit->u.inout.in) {
136 		vmexit->u.inout.eax &= ~mask;
137 		vmexit->u.inout.eax |= val & mask;
138 		error = vm_set_register(vcpu, VM_REG_GUEST_RAX,
139 		    vmexit->u.inout.eax);
140 		KASSERT(error == 0, ("emulate_ioport: error %d setting guest "
141 		    "rax register", error));
142 	}
143 	*retu = false;
144 	return (0);
145 }
146 
147 static int
148 emulate_inout_str(struct vcpu *vcpu, struct vm_exit *vmexit, bool *retu)
149 {
150 	*retu = true;
151 	return (0);	/* Return to userspace to finish emulation */
152 }
153 
154 int
155 vm_handle_inout(struct vcpu *vcpu, struct vm_exit *vmexit, bool *retu)
156 {
157 	int bytes __diagused, error;
158 
159 	bytes = vmexit->u.inout.bytes;
160 	KASSERT(bytes == 1 || bytes == 2 || bytes == 4,
161 	    ("vm_handle_inout: invalid operand size %d", bytes));
162 
163 	if (vmexit->u.inout.string)
164 		error = emulate_inout_str(vcpu, vmexit, retu);
165 	else
166 		error = emulate_inout_port(vcpu, vmexit, retu);
167 
168 	VCPU_CTR4(vcpu_vm(vcpu), vcpu_vcpuid(vcpu), "%s%s 0x%04x: %s",
169 	    vmexit->u.inout.rep ? "rep " : "",
170 	    inout_instruction(vmexit),
171 	    vmexit->u.inout.port,
172 	    error ? "error" : (*retu ? "userspace" : "handled"));
173 
174 	return (error);
175 }
176