xref: /titanic_41/usr/src/uts/i86xpv/io/domcaps.c (revision fcf3ce441efd61da9bb2884968af01cb7c1452cc)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*
28  * This rather uninspiring device enables userland to discover if
29  * the current kernel is actually a dom0 or other domain e.g. domU.
30  */
31 
32 #include <sys/types.h>
33 #include <sys/file.h>
34 #include <sys/errno.h>
35 #include <sys/open.h>
36 #include <sys/cred.h>
37 #include <sys/conf.h>
38 #include <sys/stat.h>
39 #include <sys/modctl.h>
40 #include <sys/ddi.h>
41 #include <sys/sunddi.h>
42 #include <sys/hypervisor.h>
43 #include <sys/sysmacros.h>
44 
45 #include <sys/domcaps_impl.h>
46 
47 static dev_info_t *domcaps_devi;
48 
49 /*ARGSUSED*/
50 static int
51 domcaps_getinfo(dev_info_t *devi, ddi_info_cmd_t cmd, void *arg, void **result)
52 {
53 	if (getminor((dev_t)arg) != DOMCAPS_MINOR)
54 		return (DDI_FAILURE);
55 
56 	switch (cmd) {
57 	case DDI_INFO_DEVT2DEVINFO:
58 		*result = domcaps_devi;
59 		break;
60 	case DDI_INFO_DEVT2INSTANCE:
61 		*result = 0;
62 		break;
63 	default:
64 		return (DDI_FAILURE);
65 	}
66 
67 	return (DDI_SUCCESS);
68 }
69 
70 static int
71 domcaps_attach(dev_info_t *devi, ddi_attach_cmd_t cmd)
72 {
73 	if (cmd != DDI_ATTACH)
74 		return (DDI_FAILURE);
75 
76 	if (ddi_create_minor_node(devi, ddi_get_name(devi), S_IFCHR,
77 	    ddi_get_instance(devi), DDI_PSEUDO, 0) != DDI_SUCCESS)
78 		return (DDI_FAILURE);
79 
80 	domcaps_devi = devi;
81 	ddi_report_dev(devi);
82 	return (DDI_SUCCESS);
83 }
84 
85 static int
86 domcaps_detach(dev_info_t *devi, ddi_detach_cmd_t cmd)
87 {
88 	if (cmd != DDI_DETACH)
89 		return (DDI_FAILURE);
90 	ddi_remove_minor_node(devi, NULL);
91 	domcaps_devi = NULL;
92 	return (DDI_SUCCESS);
93 }
94 
95 /*ARGSUSED1*/
96 static int
97 domcaps_open(dev_t *dev, int flag, int otyp, cred_t *cr)
98 {
99 	return (getminor(*dev) == DOMCAPS_MINOR ? 0 : ENXIO);
100 }
101 
102 /*ARGSUSED*/
103 static int
104 domcaps_read(dev_t dev, uio_t *uio, cred_t *cr)
105 {
106 	if (DOMAIN_IS_INITDOMAIN(xen_info)) {
107 		static char data[] = "control_d\n";
108 		size_t nbytes;
109 
110 		if (uio->uio_loffset > sizeof (data))
111 			return (0);
112 		nbytes = MIN(uio->uio_resid, sizeof (data) - uio->uio_loffset);
113 
114 		return (uiomove(data + uio->uio_loffset, nbytes,
115 		    UIO_READ, uio));
116 	}
117 
118 	return (0);
119 }
120 
121 static struct cb_ops domcaps_cb_ops = {
122 	domcaps_open,
123 	nulldev,	/* close */
124 	nodev,		/* strategy */
125 	nodev,		/* print */
126 	nodev,		/* dump */
127 	domcaps_read,
128 	nodev,		/* write */
129 	nodev,		/* ioctl */
130 	nodev,		/* devmap */
131 	nodev,		/* mmap */
132 	nodev,		/* segmap */
133 	nochpoll,	/* poll */
134 	ddi_prop_op,
135 	NULL,
136 	D_64BIT | D_MP,
137 	CB_REV,
138 	NULL,
139 	NULL
140 };
141 
142 static struct dev_ops domcaps_dv_ops = {
143 	DEVO_REV,
144 	0,
145 	domcaps_getinfo,
146 	nulldev,		/* identify */
147 	nulldev,		/* probe */
148 	domcaps_attach,
149 	domcaps_detach,
150 	nodev,			/* reset */
151 	&domcaps_cb_ops,
152 	NULL,			/* struct bus_ops */
153 	NULL,			/* power */
154 	ddi_quiesce_not_needed,		/* quiesce */
155 };
156 
157 static struct modldrv modldrv = {
158 	&mod_driverops,
159 	"hypervisor capabilities driver",
160 	&domcaps_dv_ops
161 };
162 
163 static struct modlinkage modl = {
164 	MODREV_1,
165 	{
166 		(void *)&modldrv,
167 		NULL		/* null termination */
168 	}
169 };
170 
171 int
172 _init(void)
173 {
174 	return (mod_install(&modl));
175 }
176 
177 int
178 _fini(void)
179 {
180 	return (mod_remove(&modl));
181 }
182 
183 int
184 _info(struct modinfo *modinfo)
185 {
186 	return (mod_info(&modl, modinfo));
187 }
188