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
domcaps_getinfo(dev_info_t * devi,ddi_info_cmd_t cmd,void * arg,void ** result)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
domcaps_attach(dev_info_t * devi,ddi_attach_cmd_t cmd)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
domcaps_detach(dev_info_t * devi,ddi_detach_cmd_t cmd)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
domcaps_open(dev_t * dev,int flag,int otyp,cred_t * cr)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
domcaps_read(dev_t dev,uio_t * uio,cred_t * cr)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
_init(void)172 _init(void)
173 {
174 return (mod_install(&modl));
175 }
176
177 int
_fini(void)178 _fini(void)
179 {
180 return (mod_remove(&modl));
181 }
182
183 int
_info(struct modinfo * modinfo)184 _info(struct modinfo *modinfo)
185 {
186 return (mod_info(&modl, modinfo));
187 }
188