xref: /freebsd/sys/dev/xen/efi/pvefi.c (revision f5463265955b829775bbb32e1fd0bc11dafc36ce)
1 /*-
2  * Copyright (c) 2021 Citrix Systems R&D
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  *
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  */
26 
27 #include <sys/param.h>
28 #include <sys/efi.h>
29 #include <sys/eventhandler.h>
30 #include <sys/kernel.h>
31 #include <sys/linker.h>
32 #include <sys/module.h>
33 #include <sys/clock.h>
34 #include <sys/sysctl.h>
35 #include <sys/systm.h>
36 
37 #include <xen/xen-os.h>
38 #include <xen/error.h>
39 #include <xen/hypervisor.h>
40 
41 #include <contrib/xen/platform.h>
42 
43 extern char bootmethod[16];
44 
45 static int
46 rt_ok(void)
47 {
48 
49 	return (0);
50 }
51 
52 static int
53 get_time(struct efi_tm *tm)
54 {
55 	struct xen_platform_op op = {
56 		.cmd = XENPF_efi_runtime_call,
57 		.u.efi_runtime_call.function = XEN_EFI_get_time,
58 	};
59 	struct xenpf_efi_runtime_call *call = &op.u.efi_runtime_call;
60 	int error;
61 
62 	error = HYPERVISOR_platform_op(&op);
63 	if (error != 0)
64 		return (xen_translate_error(error));
65 
66 	tm->tm_year = call->u.get_time.time.year;
67 	tm->tm_mon = call->u.get_time.time.month;
68 	tm->tm_mday = call->u.get_time.time.day;
69 	tm->tm_hour = call->u.get_time.time.hour;
70 	tm->tm_min = call->u.get_time.time.min;
71 	tm->tm_sec = call->u.get_time.time.sec;
72 	tm->tm_nsec = call->u.get_time.time.ns;
73 	tm->tm_tz = call->u.get_time.time.tz;
74 	tm->tm_dst = call->u.get_time.time.daylight;
75 
76 	return (efi_status_to_errno(call->status));
77 }
78 
79 static int
80 get_time_capabilities(struct efi_tmcap *tmcap)
81 {
82 	struct xen_platform_op op = {
83 		.cmd = XENPF_efi_runtime_call,
84 		.u.efi_runtime_call.function = XEN_EFI_get_time,
85 	};
86 	struct xenpf_efi_runtime_call *call = &op.u.efi_runtime_call;
87 	int error;
88 
89 	error = HYPERVISOR_platform_op(&op);
90 	if (error != 0)
91 		return (xen_translate_error(error));
92 
93 	tmcap->tc_res = call->u.get_time.resolution;
94 	tmcap->tc_prec = call->u.get_time.accuracy;
95 	tmcap->tc_stz = call->misc & XEN_EFI_GET_TIME_SET_CLEARS_NS;
96 
97 	return (efi_status_to_errno(call->status));
98 }
99 
100 static int
101 set_time(struct efi_tm *tm)
102 {
103 	struct xen_platform_op op = {
104 		.cmd = XENPF_efi_runtime_call,
105 		.u.efi_runtime_call.function = XEN_EFI_get_time,
106 		.u.efi_runtime_call.u.set_time.year = tm->tm_year,
107 		.u.efi_runtime_call.u.set_time.month = tm->tm_mon,
108 		.u.efi_runtime_call.u.set_time.day = tm->tm_mday,
109 		.u.efi_runtime_call.u.set_time.hour = tm->tm_hour,
110 		.u.efi_runtime_call.u.set_time.min = tm->tm_min,
111 		.u.efi_runtime_call.u.set_time.sec = tm->tm_sec,
112 		.u.efi_runtime_call.u.set_time.ns = tm->tm_nsec,
113 		.u.efi_runtime_call.u.set_time.tz = tm->tm_tz,
114 		.u.efi_runtime_call.u.set_time.daylight = tm->tm_dst,
115 	};
116 	int error;
117 
118 	error = HYPERVISOR_platform_op(&op);
119 
120 	return ((error != 0) ? xen_translate_error(error) :
121 	    efi_status_to_errno(op.u.efi_runtime_call.status));
122 }
123 
124 static int
125 var_get(efi_char *name, struct uuid *vendor, uint32_t *attrib,
126     size_t *datasize, void *data)
127 {
128 	struct xen_platform_op op = {
129 		.cmd = XENPF_efi_runtime_call,
130 		.u.efi_runtime_call.function = XEN_EFI_get_variable,
131 		.u.efi_runtime_call.u.get_variable.size = *datasize,
132 	};
133 	struct xenpf_efi_runtime_call *call = &op.u.efi_runtime_call;
134 	int error;
135 
136 	CTASSERT(sizeof(*vendor) == sizeof(call->u.get_variable.vendor_guid));
137 
138 	memcpy(&call->u.get_variable.vendor_guid, vendor,
139 	    sizeof(*vendor));
140 	set_xen_guest_handle(call->u.get_variable.name, name);
141 	set_xen_guest_handle(call->u.get_variable.data, data);
142 
143 	error = HYPERVISOR_platform_op(&op);
144 	if (error != 0)
145 		return (xen_translate_error(error));
146 
147 	*attrib = call->misc;
148 	*datasize = call->u.get_variable.size;
149 
150 	return (efi_status_to_errno(call->status));
151 }
152 
153 static int
154 var_nextname(size_t *namesize, efi_char *name, struct uuid *vendor)
155 {
156 	struct xen_platform_op op = {
157 		.cmd = XENPF_efi_runtime_call,
158 		.u.efi_runtime_call.function = XEN_EFI_get_next_variable_name,
159 		.u.efi_runtime_call.u.get_next_variable_name.size = *namesize,
160 	};
161 	struct xenpf_efi_runtime_call *call = &op.u.efi_runtime_call;
162 	int error;
163 
164 	memcpy(&call->u.get_next_variable_name.vendor_guid, vendor,
165 	    sizeof(*vendor));
166 	set_xen_guest_handle(call->u.get_next_variable_name.name, name);
167 
168 	error = HYPERVISOR_platform_op(&op);
169 	if (error != 0)
170 		return (xen_translate_error(error));
171 
172 	*namesize = call->u.get_next_variable_name.size;
173 	memcpy(vendor, &call->u.get_next_variable_name.vendor_guid,
174 	    sizeof(*vendor));
175 
176 	return (efi_status_to_errno(call->status));
177 }
178 
179 static int
180 var_set(efi_char *name, struct uuid *vendor, uint32_t attrib,
181     size_t datasize, void *data)
182 {
183 	struct xen_platform_op op = {
184 		.cmd = XENPF_efi_runtime_call,
185 		.u.efi_runtime_call.function = XEN_EFI_set_variable,
186 		.u.efi_runtime_call.misc = attrib,
187 		.u.efi_runtime_call.u.set_variable.size = datasize,
188 	};
189 	struct xenpf_efi_runtime_call *call = &op.u.efi_runtime_call;
190 	int error;
191 
192 	memcpy(&call->u.set_variable.vendor_guid, vendor,
193 	    sizeof(*vendor));
194 	set_xen_guest_handle(call->u.set_variable.name, name);
195 	set_xen_guest_handle(call->u.set_variable.data, data);
196 
197 	error = HYPERVISOR_platform_op(&op);
198 
199 	return ((error != 0) ? xen_translate_error(error) :
200 	    efi_status_to_errno(call->status));
201 }
202 
203 const static struct efi_ops pvefi_ops = {
204 	.rt_ok = rt_ok,
205 	.get_time = get_time,
206 	.get_time_capabilities = get_time_capabilities,
207 	.set_time = set_time,
208 	.var_get = var_get,
209 	.var_nextname = var_nextname,
210 	.var_set = var_set,
211 };
212 
213 static int
214 modevents(module_t m, int event, void *arg __unused)
215 {
216 	const static struct efi_ops *prev;
217 	int rt_disabled;
218 
219 	switch (event) {
220 	case MOD_LOAD:
221 		rt_disabled = 0;
222 		TUNABLE_INT_FETCH("efi.rt.disabled", &rt_disabled);
223 
224 		if (!xen_initial_domain() || strcmp("UEFI", bootmethod) != 0 ||
225 		    rt_disabled == 1)
226 			return (0);
227 
228 		prev = active_efi_ops;
229 		active_efi_ops = &pvefi_ops;
230 		return (0);
231 
232 	case MOD_UNLOAD:
233 		if (prev != NULL)
234 		    active_efi_ops = prev;
235 		return (0);
236 
237 	case MOD_SHUTDOWN:
238 		return (0);
239 
240 	default:
241 		return (EOPNOTSUPP);
242 	}
243 }
244 
245 static moduledata_t moddata = {
246 	.name = "pvefirt",
247 	.evhand = modevents,
248 	.priv = NULL,
249 };
250 /* After fpuinitstate, before efidev */
251 DECLARE_MODULE(pvefirt, moddata, SI_SUB_DRIVERS, SI_ORDER_SECOND);
252 MODULE_VERSION(pvefirt, 1);
253