xref: /freebsd/sys/dev/xen/efi/pvefi.c (revision edf8578117e8844e02c0121147f45e4609b30680)
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/cdefs.h>
28 #include <sys/param.h>
29 #include <sys/efi.h>
30 #include <sys/eventhandler.h>
31 #include <sys/kernel.h>
32 #include <sys/linker.h>
33 #include <sys/module.h>
34 #include <sys/clock.h>
35 #include <sys/sysctl.h>
36 #include <sys/systm.h>
37 
38 #include <xen/xen-os.h>
39 #include <xen/error.h>
40 #include <xen/hypervisor.h>
41 
42 #include <contrib/xen/platform.h>
43 
44 extern char bootmethod[16];
45 
46 static int
47 rt_ok(void)
48 {
49 
50 	return (0);
51 }
52 
53 static int
54 get_time(struct efi_tm *tm)
55 {
56 	struct xen_platform_op op = {
57 		.cmd = XENPF_efi_runtime_call,
58 		.u.efi_runtime_call.function = XEN_EFI_get_time,
59 	};
60 	struct xenpf_efi_runtime_call *call = &op.u.efi_runtime_call;
61 	int error;
62 
63 	error = HYPERVISOR_platform_op(&op);
64 	if (error != 0)
65 		return (xen_translate_error(error));
66 
67 	tm->tm_year = call->u.get_time.time.year;
68 	tm->tm_mon = call->u.get_time.time.month;
69 	tm->tm_mday = call->u.get_time.time.day;
70 	tm->tm_hour = call->u.get_time.time.hour;
71 	tm->tm_min = call->u.get_time.time.min;
72 	tm->tm_sec = call->u.get_time.time.sec;
73 	tm->tm_nsec = call->u.get_time.time.ns;
74 	tm->tm_tz = call->u.get_time.time.tz;
75 	tm->tm_dst = call->u.get_time.time.daylight;
76 
77 	return (efi_status_to_errno(call->status));
78 }
79 
80 static int
81 get_time_capabilities(struct efi_tmcap *tmcap)
82 {
83 	struct xen_platform_op op = {
84 		.cmd = XENPF_efi_runtime_call,
85 		.u.efi_runtime_call.function = XEN_EFI_get_time,
86 	};
87 	struct xenpf_efi_runtime_call *call = &op.u.efi_runtime_call;
88 	int error;
89 
90 	error = HYPERVISOR_platform_op(&op);
91 	if (error != 0)
92 		return (xen_translate_error(error));
93 
94 	tmcap->tc_res = call->u.get_time.resolution;
95 	tmcap->tc_prec = call->u.get_time.accuracy;
96 	tmcap->tc_stz = call->misc & XEN_EFI_GET_TIME_SET_CLEARS_NS;
97 
98 	return (efi_status_to_errno(call->status));
99 }
100 
101 static int
102 set_time(struct efi_tm *tm)
103 {
104 	struct xen_platform_op op = {
105 		.cmd = XENPF_efi_runtime_call,
106 		.u.efi_runtime_call.function = XEN_EFI_get_time,
107 		.u.efi_runtime_call.u.set_time.year = tm->tm_year,
108 		.u.efi_runtime_call.u.set_time.month = tm->tm_mon,
109 		.u.efi_runtime_call.u.set_time.day = tm->tm_mday,
110 		.u.efi_runtime_call.u.set_time.hour = tm->tm_hour,
111 		.u.efi_runtime_call.u.set_time.min = tm->tm_min,
112 		.u.efi_runtime_call.u.set_time.sec = tm->tm_sec,
113 		.u.efi_runtime_call.u.set_time.ns = tm->tm_nsec,
114 		.u.efi_runtime_call.u.set_time.tz = tm->tm_tz,
115 		.u.efi_runtime_call.u.set_time.daylight = tm->tm_dst,
116 	};
117 	int error;
118 
119 	error = HYPERVISOR_platform_op(&op);
120 
121 	return ((error != 0) ? xen_translate_error(error) :
122 	    efi_status_to_errno(op.u.efi_runtime_call.status));
123 }
124 
125 static int
126 var_get(efi_char *name, struct uuid *vendor, uint32_t *attrib,
127     size_t *datasize, void *data)
128 {
129 	struct xen_platform_op op = {
130 		.cmd = XENPF_efi_runtime_call,
131 		.u.efi_runtime_call.function = XEN_EFI_get_variable,
132 		.u.efi_runtime_call.u.get_variable.size = *datasize,
133 	};
134 	struct xenpf_efi_runtime_call *call = &op.u.efi_runtime_call;
135 	int error;
136 
137 	CTASSERT(sizeof(*vendor) == sizeof(call->u.get_variable.vendor_guid));
138 
139 	memcpy(&call->u.get_variable.vendor_guid, vendor,
140 	    sizeof(*vendor));
141 	set_xen_guest_handle(call->u.get_variable.name, name);
142 	set_xen_guest_handle(call->u.get_variable.data, data);
143 
144 	error = HYPERVISOR_platform_op(&op);
145 	if (error != 0)
146 		return (xen_translate_error(error));
147 
148 	*attrib = call->misc;
149 	*datasize = call->u.get_variable.size;
150 
151 	return (efi_status_to_errno(call->status));
152 }
153 
154 static int
155 var_nextname(size_t *namesize, efi_char *name, struct uuid *vendor)
156 {
157 	struct xen_platform_op op = {
158 		.cmd = XENPF_efi_runtime_call,
159 		.u.efi_runtime_call.function = XEN_EFI_get_next_variable_name,
160 		.u.efi_runtime_call.u.get_next_variable_name.size = *namesize,
161 	};
162 	struct xenpf_efi_runtime_call *call = &op.u.efi_runtime_call;
163 	int error;
164 
165 	memcpy(&call->u.get_next_variable_name.vendor_guid, vendor,
166 	    sizeof(*vendor));
167 	set_xen_guest_handle(call->u.get_next_variable_name.name, name);
168 
169 	error = HYPERVISOR_platform_op(&op);
170 	if (error != 0)
171 		return (xen_translate_error(error));
172 
173 	*namesize = call->u.get_next_variable_name.size;
174 	memcpy(vendor, &call->u.get_next_variable_name.vendor_guid,
175 	    sizeof(*vendor));
176 
177 	return (efi_status_to_errno(call->status));
178 }
179 
180 static int
181 var_set(efi_char *name, struct uuid *vendor, uint32_t attrib,
182     size_t datasize, void *data)
183 {
184 	struct xen_platform_op op = {
185 		.cmd = XENPF_efi_runtime_call,
186 		.u.efi_runtime_call.function = XEN_EFI_set_variable,
187 		.u.efi_runtime_call.misc = attrib,
188 		.u.efi_runtime_call.u.set_variable.size = datasize,
189 	};
190 	struct xenpf_efi_runtime_call *call = &op.u.efi_runtime_call;
191 	int error;
192 
193 	memcpy(&call->u.set_variable.vendor_guid, vendor,
194 	    sizeof(*vendor));
195 	set_xen_guest_handle(call->u.set_variable.name, name);
196 	set_xen_guest_handle(call->u.set_variable.data, data);
197 
198 	error = HYPERVISOR_platform_op(&op);
199 
200 	return ((error != 0) ? xen_translate_error(error) :
201 	    efi_status_to_errno(call->status));
202 }
203 
204 const static struct efi_ops pvefi_ops = {
205 	.rt_ok = rt_ok,
206 	.get_time = get_time,
207 	.get_time_capabilities = get_time_capabilities,
208 	.set_time = set_time,
209 	.var_get = var_get,
210 	.var_nextname = var_nextname,
211 	.var_set = var_set,
212 };
213 
214 static int
215 modevents(module_t m, int event, void *arg __unused)
216 {
217 	const static struct efi_ops *prev;
218 	int rt_disabled;
219 
220 	switch (event) {
221 	case MOD_LOAD:
222 		rt_disabled = 0;
223 		TUNABLE_INT_FETCH("efi.rt.disabled", &rt_disabled);
224 
225 		if (!xen_initial_domain() || strcmp("UEFI", bootmethod) != 0 ||
226 		    rt_disabled == 1)
227 			return (0);
228 
229 		prev = active_efi_ops;
230 		active_efi_ops = &pvefi_ops;
231 		return (0);
232 
233 	case MOD_UNLOAD:
234 		if (prev != NULL)
235 		    active_efi_ops = prev;
236 		return (0);
237 
238 	case MOD_SHUTDOWN:
239 		return (0);
240 
241 	default:
242 		return (EOPNOTSUPP);
243 	}
244 }
245 
246 static moduledata_t moddata = {
247 	.name = "pvefirt",
248 	.evhand = modevents,
249 	.priv = NULL,
250 };
251 /* After fpuinitstate, before efidev */
252 DECLARE_MODULE(pvefirt, moddata, SI_SUB_DRIVERS, SI_ORDER_SECOND);
253 MODULE_VERSION(pvefirt, 1);
254