xref: /freebsd/sys/dev/xen/efi/pvefi.c (revision 5aa839c9e2c373275091b8bf529c1311d0b84d76)
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  __FBSDID("$FreeBSD$");
29  
30  #include <sys/param.h>
31  #include <sys/efi.h>
32  #include <sys/eventhandler.h>
33  #include <sys/kernel.h>
34  #include <sys/linker.h>
35  #include <sys/module.h>
36  #include <sys/clock.h>
37  #include <sys/sysctl.h>
38  #include <sys/systm.h>
39  
40  #include <xen/xen-os.h>
41  #include <xen/error.h>
42  #include <xen/hypervisor.h>
43  
44  #include <contrib/xen/platform.h>
45  
46  extern char bootmethod[16];
47  
48  static int
49  rt_ok(void)
50  {
51  
52  	return (0);
53  }
54  
55  static int
56  get_time(struct efi_tm *tm)
57  {
58  	struct xen_platform_op op = {
59  		.cmd = XENPF_efi_runtime_call,
60  		.u.efi_runtime_call.function = XEN_EFI_get_time,
61  	};
62  	struct xenpf_efi_runtime_call *call = &op.u.efi_runtime_call;
63  	int error;
64  
65  	error = HYPERVISOR_platform_op(&op);
66  	if (error != 0)
67  		return (xen_translate_error(error));
68  
69  	tm->tm_year = call->u.get_time.time.year;
70  	tm->tm_mon = call->u.get_time.time.month;
71  	tm->tm_mday = call->u.get_time.time.day;
72  	tm->tm_hour = call->u.get_time.time.hour;
73  	tm->tm_min = call->u.get_time.time.min;
74  	tm->tm_sec = call->u.get_time.time.sec;
75  	tm->tm_nsec = call->u.get_time.time.ns;
76  	tm->tm_tz = call->u.get_time.time.tz;
77  	tm->tm_dst = call->u.get_time.time.daylight;
78  
79  	return (efi_status_to_errno(call->status));
80  }
81  
82  static int
83  get_time_capabilities(struct efi_tmcap *tmcap)
84  {
85  	struct xen_platform_op op = {
86  		.cmd = XENPF_efi_runtime_call,
87  		.u.efi_runtime_call.function = XEN_EFI_get_time,
88  	};
89  	struct xenpf_efi_runtime_call *call = &op.u.efi_runtime_call;
90  	int error;
91  
92  	error = HYPERVISOR_platform_op(&op);
93  	if (error != 0)
94  		return (xen_translate_error(error));
95  
96  	tmcap->tc_res = call->u.get_time.resolution;
97  	tmcap->tc_prec = call->u.get_time.accuracy;
98  	tmcap->tc_stz = call->misc & XEN_EFI_GET_TIME_SET_CLEARS_NS;
99  
100  	return (efi_status_to_errno(call->status));
101  }
102  
103  static int
104  set_time(struct efi_tm *tm)
105  {
106  	struct xen_platform_op op = {
107  		.cmd = XENPF_efi_runtime_call,
108  		.u.efi_runtime_call.function = XEN_EFI_get_time,
109  		.u.efi_runtime_call.u.set_time.year = tm->tm_year,
110  		.u.efi_runtime_call.u.set_time.month = tm->tm_mon,
111  		.u.efi_runtime_call.u.set_time.day = tm->tm_mday,
112  		.u.efi_runtime_call.u.set_time.hour = tm->tm_hour,
113  		.u.efi_runtime_call.u.set_time.min = tm->tm_min,
114  		.u.efi_runtime_call.u.set_time.sec = tm->tm_sec,
115  		.u.efi_runtime_call.u.set_time.ns = tm->tm_nsec,
116  		.u.efi_runtime_call.u.set_time.tz = tm->tm_tz,
117  		.u.efi_runtime_call.u.set_time.daylight = tm->tm_dst,
118  	};
119  	int error;
120  
121  	error = HYPERVISOR_platform_op(&op);
122  
123  	return ((error != 0) ? xen_translate_error(error) :
124  	    efi_status_to_errno(op.u.efi_runtime_call.status));
125  }
126  
127  static int
128  var_get(efi_char *name, struct uuid *vendor, uint32_t *attrib,
129      size_t *datasize, void *data)
130  {
131  	struct xen_platform_op op = {
132  		.cmd = XENPF_efi_runtime_call,
133  		.u.efi_runtime_call.function = XEN_EFI_get_variable,
134  		.u.efi_runtime_call.u.get_variable.size = *datasize,
135  	};
136  	struct xenpf_efi_runtime_call *call = &op.u.efi_runtime_call;
137  	int error;
138  
139  	CTASSERT(sizeof(*vendor) == sizeof(call->u.get_variable.vendor_guid));
140  
141  	memcpy(&call->u.get_variable.vendor_guid, vendor,
142  	    sizeof(*vendor));
143  	set_xen_guest_handle(call->u.get_variable.name, name);
144  	set_xen_guest_handle(call->u.get_variable.data, data);
145  
146  	error = HYPERVISOR_platform_op(&op);
147  	if (error != 0)
148  		return (xen_translate_error(error));
149  
150  	*attrib = call->misc;
151  	*datasize = call->u.get_variable.size;
152  
153  	return (efi_status_to_errno(call->status));
154  }
155  
156  static int
157  var_nextname(size_t *namesize, efi_char *name, struct uuid *vendor)
158  {
159  	struct xen_platform_op op = {
160  		.cmd = XENPF_efi_runtime_call,
161  		.u.efi_runtime_call.function = XEN_EFI_get_next_variable_name,
162  		.u.efi_runtime_call.u.get_next_variable_name.size = *namesize,
163  	};
164  	struct xenpf_efi_runtime_call *call = &op.u.efi_runtime_call;
165  	int error;
166  
167  	memcpy(&call->u.get_next_variable_name.vendor_guid, vendor,
168  	    sizeof(*vendor));
169  	set_xen_guest_handle(call->u.get_next_variable_name.name, name);
170  
171  	error = HYPERVISOR_platform_op(&op);
172  	if (error != 0)
173  		return (xen_translate_error(error));
174  
175  	*namesize = call->u.get_next_variable_name.size;
176  	memcpy(vendor, &call->u.get_next_variable_name.vendor_guid,
177  	    sizeof(*vendor));
178  
179  	return (efi_status_to_errno(call->status));
180  }
181  
182  static int
183  var_set(efi_char *name, struct uuid *vendor, uint32_t attrib,
184      size_t datasize, void *data)
185  {
186  	struct xen_platform_op op = {
187  		.cmd = XENPF_efi_runtime_call,
188  		.u.efi_runtime_call.function = XEN_EFI_set_variable,
189  		.u.efi_runtime_call.misc = attrib,
190  		.u.efi_runtime_call.u.set_variable.size = datasize,
191  	};
192  	struct xenpf_efi_runtime_call *call = &op.u.efi_runtime_call;
193  	int error;
194  
195  	memcpy(&call->u.set_variable.vendor_guid, vendor,
196  	    sizeof(*vendor));
197  	set_xen_guest_handle(call->u.set_variable.name, name);
198  	set_xen_guest_handle(call->u.set_variable.data, data);
199  
200  	error = HYPERVISOR_platform_op(&op);
201  
202  	return ((error != 0) ? xen_translate_error(error) :
203  	    efi_status_to_errno(call->status));
204  }
205  
206  const static struct efi_ops pvefi_ops = {
207  	.rt_ok = rt_ok,
208  	.get_time = get_time,
209  	.get_time_capabilities = get_time_capabilities,
210  	.set_time = set_time,
211  	.var_get = var_get,
212  	.var_nextname = var_nextname,
213  	.var_set = var_set,
214  };
215  
216  static int
217  modevents(module_t m, int event, void *arg __unused)
218  {
219  	const static struct efi_ops *prev;
220  	int rt_disabled;
221  
222  	switch (event) {
223  	case MOD_LOAD:
224  		rt_disabled = 0;
225  		TUNABLE_INT_FETCH("efi.rt.disabled", &rt_disabled);
226  
227  		if (!xen_initial_domain() || strcmp("UEFI", bootmethod) != 0 ||
228  		    rt_disabled == 1)
229  			return (0);
230  
231  		prev = active_efi_ops;
232  		active_efi_ops = &pvefi_ops;
233  		return (0);
234  
235  	case MOD_UNLOAD:
236  		if (prev != NULL)
237  		    active_efi_ops = prev;
238  		return (0);
239  
240  	case MOD_SHUTDOWN:
241  		return (0);
242  
243  	default:
244  		return (EOPNOTSUPP);
245  	}
246  }
247  
248  static moduledata_t moddata = {
249  	.name = "pvefirt",
250  	.evhand = modevents,
251  	.priv = NULL,
252  };
253  /* After fpuinitstate, before efidev */
254  DECLARE_MODULE(pvefirt, moddata, SI_SUB_DRIVERS, SI_ORDER_SECOND);
255  MODULE_VERSION(pvefirt, 1);
256