xref: /openbmc/qemu/backends/tpm/tpm_backend.c (revision ffe98631)
1 /*
2  * QEMU TPM Backend
3  *
4  * Copyright IBM, Corp. 2013
5  *
6  * Authors:
7  *  Stefan Berger   <stefanb@us.ibm.com>
8  *
9  * This work is licensed under the terms of the GNU GPL, version 2 or later.
10  * See the COPYING file in the top-level directory.
11  *
12  * Based on backends/rng.c by Anthony Liguori
13  */
14 
15 #include "qemu/osdep.h"
16 #include "sysemu/tpm_backend.h"
17 #include "qapi/error.h"
18 #include "sysemu/tpm.h"
19 #include "qemu/thread.h"
20 #include "qemu/main-loop.h"
21 #include "qemu/module.h"
22 #include "block/thread-pool.h"
23 #include "qemu/error-report.h"
24 
25 static void tpm_backend_request_completed(void *opaque, int ret)
26 {
27     TPMBackend *s = TPM_BACKEND(opaque);
28     TPMIfClass *tic = TPM_IF_GET_CLASS(s->tpmif);
29 
30     tic->request_completed(s->tpmif, ret);
31 
32     /* no need for atomic, as long the BQL is taken */
33     s->cmd = NULL;
34     object_unref(OBJECT(s));
35 }
36 
37 static int tpm_backend_worker_thread(gpointer data)
38 {
39     TPMBackend *s = TPM_BACKEND(data);
40     TPMBackendClass *k = TPM_BACKEND_GET_CLASS(s);
41     Error *err = NULL;
42 
43     k->handle_request(s, s->cmd, &err);
44     if (err) {
45         error_report_err(err);
46         return -1;
47     }
48 
49     return 0;
50 }
51 
52 void tpm_backend_finish_sync(TPMBackend *s)
53 {
54     while (s->cmd) {
55         aio_poll(qemu_get_aio_context(), true);
56     }
57 }
58 
59 enum TpmType tpm_backend_get_type(TPMBackend *s)
60 {
61     TPMBackendClass *k = TPM_BACKEND_GET_CLASS(s);
62 
63     return k->type;
64 }
65 
66 int tpm_backend_init(TPMBackend *s, TPMIf *tpmif, Error **errp)
67 {
68     if (s->tpmif) {
69         error_setg(errp, "TPM backend '%s' is already initialized", s->id);
70         return -1;
71     }
72 
73     s->tpmif = tpmif;
74     object_ref(OBJECT(tpmif));
75 
76     s->had_startup_error = false;
77 
78     return 0;
79 }
80 
81 int tpm_backend_startup_tpm(TPMBackend *s, size_t buffersize)
82 {
83     int res = 0;
84     TPMBackendClass *k = TPM_BACKEND_GET_CLASS(s);
85 
86     /* terminate a running TPM */
87     tpm_backend_finish_sync(s);
88 
89     res = k->startup_tpm ? k->startup_tpm(s, buffersize) : 0;
90 
91     s->had_startup_error = (res != 0);
92 
93     return res;
94 }
95 
96 bool tpm_backend_had_startup_error(TPMBackend *s)
97 {
98     return s->had_startup_error;
99 }
100 
101 void tpm_backend_deliver_request(TPMBackend *s, TPMBackendCmd *cmd)
102 {
103     ThreadPool *pool = aio_get_thread_pool(qemu_get_aio_context());
104 
105     if (s->cmd != NULL) {
106         error_report("There is a TPM request pending");
107         return;
108     }
109 
110     s->cmd = cmd;
111     object_ref(OBJECT(s));
112     thread_pool_submit_aio(pool, tpm_backend_worker_thread, s,
113                            tpm_backend_request_completed, s);
114 }
115 
116 void tpm_backend_reset(TPMBackend *s)
117 {
118     TPMBackendClass *k = TPM_BACKEND_GET_CLASS(s);
119 
120     if (k->reset) {
121         k->reset(s);
122     }
123 
124     tpm_backend_finish_sync(s);
125 
126     s->had_startup_error = false;
127 }
128 
129 void tpm_backend_cancel_cmd(TPMBackend *s)
130 {
131     TPMBackendClass *k = TPM_BACKEND_GET_CLASS(s);
132 
133     k->cancel_cmd(s);
134 }
135 
136 bool tpm_backend_get_tpm_established_flag(TPMBackend *s)
137 {
138     TPMBackendClass *k = TPM_BACKEND_GET_CLASS(s);
139 
140     return k->get_tpm_established_flag ?
141            k->get_tpm_established_flag(s) : false;
142 }
143 
144 int tpm_backend_reset_tpm_established_flag(TPMBackend *s, uint8_t locty)
145 {
146     TPMBackendClass *k = TPM_BACKEND_GET_CLASS(s);
147 
148     return k->reset_tpm_established_flag ?
149            k->reset_tpm_established_flag(s, locty) : 0;
150 }
151 
152 TPMVersion tpm_backend_get_tpm_version(TPMBackend *s)
153 {
154     TPMBackendClass *k = TPM_BACKEND_GET_CLASS(s);
155 
156     return k->get_tpm_version(s);
157 }
158 
159 size_t tpm_backend_get_buffer_size(TPMBackend *s)
160 {
161     TPMBackendClass *k = TPM_BACKEND_GET_CLASS(s);
162 
163     return k->get_buffer_size(s);
164 }
165 
166 TPMInfo *tpm_backend_query_tpm(TPMBackend *s)
167 {
168     TPMInfo *info = g_new0(TPMInfo, 1);
169     TPMBackendClass *k = TPM_BACKEND_GET_CLASS(s);
170     TPMIfClass *tic = TPM_IF_GET_CLASS(s->tpmif);
171 
172     info->id = g_strdup(s->id);
173     info->model = tic->model;
174     info->options = k->get_tpm_options(s);
175 
176     return info;
177 }
178 
179 static void tpm_backend_instance_finalize(Object *obj)
180 {
181     TPMBackend *s = TPM_BACKEND(obj);
182 
183     object_unref(OBJECT(s->tpmif));
184     g_free(s->id);
185 }
186 
187 static const TypeInfo tpm_backend_info = {
188     .name = TYPE_TPM_BACKEND,
189     .parent = TYPE_OBJECT,
190     .instance_size = sizeof(TPMBackend),
191     .instance_finalize = tpm_backend_instance_finalize,
192     .class_size = sizeof(TPMBackendClass),
193     .abstract = true,
194 };
195 
196 static const TypeInfo tpm_if_info = {
197     .name = TYPE_TPM_IF,
198     .parent = TYPE_INTERFACE,
199     .class_size = sizeof(TPMIfClass),
200 };
201 
202 static void register_types(void)
203 {
204     type_register_static(&tpm_backend_info);
205     type_register_static(&tpm_if_info);
206 }
207 
208 type_init(register_types);
209