xref: /openbmc/qemu/hw/tpm/tpm_crb.c (revision eab15862)
1 /*
2  * tpm_crb.c - QEMU's TPM CRB interface emulator
3  *
4  * Copyright (c) 2018 Red Hat, Inc.
5  *
6  * Authors:
7  *   Marc-André Lureau <marcandre.lureau@redhat.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  * tpm_crb is a device for TPM 2.0 Command Response Buffer (CRB) Interface
13  * as defined in TCG PC Client Platform TPM Profile (PTP) Specification
14  * Family “2.0” Level 00 Revision 01.03 v22
15  */
16 
17 #include "qemu/osdep.h"
18 
19 #include "qemu-common.h"
20 #include "qapi/error.h"
21 #include "exec/address-spaces.h"
22 
23 #include "hw/qdev-core.h"
24 #include "hw/qdev-properties.h"
25 #include "hw/pci/pci_ids.h"
26 #include "hw/acpi/tpm.h"
27 #include "migration/vmstate.h"
28 #include "sysemu/tpm_backend.h"
29 #include "sysemu/reset.h"
30 #include "tpm_int.h"
31 #include "tpm_util.h"
32 #include "trace.h"
33 
34 typedef struct CRBState {
35     DeviceState parent_obj;
36 
37     TPMBackend *tpmbe;
38     TPMBackendCmd cmd;
39     uint32_t regs[TPM_CRB_R_MAX];
40     MemoryRegion mmio;
41     MemoryRegion cmdmem;
42 
43     size_t be_buffer_size;
44 } CRBState;
45 
46 #define CRB(obj) OBJECT_CHECK(CRBState, (obj), TYPE_TPM_CRB)
47 
48 #define CRB_INTF_TYPE_CRB_ACTIVE 0b1
49 #define CRB_INTF_VERSION_CRB 0b1
50 #define CRB_INTF_CAP_LOCALITY_0_ONLY 0b0
51 #define CRB_INTF_CAP_IDLE_FAST 0b0
52 #define CRB_INTF_CAP_XFER_SIZE_64 0b11
53 #define CRB_INTF_CAP_FIFO_NOT_SUPPORTED 0b0
54 #define CRB_INTF_CAP_CRB_SUPPORTED 0b1
55 #define CRB_INTF_IF_SELECTOR_CRB 0b1
56 
57 #define CRB_CTRL_CMD_SIZE (TPM_CRB_ADDR_SIZE - A_CRB_DATA_BUFFER)
58 
59 enum crb_loc_ctrl {
60     CRB_LOC_CTRL_REQUEST_ACCESS = BIT(0),
61     CRB_LOC_CTRL_RELINQUISH = BIT(1),
62     CRB_LOC_CTRL_SEIZE = BIT(2),
63     CRB_LOC_CTRL_RESET_ESTABLISHMENT_BIT = BIT(3),
64 };
65 
66 enum crb_ctrl_req {
67     CRB_CTRL_REQ_CMD_READY = BIT(0),
68     CRB_CTRL_REQ_GO_IDLE = BIT(1),
69 };
70 
71 enum crb_start {
72     CRB_START_INVOKE = BIT(0),
73 };
74 
75 enum crb_cancel {
76     CRB_CANCEL_INVOKE = BIT(0),
77 };
78 
79 static uint64_t tpm_crb_mmio_read(void *opaque, hwaddr addr,
80                                   unsigned size)
81 {
82     CRBState *s = CRB(opaque);
83     void *regs = (void *)&s->regs + (addr & ~3);
84     unsigned offset = addr & 3;
85     uint32_t val = *(uint32_t *)regs >> (8 * offset);
86 
87     switch (addr) {
88     case A_CRB_LOC_STATE:
89         val |= !tpm_backend_get_tpm_established_flag(s->tpmbe);
90         break;
91     }
92 
93     trace_tpm_crb_mmio_read(addr, size, val);
94 
95     return val;
96 }
97 
98 static void tpm_crb_mmio_write(void *opaque, hwaddr addr,
99                                uint64_t val, unsigned size)
100 {
101     CRBState *s = CRB(opaque);
102 
103     trace_tpm_crb_mmio_write(addr, size, val);
104 
105     switch (addr) {
106     case A_CRB_CTRL_REQ:
107         switch (val) {
108         case CRB_CTRL_REQ_CMD_READY:
109             ARRAY_FIELD_DP32(s->regs, CRB_CTRL_STS,
110                              tpmIdle, 0);
111             break;
112         case CRB_CTRL_REQ_GO_IDLE:
113             ARRAY_FIELD_DP32(s->regs, CRB_CTRL_STS,
114                              tpmIdle, 1);
115             break;
116         }
117         break;
118     case A_CRB_CTRL_CANCEL:
119         if (val == CRB_CANCEL_INVOKE &&
120             s->regs[R_CRB_CTRL_START] & CRB_START_INVOKE) {
121             tpm_backend_cancel_cmd(s->tpmbe);
122         }
123         break;
124     case A_CRB_CTRL_START:
125         if (val == CRB_START_INVOKE &&
126             !(s->regs[R_CRB_CTRL_START] & CRB_START_INVOKE)) {
127             void *mem = memory_region_get_ram_ptr(&s->cmdmem);
128 
129             s->regs[R_CRB_CTRL_START] |= CRB_START_INVOKE;
130             s->cmd = (TPMBackendCmd) {
131                 .in = mem,
132                 .in_len = MIN(tpm_cmd_get_size(mem), s->be_buffer_size),
133                 .out = mem,
134                 .out_len = s->be_buffer_size,
135             };
136 
137             tpm_backend_deliver_request(s->tpmbe, &s->cmd);
138         }
139         break;
140     case A_CRB_LOC_CTRL:
141         switch (val) {
142         case CRB_LOC_CTRL_RESET_ESTABLISHMENT_BIT:
143             /* not loc 3 or 4 */
144             break;
145         case CRB_LOC_CTRL_RELINQUISH:
146             ARRAY_FIELD_DP32(s->regs, CRB_LOC_STATE,
147                              locAssigned, 0);
148             break;
149         case CRB_LOC_CTRL_REQUEST_ACCESS:
150             ARRAY_FIELD_DP32(s->regs, CRB_LOC_STS,
151                              Granted, 1);
152             ARRAY_FIELD_DP32(s->regs, CRB_LOC_STS,
153                              beenSeized, 0);
154             ARRAY_FIELD_DP32(s->regs, CRB_LOC_STATE,
155                              locAssigned, 1);
156             break;
157         }
158         break;
159     }
160 }
161 
162 static const MemoryRegionOps tpm_crb_memory_ops = {
163     .read = tpm_crb_mmio_read,
164     .write = tpm_crb_mmio_write,
165     .endianness = DEVICE_LITTLE_ENDIAN,
166     .valid = {
167         .min_access_size = 1,
168         .max_access_size = 4,
169     },
170 };
171 
172 static void tpm_crb_request_completed(TPMIf *ti, int ret)
173 {
174     CRBState *s = CRB(ti);
175 
176     s->regs[R_CRB_CTRL_START] &= ~CRB_START_INVOKE;
177     if (ret != 0) {
178         ARRAY_FIELD_DP32(s->regs, CRB_CTRL_STS,
179                          tpmSts, 1); /* fatal error */
180     }
181 }
182 
183 static enum TPMVersion tpm_crb_get_version(TPMIf *ti)
184 {
185     CRBState *s = CRB(ti);
186 
187     return tpm_backend_get_tpm_version(s->tpmbe);
188 }
189 
190 static int tpm_crb_pre_save(void *opaque)
191 {
192     CRBState *s = opaque;
193 
194     tpm_backend_finish_sync(s->tpmbe);
195 
196     return 0;
197 }
198 
199 static const VMStateDescription vmstate_tpm_crb = {
200     .name = "tpm-crb",
201     .pre_save = tpm_crb_pre_save,
202     .fields = (VMStateField[]) {
203         VMSTATE_UINT32_ARRAY(regs, CRBState, TPM_CRB_R_MAX),
204         VMSTATE_END_OF_LIST(),
205     }
206 };
207 
208 static Property tpm_crb_properties[] = {
209     DEFINE_PROP_TPMBE("tpmdev", CRBState, tpmbe),
210     DEFINE_PROP_END_OF_LIST(),
211 };
212 
213 static void tpm_crb_reset(void *dev)
214 {
215     CRBState *s = CRB(dev);
216 
217     tpm_backend_reset(s->tpmbe);
218 
219     memset(s->regs, 0, sizeof(s->regs));
220 
221     ARRAY_FIELD_DP32(s->regs, CRB_LOC_STATE,
222                      tpmRegValidSts, 1);
223     ARRAY_FIELD_DP32(s->regs, CRB_INTF_ID,
224                      InterfaceType, CRB_INTF_TYPE_CRB_ACTIVE);
225     ARRAY_FIELD_DP32(s->regs, CRB_INTF_ID,
226                      InterfaceVersion, CRB_INTF_VERSION_CRB);
227     ARRAY_FIELD_DP32(s->regs, CRB_INTF_ID,
228                      CapLocality, CRB_INTF_CAP_LOCALITY_0_ONLY);
229     ARRAY_FIELD_DP32(s->regs, CRB_INTF_ID,
230                      CapCRBIdleBypass, CRB_INTF_CAP_IDLE_FAST);
231     ARRAY_FIELD_DP32(s->regs, CRB_INTF_ID,
232                      CapDataXferSizeSupport, CRB_INTF_CAP_XFER_SIZE_64);
233     ARRAY_FIELD_DP32(s->regs, CRB_INTF_ID,
234                      CapFIFO, CRB_INTF_CAP_FIFO_NOT_SUPPORTED);
235     ARRAY_FIELD_DP32(s->regs, CRB_INTF_ID,
236                      CapCRB, CRB_INTF_CAP_CRB_SUPPORTED);
237     ARRAY_FIELD_DP32(s->regs, CRB_INTF_ID,
238                      InterfaceSelector, CRB_INTF_IF_SELECTOR_CRB);
239     ARRAY_FIELD_DP32(s->regs, CRB_INTF_ID,
240                      RID, 0b0000);
241     ARRAY_FIELD_DP32(s->regs, CRB_INTF_ID2,
242                      VID, PCI_VENDOR_ID_IBM);
243 
244     s->regs[R_CRB_CTRL_CMD_SIZE] = CRB_CTRL_CMD_SIZE;
245     s->regs[R_CRB_CTRL_CMD_LADDR] = TPM_CRB_ADDR_BASE + A_CRB_DATA_BUFFER;
246     s->regs[R_CRB_CTRL_RSP_SIZE] = CRB_CTRL_CMD_SIZE;
247     s->regs[R_CRB_CTRL_RSP_ADDR] = TPM_CRB_ADDR_BASE + A_CRB_DATA_BUFFER;
248 
249     s->be_buffer_size = MIN(tpm_backend_get_buffer_size(s->tpmbe),
250                             CRB_CTRL_CMD_SIZE);
251 
252     tpm_backend_startup_tpm(s->tpmbe, s->be_buffer_size);
253 }
254 
255 static void tpm_crb_realize(DeviceState *dev, Error **errp)
256 {
257     CRBState *s = CRB(dev);
258 
259     if (!tpm_find()) {
260         error_setg(errp, "at most one TPM device is permitted");
261         return;
262     }
263     if (!s->tpmbe) {
264         error_setg(errp, "'tpmdev' property is required");
265         return;
266     }
267 
268     memory_region_init_io(&s->mmio, OBJECT(s), &tpm_crb_memory_ops, s,
269         "tpm-crb-mmio", sizeof(s->regs));
270     memory_region_init_ram(&s->cmdmem, OBJECT(s),
271         "tpm-crb-cmd", CRB_CTRL_CMD_SIZE, errp);
272 
273     memory_region_add_subregion(get_system_memory(),
274         TPM_CRB_ADDR_BASE, &s->mmio);
275     memory_region_add_subregion(get_system_memory(),
276         TPM_CRB_ADDR_BASE + sizeof(s->regs), &s->cmdmem);
277 
278     qemu_register_reset(tpm_crb_reset, dev);
279 }
280 
281 static void tpm_crb_class_init(ObjectClass *klass, void *data)
282 {
283     DeviceClass *dc = DEVICE_CLASS(klass);
284     TPMIfClass *tc = TPM_IF_CLASS(klass);
285 
286     dc->realize = tpm_crb_realize;
287     dc->props = tpm_crb_properties;
288     dc->vmsd  = &vmstate_tpm_crb;
289     dc->user_creatable = true;
290     tc->model = TPM_MODEL_TPM_CRB;
291     tc->get_version = tpm_crb_get_version;
292     tc->request_completed = tpm_crb_request_completed;
293 
294     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
295 }
296 
297 static const TypeInfo tpm_crb_info = {
298     .name = TYPE_TPM_CRB,
299     /* could be TYPE_SYS_BUS_DEVICE (or LPC etc) */
300     .parent = TYPE_DEVICE,
301     .instance_size = sizeof(CRBState),
302     .class_init  = tpm_crb_class_init,
303     .interfaces = (InterfaceInfo[]) {
304         { TYPE_TPM_IF },
305         { }
306     }
307 };
308 
309 static void tpm_crb_register(void)
310 {
311     type_register_static(&tpm_crb_info);
312 }
313 
314 type_init(tpm_crb_register)
315