xref: /openbmc/qemu/hw/tpm/tpm_crb.c (revision dc5bd18f)
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 
33 typedef struct CRBState {
34     DeviceState parent_obj;
35 
36     TPMBackend *tpmbe;
37     TPMBackendCmd cmd;
38     uint32_t regs[TPM_CRB_R_MAX];
39     MemoryRegion mmio;
40     MemoryRegion cmdmem;
41 
42     size_t be_buffer_size;
43 } CRBState;
44 
45 #define CRB(obj) OBJECT_CHECK(CRBState, (obj), TYPE_TPM_CRB)
46 
47 #define DEBUG_CRB 0
48 
49 #define DPRINTF(fmt, ...) do {                  \
50         if (DEBUG_CRB) {                        \
51             printf(fmt, ## __VA_ARGS__);        \
52         }                                       \
53     } while (0)
54 
55 #define CRB_INTF_TYPE_CRB_ACTIVE 0b1
56 #define CRB_INTF_VERSION_CRB 0b1
57 #define CRB_INTF_CAP_LOCALITY_0_ONLY 0b0
58 #define CRB_INTF_CAP_IDLE_FAST 0b0
59 #define CRB_INTF_CAP_XFER_SIZE_64 0b11
60 #define CRB_INTF_CAP_FIFO_NOT_SUPPORTED 0b0
61 #define CRB_INTF_CAP_CRB_SUPPORTED 0b1
62 #define CRB_INTF_IF_SELECTOR_CRB 0b1
63 
64 #define CRB_CTRL_CMD_SIZE (TPM_CRB_ADDR_SIZE - A_CRB_DATA_BUFFER)
65 
66 enum crb_loc_ctrl {
67     CRB_LOC_CTRL_REQUEST_ACCESS = BIT(0),
68     CRB_LOC_CTRL_RELINQUISH = BIT(1),
69     CRB_LOC_CTRL_SEIZE = BIT(2),
70     CRB_LOC_CTRL_RESET_ESTABLISHMENT_BIT = BIT(3),
71 };
72 
73 enum crb_ctrl_req {
74     CRB_CTRL_REQ_CMD_READY = BIT(0),
75     CRB_CTRL_REQ_GO_IDLE = BIT(1),
76 };
77 
78 enum crb_start {
79     CRB_START_INVOKE = BIT(0),
80 };
81 
82 enum crb_cancel {
83     CRB_CANCEL_INVOKE = BIT(0),
84 };
85 
86 static uint64_t tpm_crb_mmio_read(void *opaque, hwaddr addr,
87                                   unsigned size)
88 {
89     CRBState *s = CRB(opaque);
90     void *regs = (void *)&s->regs + (addr & ~3);
91     unsigned offset = addr & 3;
92     uint32_t val = *(uint32_t *)regs >> (8 * offset);
93 
94     DPRINTF("CRB read 0x" TARGET_FMT_plx " len:%u val: 0x%" PRIx32 "\n",
95             addr, size, val);
96     return val;
97 }
98 
99 static void tpm_crb_mmio_write(void *opaque, hwaddr addr,
100                                uint64_t val, unsigned size)
101 {
102     CRBState *s = CRB(opaque);
103     DPRINTF("CRB write 0x" TARGET_FMT_plx " len:%u val: 0x%" PRIx64 "\n",
104             addr, size, val);
105 
106     switch (addr) {
107     case A_CRB_CTRL_REQ:
108         switch (val) {
109         case CRB_CTRL_REQ_CMD_READY:
110             ARRAY_FIELD_DP32(s->regs, CRB_CTRL_STS,
111                              tpmIdle, 0);
112             break;
113         case CRB_CTRL_REQ_GO_IDLE:
114             ARRAY_FIELD_DP32(s->regs, CRB_CTRL_STS,
115                              tpmIdle, 1);
116             break;
117         }
118         break;
119     case A_CRB_CTRL_CANCEL:
120         if (val == CRB_CANCEL_INVOKE &&
121             s->regs[R_CRB_CTRL_START] & CRB_START_INVOKE) {
122             tpm_backend_cancel_cmd(s->tpmbe);
123         }
124         break;
125     case A_CRB_CTRL_START:
126         if (val == CRB_START_INVOKE &&
127             !(s->regs[R_CRB_CTRL_START] & CRB_START_INVOKE)) {
128             void *mem = memory_region_get_ram_ptr(&s->cmdmem);
129 
130             s->regs[R_CRB_CTRL_START] |= CRB_START_INVOKE;
131             s->cmd = (TPMBackendCmd) {
132                 .in = mem,
133                 .in_len = MIN(tpm_cmd_get_size(mem), s->be_buffer_size),
134                 .out = mem,
135                 .out_len = s->be_buffer_size,
136             };
137 
138             tpm_backend_deliver_request(s->tpmbe, &s->cmd);
139         }
140         break;
141     case A_CRB_LOC_CTRL:
142         switch (val) {
143         case CRB_LOC_CTRL_RESET_ESTABLISHMENT_BIT:
144             /* not loc 3 or 4 */
145             break;
146         case CRB_LOC_CTRL_RELINQUISH:
147             break;
148         case CRB_LOC_CTRL_REQUEST_ACCESS:
149             ARRAY_FIELD_DP32(s->regs, CRB_LOC_STS,
150                              Granted, 1);
151             ARRAY_FIELD_DP32(s->regs, CRB_LOC_STS,
152                              beenSeized, 0);
153             ARRAY_FIELD_DP32(s->regs, CRB_LOC_STATE,
154                              locAssigned, 1);
155             ARRAY_FIELD_DP32(s->regs, CRB_LOC_STATE,
156                              tpmRegValidSts, 1);
157             break;
158         }
159         break;
160     }
161 }
162 
163 static const MemoryRegionOps tpm_crb_memory_ops = {
164     .read = tpm_crb_mmio_read,
165     .write = tpm_crb_mmio_write,
166     .endianness = DEVICE_LITTLE_ENDIAN,
167     .valid = {
168         .min_access_size = 1,
169         .max_access_size = 4,
170     },
171 };
172 
173 static void tpm_crb_request_completed(TPMIf *ti, int ret)
174 {
175     CRBState *s = CRB(ti);
176 
177     s->regs[R_CRB_CTRL_START] &= ~CRB_START_INVOKE;
178     if (ret != 0) {
179         ARRAY_FIELD_DP32(s->regs, CRB_CTRL_STS,
180                          tpmSts, 1); /* fatal error */
181     }
182 }
183 
184 static enum TPMVersion tpm_crb_get_version(TPMIf *ti)
185 {
186     CRBState *s = CRB(ti);
187 
188     return tpm_backend_get_tpm_version(s->tpmbe);
189 }
190 
191 static int tpm_crb_pre_save(void *opaque)
192 {
193     CRBState *s = opaque;
194 
195     tpm_backend_finish_sync(s->tpmbe);
196 
197     return 0;
198 }
199 
200 static const VMStateDescription vmstate_tpm_crb = {
201     .name = "tpm-crb",
202     .pre_save = tpm_crb_pre_save,
203     .fields = (VMStateField[]) {
204         VMSTATE_UINT32_ARRAY(regs, CRBState, TPM_CRB_R_MAX),
205         VMSTATE_END_OF_LIST(),
206     }
207 };
208 
209 static Property tpm_crb_properties[] = {
210     DEFINE_PROP_TPMBE("tpmdev", CRBState, tpmbe),
211     DEFINE_PROP_END_OF_LIST(),
212 };
213 
214 static void tpm_crb_reset(void *dev)
215 {
216     CRBState *s = CRB(dev);
217 
218     tpm_backend_reset(s->tpmbe);
219 
220     ARRAY_FIELD_DP32(s->regs, CRB_INTF_ID,
221                      InterfaceType, CRB_INTF_TYPE_CRB_ACTIVE);
222     ARRAY_FIELD_DP32(s->regs, CRB_INTF_ID,
223                      InterfaceVersion, CRB_INTF_VERSION_CRB);
224     ARRAY_FIELD_DP32(s->regs, CRB_INTF_ID,
225                      CapLocality, CRB_INTF_CAP_LOCALITY_0_ONLY);
226     ARRAY_FIELD_DP32(s->regs, CRB_INTF_ID,
227                      CapCRBIdleBypass, CRB_INTF_CAP_IDLE_FAST);
228     ARRAY_FIELD_DP32(s->regs, CRB_INTF_ID,
229                      CapDataXferSizeSupport, CRB_INTF_CAP_XFER_SIZE_64);
230     ARRAY_FIELD_DP32(s->regs, CRB_INTF_ID,
231                      CapFIFO, CRB_INTF_CAP_FIFO_NOT_SUPPORTED);
232     ARRAY_FIELD_DP32(s->regs, CRB_INTF_ID,
233                      CapCRB, CRB_INTF_CAP_CRB_SUPPORTED);
234     ARRAY_FIELD_DP32(s->regs, CRB_INTF_ID,
235                      InterfaceSelector, CRB_INTF_IF_SELECTOR_CRB);
236     ARRAY_FIELD_DP32(s->regs, CRB_INTF_ID,
237                      RID, 0b0000);
238     ARRAY_FIELD_DP32(s->regs, CRB_INTF_ID2,
239                      VID, PCI_VENDOR_ID_IBM);
240 
241     s->regs[R_CRB_CTRL_CMD_SIZE] = CRB_CTRL_CMD_SIZE;
242     s->regs[R_CRB_CTRL_CMD_LADDR] = TPM_CRB_ADDR_BASE + A_CRB_DATA_BUFFER;
243     s->regs[R_CRB_CTRL_RSP_SIZE] = CRB_CTRL_CMD_SIZE;
244     s->regs[R_CRB_CTRL_RSP_ADDR] = TPM_CRB_ADDR_BASE + A_CRB_DATA_BUFFER;
245 
246     s->be_buffer_size = MIN(tpm_backend_get_buffer_size(s->tpmbe),
247                             CRB_CTRL_CMD_SIZE);
248 
249     tpm_backend_startup_tpm(s->tpmbe, s->be_buffer_size);
250 }
251 
252 static void tpm_crb_realize(DeviceState *dev, Error **errp)
253 {
254     CRBState *s = CRB(dev);
255 
256     if (!tpm_find()) {
257         error_setg(errp, "at most one TPM device is permitted");
258         return;
259     }
260     if (!s->tpmbe) {
261         error_setg(errp, "'tpmdev' property is required");
262         return;
263     }
264 
265     memory_region_init_io(&s->mmio, OBJECT(s), &tpm_crb_memory_ops, s,
266         "tpm-crb-mmio", sizeof(s->regs));
267     memory_region_init_ram(&s->cmdmem, OBJECT(s),
268         "tpm-crb-cmd", CRB_CTRL_CMD_SIZE, errp);
269 
270     memory_region_add_subregion(get_system_memory(),
271         TPM_CRB_ADDR_BASE, &s->mmio);
272     memory_region_add_subregion(get_system_memory(),
273         TPM_CRB_ADDR_BASE + sizeof(s->regs), &s->cmdmem);
274 
275     qemu_register_reset(tpm_crb_reset, dev);
276 }
277 
278 static void tpm_crb_class_init(ObjectClass *klass, void *data)
279 {
280     DeviceClass *dc = DEVICE_CLASS(klass);
281     TPMIfClass *tc = TPM_IF_CLASS(klass);
282 
283     dc->realize = tpm_crb_realize;
284     dc->props = tpm_crb_properties;
285     dc->vmsd  = &vmstate_tpm_crb;
286     dc->user_creatable = true;
287     tc->model = TPM_MODEL_TPM_CRB;
288     tc->get_version = tpm_crb_get_version;
289     tc->request_completed = tpm_crb_request_completed;
290 
291     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
292 }
293 
294 static const TypeInfo tpm_crb_info = {
295     .name = TYPE_TPM_CRB,
296     /* could be TYPE_SYS_BUS_DEVICE (or LPC etc) */
297     .parent = TYPE_DEVICE,
298     .instance_size = sizeof(CRBState),
299     .class_init  = tpm_crb_class_init,
300     .interfaces = (InterfaceInfo[]) {
301         { TYPE_TPM_IF },
302         { }
303     }
304 };
305 
306 static void tpm_crb_register(void)
307 {
308     type_register_static(&tpm_crb_info);
309 }
310 
311 type_init(tpm_crb_register)
312