xref: /openbmc/qemu/hw/tpm/tpm_crb.c (revision 438c78da)
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 #define TPM_CRB_NO_LOCALITY 0xff
80 
81 static uint64_t tpm_crb_mmio_read(void *opaque, hwaddr addr,
82                                   unsigned size)
83 {
84     CRBState *s = CRB(opaque);
85     void *regs = (void *)&s->regs + (addr & ~3);
86     unsigned offset = addr & 3;
87     uint32_t val = *(uint32_t *)regs >> (8 * offset);
88 
89     switch (addr) {
90     case A_CRB_LOC_STATE:
91         val |= !tpm_backend_get_tpm_established_flag(s->tpmbe);
92         break;
93     }
94 
95     trace_tpm_crb_mmio_read(addr, size, val);
96 
97     return val;
98 }
99 
100 static uint8_t tpm_crb_get_active_locty(CRBState *s)
101 {
102     if (!ARRAY_FIELD_EX32(s->regs, CRB_LOC_STATE, locAssigned)) {
103         return TPM_CRB_NO_LOCALITY;
104     }
105     return ARRAY_FIELD_EX32(s->regs, CRB_LOC_STATE, activeLocality);
106 }
107 
108 static void tpm_crb_mmio_write(void *opaque, hwaddr addr,
109                                uint64_t val, unsigned size)
110 {
111     CRBState *s = CRB(opaque);
112     uint8_t locty =  addr >> 12;
113 
114     trace_tpm_crb_mmio_write(addr, size, val);
115 
116     switch (addr) {
117     case A_CRB_CTRL_REQ:
118         switch (val) {
119         case CRB_CTRL_REQ_CMD_READY:
120             ARRAY_FIELD_DP32(s->regs, CRB_CTRL_STS,
121                              tpmIdle, 0);
122             break;
123         case CRB_CTRL_REQ_GO_IDLE:
124             ARRAY_FIELD_DP32(s->regs, CRB_CTRL_STS,
125                              tpmIdle, 1);
126             break;
127         }
128         break;
129     case A_CRB_CTRL_CANCEL:
130         if (val == CRB_CANCEL_INVOKE &&
131             s->regs[R_CRB_CTRL_START] & CRB_START_INVOKE) {
132             tpm_backend_cancel_cmd(s->tpmbe);
133         }
134         break;
135     case A_CRB_CTRL_START:
136         if (val == CRB_START_INVOKE &&
137             !(s->regs[R_CRB_CTRL_START] & CRB_START_INVOKE) &&
138             tpm_crb_get_active_locty(s) == locty) {
139             void *mem = memory_region_get_ram_ptr(&s->cmdmem);
140 
141             s->regs[R_CRB_CTRL_START] |= CRB_START_INVOKE;
142             s->cmd = (TPMBackendCmd) {
143                 .in = mem,
144                 .in_len = MIN(tpm_cmd_get_size(mem), s->be_buffer_size),
145                 .out = mem,
146                 .out_len = s->be_buffer_size,
147             };
148 
149             tpm_backend_deliver_request(s->tpmbe, &s->cmd);
150         }
151         break;
152     case A_CRB_LOC_CTRL:
153         switch (val) {
154         case CRB_LOC_CTRL_RESET_ESTABLISHMENT_BIT:
155             /* not loc 3 or 4 */
156             break;
157         case CRB_LOC_CTRL_RELINQUISH:
158             ARRAY_FIELD_DP32(s->regs, CRB_LOC_STATE,
159                              locAssigned, 0);
160             ARRAY_FIELD_DP32(s->regs, CRB_LOC_STS,
161                              Granted, 0);
162             break;
163         case CRB_LOC_CTRL_REQUEST_ACCESS:
164             ARRAY_FIELD_DP32(s->regs, CRB_LOC_STS,
165                              Granted, 1);
166             ARRAY_FIELD_DP32(s->regs, CRB_LOC_STS,
167                              beenSeized, 0);
168             ARRAY_FIELD_DP32(s->regs, CRB_LOC_STATE,
169                              locAssigned, 1);
170             break;
171         }
172         break;
173     }
174 }
175 
176 static const MemoryRegionOps tpm_crb_memory_ops = {
177     .read = tpm_crb_mmio_read,
178     .write = tpm_crb_mmio_write,
179     .endianness = DEVICE_LITTLE_ENDIAN,
180     .valid = {
181         .min_access_size = 1,
182         .max_access_size = 4,
183     },
184 };
185 
186 static void tpm_crb_request_completed(TPMIf *ti, int ret)
187 {
188     CRBState *s = CRB(ti);
189 
190     s->regs[R_CRB_CTRL_START] &= ~CRB_START_INVOKE;
191     if (ret != 0) {
192         ARRAY_FIELD_DP32(s->regs, CRB_CTRL_STS,
193                          tpmSts, 1); /* fatal error */
194     }
195 }
196 
197 static enum TPMVersion tpm_crb_get_version(TPMIf *ti)
198 {
199     CRBState *s = CRB(ti);
200 
201     return tpm_backend_get_tpm_version(s->tpmbe);
202 }
203 
204 static int tpm_crb_pre_save(void *opaque)
205 {
206     CRBState *s = opaque;
207 
208     tpm_backend_finish_sync(s->tpmbe);
209 
210     return 0;
211 }
212 
213 static const VMStateDescription vmstate_tpm_crb = {
214     .name = "tpm-crb",
215     .pre_save = tpm_crb_pre_save,
216     .fields = (VMStateField[]) {
217         VMSTATE_UINT32_ARRAY(regs, CRBState, TPM_CRB_R_MAX),
218         VMSTATE_END_OF_LIST(),
219     }
220 };
221 
222 static Property tpm_crb_properties[] = {
223     DEFINE_PROP_TPMBE("tpmdev", CRBState, tpmbe),
224     DEFINE_PROP_END_OF_LIST(),
225 };
226 
227 static void tpm_crb_reset(void *dev)
228 {
229     CRBState *s = CRB(dev);
230 
231     tpm_backend_reset(s->tpmbe);
232 
233     memset(s->regs, 0, sizeof(s->regs));
234 
235     ARRAY_FIELD_DP32(s->regs, CRB_LOC_STATE,
236                      tpmRegValidSts, 1);
237     ARRAY_FIELD_DP32(s->regs, CRB_CTRL_STS,
238                      tpmIdle, 1);
239     ARRAY_FIELD_DP32(s->regs, CRB_INTF_ID,
240                      InterfaceType, CRB_INTF_TYPE_CRB_ACTIVE);
241     ARRAY_FIELD_DP32(s->regs, CRB_INTF_ID,
242                      InterfaceVersion, CRB_INTF_VERSION_CRB);
243     ARRAY_FIELD_DP32(s->regs, CRB_INTF_ID,
244                      CapLocality, CRB_INTF_CAP_LOCALITY_0_ONLY);
245     ARRAY_FIELD_DP32(s->regs, CRB_INTF_ID,
246                      CapCRBIdleBypass, CRB_INTF_CAP_IDLE_FAST);
247     ARRAY_FIELD_DP32(s->regs, CRB_INTF_ID,
248                      CapDataXferSizeSupport, CRB_INTF_CAP_XFER_SIZE_64);
249     ARRAY_FIELD_DP32(s->regs, CRB_INTF_ID,
250                      CapFIFO, CRB_INTF_CAP_FIFO_NOT_SUPPORTED);
251     ARRAY_FIELD_DP32(s->regs, CRB_INTF_ID,
252                      CapCRB, CRB_INTF_CAP_CRB_SUPPORTED);
253     ARRAY_FIELD_DP32(s->regs, CRB_INTF_ID,
254                      InterfaceSelector, CRB_INTF_IF_SELECTOR_CRB);
255     ARRAY_FIELD_DP32(s->regs, CRB_INTF_ID,
256                      RID, 0b0000);
257     ARRAY_FIELD_DP32(s->regs, CRB_INTF_ID2,
258                      VID, PCI_VENDOR_ID_IBM);
259 
260     s->regs[R_CRB_CTRL_CMD_SIZE] = CRB_CTRL_CMD_SIZE;
261     s->regs[R_CRB_CTRL_CMD_LADDR] = TPM_CRB_ADDR_BASE + A_CRB_DATA_BUFFER;
262     s->regs[R_CRB_CTRL_RSP_SIZE] = CRB_CTRL_CMD_SIZE;
263     s->regs[R_CRB_CTRL_RSP_ADDR] = TPM_CRB_ADDR_BASE + A_CRB_DATA_BUFFER;
264 
265     s->be_buffer_size = MIN(tpm_backend_get_buffer_size(s->tpmbe),
266                             CRB_CTRL_CMD_SIZE);
267 
268     tpm_backend_startup_tpm(s->tpmbe, s->be_buffer_size);
269 }
270 
271 static void tpm_crb_realize(DeviceState *dev, Error **errp)
272 {
273     CRBState *s = CRB(dev);
274 
275     if (!tpm_find()) {
276         error_setg(errp, "at most one TPM device is permitted");
277         return;
278     }
279     if (!s->tpmbe) {
280         error_setg(errp, "'tpmdev' property is required");
281         return;
282     }
283 
284     memory_region_init_io(&s->mmio, OBJECT(s), &tpm_crb_memory_ops, s,
285         "tpm-crb-mmio", sizeof(s->regs));
286     memory_region_init_ram(&s->cmdmem, OBJECT(s),
287         "tpm-crb-cmd", CRB_CTRL_CMD_SIZE, errp);
288 
289     memory_region_add_subregion(get_system_memory(),
290         TPM_CRB_ADDR_BASE, &s->mmio);
291     memory_region_add_subregion(get_system_memory(),
292         TPM_CRB_ADDR_BASE + sizeof(s->regs), &s->cmdmem);
293 
294     qemu_register_reset(tpm_crb_reset, dev);
295 }
296 
297 static void tpm_crb_class_init(ObjectClass *klass, void *data)
298 {
299     DeviceClass *dc = DEVICE_CLASS(klass);
300     TPMIfClass *tc = TPM_IF_CLASS(klass);
301 
302     dc->realize = tpm_crb_realize;
303     dc->props = tpm_crb_properties;
304     dc->vmsd  = &vmstate_tpm_crb;
305     dc->user_creatable = true;
306     tc->model = TPM_MODEL_TPM_CRB;
307     tc->get_version = tpm_crb_get_version;
308     tc->request_completed = tpm_crb_request_completed;
309 
310     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
311 }
312 
313 static const TypeInfo tpm_crb_info = {
314     .name = TYPE_TPM_CRB,
315     /* could be TYPE_SYS_BUS_DEVICE (or LPC etc) */
316     .parent = TYPE_DEVICE,
317     .instance_size = sizeof(CRBState),
318     .class_init  = tpm_crb_class_init,
319     .interfaces = (InterfaceInfo[]) {
320         { TYPE_TPM_IF },
321         { }
322     }
323 };
324 
325 static void tpm_crb_register(void)
326 {
327     type_register_static(&tpm_crb_info);
328 }
329 
330 type_init(tpm_crb_register)
331