xref: /openbmc/qemu/hw/tpm/tpm_crb.c (revision effd60c8)
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/module.h"
20 #include "qapi/error.h"
21 #include "exec/address-spaces.h"
22 #include "hw/qdev-properties.h"
23 #include "hw/pci/pci_ids.h"
24 #include "hw/acpi/tpm.h"
25 #include "migration/vmstate.h"
26 #include "sysemu/tpm_backend.h"
27 #include "sysemu/tpm_util.h"
28 #include "sysemu/reset.h"
29 #include "sysemu/xen.h"
30 #include "tpm_prop.h"
31 #include "tpm_ppi.h"
32 #include "trace.h"
33 #include "qom/object.h"
34 
35 struct CRBState {
36     DeviceState parent_obj;
37 
38     TPMBackend *tpmbe;
39     TPMBackendCmd cmd;
40     uint32_t regs[TPM_CRB_R_MAX];
41     MemoryRegion mmio;
42     MemoryRegion cmdmem;
43 
44     size_t be_buffer_size;
45 
46     bool ppi_enabled;
47     TPMPPI ppi;
48 };
49 typedef struct CRBState CRBState;
50 
51 DECLARE_INSTANCE_CHECKER(CRBState, CRB,
52                          TYPE_TPM_CRB)
53 
54 #define CRB_INTF_TYPE_CRB_ACTIVE 0b1
55 #define CRB_INTF_VERSION_CRB 0b1
56 #define CRB_INTF_CAP_LOCALITY_0_ONLY 0b0
57 #define CRB_INTF_CAP_IDLE_FAST 0b0
58 #define CRB_INTF_CAP_XFER_SIZE_64 0b11
59 #define CRB_INTF_CAP_FIFO_NOT_SUPPORTED 0b0
60 #define CRB_INTF_CAP_CRB_SUPPORTED 0b1
61 #define CRB_INTF_IF_SELECTOR_CRB 0b1
62 
63 #define CRB_CTRL_CMD_SIZE (TPM_CRB_ADDR_SIZE - A_CRB_DATA_BUFFER)
64 
65 enum crb_loc_ctrl {
66     CRB_LOC_CTRL_REQUEST_ACCESS = BIT(0),
67     CRB_LOC_CTRL_RELINQUISH = BIT(1),
68     CRB_LOC_CTRL_SEIZE = BIT(2),
69     CRB_LOC_CTRL_RESET_ESTABLISHMENT_BIT = BIT(3),
70 };
71 
72 enum crb_ctrl_req {
73     CRB_CTRL_REQ_CMD_READY = BIT(0),
74     CRB_CTRL_REQ_GO_IDLE = BIT(1),
75 };
76 
77 enum crb_start {
78     CRB_START_INVOKE = BIT(0),
79 };
80 
81 enum crb_cancel {
82     CRB_CANCEL_INVOKE = BIT(0),
83 };
84 
85 #define TPM_CRB_NO_LOCALITY 0xff
86 
87 static uint64_t tpm_crb_mmio_read(void *opaque, hwaddr addr,
88                                   unsigned size)
89 {
90     CRBState *s = CRB(opaque);
91     void *regs = (void *)&s->regs + (addr & ~3);
92     unsigned offset = addr & 3;
93     uint32_t val = *(uint32_t *)regs >> (8 * offset);
94 
95     switch (addr) {
96     case A_CRB_LOC_STATE:
97         val |= !tpm_backend_get_tpm_established_flag(s->tpmbe);
98         break;
99     }
100 
101     trace_tpm_crb_mmio_read(addr, size, val);
102 
103     return val;
104 }
105 
106 static uint8_t tpm_crb_get_active_locty(CRBState *s)
107 {
108     if (!ARRAY_FIELD_EX32(s->regs, CRB_LOC_STATE, locAssigned)) {
109         return TPM_CRB_NO_LOCALITY;
110     }
111     return ARRAY_FIELD_EX32(s->regs, CRB_LOC_STATE, activeLocality);
112 }
113 
114 static void tpm_crb_mmio_write(void *opaque, hwaddr addr,
115                                uint64_t val, unsigned size)
116 {
117     CRBState *s = CRB(opaque);
118     uint8_t locty =  addr >> 12;
119 
120     trace_tpm_crb_mmio_write(addr, size, val);
121 
122     switch (addr) {
123     case A_CRB_CTRL_REQ:
124         switch (val) {
125         case CRB_CTRL_REQ_CMD_READY:
126             ARRAY_FIELD_DP32(s->regs, CRB_CTRL_STS,
127                              tpmIdle, 0);
128             break;
129         case CRB_CTRL_REQ_GO_IDLE:
130             ARRAY_FIELD_DP32(s->regs, CRB_CTRL_STS,
131                              tpmIdle, 1);
132             break;
133         }
134         break;
135     case A_CRB_CTRL_CANCEL:
136         if (val == CRB_CANCEL_INVOKE &&
137             s->regs[R_CRB_CTRL_START] & CRB_START_INVOKE) {
138             tpm_backend_cancel_cmd(s->tpmbe);
139         }
140         break;
141     case A_CRB_CTRL_START:
142         if (val == CRB_START_INVOKE &&
143             !(s->regs[R_CRB_CTRL_START] & CRB_START_INVOKE) &&
144             tpm_crb_get_active_locty(s) == locty) {
145             void *mem = memory_region_get_ram_ptr(&s->cmdmem);
146 
147             s->regs[R_CRB_CTRL_START] |= CRB_START_INVOKE;
148             s->cmd = (TPMBackendCmd) {
149                 .in = mem,
150                 .in_len = MIN(tpm_cmd_get_size(mem), s->be_buffer_size),
151                 .out = mem,
152                 .out_len = s->be_buffer_size,
153             };
154 
155             tpm_backend_deliver_request(s->tpmbe, &s->cmd);
156         }
157         break;
158     case A_CRB_LOC_CTRL:
159         switch (val) {
160         case CRB_LOC_CTRL_RESET_ESTABLISHMENT_BIT:
161             /* not loc 3 or 4 */
162             break;
163         case CRB_LOC_CTRL_RELINQUISH:
164             ARRAY_FIELD_DP32(s->regs, CRB_LOC_STATE,
165                              locAssigned, 0);
166             ARRAY_FIELD_DP32(s->regs, CRB_LOC_STS,
167                              Granted, 0);
168             break;
169         case CRB_LOC_CTRL_REQUEST_ACCESS:
170             ARRAY_FIELD_DP32(s->regs, CRB_LOC_STS,
171                              Granted, 1);
172             ARRAY_FIELD_DP32(s->regs, CRB_LOC_STS,
173                              beenSeized, 0);
174             ARRAY_FIELD_DP32(s->regs, CRB_LOC_STATE,
175                              locAssigned, 1);
176             break;
177         }
178         break;
179     }
180 }
181 
182 static const MemoryRegionOps tpm_crb_memory_ops = {
183     .read = tpm_crb_mmio_read,
184     .write = tpm_crb_mmio_write,
185     .endianness = DEVICE_LITTLE_ENDIAN,
186     .valid = {
187         .min_access_size = 1,
188         .max_access_size = 4,
189     },
190 };
191 
192 static void tpm_crb_request_completed(TPMIf *ti, int ret)
193 {
194     CRBState *s = CRB(ti);
195 
196     s->regs[R_CRB_CTRL_START] &= ~CRB_START_INVOKE;
197     if (ret != 0) {
198         ARRAY_FIELD_DP32(s->regs, CRB_CTRL_STS,
199                          tpmSts, 1); /* fatal error */
200     }
201     memory_region_set_dirty(&s->cmdmem, 0, CRB_CTRL_CMD_SIZE);
202 }
203 
204 static enum TPMVersion tpm_crb_get_version(TPMIf *ti)
205 {
206     CRBState *s = CRB(ti);
207 
208     return tpm_backend_get_tpm_version(s->tpmbe);
209 }
210 
211 static int tpm_crb_pre_save(void *opaque)
212 {
213     CRBState *s = opaque;
214 
215     tpm_backend_finish_sync(s->tpmbe);
216 
217     return 0;
218 }
219 
220 static const VMStateDescription vmstate_tpm_crb = {
221     .name = "tpm-crb",
222     .pre_save = tpm_crb_pre_save,
223     .fields = (const VMStateField[]) {
224         VMSTATE_UINT32_ARRAY(regs, CRBState, TPM_CRB_R_MAX),
225         VMSTATE_END_OF_LIST(),
226     }
227 };
228 
229 static Property tpm_crb_properties[] = {
230     DEFINE_PROP_TPMBE("tpmdev", CRBState, tpmbe),
231     DEFINE_PROP_BOOL("ppi", CRBState, ppi_enabled, true),
232     DEFINE_PROP_END_OF_LIST(),
233 };
234 
235 static void tpm_crb_reset(void *dev)
236 {
237     CRBState *s = CRB(dev);
238 
239     if (s->ppi_enabled) {
240         tpm_ppi_reset(&s->ppi);
241     }
242     tpm_backend_reset(s->tpmbe);
243 
244     memset(s->regs, 0, sizeof(s->regs));
245 
246     ARRAY_FIELD_DP32(s->regs, CRB_LOC_STATE,
247                      tpmRegValidSts, 1);
248     ARRAY_FIELD_DP32(s->regs, CRB_CTRL_STS,
249                      tpmIdle, 1);
250     ARRAY_FIELD_DP32(s->regs, CRB_INTF_ID,
251                      InterfaceType, CRB_INTF_TYPE_CRB_ACTIVE);
252     ARRAY_FIELD_DP32(s->regs, CRB_INTF_ID,
253                      InterfaceVersion, CRB_INTF_VERSION_CRB);
254     ARRAY_FIELD_DP32(s->regs, CRB_INTF_ID,
255                      CapLocality, CRB_INTF_CAP_LOCALITY_0_ONLY);
256     ARRAY_FIELD_DP32(s->regs, CRB_INTF_ID,
257                      CapCRBIdleBypass, CRB_INTF_CAP_IDLE_FAST);
258     ARRAY_FIELD_DP32(s->regs, CRB_INTF_ID,
259                      CapDataXferSizeSupport, CRB_INTF_CAP_XFER_SIZE_64);
260     ARRAY_FIELD_DP32(s->regs, CRB_INTF_ID,
261                      CapFIFO, CRB_INTF_CAP_FIFO_NOT_SUPPORTED);
262     ARRAY_FIELD_DP32(s->regs, CRB_INTF_ID,
263                      CapCRB, CRB_INTF_CAP_CRB_SUPPORTED);
264     ARRAY_FIELD_DP32(s->regs, CRB_INTF_ID,
265                      InterfaceSelector, CRB_INTF_IF_SELECTOR_CRB);
266     ARRAY_FIELD_DP32(s->regs, CRB_INTF_ID,
267                      RID, 0b0000);
268     ARRAY_FIELD_DP32(s->regs, CRB_INTF_ID2,
269                      VID, PCI_VENDOR_ID_IBM);
270 
271     s->regs[R_CRB_CTRL_CMD_SIZE] = CRB_CTRL_CMD_SIZE;
272     s->regs[R_CRB_CTRL_CMD_LADDR] = TPM_CRB_ADDR_BASE + A_CRB_DATA_BUFFER;
273     s->regs[R_CRB_CTRL_RSP_SIZE] = CRB_CTRL_CMD_SIZE;
274     s->regs[R_CRB_CTRL_RSP_ADDR] = TPM_CRB_ADDR_BASE + A_CRB_DATA_BUFFER;
275 
276     s->be_buffer_size = MIN(tpm_backend_get_buffer_size(s->tpmbe),
277                             CRB_CTRL_CMD_SIZE);
278 
279     if (tpm_backend_startup_tpm(s->tpmbe, s->be_buffer_size) < 0) {
280         exit(1);
281     }
282 }
283 
284 static void tpm_crb_realize(DeviceState *dev, Error **errp)
285 {
286     CRBState *s = CRB(dev);
287 
288     if (!tpm_find()) {
289         error_setg(errp, "at most one TPM device is permitted");
290         return;
291     }
292     if (!s->tpmbe) {
293         error_setg(errp, "'tpmdev' property is required");
294         return;
295     }
296 
297     memory_region_init_io(&s->mmio, OBJECT(s), &tpm_crb_memory_ops, s,
298         "tpm-crb-mmio", sizeof(s->regs));
299     memory_region_init_ram(&s->cmdmem, OBJECT(s),
300         "tpm-crb-cmd", CRB_CTRL_CMD_SIZE, errp);
301 
302     memory_region_add_subregion(get_system_memory(),
303         TPM_CRB_ADDR_BASE, &s->mmio);
304     memory_region_add_subregion(get_system_memory(),
305         TPM_CRB_ADDR_BASE + sizeof(s->regs), &s->cmdmem);
306 
307     if (s->ppi_enabled) {
308         tpm_ppi_init(&s->ppi, get_system_memory(),
309                      TPM_PPI_ADDR_BASE, OBJECT(s));
310     }
311 
312     if (xen_enabled()) {
313         tpm_crb_reset(dev);
314     } else {
315         qemu_register_reset(tpm_crb_reset, dev);
316     }
317 }
318 
319 static void tpm_crb_class_init(ObjectClass *klass, void *data)
320 {
321     DeviceClass *dc = DEVICE_CLASS(klass);
322     TPMIfClass *tc = TPM_IF_CLASS(klass);
323 
324     dc->realize = tpm_crb_realize;
325     device_class_set_props(dc, tpm_crb_properties);
326     dc->vmsd  = &vmstate_tpm_crb;
327     dc->user_creatable = true;
328     tc->model = TPM_MODEL_TPM_CRB;
329     tc->get_version = tpm_crb_get_version;
330     tc->request_completed = tpm_crb_request_completed;
331 
332     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
333 }
334 
335 static const TypeInfo tpm_crb_info = {
336     .name = TYPE_TPM_CRB,
337     /* could be TYPE_SYS_BUS_DEVICE (or LPC etc) */
338     .parent = TYPE_DEVICE,
339     .instance_size = sizeof(CRBState),
340     .class_init  = tpm_crb_class_init,
341     .interfaces = (InterfaceInfo[]) {
342         { TYPE_TPM_IF },
343         { }
344     }
345 };
346 
347 static void tpm_crb_register(void)
348 {
349     type_register_static(&tpm_crb_info);
350 }
351 
352 type_init(tpm_crb_register)
353