xref: /qemu/hw/tpm/tpm_crb.c (revision e1880ed80a4718ae0df49d115b6079183a01a716)
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     trace_tpm_crb_mmio_read(addr, size, val);
88 
89     return val;
90 }
91 
92 static void tpm_crb_mmio_write(void *opaque, hwaddr addr,
93                                uint64_t val, unsigned size)
94 {
95     CRBState *s = CRB(opaque);
96 
97     trace_tpm_crb_mmio_write(addr, size, val);
98 
99     switch (addr) {
100     case A_CRB_CTRL_REQ:
101         switch (val) {
102         case CRB_CTRL_REQ_CMD_READY:
103             ARRAY_FIELD_DP32(s->regs, CRB_CTRL_STS,
104                              tpmIdle, 0);
105             break;
106         case CRB_CTRL_REQ_GO_IDLE:
107             ARRAY_FIELD_DP32(s->regs, CRB_CTRL_STS,
108                              tpmIdle, 1);
109             break;
110         }
111         break;
112     case A_CRB_CTRL_CANCEL:
113         if (val == CRB_CANCEL_INVOKE &&
114             s->regs[R_CRB_CTRL_START] & CRB_START_INVOKE) {
115             tpm_backend_cancel_cmd(s->tpmbe);
116         }
117         break;
118     case A_CRB_CTRL_START:
119         if (val == CRB_START_INVOKE &&
120             !(s->regs[R_CRB_CTRL_START] & CRB_START_INVOKE)) {
121             void *mem = memory_region_get_ram_ptr(&s->cmdmem);
122 
123             s->regs[R_CRB_CTRL_START] |= CRB_START_INVOKE;
124             s->cmd = (TPMBackendCmd) {
125                 .in = mem,
126                 .in_len = MIN(tpm_cmd_get_size(mem), s->be_buffer_size),
127                 .out = mem,
128                 .out_len = s->be_buffer_size,
129             };
130 
131             tpm_backend_deliver_request(s->tpmbe, &s->cmd);
132         }
133         break;
134     case A_CRB_LOC_CTRL:
135         switch (val) {
136         case CRB_LOC_CTRL_RESET_ESTABLISHMENT_BIT:
137             /* not loc 3 or 4 */
138             break;
139         case CRB_LOC_CTRL_RELINQUISH:
140             break;
141         case CRB_LOC_CTRL_REQUEST_ACCESS:
142             ARRAY_FIELD_DP32(s->regs, CRB_LOC_STS,
143                              Granted, 1);
144             ARRAY_FIELD_DP32(s->regs, CRB_LOC_STS,
145                              beenSeized, 0);
146             ARRAY_FIELD_DP32(s->regs, CRB_LOC_STATE,
147                              locAssigned, 1);
148             break;
149         }
150         break;
151     }
152 }
153 
154 static const MemoryRegionOps tpm_crb_memory_ops = {
155     .read = tpm_crb_mmio_read,
156     .write = tpm_crb_mmio_write,
157     .endianness = DEVICE_LITTLE_ENDIAN,
158     .valid = {
159         .min_access_size = 1,
160         .max_access_size = 4,
161     },
162 };
163 
164 static void tpm_crb_request_completed(TPMIf *ti, int ret)
165 {
166     CRBState *s = CRB(ti);
167 
168     s->regs[R_CRB_CTRL_START] &= ~CRB_START_INVOKE;
169     if (ret != 0) {
170         ARRAY_FIELD_DP32(s->regs, CRB_CTRL_STS,
171                          tpmSts, 1); /* fatal error */
172     }
173 }
174 
175 static enum TPMVersion tpm_crb_get_version(TPMIf *ti)
176 {
177     CRBState *s = CRB(ti);
178 
179     return tpm_backend_get_tpm_version(s->tpmbe);
180 }
181 
182 static int tpm_crb_pre_save(void *opaque)
183 {
184     CRBState *s = opaque;
185 
186     tpm_backend_finish_sync(s->tpmbe);
187 
188     return 0;
189 }
190 
191 static const VMStateDescription vmstate_tpm_crb = {
192     .name = "tpm-crb",
193     .pre_save = tpm_crb_pre_save,
194     .fields = (VMStateField[]) {
195         VMSTATE_UINT32_ARRAY(regs, CRBState, TPM_CRB_R_MAX),
196         VMSTATE_END_OF_LIST(),
197     }
198 };
199 
200 static Property tpm_crb_properties[] = {
201     DEFINE_PROP_TPMBE("tpmdev", CRBState, tpmbe),
202     DEFINE_PROP_END_OF_LIST(),
203 };
204 
205 static void tpm_crb_reset(void *dev)
206 {
207     CRBState *s = CRB(dev);
208 
209     tpm_backend_reset(s->tpmbe);
210 
211     memset(s->regs, 0, sizeof(s->regs));
212 
213     ARRAY_FIELD_DP32(s->regs, CRB_LOC_STATE,
214                      tpmRegValidSts, 1);
215     ARRAY_FIELD_DP32(s->regs, CRB_INTF_ID,
216                      InterfaceType, CRB_INTF_TYPE_CRB_ACTIVE);
217     ARRAY_FIELD_DP32(s->regs, CRB_INTF_ID,
218                      InterfaceVersion, CRB_INTF_VERSION_CRB);
219     ARRAY_FIELD_DP32(s->regs, CRB_INTF_ID,
220                      CapLocality, CRB_INTF_CAP_LOCALITY_0_ONLY);
221     ARRAY_FIELD_DP32(s->regs, CRB_INTF_ID,
222                      CapCRBIdleBypass, CRB_INTF_CAP_IDLE_FAST);
223     ARRAY_FIELD_DP32(s->regs, CRB_INTF_ID,
224                      CapDataXferSizeSupport, CRB_INTF_CAP_XFER_SIZE_64);
225     ARRAY_FIELD_DP32(s->regs, CRB_INTF_ID,
226                      CapFIFO, CRB_INTF_CAP_FIFO_NOT_SUPPORTED);
227     ARRAY_FIELD_DP32(s->regs, CRB_INTF_ID,
228                      CapCRB, CRB_INTF_CAP_CRB_SUPPORTED);
229     ARRAY_FIELD_DP32(s->regs, CRB_INTF_ID,
230                      InterfaceSelector, CRB_INTF_IF_SELECTOR_CRB);
231     ARRAY_FIELD_DP32(s->regs, CRB_INTF_ID,
232                      RID, 0b0000);
233     ARRAY_FIELD_DP32(s->regs, CRB_INTF_ID2,
234                      VID, PCI_VENDOR_ID_IBM);
235 
236     s->regs[R_CRB_CTRL_CMD_SIZE] = CRB_CTRL_CMD_SIZE;
237     s->regs[R_CRB_CTRL_CMD_LADDR] = TPM_CRB_ADDR_BASE + A_CRB_DATA_BUFFER;
238     s->regs[R_CRB_CTRL_RSP_SIZE] = CRB_CTRL_CMD_SIZE;
239     s->regs[R_CRB_CTRL_RSP_ADDR] = TPM_CRB_ADDR_BASE + A_CRB_DATA_BUFFER;
240 
241     s->be_buffer_size = MIN(tpm_backend_get_buffer_size(s->tpmbe),
242                             CRB_CTRL_CMD_SIZE);
243 
244     tpm_backend_startup_tpm(s->tpmbe, s->be_buffer_size);
245 }
246 
247 static void tpm_crb_realize(DeviceState *dev, Error **errp)
248 {
249     CRBState *s = CRB(dev);
250 
251     if (!tpm_find()) {
252         error_setg(errp, "at most one TPM device is permitted");
253         return;
254     }
255     if (!s->tpmbe) {
256         error_setg(errp, "'tpmdev' property is required");
257         return;
258     }
259 
260     memory_region_init_io(&s->mmio, OBJECT(s), &tpm_crb_memory_ops, s,
261         "tpm-crb-mmio", sizeof(s->regs));
262     memory_region_init_ram(&s->cmdmem, OBJECT(s),
263         "tpm-crb-cmd", CRB_CTRL_CMD_SIZE, errp);
264 
265     memory_region_add_subregion(get_system_memory(),
266         TPM_CRB_ADDR_BASE, &s->mmio);
267     memory_region_add_subregion(get_system_memory(),
268         TPM_CRB_ADDR_BASE + sizeof(s->regs), &s->cmdmem);
269 
270     qemu_register_reset(tpm_crb_reset, dev);
271 }
272 
273 static void tpm_crb_class_init(ObjectClass *klass, void *data)
274 {
275     DeviceClass *dc = DEVICE_CLASS(klass);
276     TPMIfClass *tc = TPM_IF_CLASS(klass);
277 
278     dc->realize = tpm_crb_realize;
279     dc->props = tpm_crb_properties;
280     dc->vmsd  = &vmstate_tpm_crb;
281     dc->user_creatable = true;
282     tc->model = TPM_MODEL_TPM_CRB;
283     tc->get_version = tpm_crb_get_version;
284     tc->request_completed = tpm_crb_request_completed;
285 
286     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
287 }
288 
289 static const TypeInfo tpm_crb_info = {
290     .name = TYPE_TPM_CRB,
291     /* could be TYPE_SYS_BUS_DEVICE (or LPC etc) */
292     .parent = TYPE_DEVICE,
293     .instance_size = sizeof(CRBState),
294     .class_init  = tpm_crb_class_init,
295     .interfaces = (InterfaceInfo[]) {
296         { TYPE_TPM_IF },
297         { }
298     }
299 };
300 
301 static void tpm_crb_register(void)
302 {
303     type_register_static(&tpm_crb_info);
304 }
305 
306 type_init(tpm_crb_register)
307