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