qemu-e2k/hw/tpm/tpm_emulator.c

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/*
* Emulator TPM driver
*
* Copyright (c) 2017 Intel Corporation
* Author: Amarnath Valluri <amarnath.valluri@intel.com>
*
* Copyright (c) 2010 - 2013 IBM Corporation
* Authors:
* Stefan Berger <stefanb@us.ibm.com>
*
* Copyright (C) 2011 IAIK, Graz University of Technology
* Author: Andreas Niederl
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see <http://www.gnu.org/licenses/>
*
*/
#include "qemu/osdep.h"
#include "qemu/error-report.h"
#include "qemu/sockets.h"
#include "io/channel-socket.h"
#include "sysemu/tpm_backend.h"
#include "tpm_int.h"
#include "hw/hw.h"
#include "tpm_util.h"
#include "tpm_ioctl.h"
#include "migration/blocker.h"
#include "qapi/error.h"
#include "qapi/clone-visitor.h"
#include "chardev/char-fe.h"
#define DEBUG_TPM 0
#define DPRINTF(fmt, ...) do { \
if (DEBUG_TPM) { \
fprintf(stderr, "tpm-emulator:"fmt"\n", ## __VA_ARGS__); \
} \
} while (0)
#define TYPE_TPM_EMULATOR "tpm-emulator"
#define TPM_EMULATOR(obj) \
OBJECT_CHECK(TPMEmulator, (obj), TYPE_TPM_EMULATOR)
#define TPM_EMULATOR_IMPLEMENTS_ALL_CAPS(S, cap) (((S)->caps & (cap)) == (cap))
/* data structures */
typedef struct TPMEmulator {
TPMBackend parent;
TPMEmulatorOptions *options;
CharBackend ctrl_chr;
QIOChannel *data_ioc;
TPMVersion tpm_version;
ptm_cap caps; /* capabilities of the TPM */
uint8_t cur_locty_number; /* last set locality */
Error *migration_blocker;
QemuMutex mutex;
unsigned int established_flag:1;
unsigned int established_flag_cached:1;
} TPMEmulator;
static int tpm_emulator_ctrlcmd(TPMEmulator *tpm, unsigned long cmd, void *msg,
size_t msg_len_in, size_t msg_len_out)
{
CharBackend *dev = &tpm->ctrl_chr;
uint32_t cmd_no = cpu_to_be32(cmd);
ssize_t n = sizeof(uint32_t) + msg_len_in;
uint8_t *buf = NULL;
int ret = -1;
qemu_mutex_lock(&tpm->mutex);
buf = g_alloca(n);
memcpy(buf, &cmd_no, sizeof(cmd_no));
memcpy(buf + sizeof(cmd_no), msg, msg_len_in);
n = qemu_chr_fe_write_all(dev, buf, n);
if (n <= 0) {
goto end;
}
if (msg_len_out != 0) {
n = qemu_chr_fe_read_all(dev, msg, msg_len_out);
if (n <= 0) {
goto end;
}
}
ret = 0;
end:
qemu_mutex_unlock(&tpm->mutex);
return ret;
}
static int tpm_emulator_unix_tx_bufs(TPMEmulator *tpm_emu,
const uint8_t *in, uint32_t in_len,
uint8_t *out, uint32_t out_len,
bool *selftest_done,
Error **err)
{
ssize_t ret;
bool is_selftest = false;
if (selftest_done) {
*selftest_done = false;
is_selftest = tpm_util_is_selftest(in, in_len);
}
ret = qio_channel_write_all(tpm_emu->data_ioc, (char *)in, in_len, err);
if (ret != 0) {
return -1;
}
ret = qio_channel_read_all(tpm_emu->data_ioc, (char *)out,
sizeof(struct tpm_resp_hdr), err);
if (ret != 0) {
return -1;
}
ret = qio_channel_read_all(tpm_emu->data_ioc,
(char *)out + sizeof(struct tpm_resp_hdr),
tpm_cmd_get_size(out) - sizeof(struct tpm_resp_hdr), err);
if (ret != 0) {
return -1;
}
if (is_selftest) {
*selftest_done = tpm_cmd_get_errcode(out) == 0;
}
return 0;
}
static int tpm_emulator_set_locality(TPMEmulator *tpm_emu, uint8_t locty_number,
Error **errp)
{
ptm_loc loc;
DPRINTF("%s : locality: 0x%x", __func__, locty_number);
if (tpm_emu->cur_locty_number == locty_number) {
return 0;
}
DPRINTF("setting locality : 0x%x", locty_number);
loc.u.req.loc = locty_number;
if (tpm_emulator_ctrlcmd(tpm_emu, CMD_SET_LOCALITY, &loc,
sizeof(loc), sizeof(loc)) < 0) {
error_setg(errp, "tpm-emulator: could not set locality : %s",
strerror(errno));
return -1;
}
loc.u.resp.tpm_result = be32_to_cpu(loc.u.resp.tpm_result);
if (loc.u.resp.tpm_result != 0) {
error_setg(errp, "tpm-emulator: TPM result for set locality : 0x%x",
loc.u.resp.tpm_result);
return -1;
}
tpm_emu->cur_locty_number = locty_number;
return 0;
}
static void tpm_emulator_handle_request(TPMBackend *tb, TPMBackendCmd *cmd,
Error **errp)
{
TPMEmulator *tpm_emu = TPM_EMULATOR(tb);
DPRINTF("processing TPM command");
if (tpm_emulator_set_locality(tpm_emu, cmd->locty, errp) < 0 ||
tpm_emulator_unix_tx_bufs(tpm_emu, cmd->in, cmd->in_len,
cmd->out, cmd->out_len,
&cmd->selftest_done, errp) < 0) {
tpm_util_write_fatal_error_response(cmd->out, cmd->out_len);
}
}
static int tpm_emulator_probe_caps(TPMEmulator *tpm_emu)
{
DPRINTF("%s", __func__);
if (tpm_emulator_ctrlcmd(tpm_emu, CMD_GET_CAPABILITY,
&tpm_emu->caps, 0, sizeof(tpm_emu->caps)) < 0) {
error_report("tpm-emulator: probing failed : %s", strerror(errno));
return -1;
}
tpm_emu->caps = be64_to_cpu(tpm_emu->caps);
DPRINTF("capabilities : 0x%"PRIx64, tpm_emu->caps);
return 0;
}
static int tpm_emulator_check_caps(TPMEmulator *tpm_emu)
{
ptm_cap caps = 0;
const char *tpm = NULL;
/* check for min. required capabilities */
switch (tpm_emu->tpm_version) {
case TPM_VERSION_1_2:
caps = PTM_CAP_INIT | PTM_CAP_SHUTDOWN | PTM_CAP_GET_TPMESTABLISHED |
PTM_CAP_SET_LOCALITY | PTM_CAP_SET_DATAFD | PTM_CAP_STOP |
PTM_CAP_SET_BUFFERSIZE;
tpm = "1.2";
break;
case TPM_VERSION_2_0:
caps = PTM_CAP_INIT | PTM_CAP_SHUTDOWN | PTM_CAP_GET_TPMESTABLISHED |
PTM_CAP_SET_LOCALITY | PTM_CAP_RESET_TPMESTABLISHED |
PTM_CAP_SET_DATAFD | PTM_CAP_STOP | PTM_CAP_SET_BUFFERSIZE;
tpm = "2";
break;
case TPM_VERSION_UNSPEC:
error_report("tpm-emulator: TPM version has not been set");
return -1;
}
if (!TPM_EMULATOR_IMPLEMENTS_ALL_CAPS(tpm_emu, caps)) {
error_report("tpm-emulator: TPM does not implement minimum set of "
"required capabilities for TPM %s (0x%x)", tpm, (int)caps);
return -1;
}
return 0;
}
static int tpm_emulator_stop_tpm(TPMBackend *tb)
{
TPMEmulator *tpm_emu = TPM_EMULATOR(tb);
ptm_res res;
if (tpm_emulator_ctrlcmd(tpm_emu, CMD_STOP, &res, 0, sizeof(res)) < 0) {
error_report("tpm-emulator: Could not stop TPM: %s",
strerror(errno));
return -1;
}
res = be32_to_cpu(res);
if (res) {
error_report("tpm-emulator: TPM result for CMD_STOP: 0x%x", res);
return -1;
}
return 0;
}
static int tpm_emulator_set_buffer_size(TPMBackend *tb,
size_t wanted_size,
size_t *actual_size)
{
TPMEmulator *tpm_emu = TPM_EMULATOR(tb);
ptm_setbuffersize psbs;
if (tpm_emulator_stop_tpm(tb) < 0) {
return -1;
}
psbs.u.req.buffersize = cpu_to_be32(wanted_size);
if (tpm_emulator_ctrlcmd(tpm_emu, CMD_SET_BUFFERSIZE, &psbs,
sizeof(psbs.u.req), sizeof(psbs.u.resp)) < 0) {
error_report("tpm-emulator: Could not set buffer size: %s",
strerror(errno));
return -1;
}
psbs.u.resp.tpm_result = be32_to_cpu(psbs.u.resp.tpm_result);
if (psbs.u.resp.tpm_result != 0) {
error_report("tpm-emulator: TPM result for set buffer size : 0x%x",
psbs.u.resp.tpm_result);
return -1;
}
if (actual_size) {
*actual_size = be32_to_cpu(psbs.u.resp.buffersize);
}
DPRINTF("buffer size: %u, min: %u, max: %u\n",
be32_to_cpu(psbs.u.resp.buffersize),
be32_to_cpu(psbs.u.resp.minsize),
be32_to_cpu(psbs.u.resp.maxsize));
return 0;
}
static int tpm_emulator_startup_tpm(TPMBackend *tb, size_t buffersize)
{
TPMEmulator *tpm_emu = TPM_EMULATOR(tb);
ptm_init init = {
.u.req.init_flags = 0,
};
ptm_res res;
if (buffersize != 0 &&
tpm_emulator_set_buffer_size(tb, buffersize, NULL) < 0) {
goto err_exit;
}
DPRINTF("%s", __func__);
if (tpm_emulator_ctrlcmd(tpm_emu, CMD_INIT, &init, sizeof(init),
sizeof(init)) < 0) {
error_report("tpm-emulator: could not send INIT: %s",
strerror(errno));
goto err_exit;
}
res = be32_to_cpu(init.u.resp.tpm_result);
if (res) {
error_report("tpm-emulator: TPM result for CMD_INIT: 0x%x", res);
goto err_exit;
}
return 0;
err_exit:
return -1;
}
static bool tpm_emulator_get_tpm_established_flag(TPMBackend *tb)
{
TPMEmulator *tpm_emu = TPM_EMULATOR(tb);
ptm_est est;
if (tpm_emu->established_flag_cached) {
return tpm_emu->established_flag;
}
if (tpm_emulator_ctrlcmd(tpm_emu, CMD_GET_TPMESTABLISHED, &est,
0, sizeof(est)) < 0) {
error_report("tpm-emulator: Could not get the TPM established flag: %s",
strerror(errno));
return false;
}
DPRINTF("got established flag: %0x", est.u.resp.bit);
tpm_emu->established_flag_cached = 1;
tpm_emu->established_flag = (est.u.resp.bit != 0);
return tpm_emu->established_flag;
}
static int tpm_emulator_reset_tpm_established_flag(TPMBackend *tb,
uint8_t locty)
{
TPMEmulator *tpm_emu = TPM_EMULATOR(tb);
ptm_reset_est reset_est;
ptm_res res;
/* only a TPM 2.0 will support this */
if (tpm_emu->tpm_version != TPM_VERSION_2_0) {
return 0;
}
reset_est.u.req.loc = tpm_emu->cur_locty_number;
if (tpm_emulator_ctrlcmd(tpm_emu, CMD_RESET_TPMESTABLISHED,
&reset_est, sizeof(reset_est),
sizeof(reset_est)) < 0) {
error_report("tpm-emulator: Could not reset the establishment bit: %s",
strerror(errno));
return -1;
}
res = be32_to_cpu(reset_est.u.resp.tpm_result);
if (res) {
error_report("tpm-emulator: TPM result for rest establixhed flag: 0x%x",
res);
return -1;
}
tpm_emu->established_flag_cached = 0;
return 0;
}
static void tpm_emulator_cancel_cmd(TPMBackend *tb)
{
TPMEmulator *tpm_emu = TPM_EMULATOR(tb);
ptm_res res;
if (!TPM_EMULATOR_IMPLEMENTS_ALL_CAPS(tpm_emu, PTM_CAP_CANCEL_TPM_CMD)) {
DPRINTF("Backend does not support CANCEL_TPM_CMD");
return;
}
/* FIXME: make the function non-blocking, or it may block a VCPU */
if (tpm_emulator_ctrlcmd(tpm_emu, CMD_CANCEL_TPM_CMD, &res, 0,
sizeof(res)) < 0) {
error_report("tpm-emulator: Could not cancel command: %s",
strerror(errno));
} else if (res != 0) {
error_report("tpm-emulator: Failed to cancel TPM: 0x%x",
be32_to_cpu(res));
}
}
static TPMVersion tpm_emulator_get_tpm_version(TPMBackend *tb)
{
TPMEmulator *tpm_emu = TPM_EMULATOR(tb);
return tpm_emu->tpm_version;
}
static size_t tpm_emulator_get_buffer_size(TPMBackend *tb)
{
size_t actual_size;
if (tpm_emulator_set_buffer_size(tb, 0, &actual_size) < 0) {
return 4096;
}
return actual_size;
}
static int tpm_emulator_block_migration(TPMEmulator *tpm_emu)
{
Error *err = NULL;
error_setg(&tpm_emu->migration_blocker,
"Migration disabled: TPM emulator not yet migratable");
migrate_add_blocker(tpm_emu->migration_blocker, &err);
if (err) {
error_report_err(err);
error_free(tpm_emu->migration_blocker);
tpm_emu->migration_blocker = NULL;
return -1;
}
return 0;
}
static int tpm_emulator_prepare_data_fd(TPMEmulator *tpm_emu)
{
ptm_res res;
Error *err = NULL;
int fds[2] = { -1, -1 };
if (socketpair(AF_UNIX, SOCK_STREAM, 0, fds) < 0) {
error_report("tpm-emulator: Failed to create socketpair");
return -1;
}
qemu_chr_fe_set_msgfds(&tpm_emu->ctrl_chr, fds + 1, 1);
if (tpm_emulator_ctrlcmd(tpm_emu, CMD_SET_DATAFD, &res, 0,
sizeof(res)) < 0 || res != 0) {
error_report("tpm-emulator: Failed to send CMD_SET_DATAFD: %s",
strerror(errno));
goto err_exit;
}
tpm_emu->data_ioc = QIO_CHANNEL(qio_channel_socket_new_fd(fds[0], &err));
if (err) {
error_prepend(&err, "tpm-emulator: Failed to create io channel: ");
error_report_err(err);
goto err_exit;
}
closesocket(fds[1]);
return 0;
err_exit:
closesocket(fds[0]);
closesocket(fds[1]);
return -1;
}
static int tpm_emulator_handle_device_opts(TPMEmulator *tpm_emu, QemuOpts *opts)
{
const char *value;
value = qemu_opt_get(opts, "chardev");
if (value) {
Error *err = NULL;
Chardev *dev = qemu_chr_find(value);
if (!dev) {
error_report("tpm-emulator: tpm chardev '%s' not found.", value);
goto err;
}
if (!qemu_chr_fe_init(&tpm_emu->ctrl_chr, dev, &err)) {
error_prepend(&err, "tpm-emulator: No valid chardev found at '%s':",
value);
error_report_err(err);
goto err;
}
tpm_emu->options->chardev = g_strdup(value);
}
if (tpm_emulator_prepare_data_fd(tpm_emu) < 0) {
goto err;
}
/* FIXME: tpm_util_test_tpmdev() accepts only on socket fd, as it also used
* by passthrough driver, which not yet using GIOChannel.
*/
if (tpm_util_test_tpmdev(QIO_CHANNEL_SOCKET(tpm_emu->data_ioc)->fd,
&tpm_emu->tpm_version)) {
error_report("'%s' is not emulating TPM device. Error: %s",
tpm_emu->options->chardev, strerror(errno));
goto err;
}
DPRINTF("TPM Version %s", tpm_emu->tpm_version == TPM_VERSION_1_2 ? "1.2" :
(tpm_emu->tpm_version == TPM_VERSION_2_0 ? "2.0" : "Unspecified"));
if (tpm_emulator_probe_caps(tpm_emu) ||
tpm_emulator_check_caps(tpm_emu)) {
goto err;
}
return tpm_emulator_block_migration(tpm_emu);
err:
DPRINTF("Startup error");
return -1;
}
static TPMBackend *tpm_emulator_create(QemuOpts *opts)
{
TPMBackend *tb = TPM_BACKEND(object_new(TYPE_TPM_EMULATOR));
if (tpm_emulator_handle_device_opts(TPM_EMULATOR(tb), opts)) {
object_unref(OBJECT(tb));
return NULL;
}
return tb;
}
static TpmTypeOptions *tpm_emulator_get_tpm_options(TPMBackend *tb)
{
TPMEmulator *tpm_emu = TPM_EMULATOR(tb);
TpmTypeOptions *options = g_new0(TpmTypeOptions, 1);
options->type = TPM_TYPE_OPTIONS_KIND_EMULATOR;
options->u.emulator.data = QAPI_CLONE(TPMEmulatorOptions, tpm_emu->options);
return options;
}
static const QemuOptDesc tpm_emulator_cmdline_opts[] = {
TPM_STANDARD_CMDLINE_OPTS,
{
.name = "chardev",
.type = QEMU_OPT_STRING,
.help = "Character device to use for out-of-band control messages",
},
{ /* end of list */ },
};
static void tpm_emulator_inst_init(Object *obj)
{
TPMEmulator *tpm_emu = TPM_EMULATOR(obj);
DPRINTF("%s", __func__);
tpm_emu->options = g_new0(TPMEmulatorOptions, 1);
tpm_emu->cur_locty_number = ~0;
qemu_mutex_init(&tpm_emu->mutex);
}
/*
* Gracefully shut down the external TPM
*/
static void tpm_emulator_shutdown(TPMEmulator *tpm_emu)
{
ptm_res res;
if (tpm_emulator_ctrlcmd(tpm_emu, CMD_SHUTDOWN, &res, 0, sizeof(res)) < 0) {
error_report("tpm-emulator: Could not cleanly shutdown the TPM: %s",
strerror(errno));
} else if (res != 0) {
error_report("tpm-emulator: TPM result for sutdown: 0x%x",
be32_to_cpu(res));
}
}
static void tpm_emulator_inst_finalize(Object *obj)
{
TPMEmulator *tpm_emu = TPM_EMULATOR(obj);
tpm_emulator_shutdown(tpm_emu);
object_unref(OBJECT(tpm_emu->data_ioc));
qemu_chr_fe_deinit(&tpm_emu->ctrl_chr, false);
qapi_free_TPMEmulatorOptions(tpm_emu->options);
if (tpm_emu->migration_blocker) {
migrate_del_blocker(tpm_emu->migration_blocker);
error_free(tpm_emu->migration_blocker);
}
qemu_mutex_destroy(&tpm_emu->mutex);
}
static void tpm_emulator_class_init(ObjectClass *klass, void *data)
{
TPMBackendClass *tbc = TPM_BACKEND_CLASS(klass);
tbc->type = TPM_TYPE_EMULATOR;
tbc->opts = tpm_emulator_cmdline_opts;
tbc->desc = "TPM emulator backend driver";
tbc->create = tpm_emulator_create;
tbc->startup_tpm = tpm_emulator_startup_tpm;
tbc->cancel_cmd = tpm_emulator_cancel_cmd;
tbc->get_tpm_established_flag = tpm_emulator_get_tpm_established_flag;
tbc->reset_tpm_established_flag = tpm_emulator_reset_tpm_established_flag;
tbc->get_tpm_version = tpm_emulator_get_tpm_version;
tbc->get_buffer_size = tpm_emulator_get_buffer_size;
tbc->get_tpm_options = tpm_emulator_get_tpm_options;
tbc->handle_request = tpm_emulator_handle_request;
}
static const TypeInfo tpm_emulator_info = {
.name = TYPE_TPM_EMULATOR,
.parent = TYPE_TPM_BACKEND,
.instance_size = sizeof(TPMEmulator),
.class_init = tpm_emulator_class_init,
.instance_init = tpm_emulator_inst_init,
.instance_finalize = tpm_emulator_inst_finalize,
};
static void tpm_emulator_register(void)
{
type_register_static(&tpm_emulator_info);
}
type_init(tpm_emulator_register)