[v5,8/8] tpm: Added support for TPM emulator

Commit Message

Amarnath Valluri June 5, 2017, 12:45 p.m. UTC

This change introduces a new TPM backend driver that can communicate with
swtpm(software TPM emulator) using unix domain socket interface.

Swtpm uses two unix sockets, one for plain TPM commands and responses, and one
for out-of-band control messages.

The swtpm and associated tools can be found here:
    https://github.com/stefanberger/swtpm

The swtpm's control channel protocol specification can be found here:
    https://github.com/stefanberger/swtpm/wiki/Control-Channel-Specification

Usage:
    # setup TPM state directory
    mkdir /tmp/mytpm
    chown -R tss:root /tmp/mytpm
    /usr/bin/swtpm_setup --tpm-state /tmp/mytpm --createek

    # Ask qemu to use TPM emulator with given tpm state directory
    qemu-system-x86_64 \
        [...] \
        -tpmdev emulator,id=tpm0,tpmstatedir=/tmp/mytpm,logfile=/tmp/swtpm.log \
        -device tpm-tis,tpmdev=tpm0 \
        [...]

Signed-off-by: Amarnath Valluri <[e-mail]>
---
 configure             |  15 +-
 hmp.c                 |  21 ++
 hw/tpm/Makefile.objs  |   1 +
 hw/tpm/tpm_emulator.c | 973 ++++++++++++++++++++++++++++++++++++++++++++++++++
 hw/tpm/tpm_ioctl.h    | 243 +++++++++++++
 qapi-schema.json      |  41 ++-
 qemu-options.hx       |  53 ++-
 tpm.c                 |   2 +-
 8 files changed, 1339 insertions(+), 10 deletions(-)
 create mode 100644 hw/tpm/tpm_emulator.c
 create mode 100644 hw/tpm/tpm_ioctl.h

Comments

Stefan Berger July 12, 2017, 6:24 p.m. UTC | #1

On 06/05/2017 08:45 AM, Amarnath Valluri wrote:
> This change introduces a new TPM backend driver that can communicate with
> swtpm(software TPM emulator) using unix domain socket interface.
>
> Swtpm uses two unix sockets, one for plain TPM commands and responses, and one
> for out-of-band control messages.
>
> The swtpm and associated tools can be found here:
>      https://github.com/stefanberger/swtpm
>
> The swtpm's control channel protocol specification can be found here:
>      https://github.com/stefanberger/swtpm/wiki/Control-Channel-Specification
>
> Usage:
>      # setup TPM state directory
>      mkdir /tmp/mytpm
>      chown -R tss:root /tmp/mytpm
>      /usr/bin/swtpm_setup --tpm-state /tmp/mytpm --createek
>
>      # Ask qemu to use TPM emulator with given tpm state directory
>      qemu-system-x86_64 \
>          [...] \
>          -tpmdev emulator,id=tpm0,tpmstatedir=/tmp/mytpm,logfile=/tmp/swtpm.log \
>          -device tpm-tis,tpmdev=tpm0 \
>          [...]
>
> Signed-off-by: Amarnath Valluri <[e-mail]>
> ---
>   configure             |  15 +-
>   hmp.c                 |  21 ++
>   hw/tpm/Makefile.objs  |   1 +
>   hw/tpm/tpm_emulator.c | 973 ++++++++++++++++++++++++++++++++++++++++++++++++++
>   hw/tpm/tpm_ioctl.h    | 243 +++++++++++++
>   qapi-schema.json      |  41 ++-
>   qemu-options.hx       |  53 ++-
>   tpm.c                 |   2 +-
>   8 files changed, 1339 insertions(+), 10 deletions(-)
>   create mode 100644 hw/tpm/tpm_emulator.c
>   create mode 100644 hw/tpm/tpm_ioctl.h
>
> diff --git a/configure b/configure
> index 39e727e..b010bfb 100755
> --- a/configure
> +++ b/configure
> @@ -3404,10 +3404,15 @@ fi
>   ##########################################
>   # TPM passthrough is only on x86 Linux
>
> -if test "$targetos" = Linux && test "$cpu" = i386 -o "$cpu" = x86_64; then
> -  tpm_passthrough=$tpm
> +if test "$targetos" = Linux; then
> +  tpm_emulator=$tpm
> +  if test "$cpu" = i386 -o "$cpu" = x86_64; then
> +    tpm_passthrough=$tpm
> +  else
> +    tpm_passthrough=no
> +  fi
>   else
> -  tpm_passthrough=no
> +  tpm_emulator=no
>   fi
>
>   ##########################################
> @@ -5214,6 +5219,7 @@ echo "gcov enabled      $gcov"
>   echo "TPM support       $tpm"
>   echo "libssh2 support   $libssh2"
>   echo "TPM passthrough   $tpm_passthrough"
> +echo "TPM emulator      $tpm_emulator"
>   echo "QOM debugging     $qom_cast_debug"
>   echo "lzo support       $lzo"
>   echo "snappy support    $snappy"
> @@ -5794,6 +5800,9 @@ if test "$tpm" = "yes"; then
>     if test "$tpm_passthrough" = "yes"; then
>       echo "CONFIG_TPM_PASSTHROUGH=y" >> $config_host_mak
>     fi
> +  if test "$tpm_emulator" = "yes"; then
> +    echo "CONFIG_TPM_EMULATOR=y" >> $config_host_mak
> +  fi
>   fi
>
>   echo "TRACE_BACKENDS=$trace_backends" >> $config_host_mak
> diff --git a/hmp.c b/hmp.c
> index 9338938..073faef 100644
> --- a/hmp.c
> +++ b/hmp.c
> @@ -938,6 +938,7 @@ void hmp_info_tpm(Monitor *mon, const QDict *qdict)
>       Error *err = NULL;
>       unsigned int c = 0;
>       TPMPassthroughOptions *tpo;
> +    TPMEmulatorOptions *teo;
>
>       info_list = qmp_query_tpm(&err);
>       if (err) {
> @@ -967,6 +968,26 @@ void hmp_info_tpm(Monitor *mon, const QDict *qdict)
>                              tpo->has_cancel_path ? ",cancel-path=" : "",
>                              tpo->has_cancel_path ? tpo->cancel_path : "");
>               break;
> +        case TPM_TYPE_EMULATOR:
> +            teo = ti->options->u.emulator.data;
> +            monitor_printf(mon, ",tmpstatedir=%s", teo->tpmstatedir);
> +            monitor_printf(mon, ",spawn=%s", teo->spawn ? "on" : "off");
> +            if (teo->has_path) {
> +                monitor_printf(mon, ",path=%s", teo->path);
> +            }
> +            if (teo->has_data_path) {
> +                monitor_printf(mon, ",data-path=%s", teo->data_path);
> +            }
> +            if (teo->has_ctrl_path) {
> +                monitor_printf(mon, ",ctrl-path=%s", teo->ctrl_path);
> +            }
> +            if (teo->has_logfile) {
> +                monitor_printf(mon, ",logfile=%s", teo->logfile);
> +            }
> +            if (teo->has_loglevel) {
> +                monitor_printf(mon, ",loglevel=%u", teo->loglevel);
> +            }
> +            break;
>           default:
>               break;
>           }
> diff --git a/hw/tpm/Makefile.objs b/hw/tpm/Makefile.objs
> index 64cecc3..41f0b7a 100644
> --- a/hw/tpm/Makefile.objs
> +++ b/hw/tpm/Makefile.objs
> @@ -1,2 +1,3 @@
>   common-obj-$(CONFIG_TPM_TIS) += tpm_tis.o
>   common-obj-$(CONFIG_TPM_PASSTHROUGH) += tpm_passthrough.o tpm_util.o
> +common-obj-$(CONFIG_TPM_EMULATOR) += tpm_emulator.o tpm_util.o
> diff --git a/hw/tpm/tpm_emulator.c b/hw/tpm/tpm_emulator.c
> new file mode 100644
> index 0000000..c90914c
> --- /dev/null
> +++ b/hw/tpm/tpm_emulator.c
> @@ -0,0 +1,973 @@
> +/*
> + *  emulator TPM driver
> + *
> + *  Copyright (c) 2017 Intel Corporation
> + *  Author: Amarnath Valluri <[e-mail]>
> + *
> + *  Copyright (c) 2010 - 2013 IBM Corporation
> + *  Authors:
> + *    Stefan Berger <[e-mail]>
> + *
> + *  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 "hw/i386/pc.h"
> +#include "tpm_util.h"
> +#include "tpm_ioctl.h"
> +#include "migration/migration.h"
> +#include "qapi/error.h"
> +
> +#include <fcntl.h>
> +#include <sys/types.h>
> +#include <sys/stat.h>
> +#include <stdio.h>
> +
> +#define DEBUG_TPM 0
> +
> +#define DPRINT(fmt, ...) do { \
> +    if (DEBUG_TPM) { \
> +        fprintf(stderr, fmt, ## __VA_ARGS__); \
> +    } \
> +} while (0);
> +
> +#define DPRINTF(fmt, ...) DPRINT("tpm-emulator: "fmt"\n", __VA_ARGS__)
> +
> +#define TYPE_TPM_EMULATOR "tpm-emulator"
> +#define TPM_EMULATOR(obj) \
> +    OBJECT_CHECK(TPMEmulator, (obj), TYPE_TPM_EMULATOR)
> +
> +static const TPMDriverOps tpm_emulator_driver;
> +
> +/* data structures */
> +typedef struct TPMEmulator {
> +    TPMBackend parent;
> +
> +    TPMEmulatorOptions *ops;
> +    QIOChannel *data_ioc;
> +    QIOChannel *ctrl_ioc;
> +    bool op_executing;
> +    bool op_canceled;
> +    bool child_running;
> +    TPMVersion tpm_version;
> +    ptm_cap caps; /* capabilities of the TPM */
> +    uint8_t cur_locty_number; /* last set locality */
> +    QemuMutex state_lock;
> +    Error *migration_blocker;
> +} TPMEmulator;
> +
> +#define TPM_DEFAULT_EMULATOR "swtpm"
> +#define TPM_DEFAULT_LOGLEVEL 5
> +#define TPM_EMULATOR_PIDFILE "/tmp/qemu-tpm.pid"

Is this a single PID file used by all QEMUs running on the same system? 
I don't think this works when multiple QEMUs try to start TPMs 
concurrently. You may want to encode the pid of the QEMU process into it 
-> "/tmp/qemu-tpm.%u.pid", getpid() or something like that.

> +#define TPM_EMULATOR_IMPLEMENTS_ALL_CAPS(S, cap) (((S)->caps & (cap)) == (cap))
> +
> +static int tpm_emulator_ctrlcmd(QIOChannel *ioc, unsigned long cmd, void *msg,
> +                                size_t msg_len_in, size_t msg_len_out)
> +{
> +    ssize_t n;
> +
> +    uint32_t cmd_no = cpu_to_be32(cmd);
> +    struct iovec iov[2] = {
> +        { .iov_base = &cmd_no, .iov_len = sizeof(cmd_no), },
> +        { .iov_base = msg, .iov_len = msg_len_in, },
> +    };
> +
> +    n = qio_channel_writev(ioc, iov, 2, NULL);
> +    if (n > 0) {
> +        if (msg_len_out > 0) {
> +            n = qio_channel_read(ioc, (char *)msg, msg_len_out, NULL);
> +            /* simulate ioctl return value */
> +            if (n > 0) {
> +                n = 0;
> +            }
> +        } else {
> +            n = 0;
> +        }
> +    }
> +    return n;
> +}
> +
> +static int tpm_emulator_unix_tx_bufs(TPMEmulator *tpm_pt,
> +                                     const uint8_t *in, uint32_t in_len,
> +                                     uint8_t *out, uint32_t out_len,
> +                                     bool *selftest_done)
> +{
> +    ssize_t ret;
> +    bool is_selftest;
> +    const struct tpm_resp_hdr *hdr;
> +
> +    if (!tpm_pt->child_running) {
> +        return -1;
> +    }
> +
> +    tpm_pt->op_canceled = false;
> +    tpm_pt->op_executing = true;
> +    *selftest_done = false;
> +
> +    is_selftest = tpm_util_is_selftest(in, in_len);
> +
> +    ret = qio_channel_write(tpm_pt->data_ioc, (const char *)in, (size_t)in_len,
> +                            NULL);
> +    if (ret != in_len) {
> +        if (!tpm_pt->op_canceled || errno != ECANCELED) {
> +            error_report("tpm-emulator: error while transmitting data "
> +                         "to TPM: %s (%i)", strerror(errno), errno);
> +        }
> +        goto err_exit;
> +    }
> +
> +    tpm_pt->op_executing = false;
> +
> +    ret = qio_channel_read(tpm_pt->data_ioc, (char *)out, (size_t)out_len,
> +                           NULL);
> +    if (ret < 0) {
> +        if (!tpm_pt->op_canceled || errno != ECANCELED) {
> +            error_report("tpm-emulator: error while reading data from "
> +                         "TPM: %s (%i)", strerror(errno), errno);
> +        }
> +    } else if (ret < sizeof(struct tpm_resp_hdr) ||
> +               be32_to_cpu(((struct tpm_resp_hdr *)out)->len) != ret) {
> +        ret = -1;
> +        error_report("tpm-emulator: received invalid response "
> +                     "packet from TPM");
> +    }
> +
> +    if (is_selftest && (ret >= sizeof(struct tpm_resp_hdr))) {
> +        hdr = (struct tpm_resp_hdr *)out;
> +        *selftest_done = (be32_to_cpu(hdr->errcode) == 0);
> +    }
> +
> +err_exit:
> +    if (ret < 0) {
> +        tpm_util_write_fatal_error_response(out, out_len);
> +    }
> +
> +    tpm_pt->op_executing = false;
> +
> +    return ret;
> +}
> +
> +static int tpm_emulator_set_locality(TPMEmulator *tpm_pt,
> +                                     uint8_t locty_number)
> +{
> +    ptm_loc loc;
> +
> +    if (!tpm_pt->child_running) {
> +        return -1;
> +    }
> +
> +    DPRINTF("%s : locality: 0x%x", __func__, locty_number);
> +
> +    if (tpm_pt->cur_locty_number != locty_number) {
> +        DPRINTF("setting locality : 0x%x", locty_number);
> +        loc.u.req.loc = locty_number;
> +        if (tpm_emulator_ctrlcmd(tpm_pt->ctrl_ioc, CMD_SET_LOCALITY, &loc,
> +                             sizeof(loc), sizeof(loc)) < 0) {
> +            error_report("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_report("tpm-emulator: TPM result for set locality : 0x%x",
> +                         loc.u.resp.tpm_result);
> +            return -1;
> +        }
> +        tpm_pt->cur_locty_number = locty_number;
> +    }
> +    return 0;
> +}
> +
> +static void tpm_emulator_handle_request(TPMBackend *tb, TPMBackendCmd cmd)
> +{
> +    TPMEmulator *tpm_pt = TPM_EMULATOR(tb);
> +    TPMLocality *locty = NULL;
> +    bool selftest_done = false;
> +
> +    DPRINTF("processing command type %d", cmd);
> +
> +    switch (cmd) {
> +    case TPM_BACKEND_CMD_PROCESS_CMD:
> +        qemu_mutex_lock(&tpm_pt->state_lock);
> +        locty = tb->tpm_state->locty_data;
> +        if (tpm_emulator_set_locality(tpm_pt,
> +                                      tb->tpm_state->locty_number) < 0) {
> +            tpm_util_write_fatal_error_response(locty->r_buffer.buffer,
> +                                           locty->r_buffer.size);
> +        } else {
> +            tpm_emulator_unix_tx_bufs(tpm_pt, locty->w_buffer.buffer,
> +                                  locty->w_offset, locty->r_buffer.buffer,
> +                                  locty->r_buffer.size, &selftest_done);
> +        }
> +        tb->recv_data_callback(tb->tpm_state, tb->tpm_state->locty_number,
> +                               selftest_done);
> +        qemu_mutex_unlock(&tpm_pt->state_lock);
> +        break;
> +    case TPM_BACKEND_CMD_INIT:
> +    case TPM_BACKEND_CMD_END:
> +    case TPM_BACKEND_CMD_TPM_RESET:
> +        /* nothing to do */
> +        break;
> +    }
> +}
> +
> +/*
> + * Gracefully shut down the external unixio TPM
> + */
> +static void tpm_emulator_shutdown(TPMEmulator *tpm_pt)
> +{
> +    ptm_res res;
> +
> +    if (!tpm_pt->child_running) {
> +        return;
> +    }
> +
> +    if (tpm_emulator_ctrlcmd(tpm_pt->ctrl_ioc, 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 int tpm_emulator_probe_caps(TPMEmulator *tpm_pt)
> +{
> +    if (!tpm_pt->child_running) {
> +        return -1;
> +    }
> +
> +    DPRINTF("%s", __func__);
> +    if (tpm_emulator_ctrlcmd(tpm_pt->ctrl_ioc, CMD_GET_CAPABILITY,
> +                         &tpm_pt->caps, 0, sizeof(tpm_pt->caps)) < 0) {
> +        error_report("tpm-emulator: probing failed : %s", strerror(errno));
> +        return -1;
> +    }
> +
> +    tpm_pt->caps = be64_to_cpu(tpm_pt->caps);
> +
> +    DPRINTF("capbilities : 0x%lx", tpm_pt->caps);
> +
> +    return 0;
> +}
> +
> +static int tpm_emulator_check_caps(TPMEmulator *tpm_pt)
> +{
> +    ptm_cap caps = 0;
> +    const char *tpm = NULL;
> +
> +    /* check for min. required capabilities */
> +    switch (tpm_pt->tpm_version) {
> +    case TPM_VERSION_1_2:
> +        caps = PTM_CAP_INIT | PTM_CAP_SHUTDOWN | PTM_CAP_GET_TPMESTABLISHED |
> +               PTM_CAP_SET_LOCALITY;
> +        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;
> +        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_pt, 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_init_tpm(TPMEmulator *tpm_pt)
> +{
> +    ptm_init init;
> +    ptm_res res;
> +
> +    if (!tpm_pt->child_running) {
> +        return -1;
> +    }
> +
> +    DPRINTF("%s", __func__);
> +    if (tpm_emulator_ctrlcmd(tpm_pt->ctrl_ioc, CMD_INIT, &init, sizeof(init),
> +                         sizeof(init)) < 0) {
> +        error_report("tpm-emulator: could not send INIT: %s",
> +                     strerror(errno));
> +        return -1;
> +    }
> +
> +    res = be32_to_cpu(init.u.resp.tpm_result);
> +    if (res) {
> +        error_report("tpm-emulator: TPM result for CMD_INIT: 0x%x", res);
> +        return -1;
> +    }
> +
> +    return 0;
> +}
> +
> +static int tpm_emulator_startup_tpm(TPMBackend *tb)
> +{
> +    TPMEmulator *tpm_pt = TPM_EMULATOR(tb);
> +
> +    DPRINTF("%s", __func__);
> +
> +    tpm_emulator_init_tpm(tpm_pt) ;
> +
> +    return 0;
> +}
> +
> +static bool tpm_emulator_get_tpm_established_flag(TPMBackend *tb)
> +{
> +    TPMEmulator *tpm_pt = TPM_EMULATOR(tb);
> +    ptm_est est;
> +
> +    DPRINTF("%s", __func__);
> +    if (tpm_emulator_ctrlcmd(tpm_pt->ctrl_ioc, 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("established flag: %0x", est.u.resp.bit);
> +
> +    return (est.u.resp.bit != 0);
> +}
> +
> +static int tpm_emulator_reset_tpm_established_flag(TPMBackend *tb,
> +                                                   uint8_t locty)
> +{
> +    TPMEmulator *tpm_pt = TPM_EMULATOR(tb);
> +    ptm_reset_est reset_est;
> +    ptm_res res;
> +
> +    /* only a TPM 2.0 will support this */
> +    if (tpm_pt->tpm_version == TPM_VERSION_2_0) {
> +        reset_est.u.req.loc = tpm_pt->cur_locty_number;
> +
> +        if (tpm_emulator_ctrlcmd(tpm_pt->ctrl_ioc, 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;
> +        }
> +    }
> +
> +    return 0;
> +}
> +
> +static bool tpm_emulator_had_startup_error(TPMBackend *tb)
> +{
> +    TPMEmulator *tpm_pt = TPM_EMULATOR(tb);
> +
> +    return !tpm_pt->child_running;
> +}
> +
> +static void tpm_emulator_cancel_cmd(TPMBackend *tb)
> +{
> +    TPMEmulator *tpm_pt = TPM_EMULATOR(tb);
> +    ptm_res res;
> +
> +    /*
> +     * As of Linux 3.7 the tpm_tis driver does not properly cancel
> +     * commands on all TPM manufacturers' TPMs.
> +     * Only cancel if we're busy so we don't cancel someone else's
> +     * command, e.g., a command executed on the host.
> +     */
> +    if (tpm_pt->op_executing) {
> +        if (TPM_EMULATOR_IMPLEMENTS_ALL_CAPS(tpm_pt, PTM_CAP_CANCEL_TPM_CMD)) {
> +            if (tpm_emulator_ctrlcmd(tpm_pt->ctrl_ioc, 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));
> +            } else {
> +                tpm_pt->op_canceled = true;
> +            }
> +        }
> +    }
> +}
> +
> +static void tpm_emulator_reset(TPMBackend *tb)
> +{
> +    DPRINTF("%s", __func__);
> +
> +    tpm_emulator_cancel_cmd(tb);
> +}
> +
> +static TPMVersion tpm_emulator_get_tpm_version(TPMBackend *tb)
> +{
> +    TPMEmulator *tpm_pt = TPM_EMULATOR(tb);
> +
> +    return tpm_pt->tpm_version;
> +}
> +
> +static gboolean tpm_emulator_fd_handler(QIOChannel *ioc, GIOCondition cnd,
> +                                        void *opaque)
> +{
> +    TPMEmulator *tpm_pt = opaque;
> +
> +    if (cnd & G_IO_ERR || cnd & G_IO_HUP) {
> +        error_report("TPM backend disappeared");
> +        tpm_pt->child_running = false;
> +        return false;
> +    }
> +
> +    return true;
> +}
> +
> +static QIOChannel *_iochannel_new(const char *path, int fd, Error **err)
> +{
> +    int socket = path ?  unix_connect(path, err) : fd;
> +    if (socket < 0) {
> +        return NULL;
> +    }
> +
> +    return QIO_CHANNEL(qio_channel_socket_new_fd(socket, err));
> +}
> +
> +static int tpm_emulator_spawn_emulator(TPMEmulator *tpm_pt)
> +{
> +    int fds[2] = { -1, -1 };
> +    int ctrl_fds[2] = { -1, -1 };
> +    pid_t cpid;
> +
> +    if (!tpm_pt->ops->has_data_path) {
> +        if (socketpair(AF_UNIX, SOCK_SEQPACKET, 0, fds) < 0) {
> +            return -1;
> +        }
> +    }
> +
> +    if (!tpm_pt->ops->has_ctrl_path) {
> +        if (socketpair(AF_UNIX, SOCK_SEQPACKET, 0, ctrl_fds) < 0) {
> +            if (!tpm_pt->ops->has_data_path) {
> +                closesocket(fds[0]);
> +                closesocket(fds[1]);
> +            }
> +            return -1;
> +        }
> +    }
> +
> +    cpid = qemu_fork(NULL);
> +    if (cpid < 0) {
> +        error_report("tpm-emulator: Fork failure: %s", strerror(errno));
> +        if (!tpm_pt->ops->has_data_path) {
> +            closesocket(fds[0]);
> +            closesocket(fds[1]);
> +        }
> +        if (!tpm_pt->ops->has_ctrl_path) {
> +            closesocket(ctrl_fds[0]);
> +            closesocket(ctrl_fds[1]);
> +        }
> +        return -1;
> +    }
> +
> +    unlink(TPM_EMULATOR_PIDFILE);
> +
> +    if (cpid == 0) { /* CHILD */
> +        enum {
> +            PARAM_PATH,
> +            PARAM_IFACE,
> +            PARAM_SERVER,  PARAM_SERVER_ARGS,
> +            PARAM_CTRL,    PARAM_CTRL_ARGS,
> +            PARAM_STATE,   PARAM_STATE_ARGS,
> +            PARAM_PIDFILE, PARAM_PIDFILE_ARGS,
> +            PARAM_LOG,     PARAM_LOG_ARGS,
> +            PARAM_MAX
> +        };
> +
> +        int i;
> +        int data_fd = -1, ctrl_fd = -1;
> +        char *argv[PARAM_MAX + 1];
> +
> +        /* close all unused inherited sockets */
> +        if (fds[0] >= 0) {
> +            closesocket(fds[0]);
> +        }
> +        if (ctrl_fds[0] >= 0) {
> +            closesocket(ctrl_fds[0]);
> +        }
> +
> +        i = STDERR_FILENO + 1;
> +        if (fds[1] >= 0) {
> +            data_fd = dup2(fds[1], i++);
> +            if (data_fd < 0) {
> +                error_report("tpm-emulator: dup2() failure - %s",
> +                             strerror(errno));
> +                goto exit_child;
> +            }
> +        }
> +        if (ctrl_fds[1] >= 0) {
> +            ctrl_fd = dup2(ctrl_fds[1], i++);
> +            if (ctrl_fd < 0) {
> +                error_report("tpm-emulator: dup2() failure - %s",
> +                             strerror(errno));
> +                goto exit_child;
> +            }
> +        }
> +        for ( ; i < sysconf(_SC_OPEN_MAX); i++) {
> +            close(i);
> +        }
> +
> +        argv[PARAM_MAX] = NULL;
> +        argv[PARAM_PATH] = g_strdup(tpm_pt->ops->path);
> +        argv[PARAM_IFACE] = g_strdup("socket");
> +        if (tpm_pt->ops->has_data_path) {
> +            argv[PARAM_SERVER] = g_strdup("--server");
> +            argv[PARAM_SERVER_ARGS] = g_strdup_printf("type=unixio,path=%s",
> +                                               tpm_pt->ops->data_path);
> +        } else {
> +            argv[PARAM_SERVER] = g_strdup("--fd");
> +            argv[PARAM_SERVER_ARGS] = g_strdup_printf("%d", data_fd);
> +        }
> +
> +        argv[PARAM_CTRL] = g_strdup("--ctrl");
> +        if (tpm_pt->ops->has_ctrl_path) {
> +            argv[PARAM_CTRL_ARGS] = g_strdup_printf("type=unixio,path=%s",
> +                                                    tpm_pt->ops->ctrl_path);
> +        } else {
> +            argv[PARAM_CTRL_ARGS] = g_strdup_printf("type=unixio,clientfd=%d",
> +                                                    ctrl_fd);
> +        }
> +
> +        argv[PARAM_STATE] = g_strdup("--tpmstate");
> +        argv[PARAM_STATE_ARGS] = g_strdup_printf("dir=%s",
> +                                        tpm_pt->ops->tpmstatedir);
> +        argv[PARAM_PIDFILE] = g_strdup("--pid");
> +        argv[PARAM_PIDFILE_ARGS] = g_strdup_printf("file=%s",
> +                                            TPM_EMULATOR_PIDFILE);
> +        if (tpm_pt->ops->has_logfile) {
> +            argv[PARAM_LOG] = g_strdup("--log");
> +            argv[PARAM_LOG_ARGS] = g_strdup_printf("file=%s,level=%d",
> +                    tpm_pt->ops->logfile, (int)tpm_pt->ops->loglevel);
> +        } else {
> +            /* truncate logs */
> +            argv[PARAM_LOG] = NULL;
> +        }
> +        DPRINTF("%s", "Running cmd: ")
> +        for (i = 0; argv[i]; i++) {
> +            DPRINT(" %s", argv[i])
> +        }
> +        DPRINT("\n")
> +        if (execv(tpm_pt->ops->path, (char * const *)argv) < 0) {
> +            error_report("execv() failure : %s", strerror(errno));
> +        }
> +
> +exit_child:
> +        g_strfreev(argv);
> +        if (data_fd >= 0) {
> +            closesocket(data_fd);
> +        }
> +        if (ctrl_fd >= 0) {
> +            closesocket(ctrl_fd);
> +        }
> +
> +        _exit(1);
> +    } else { /* self */
> +        struct stat st;
> +        DPRINTF("child pid: %d", cpid);
> +        int rc;
> +        useconds_t usec = 100 * 1000L; /* wait for 100 milliseconds */
> +        useconds_t timeout = 10; /* max 1 second */
> +
> +        /* close unused sockets */
> +        if (fds[1] >= 0) {
> +            closesocket(fds[1]);
> +        }
> +        if (ctrl_fds[1] >= 0) {
> +            closesocket(ctrl_fds[1]);
> +        }
> +
> +        tpm_pt->data_ioc = _iochannel_new(tpm_pt->ops->data_path, fds[0], NULL);
> +        if (!tpm_pt->data_ioc) {
> +            error_report("tpm-emulator: Unable to connect socket : %s",
> +                          tpm_pt->ops->data_path);
> +            goto err_kill_child;
> +        }
> +
> +        tpm_pt->ctrl_ioc = _iochannel_new(tpm_pt->ops->ctrl_path, ctrl_fds[0],
> +                                          NULL);
> +        if (!tpm_pt->ctrl_ioc) {
> +            error_report("tpm-emulator: Unable to connect socket : %s",
> +                          tpm_pt->ops->ctrl_path);
> +            goto err_kill_child;
> +        }
> +
> +        qemu_add_child_watch(cpid);
> +
> +        qio_channel_add_watch(tpm_pt->data_ioc, G_IO_HUP | G_IO_ERR,
> +                              tpm_emulator_fd_handler, tpm_pt, NULL);
> +
> +        while ((rc = stat(TPM_EMULATOR_PIDFILE, &st)) < 0 && timeout--) {
> +            usleep(usec);
> +        }
> +
> +        if (timeout == -1) {
> +            error_report("tpm-emulator: pid file not ready: %s",
> +                         strerror(errno));
> +            goto err_kill_child;
> +        }
> +
> +        /* check if child really running */
> +        if (kill(cpid, 0) < 0 && errno == ESRCH) {
> +            goto err_no_child;
> +        }
> +
> +        tpm_pt->child_running = true;
> +    }
> +
> +    return 0;
> +
> +err_kill_child:
> +    kill(cpid, SIGTERM);
> +    /* wait for 10 mill-seconds */
> +    usleep(10 * 1000);
> +    /* force kill if still reachable */
> +    if (kill(cpid, 0) == 0) {
> +        kill(cpid, SIGKILL);
> +    }

You may want to loop on this as well checking whether it is still 
reachable. It will  terminate faster once it's gone.

timeout = 10;
while (kill(cpid, 0) == 0 && timeout--) {
     usleep(1000):
}
if (timeout == -1) {
     kill(cpid, SIGKILL);
}

> +
> +err_no_child:
> +    tpm_pt->child_running = false;
> +
> +    return -1;
> +}
> +
> +static void tpm_emulator_block_migration(TPMEmulator *tpm_pt)
> +{
> +   Error *err = NULL;
> +
> +   error_setg(&tpm_pt->migration_blocker,
> +              "Migration disabled: TPM emulator not yet migratable");

indentation

> +    migrate_add_blocker(tpm_pt->migration_blocker, &err);
> +    if (err) {
> +        error_free(err);
> +        error_free(tpm_pt->migration_blocker);
> +        tpm_pt->migration_blocker = NULL;
> +    }
> +}
> +
> +static int tpm_emulator_handle_device_opts(TPMEmulator *tpm_pt, QemuOpts *opts)
> +{
> +    const char *value;
> +
> +    value = qemu_opt_get(opts, "tpmstatedir");
> +    if (!value) {
> +        error_report("tpm-emulator: Missing tpm state directory");
> +        return -1;
> +    }
> +    tpm_pt->ops->tpmstatedir = g_strdup(value);
> +
> +    tpm_pt->ops->spawn = qemu_opt_get_bool(opts, "spawn", false);
> +
> +    value = qemu_opt_get(opts, "path");
> +    if (!value) {
> +        value = TPM_DEFAULT_EMULATOR;
> +        tpm_pt->ops->has_path = false;
> +    } else {
> +        tpm_pt->ops->has_path = true;
> +        if (value[0] == '/') {
> +            struct stat st;
> +            if (stat(value, &st) < 0 || !(S_ISREG(st.st_mode)
> +                || S_ISLNK(st.st_mode))) {
> +                error_report("tpm-emulator: Invalid emulator path: %s", value);
> +                return -1;
> +            }
> +        }
> +    }
> +    tpm_pt->ops->path = g_strdup(value);
> +
> +    value = qemu_opt_get(opts, "data-path");
> +    if (value) {
> +        tpm_pt->ops->has_data_path = true;
> +        tpm_pt->ops->data_path = g_strdup(value);
> +    } else {
> +        tpm_pt->ops->has_data_path = false;
> +        if (!tpm_pt->ops->spawn) {
> +            error_report("tpm-emulator: missing mandatory data-path");
> +            return -1;
> +        }
> +    }
> +
> +    value = qemu_opt_get(opts, "ctrl-path");
> +    if (value) {
> +        tpm_pt->ops->has_ctrl_path = true;
> +        tpm_pt->ops->ctrl_path = g_strdup(value);
> +    } else {
> +        tpm_pt->ops->has_ctrl_path = false;
> +        if (!tpm_pt->ops->spawn) {
> +            error_report("tpm-emulator: missing mandatory ctrl-path");
> +            return -1;
> +        }
> +    }
> +
> +    value = qemu_opt_get(opts, "logfile");
> +    if (value) {
> +        tpm_pt->ops->has_logfile = true;
> +        tpm_pt->ops->logfile = g_strdup(value);
> +        tpm_pt->ops->loglevel = qemu_opt_get_number(opts, "loglevel",
> +                                                   TPM_DEFAULT_LOGLEVEL);
> +        tpm_pt->ops->has_loglevel = tpm_pt->ops->loglevel !=
> +                                     TPM_DEFAULT_LOGLEVEL;
> +    }
> +
> +    if (tpm_pt->ops->spawn) {
> +        if (tpm_emulator_spawn_emulator(tpm_pt) < 0) {
> +            goto err_close_dev;
> +        }
> +    } else {
> +        tpm_pt->data_ioc = _iochannel_new(tpm_pt->ops->data_path, -1, NULL);
> +        if (tpm_pt->data_ioc  == NULL) {
> +            error_report("tpm-emulator: Failed to connect data socket: %s",
> +                         tpm_pt->ops->data_path);
> +            goto err_close_dev;
> +        }
> +        tpm_pt->ctrl_ioc = _iochannel_new(tpm_pt->ops->ctrl_path, -1, NULL);
> +        if (tpm_pt->ctrl_ioc == NULL) {
> +            DPRINTF("Failed to connect control socket: %s",
> +                    strerror(errno));
> +            goto err_close_dev;
> +        }
> +        tpm_pt->child_running = true;
> +    }
> +
> +    /* FIXME: tpm_util_test_tpmdev() accepts only on socket fd, as it also used

on -> one

> +     * by passthrough driver, which not yet using GIOChannel.

-> which is not yet

> +     */
> +    if (tpm_util_test_tpmdev(QIO_CHANNEL_SOCKET(tpm_pt->data_ioc)->fd,
> +                             &tpm_pt->tpm_version)) {
> +        error_report("'%s' is not emulating TPM device.", tpm_pt->ops->path);
> +        goto err_close_dev;
> +    }
> +
> +    DPRINTF("TPM Version %s", tpm_pt->tpm_version == TPM_VERSION_1_2 ? "1.2" :
> +             (tpm_pt->tpm_version == TPM_VERSION_2_0 ?  "2.0" : "Unspecified"));
> +
> +    if (tpm_emulator_probe_caps(tpm_pt) ||
> +        tpm_emulator_check_caps(tpm_pt)) {
> +        goto err_close_dev;
> +    }
> +
> +    tpm_emulator_block_migration(tpm_pt);
> +
> +    return 0;
> +
> +err_close_dev:

'close_dev' seems a bit misleading here...

> +    DPRINT("Startup error\n");
> +    return -1;
> +}
> +
> +static TPMBackend *tpm_emulator_create(QemuOpts *opts, const char *id)
> +{
> +    TPMBackend *tb = TPM_BACKEND(object_new(TYPE_TPM_EMULATOR));
> +
> +    tb->id = g_strdup(id);
> +
> +    if (tpm_emulator_handle_device_opts(TPM_EMULATOR(tb), opts)) {
> +        goto err_exit;
> +    }
> +
> +    return tb;
> +
> +err_exit:
> +    object_unref(OBJECT(tb));
> +
> +    return NULL;
> +}
> +
> +static TpmTypeOptions *tpm_emulator_get_tpm_options(TPMBackend *tb)
> +{
> +    TPMEmulator *tpm_pt = TPM_EMULATOR(tb);
> +    TpmTypeOptions *ops = NULL;
> +    TPMEmulatorOptions *eops = NULL;
> +
> +    eops = g_new0(TPMEmulatorOptions, 1);
> +    if (!eops) {
> +        return NULL;
> +    }
> +    DPRINTF("%s", __func__);
> +
> +    eops->tpmstatedir = g_strdup(tpm_pt->ops->tpmstatedir);
> +    eops->spawn = tpm_pt->ops->spawn;
> +    if (tpm_pt->ops->has_path) {
> +        eops->has_path = true;
> +        eops->path = g_strdup(tpm_pt->ops->path);
> +    }
> +    if (tpm_pt->ops->has_data_path) {
> +        eops->has_data_path = true;
> +        eops->data_path = g_strdup(tpm_pt->ops->data_path);
> +    }
> +    if (tpm_pt->ops->has_ctrl_path) {
> +        eops->has_ctrl_path = true;
> +        eops->ctrl_path = g_strdup(tpm_pt->ops->ctrl_path);
> +    }
> +    if (tpm_pt->ops->has_logfile) {
> +        eops->has_logfile = true;
> +        eops->logfile = g_strdup(tpm_pt->ops->logfile);
> +    }
> +    if (tpm_pt->ops->has_loglevel) {
> +        eops->has_loglevel = true;
> +        eops->loglevel = tpm_pt->ops->loglevel;
> +    }
> +
> +    ops = g_new0(TpmTypeOptions, 1);
> +    if (!ops) {
> +        qapi_free_TPMEmulatorOptions(eops);
> +        return NULL;
> +    }
> +
> +    ops->type = TPM_TYPE_EMULATOR;
> +    ops->u.emulator.data = eops;
> +
> +    return ops;
> +}
> +
> +static const QemuOptDesc tpm_emulator_cmdline_opts[] = {
> +    TPM_STANDARD_CMDLINE_OPTS,
> +    {
> +        .name = "tpmstatedir",
> +        .type = QEMU_OPT_STRING,
> +        .help = "TPM state directroy",

directroy -> directory

> +    },
> +    {
> +        .name = "spawn",
> +        .type = QEMU_OPT_BOOL,
> +        .help = "Wether to spwan given emlatory binary",

emlatory -> emulator

> +    },
> +    {
> +        .name = "path",
> +        .type = QEMU_OPT_STRING,
> +        .help = "Path to TPM emulator binary",
> +    },
> +    {
> +        .name = "data-path",
> +        .type = QEMU_OPT_STRING,
> +        .help = "Socket path to use for data exhange",

exhange -> exchange

> +    },
> +    {
> +        .name = "ctrl-path",
> +        .type = QEMU_OPT_STRING,
> +        .help = "Socket path to use for out-of-band control messages",
> +    },
> +    {
> +        .name = "logfile",
> +        .type = QEMU_OPT_STRING,
> +        .help = "Path to log file",
> +    },
> +    {
> +        .name = "loglevel",
> +        .type = QEMU_OPT_NUMBER,
> +        .help = "Log level number",
> +    },
> +    { /* end of list */ },
> +};
> +
> +static const TPMDriverOps tpm_emulator_driver = {
> +    .type                     = TPM_TYPE_EMULATOR,
> +    .opts                     = tpm_emulator_cmdline_opts,
> +    .desc                     = "TPM emulator backend driver",
> +
> +    .create                   = tpm_emulator_create,
> +    .startup_tpm              = tpm_emulator_startup_tpm,
> +    .reset                    = tpm_emulator_reset,
> +    .had_startup_error        = tpm_emulator_had_startup_error,
> +    .cancel_cmd               = tpm_emulator_cancel_cmd,
> +    .get_tpm_established_flag = tpm_emulator_get_tpm_established_flag,
> +    .reset_tpm_established_flag = tpm_emulator_reset_tpm_established_flag,
> +    .get_tpm_version          = tpm_emulator_get_tpm_version,
> +    .get_tpm_options          = tpm_emulator_get_tpm_options,
> +};
> +
> +static void tpm_emulator_inst_init(Object *obj)
> +{
> +    TPMEmulator *tpm_pt = TPM_EMULATOR(obj);
> +
> +    DPRINTF("%s", __func__);
> +    tpm_pt->ops = g_new0(TPMEmulatorOptions, 1);
> +    tpm_pt->data_ioc = tpm_pt->ctrl_ioc = NULL;
> +    tpm_pt->op_executing = tpm_pt->op_canceled = false;
> +    tpm_pt->child_running = false;
> +    tpm_pt->cur_locty_number = ~0;
> +    qemu_mutex_init(&tpm_pt->state_lock);
> +}
> +
> +static void tpm_emulator_inst_finalize(Object *obj)
> +{
> +    TPMEmulator *tpm_pt = TPM_EMULATOR(obj);
> +
> +    tpm_emulator_cancel_cmd(TPM_BACKEND(obj));
> +    tpm_emulator_shutdown(tpm_pt);
> +
> +    if (tpm_pt->data_ioc) {
> +        qio_channel_close(tpm_pt->data_ioc, NULL);
> +    }
> +    if (tpm_pt->ctrl_ioc) {
> +        qio_channel_close(tpm_pt->ctrl_ioc, NULL);
> +    }
> +    if (tpm_pt->ops) {
> +        qapi_free_TPMEmulatorOptions(tpm_pt->ops);
> +    }
> +
> +    if (tpm_pt->migration_blocker) {
> +        migrate_del_blocker(tpm_pt->migration_blocker);
> +        error_free(tpm_pt->migration_blocker);
> +    }
> +}
> +
> +static void tpm_emulator_class_init(ObjectClass *klass, void *data)
> +{
> +    TPMBackendClass *tbc = TPM_BACKEND_CLASS(klass);
> +    tbc->ops = &tpm_emulator_driver;
> +    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);
> +    tpm_register_driver(&tpm_emulator_driver);
> +}
> +
> +type_init(tpm_emulator_register)
> diff --git a/hw/tpm/tpm_ioctl.h b/hw/tpm/tpm_ioctl.h
> new file mode 100644
> index 0000000..af49708
> --- /dev/null
> +++ b/hw/tpm/tpm_ioctl.h
> @@ -0,0 +1,243 @@
> +/*
> + * tpm_ioctl.h
> + *
> + * (c) Copyright IBM Corporation 2014, 2015.
> + *
> + * This file is licensed under the terms of the 3-clause BSD license
> + */
> +#ifndef _TPM_IOCTL_H_
> +#define _TPM_IOCTL_H_
> +
> +#include <stdint.h>
> +#include <sys/uio.h>
> +#include <sys/types.h>
> +#include <sys/ioctl.h>
> +
> +/*
> + * Every response from a command involving a TPM command execution must hold
> + * the ptm_res as the first element.
> + * ptm_res corresponds to the error code of a command executed by the TPM.
> + */
> +
> +typedef uint32_t ptm_res;
> +
> +/* PTM_GET_TPMESTABLISHED: get the establishment bit */
> +struct ptm_est {
> +    union {
> +        struct {
> +            ptm_res tpm_result;
> +            unsigned char bit; /* TPM established bit */
> +        } resp; /* response */
> +    } u;
> +};
> +
> +/* PTM_RESET_TPMESTABLISHED: reset establishment bit */
> +struct ptm_reset_est {
> +    union {
> +        struct {
> +            uint8_t loc; /* locality to use */
> +        } req; /* request */
> +        struct {
> +            ptm_res tpm_result;
> +        } resp; /* response */
> +    } u;
> +};
> +
> +/* PTM_INIT */
> +struct ptm_init {
> +    union {
> +        struct {
> +            uint32_t init_flags; /* see definitions below */
> +        } req; /* request */
> +        struct {
> +            ptm_res tpm_result;
> +        } resp; /* response */
> +    } u;
> +};
> +
> +/* above init_flags */
> +#define PTM_INIT_FLAG_DELETE_VOLATILE (1 << 0)
> +    /* delete volatile state file after reading it */
> +
> +/* PTM_SET_LOCALITY */
> +struct ptm_loc {
> +    union {
> +        struct {
> +            uint8_t loc; /* locality to set */
> +        } req; /* request */
> +        struct {
> +            ptm_res tpm_result;
> +        } resp; /* response */
> +    } u;
> +};
> +
> +/* PTM_HASH_DATA: hash given data */
> +struct ptm_hdata {
> +    union {
> +        struct {
> +            uint32_t length;
> +            uint8_t data[4096];
> +        } req; /* request */
> +        struct {
> +            ptm_res tpm_result;
> +        } resp; /* response */
> +    } u;
> +};
> +
> +/*
> + * size of the TPM state blob to transfer; x86_64 can handle 8k,
> + * ppc64le only ~7k; keep the response below a 4k page size
> + */
> +#define PTM_STATE_BLOB_SIZE (3 * 1024)
> +
> +/*
> + * The following is the data structure to get state blobs from the TPM.
> + * If the size of the state blob exceeds the PTM_STATE_BLOB_SIZE, multiple reads
> + * with this ioctl and with adjusted offset are necessary. All bytes
> + * must be transferred and the transfer is done once the last byte has been
> + * returned.
> + * It is possible to use the read() interface for reading the data; however, the
> + * first bytes of the state blob will be part of the response to the ioctl(); a
> + * subsequent read() is only necessary if the total length (totlength) exceeds
> + * the number of received bytes. seek() is not supported.
> + */
> +struct ptm_getstate {
> +    union {
> +        struct {
> +            uint32_t state_flags; /* may be: PTM_STATE_FLAG_DECRYPTED */
> +            uint32_t type;        /* which blob to pull */
> +            uint32_t offset;      /* offset from where to read */
> +        } req; /* request */
> +        struct {
> +            ptm_res tpm_result;
> +            uint32_t state_flags; /* may be: PTM_STATE_FLAG_ENCRYPTED */
> +            uint32_t totlength;   /* total length that will be transferred */
> +            uint32_t length;      /* number of bytes in following buffer */
> +            uint8_t  data[PTM_STATE_BLOB_SIZE];
> +        } resp; /* response */
> +    } u;
> +};
> +
> +/* TPM state blob types */
> +#define PTM_BLOB_TYPE_PERMANENT  1
> +#define PTM_BLOB_TYPE_VOLATILE   2
> +#define PTM_BLOB_TYPE_SAVESTATE  3
> +
> +/* state_flags above : */
> +#define PTM_STATE_FLAG_DECRYPTED     1 /* on input:  get decrypted state */
> +#define PTM_STATE_FLAG_ENCRYPTED     2 /* on output: state is encrypted */
> +
> +/*
> + * The following is the data structure to set state blobs in the TPM.
> + * If the size of the state blob exceeds the PTM_STATE_BLOB_SIZE, multiple
> + * 'writes' using this ioctl are necessary. The last packet is indicated
> + * by the length being smaller than the PTM_STATE_BLOB_SIZE.
> + * The very first packet may have a length indicator of '0' enabling
> + * a write() with all the bytes from a buffer. If the write() interface
> + * is used, a final ioctl with a non-full buffer must be made to indicate
> + * that all data were transferred (a write with 0 bytes would not work).
> + */
> +struct ptm_setstate {
> +    union {
> +        struct {
> +            uint32_t state_flags; /* may be PTM_STATE_FLAG_ENCRYPTED */
> +            uint32_t type;        /* which blob to set */
> +            uint32_t length;      /* length of the data;
> +                                     use 0 on the first packet to
> +                                     transfer using write() */
> +            uint8_t data[PTM_STATE_BLOB_SIZE];
> +        } req; /* request */
> +        struct {
> +            ptm_res tpm_result;
> +        } resp; /* response */
> +    } u;
> +};
> +
> +/*
> + * PTM_GET_CONFIG: Data structure to get runtime configuration information
> + * such as which keys are applied.
> + */
> +struct ptm_getconfig {
> +    union {
> +        struct {
> +            ptm_res tpm_result;
> +            uint32_t flags;
> +        } resp; /* response */
> +    } u;
> +};
> +
> +#define PTM_CONFIG_FLAG_FILE_KEY        0x1
> +#define PTM_CONFIG_FLAG_MIGRATION_KEY   0x2
> +
> +
> +typedef uint64_t ptm_cap;
> +typedef struct ptm_est ptm_est;
> +typedef struct ptm_reset_est ptm_reset_est;
> +typedef struct ptm_loc ptm_loc;
> +typedef struct ptm_hdata ptm_hdata;
> +typedef struct ptm_init ptm_init;
> +typedef struct ptm_getstate ptm_getstate;
> +typedef struct ptm_setstate ptm_setstate;
> +typedef struct ptm_getconfig ptm_getconfig;
> +
> +/* capability flags returned by PTM_GET_CAPABILITY */
> +#define PTM_CAP_INIT               (1)
> +#define PTM_CAP_SHUTDOWN           (1 << 1)
> +#define PTM_CAP_GET_TPMESTABLISHED (1 << 2)
> +#define PTM_CAP_SET_LOCALITY       (1 << 3)
> +#define PTM_CAP_HASHING            (1 << 4)
> +#define PTM_CAP_CANCEL_TPM_CMD     (1 << 5)
> +#define PTM_CAP_STORE_VOLATILE     (1 << 6)
> +#define PTM_CAP_RESET_TPMESTABLISHED (1 << 7)
> +#define PTM_CAP_GET_STATEBLOB      (1 << 8)
> +#define PTM_CAP_SET_STATEBLOB      (1 << 9)
> +#define PTM_CAP_STOP               (1 << 10)
> +#define PTM_CAP_GET_CONFIG         (1 << 11)
> +
> +enum {
> +    PTM_GET_CAPABILITY     = _IOR('P', 0, ptm_cap),
> +    PTM_INIT               = _IOWR('P', 1, ptm_init),
> +    PTM_SHUTDOWN           = _IOR('P', 2, ptm_res),
> +    PTM_GET_TPMESTABLISHED = _IOR('P', 3, ptm_est),
> +    PTM_SET_LOCALITY       = _IOWR('P', 4, ptm_loc),
> +    PTM_HASH_START         = _IOR('P', 5, ptm_res),
> +    PTM_HASH_DATA          = _IOWR('P', 6, ptm_hdata),
> +    PTM_HASH_END           = _IOR('P', 7, ptm_res),
> +    PTM_CANCEL_TPM_CMD     = _IOR('P', 8, ptm_res),
> +    PTM_STORE_VOLATILE     = _IOR('P', 9, ptm_res),
> +    PTM_RESET_TPMESTABLISHED = _IOWR('P', 10, ptm_reset_est),
> +    PTM_GET_STATEBLOB      = _IOWR('P', 11, ptm_getstate),
> +    PTM_SET_STATEBLOB      = _IOWR('P', 12, ptm_setstate),
> +    PTM_STOP               = _IOR('P', 13, ptm_res),
> +    PTM_GET_CONFIG         = _IOR('P', 14, ptm_getconfig),
> +};
> +
> +/*
> + * Commands used by the non-CUSE TPMs
> + *
> + * All messages container big-endian data.
> + *
> + * The return messages only contain the 'resp' part of the unions
> + * in the data structures above. Besides that the limits in the
> + * buffers above (ptm_hdata:u.req.data and ptm_get_state:u.resp.data
> + * and ptm_set_state:u.req.data) are 0xffffffff.
> + */
> +enum {
> +    CMD_GET_CAPABILITY = 1,
> +    CMD_INIT,
> +    CMD_SHUTDOWN,
> +    CMD_GET_TPMESTABLISHED,
> +    CMD_SET_LOCALITY,
> +    CMD_HASH_START,
> +    CMD_HASH_DATA,
> +    CMD_HASH_END,
> +    CMD_CANCEL_TPM_CMD,
> +    CMD_STORE_VOLATILE,
> +    CMD_RESET_TPMESTABLISHED,
> +    CMD_GET_STATEBLOB,
> +    CMD_SET_STATEBLOB,
> +    CMD_STOP,
> +    CMD_GET_CONFIG,
> +};
> +
> +#endif /* _TPM_IOCTL_H */
> diff --git a/qapi-schema.json b/qapi-schema.json
> index 5728b7f..cfe0c94 100644
> --- a/qapi-schema.json
> +++ b/qapi-schema.json
> @@ -5123,10 +5123,12 @@
>   # An enumeration of TPM types
>   #
>   # @passthrough: TPM passthrough type
> +# @emulator: Software Emulator TPM type
> +#            Since: 2.10
>   #
>   # Since: 1.5
>   ##
> -{ 'enum': 'TpmType', 'data': [ 'passthrough' ] }
> +{ 'enum': 'TpmType', 'data': [ 'passthrough', 'emulator' ] }
>
>   ##
>   # @query-tpm-types:
> @@ -5140,7 +5142,7 @@
>   # Example:
>   #
>   # -> { "execute": "query-tpm-types" }
> -# <- { "return": [ "passthrough" ] }
> +# <- { "return": [ "passthrough", "emulator" ] }
>   #
>   ##
>   { 'command': 'query-tpm-types', 'returns': ['TpmType'] }
> @@ -5161,16 +5163,49 @@
>                                                '*cancel-path' : 'str'} }
>
>   ##
> +# @TPMEmulatorOptions:
> +#
> +# Information about the TPM emulator
> +#
> +# @tpmstatedir: TPM emulator state directory
> +# @spawn: true if, qemu has to spawn a new emulator process with given @path,

qemu -> QEMU

> +#         otherwise it connects to already rinning emulator with given @data-path

rinning -> running

> +#         and @ctrl-path sockets. (default: 'false')
> +# @path: TPM emulator binary path to spawn.(default: 'swtpm')
> +# @data-path: path of the unix socket to use for exchanging data messages, if

replace ',' with ';'

> +#             not provided socket pairs are used when @sapwn is true.

@sapwn -> @spawn

> +# @ctrl-path: path of the unix socket file to use for exchagning out-of-band

exchanging

> +#             control messages, if not provided socket pairs are used when

replace ',' with ';'

> +#             @spawn is true.
> +# @logfile: file to use to place TPM emulator logs, if not provided logging is

file to use for TPM emulator logs;

> +#           disabled.
> +# @loglevel: optional log level number, loglevel is ignored if no logfile

logfile is provided

> +#            provided. (default: 5)
> +#
> +# Since: 2.10
> +##
> +{ 'struct': 'TPMEmulatorOptions',
> +  'data': { 'tpmstatedir' : 'str',
> +            'spawn': 'bool',
> +            '*path': 'str',
> +            '*data-path': 'str',
> +            '*ctrl-path': 'str',
> +            '*logfile': 'str',
> +            '*loglevel': 'uint8' } }
> +
> +##
>   # @TpmTypeOptions:
>   #
>   # A union referencing different TPM backend types' configuration options
>   #
>   # @type: 'passthrough' The configuration options for the TPM passthrough type
> +#        'emulator' The configuration options for TPM emulator backend type
>   #
>   # Since: 1.5
>   ##
>   { 'union': 'TpmTypeOptions',
> -   'data': { 'passthrough' : 'TPMPassthroughOptions' } }
> +  'data': { 'passthrough': 'TPMPassthroughOptions',
> +            'emulator': 'TPMEmulatorOptions' } }
>
>   ##
>   # @TPMInfo:
> diff --git a/qemu-options.hx b/qemu-options.hx
> index f806af9..e4dbc33 100644
> --- a/qemu-options.hx
> +++ b/qemu-options.hx
> @@ -2883,7 +2883,15 @@ DEF("tpmdev", HAS_ARG, QEMU_OPTION_tpmdev, \
>       "-tpmdev passthrough,id=id[,path=path][,cancel-path=path]\n"
>       "                use path to provide path to a character device; default is /dev/tpm0\n"
>       "                use cancel-path to provide path to TPM's cancel sysfs entry; if\n"
> -    "                not provided it will be searched for in /sys/class/misc/tpm?/device\n",
> +    "                not provided it will be searched for in /sys/class/misc/tpm?/device\n"
> +    "-tpmdev emulator,id=id,spawn=on|off,tpmstatedir=dir[,path=emulator-path,data-path=path,ctrl-path=path,logfile=path,loglevel=level]\n"
> +    "                spawn=on|off controls spawning support\n"
> +    "                use tpmstatedir to provide path to the tpm state dirctory\n"

-> TPM state directory

> +    "                use path to provide the emulator binary to launch; default is 'swtpm'\n"
> +    "                use data-path to provide the socket path for exchanging data messages\n"
> +    "                use ctrl-path to provide the socket path for sending control messages to software emulator\n"
> +    "                use logfile to provide where to place the swtpm logs\n"

use logfile to provide a file for the swtpm logs

> +    "                use loglevel to controls the swtpm log level\n",

to control

>       QEMU_ARCH_ALL)
>   STEXI
>
> @@ -2892,8 +2900,8 @@ The general form of a TPM device option is:
>
>   @item -tpmdev @var{backend} ,id=@var{id} [,@var{options}]
>   @findex -tpmdev
> -Backend type must be:
> -@option{passthrough}.
> +Backend type must be either one of the following:
> +@option{passthrough}, @option{emulator}.
>
>   The specific backend type will determine the applicable options.
>   The @code{-tpmdev} option creates the TPM backend and requires a
> @@ -2943,6 +2951,45 @@ To create a passthrough TPM use the following two options:
>   Note that the @code{-tpmdev} id is @code{tpm0} and is referenced by
>   @code{tpmdev=tpm0} in the device option.
>
> +@item -tpmdev emulator, id=@var{id}, tpmstatedir=@var{path}, spawn=@var{on|off}, path=@var{emulator-binary-path}, data-path=@var{path}, ctrl-path=@var{path}, logfile=@var{path}, loglevel=@var{level}
> +
> +(Linux-host only) Enable access to a TPM emulator using unix domain sockets.
> +

unix -> Unix

> +@option{tpmstatedir} specifies the tpm state directory
> +

tpm -> TPM

> +@option{spawn} specifies if qemu should spawn new emulator process with given @option{path}
> +

qemu -> QEMU

spawn a new

> +@option{path} specifies the emulator binary path to use for spawning

-> specifies the path to the emulator binary

> +
> +@option{data-path} optional socket path to use for exchanging TPM data with emulator
> +

socket path to use for exchanging TPM commands with emulator; required 
when @option{spawn} is false

> +@option{ctrl-path} optional socket path to use for sending control data to emulator

socket path to use for sending control message to emulator; required 
when @option{spawn} is false

> +
> +@option{logfile} optional log file to use to place log messages
> +

optional log file to use

> +@option{loglevel} specifies the log level to use
> +
> +To create TPM emulator backend device that spawns new swtpm binary and communicate with socket pairs:

To create a TPM emulator backend device that spawns a new swtpm binary 
and communicates using socket pairs:

> +@example
> +
> +-tpmdev emulator,id=tpm0,tpmstatedir=/tmp/my-tpm,spawn=on,path=/usr/local/bin/swtpm,logfile=/tmp/qemu-tpm.log,loglevel=5 -device tpm-tis,tpmdev=tpm0
> +
> +@end example
> +
> +To create TPM emulator backend device that spawns new swtpm binary and communicate using unix file system sockets:

To create a TPM emulator backend device that spawns a new swtpm binary 
and communicates using Unix domain sockets:

> +@example
> +
> +-tpmdev emulator,id=tpm0,tpmstatedir=/tmp/my-tpm,spawn=on,path=/usr/local/bin/swtpm,data-path=/tmp/swtpm-data.socket,ctrl-path=/tmp/swtpm-ctrl.socket,logfile=/tmp/qemu-tpm.log,loglevel=5 -device tpm-tis,tpmdev=tpm0
> +
> +@end example
> +
> +To create a TOM emulator backend device that connects to already running swtpm binary using file system sockets:

To create a TPM emulator backend device that connects to an already 
running swtpm using Unix domain sockets:

> +@example
> +
> +-tpmdev emulator,id=tpm0,tpmstatedir=/tmp/my-tpm,spawn=off,data-path=/tmp/swtpm-data.socket,ctrl-path=/tmp/swtpm-ctrl.socket,logfile=/tmp/qemu-tpm.log,loglevel=5 -device tpm-tis,tpmdev=tpm0
> +
> +@end example
> +
>   @end table
>
>   ETEXI
> diff --git a/tpm.c b/tpm.c
> index 84e9667..6d2513c 100644
> --- a/tpm.c
> +++ b/tpm.c
> @@ -25,7 +25,7 @@ static QLIST_HEAD(, TPMBackend) tpm_backends =
>
>
>   #define TPM_MAX_MODELS      1
> -#define TPM_MAX_DRIVERS     1
> +#define TPM_MAX_DRIVERS     2
>
>   static TPMDriverOps const *be_drivers[TPM_MAX_DRIVERS] = {
>       NULL,

Amarnath Valluri July 18, 2017, 8:53 a.m. UTC | #2

Thank Stefan for your comments, i sent the newer version of the patchset
by addressing all your comments.

- Amarnath
On Wed, 2017-07-12 at 14:24 -0400, Stefan Berger wrote:
> On 06/05/2017 08:45 AM, Amarnath Valluri wrote:
> > This change introduces a new TPM backend driver that can communicate with
> > swtpm(software TPM emulator) using unix domain socket interface.
> >
> > Swtpm uses two unix sockets, one for plain TPM commands and responses, and one
> > for out-of-band control messages.
> >
> > The swtpm and associated tools can be found here:
> >      https://github.com/stefanberger/swtpm
> >
> > The swtpm's control channel protocol specification can be found here:
> >      https://github.com/stefanberger/swtpm/wiki/Control-Channel-Specification
> >
> > Usage:
> >      # setup TPM state directory
> >      mkdir /tmp/mytpm
> >      chown -R tss:root /tmp/mytpm
> >      /usr/bin/swtpm_setup --tpm-state /tmp/mytpm --createek
> >
> >      # Ask qemu to use TPM emulator with given tpm state directory
> >      qemu-system-x86_64 \
> >          [...] \
> >          -tpmdev emulator,id=tpm0,tpmstatedir=/tmp/mytpm,logfile=/tmp/swtpm.log \
> >          -device tpm-tis,tpmdev=tpm0 \
> >          [...]
> >
> > Signed-off-by: Amarnath Valluri <[e-mail]>
> > ---
> >   configure             |  15 +-
> >   hmp.c                 |  21 ++
> >   hw/tpm/Makefile.objs  |   1 +
> >   hw/tpm/tpm_emulator.c | 973 ++++++++++++++++++++++++++++++++++++++++++++++++++
> >   hw/tpm/tpm_ioctl.h    | 243 +++++++++++++
> >   qapi-schema.json      |  41 ++-
> >   qemu-options.hx       |  53 ++-
> >   tpm.c                 |   2 +-
> >   8 files changed, 1339 insertions(+), 10 deletions(-)
> >   create mode 100644 hw/tpm/tpm_emulator.c
> >   create mode 100644 hw/tpm/tpm_ioctl.h
> >
> > diff --git a/configure b/configure
> > index 39e727e..b010bfb 100755
> > --- a/configure
> > +++ b/configure
> > @@ -3404,10 +3404,15 @@ fi
> >   ##########################################
> >   # TPM passthrough is only on x86 Linux
> >
> > -if test "$targetos" = Linux && test "$cpu" = i386 -o "$cpu" = x86_64; then
> > -  tpm_passthrough=$tpm
> > +if test "$targetos" = Linux; then
> > +  tpm_emulator=$tpm
> > +  if test "$cpu" = i386 -o "$cpu" = x86_64; then
> > +    tpm_passthrough=$tpm
> > +  else
> > +    tpm_passthrough=no
> > +  fi
> >   else
> > -  tpm_passthrough=no
> > +  tpm_emulator=no
> >   fi
> >
> >   ##########################################
> > @@ -5214,6 +5219,7 @@ echo "gcov enabled      $gcov"
> >   echo "TPM support       $tpm"
> >   echo "libssh2 support   $libssh2"
> >   echo "TPM passthrough   $tpm_passthrough"
> > +echo "TPM emulator      $tpm_emulator"
> >   echo "QOM debugging     $qom_cast_debug"
> >   echo "lzo support       $lzo"
> >   echo "snappy support    $snappy"
> > @@ -5794,6 +5800,9 @@ if test "$tpm" = "yes"; then
> >     if test "$tpm_passthrough" = "yes"; then
> >       echo "CONFIG_TPM_PASSTHROUGH=y" >> $config_host_mak
> >     fi
> > +  if test "$tpm_emulator" = "yes"; then
> > +    echo "CONFIG_TPM_EMULATOR=y" >> $config_host_mak
> > +  fi
> >   fi
> >
> >   echo "TRACE_BACKENDS=$trace_backends" >> $config_host_mak
> > diff --git a/hmp.c b/hmp.c
> > index 9338938..073faef 100644
> > --- a/hmp.c
> > +++ b/hmp.c
> > @@ -938,6 +938,7 @@ void hmp_info_tpm(Monitor *mon, const QDict *qdict)
> >       Error *err = NULL;
> >       unsigned int c = 0;
> >       TPMPassthroughOptions *tpo;
> > +    TPMEmulatorOptions *teo;
> >
> >       info_list = qmp_query_tpm(&err);
> >       if (err) {
> > @@ -967,6 +968,26 @@ void hmp_info_tpm(Monitor *mon, const QDict *qdict)
> >                              tpo->has_cancel_path ? ",cancel-path=" : "",
> >                              tpo->has_cancel_path ? tpo->cancel_path : "");
> >               break;
> > +        case TPM_TYPE_EMULATOR:
> > +            teo = ti->options->u.emulator.data;
> > +            monitor_printf(mon, ",tmpstatedir=%s", teo->tpmstatedir);
> > +            monitor_printf(mon, ",spawn=%s", teo->spawn ? "on" : "off");
> > +            if (teo->has_path) {
> > +                monitor_printf(mon, ",path=%s", teo->path);
> > +            }
> > +            if (teo->has_data_path) {
> > +                monitor_printf(mon, ",data-path=%s", teo->data_path);
> > +            }
> > +            if (teo->has_ctrl_path) {
> > +                monitor_printf(mon, ",ctrl-path=%s", teo->ctrl_path);
> > +            }
> > +            if (teo->has_logfile) {
> > +                monitor_printf(mon, ",logfile=%s", teo->logfile);
> > +            }
> > +            if (teo->has_loglevel) {
> > +                monitor_printf(mon, ",loglevel=%u", teo->loglevel);
> > +            }
> > +            break;
> >           default:
> >               break;
> >           }
> > diff --git a/hw/tpm/Makefile.objs b/hw/tpm/Makefile.objs
> > index 64cecc3..41f0b7a 100644
> > --- a/hw/tpm/Makefile.objs
> > +++ b/hw/tpm/Makefile.objs
> > @@ -1,2 +1,3 @@
> >   common-obj-$(CONFIG_TPM_TIS) += tpm_tis.o
> >   common-obj-$(CONFIG_TPM_PASSTHROUGH) += tpm_passthrough.o tpm_util.o
> > +common-obj-$(CONFIG_TPM_EMULATOR) += tpm_emulator.o tpm_util.o
> > diff --git a/hw/tpm/tpm_emulator.c b/hw/tpm/tpm_emulator.c
> > new file mode 100644
> > index 0000000..c90914c
> > --- /dev/null
> > +++ b/hw/tpm/tpm_emulator.c
> > @@ -0,0 +1,973 @@
> > +/*
> > + *  emulator TPM driver
> > + *
> > + *  Copyright (c) 2017 Intel Corporation
> > + *  Author: Amarnath Valluri <[e-mail]>
> > + *
> > + *  Copyright (c) 2010 - 2013 IBM Corporation
> > + *  Authors:
> > + *    Stefan Berger <[e-mail]>
> > + *
> > + *  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 "hw/i386/pc.h"
> > +#include "tpm_util.h"
> > +#include "tpm_ioctl.h"
> > +#include "migration/migration.h"
> > +#include "qapi/error.h"
> > +
> > +#include <fcntl.h>
> > +#include <sys/types.h>
> > +#include <sys/stat.h>
> > +#include <stdio.h>
> > +
> > +#define DEBUG_TPM 0
> > +
> > +#define DPRINT(fmt, ...) do { \
> > +    if (DEBUG_TPM) { \
> > +        fprintf(stderr, fmt, ## __VA_ARGS__); \
> > +    } \
> > +} while (0);
> > +
> > +#define DPRINTF(fmt, ...) DPRINT("tpm-emulator: "fmt"\n", __VA_ARGS__)
> > +
> > +#define TYPE_TPM_EMULATOR "tpm-emulator"
> > +#define TPM_EMULATOR(obj) \
> > +    OBJECT_CHECK(TPMEmulator, (obj), TYPE_TPM_EMULATOR)
> > +
> > +static const TPMDriverOps tpm_emulator_driver;
> > +
> > +/* data structures */
> > +typedef struct TPMEmulator {
> > +    TPMBackend parent;
> > +
> > +    TPMEmulatorOptions *ops;
> > +    QIOChannel *data_ioc;
> > +    QIOChannel *ctrl_ioc;
> > +    bool op_executing;
> > +    bool op_canceled;
> > +    bool child_running;
> > +    TPMVersion tpm_version;
> > +    ptm_cap caps; /* capabilities of the TPM */
> > +    uint8_t cur_locty_number; /* last set locality */
> > +    QemuMutex state_lock;
> > +    Error *migration_blocker;
> > +} TPMEmulator;
> > +
> > +#define TPM_DEFAULT_EMULATOR "swtpm"
> > +#define TPM_DEFAULT_LOGLEVEL 5
> > +#define TPM_EMULATOR_PIDFILE "/tmp/qemu-tpm.pid"
> 
> Is this a single PID file used by all QEMUs running on the same system? 
> I don't think this works when multiple QEMUs try to start TPMs 
> concurrently. You may want to encode the pid of the QEMU process into it 
> -> "/tmp/qemu-tpm.%u.pid", getpid() or something like that.
> 
> > +#define TPM_EMULATOR_IMPLEMENTS_ALL_CAPS(S, cap) (((S)->caps & (cap)) == (cap))
> > +
> > +static int tpm_emulator_ctrlcmd(QIOChannel *ioc, unsigned long cmd, void *msg,
> > +                                size_t msg_len_in, size_t msg_len_out)
> > +{
> > +    ssize_t n;
> > +
> > +    uint32_t cmd_no = cpu_to_be32(cmd);
> > +    struct iovec iov[2] = {
> > +        { .iov_base = &cmd_no, .iov_len = sizeof(cmd_no), },
> > +        { .iov_base = msg, .iov_len = msg_len_in, },
> > +    };
> > +
> > +    n = qio_channel_writev(ioc, iov, 2, NULL);
> > +    if (n > 0) {
> > +        if (msg_len_out > 0) {
> > +            n = qio_channel_read(ioc, (char *)msg, msg_len_out, NULL);
> > +            /* simulate ioctl return value */
> > +            if (n > 0) {
> > +                n = 0;
> > +            }
> > +        } else {
> > +            n = 0;
> > +        }
> > +    }
> > +    return n;
> > +}
> > +
> > +static int tpm_emulator_unix_tx_bufs(TPMEmulator *tpm_pt,
> > +                                     const uint8_t *in, uint32_t in_len,
> > +                                     uint8_t *out, uint32_t out_len,
> > +                                     bool *selftest_done)
> > +{
> > +    ssize_t ret;
> > +    bool is_selftest;
> > +    const struct tpm_resp_hdr *hdr;
> > +
> > +    if (!tpm_pt->child_running) {
> > +        return -1;
> > +    }
> > +
> > +    tpm_pt->op_canceled = false;
> > +    tpm_pt->op_executing = true;
> > +    *selftest_done = false;
> > +
> > +    is_selftest = tpm_util_is_selftest(in, in_len);
> > +
> > +    ret = qio_channel_write(tpm_pt->data_ioc, (const char *)in, (size_t)in_len,
> > +                            NULL);
> > +    if (ret != in_len) {
> > +        if (!tpm_pt->op_canceled || errno != ECANCELED) {
> > +            error_report("tpm-emulator: error while transmitting data "
> > +                         "to TPM: %s (%i)", strerror(errno), errno);
> > +        }
> > +        goto err_exit;
> > +    }
> > +
> > +    tpm_pt->op_executing = false;
> > +
> > +    ret = qio_channel_read(tpm_pt->data_ioc, (char *)out, (size_t)out_len,
> > +                           NULL);
> > +    if (ret < 0) {
> > +        if (!tpm_pt->op_canceled || errno != ECANCELED) {
> > +            error_report("tpm-emulator: error while reading data from "
> > +                         "TPM: %s (%i)", strerror(errno), errno);
> > +        }
> > +    } else if (ret < sizeof(struct tpm_resp_hdr) ||
> > +               be32_to_cpu(((struct tpm_resp_hdr *)out)->len) != ret) {
> > +        ret = -1;
> > +        error_report("tpm-emulator: received invalid response "
> > +                     "packet from TPM");
> > +    }
> > +
> > +    if (is_selftest && (ret >= sizeof(struct tpm_resp_hdr))) {
> > +        hdr = (struct tpm_resp_hdr *)out;
> > +        *selftest_done = (be32_to_cpu(hdr->errcode) == 0);
> > +    }
> > +
> > +err_exit:
> > +    if (ret < 0) {
> > +        tpm_util_write_fatal_error_response(out, out_len);
> > +    }
> > +
> > +    tpm_pt->op_executing = false;
> > +
> > +    return ret;
> > +}
> > +
> > +static int tpm_emulator_set_locality(TPMEmulator *tpm_pt,
> > +                                     uint8_t locty_number)
> > +{
> > +    ptm_loc loc;
> > +
> > +    if (!tpm_pt->child_running) {
> > +        return -1;
> > +    }
> > +
> > +    DPRINTF("%s : locality: 0x%x", __func__, locty_number);
> > +
> > +    if (tpm_pt->cur_locty_number != locty_number) {
> > +        DPRINTF("setting locality : 0x%x", locty_number);
> > +        loc.u.req.loc = locty_number;
> > +        if (tpm_emulator_ctrlcmd(tpm_pt->ctrl_ioc, CMD_SET_LOCALITY, &loc,
> > +                             sizeof(loc), sizeof(loc)) < 0) {
> > +            error_report("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_report("tpm-emulator: TPM result for set locality : 0x%x",
> > +                         loc.u.resp.tpm_result);
> > +            return -1;
> > +        }
> > +        tpm_pt->cur_locty_number = locty_number;
> > +    }
> > +    return 0;
> > +}
> > +
> > +static void tpm_emulator_handle_request(TPMBackend *tb, TPMBackendCmd cmd)
> > +{
> > +    TPMEmulator *tpm_pt = TPM_EMULATOR(tb);
> > +    TPMLocality *locty = NULL;
> > +    bool selftest_done = false;
> > +
> > +    DPRINTF("processing command type %d", cmd);
> > +
> > +    switch (cmd) {
> > +    case TPM_BACKEND_CMD_PROCESS_CMD:
> > +        qemu_mutex_lock(&tpm_pt->state_lock);
> > +        locty = tb->tpm_state->locty_data;
> > +        if (tpm_emulator_set_locality(tpm_pt,
> > +                                      tb->tpm_state->locty_number) < 0) {
> > +            tpm_util_write_fatal_error_response(locty->r_buffer.buffer,
> > +                                           locty->r_buffer.size);
> > +        } else {
> > +            tpm_emulator_unix_tx_bufs(tpm_pt, locty->w_buffer.buffer,
> > +                                  locty->w_offset, locty->r_buffer.buffer,
> > +                                  locty->r_buffer.size, &selftest_done);
> > +        }
> > +        tb->recv_data_callback(tb->tpm_state, tb->tpm_state->locty_number,
> > +                               selftest_done);
> > +        qemu_mutex_unlock(&tpm_pt->state_lock);
> > +        break;
> > +    case TPM_BACKEND_CMD_INIT:
> > +    case TPM_BACKEND_CMD_END:
> > +    case TPM_BACKEND_CMD_TPM_RESET:
> > +        /* nothing to do */
> > +        break;
> > +    }
> > +}
> > +
> > +/*
> > + * Gracefully shut down the external unixio TPM
> > + */
> > +static void tpm_emulator_shutdown(TPMEmulator *tpm_pt)
> > +{
> > +    ptm_res res;
> > +
> > +    if (!tpm_pt->child_running) {
> > +        return;
> > +    }
> > +
> > +    if (tpm_emulator_ctrlcmd(tpm_pt->ctrl_ioc, 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 int tpm_emulator_probe_caps(TPMEmulator *tpm_pt)
> > +{
> > +    if (!tpm_pt->child_running) {
> > +        return -1;
> > +    }
> > +
> > +    DPRINTF("%s", __func__);
> > +    if (tpm_emulator_ctrlcmd(tpm_pt->ctrl_ioc, CMD_GET_CAPABILITY,
> > +                         &tpm_pt->caps, 0, sizeof(tpm_pt->caps)) < 0) {
> > +        error_report("tpm-emulator: probing failed : %s", strerror(errno));
> > +        return -1;
> > +    }
> > +
> > +    tpm_pt->caps = be64_to_cpu(tpm_pt->caps);
> > +
> > +    DPRINTF("capbilities : 0x%lx", tpm_pt->caps);
> > +
> > +    return 0;
> > +}
> > +
> > +static int tpm_emulator_check_caps(TPMEmulator *tpm_pt)
> > +{
> > +    ptm_cap caps = 0;
> > +    const char *tpm = NULL;
> > +
> > +    /* check for min. required capabilities */
> > +    switch (tpm_pt->tpm_version) {
> > +    case TPM_VERSION_1_2:
> > +        caps = PTM_CAP_INIT | PTM_CAP_SHUTDOWN | PTM_CAP_GET_TPMESTABLISHED |
> > +               PTM_CAP_SET_LOCALITY;
> > +        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;
> > +        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_pt, 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_init_tpm(TPMEmulator *tpm_pt)
> > +{
> > +    ptm_init init;
> > +    ptm_res res;
> > +
> > +    if (!tpm_pt->child_running) {
> > +        return -1;
> > +    }
> > +
> > +    DPRINTF("%s", __func__);
> > +    if (tpm_emulator_ctrlcmd(tpm_pt->ctrl_ioc, CMD_INIT, &init, sizeof(init),
> > +                         sizeof(init)) < 0) {
> > +        error_report("tpm-emulator: could not send INIT: %s",
> > +                     strerror(errno));
> > +        return -1;
> > +    }
> > +
> > +    res = be32_to_cpu(init.u.resp.tpm_result);
> > +    if (res) {
> > +        error_report("tpm-emulator: TPM result for CMD_INIT: 0x%x", res);
> > +        return -1;
> > +    }
> > +
> > +    return 0;
> > +}
> > +
> > +static int tpm_emulator_startup_tpm(TPMBackend *tb)
> > +{
> > +    TPMEmulator *tpm_pt = TPM_EMULATOR(tb);
> > +
> > +    DPRINTF("%s", __func__);
> > +
> > +    tpm_emulator_init_tpm(tpm_pt) ;
> > +
> > +    return 0;
> > +}
> > +
> > +static bool tpm_emulator_get_tpm_established_flag(TPMBackend *tb)
> > +{
> > +    TPMEmulator *tpm_pt = TPM_EMULATOR(tb);
> > +    ptm_est est;
> > +
> > +    DPRINTF("%s", __func__);
> > +    if (tpm_emulator_ctrlcmd(tpm_pt->ctrl_ioc, 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("established flag: %0x", est.u.resp.bit);
> > +
> > +    return (est.u.resp.bit != 0);
> > +}
> > +
> > +static int tpm_emulator_reset_tpm_established_flag(TPMBackend *tb,
> > +                                                   uint8_t locty)
> > +{
> > +    TPMEmulator *tpm_pt = TPM_EMULATOR(tb);
> > +    ptm_reset_est reset_est;
> > +    ptm_res res;
> > +
> > +    /* only a TPM 2.0 will support this */
> > +    if (tpm_pt->tpm_version == TPM_VERSION_2_0) {
> > +        reset_est.u.req.loc = tpm_pt->cur_locty_number;
> > +
> > +        if (tpm_emulator_ctrlcmd(tpm_pt->ctrl_ioc, 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;
> > +        }
> > +    }
> > +
> > +    return 0;
> > +}
> > +
> > +static bool tpm_emulator_had_startup_error(TPMBackend *tb)
> > +{
> > +    TPMEmulator *tpm_pt = TPM_EMULATOR(tb);
> > +
> > +    return !tpm_pt->child_running;
> > +}
> > +
> > +static void tpm_emulator_cancel_cmd(TPMBackend *tb)
> > +{
> > +    TPMEmulator *tpm_pt = TPM_EMULATOR(tb);
> > +    ptm_res res;
> > +
> > +    /*
> > +     * As of Linux 3.7 the tpm_tis driver does not properly cancel
> > +     * commands on all TPM manufacturers' TPMs.
> > +     * Only cancel if we're busy so we don't cancel someone else's
> > +     * command, e.g., a command executed on the host.
> > +     */
> > +    if (tpm_pt->op_executing) {
> > +        if (TPM_EMULATOR_IMPLEMENTS_ALL_CAPS(tpm_pt, PTM_CAP_CANCEL_TPM_CMD)) {
> > +            if (tpm_emulator_ctrlcmd(tpm_pt->ctrl_ioc, 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));
> > +            } else {
> > +                tpm_pt->op_canceled = true;
> > +            }
> > +        }
> > +    }
> > +}
> > +
> > +static void tpm_emulator_reset(TPMBackend *tb)
> > +{
> > +    DPRINTF("%s", __func__);
> > +
> > +    tpm_emulator_cancel_cmd(tb);
> > +}
> > +
> > +static TPMVersion tpm_emulator_get_tpm_version(TPMBackend *tb)
> > +{
> > +    TPMEmulator *tpm_pt = TPM_EMULATOR(tb);
> > +
> > +    return tpm_pt->tpm_version;
> > +}
> > +
> > +static gboolean tpm_emulator_fd_handler(QIOChannel *ioc, GIOCondition cnd,
> > +                                        void *opaque)
> > +{
> > +    TPMEmulator *tpm_pt = opaque;
> > +
> > +    if (cnd & G_IO_ERR || cnd & G_IO_HUP) {
> > +        error_report("TPM backend disappeared");
> > +        tpm_pt->child_running = false;
> > +        return false;
> > +    }
> > +
> > +    return true;
> > +}
> > +
> > +static QIOChannel *_iochannel_new(const char *path, int fd, Error **err)
> > +{
> > +    int socket = path ?  unix_connect(path, err) : fd;
> > +    if (socket < 0) {
> > +        return NULL;
> > +    }
> > +
> > +    return QIO_CHANNEL(qio_channel_socket_new_fd(socket, err));
> > +}
> > +
> > +static int tpm_emulator_spawn_emulator(TPMEmulator *tpm_pt)
> > +{
> > +    int fds[2] = { -1, -1 };
> > +    int ctrl_fds[2] = { -1, -1 };
> > +    pid_t cpid;
> > +
> > +    if (!tpm_pt->ops->has_data_path) {
> > +        if (socketpair(AF_UNIX, SOCK_SEQPACKET, 0, fds) < 0) {
> > +            return -1;
> > +        }
> > +    }
> > +
> > +    if (!tpm_pt->ops->has_ctrl_path) {
> > +        if (socketpair(AF_UNIX, SOCK_SEQPACKET, 0, ctrl_fds) < 0) {
> > +            if (!tpm_pt->ops->has_data_path) {
> > +                closesocket(fds[0]);
> > +                closesocket(fds[1]);
> > +            }
> > +            return -1;
> > +        }
> > +    }
> > +
> > +    cpid = qemu_fork(NULL);
> > +    if (cpid < 0) {
> > +        error_report("tpm-emulator: Fork failure: %s", strerror(errno));
> > +        if (!tpm_pt->ops->has_data_path) {
> > +            closesocket(fds[0]);
> > +            closesocket(fds[1]);
> > +        }
> > +        if (!tpm_pt->ops->has_ctrl_path) {
> > +            closesocket(ctrl_fds[0]);
> > +            closesocket(ctrl_fds[1]);
> > +        }
> > +        return -1;
> > +    }
> > +
> > +    unlink(TPM_EMULATOR_PIDFILE);
> > +
> > +    if (cpid == 0) { /* CHILD */
> > +        enum {
> > +            PARAM_PATH,
> > +            PARAM_IFACE,
> > +            PARAM_SERVER,  PARAM_SERVER_ARGS,
> > +            PARAM_CTRL,    PARAM_CTRL_ARGS,
> > +            PARAM_STATE,   PARAM_STATE_ARGS,
> > +            PARAM_PIDFILE, PARAM_PIDFILE_ARGS,
> > +            PARAM_LOG,     PARAM_LOG_ARGS,
> > +            PARAM_MAX
> > +        };
> > +
> > +        int i;
> > +        int data_fd = -1, ctrl_fd = -1;
> > +        char *argv[PARAM_MAX + 1];
> > +
> > +        /* close all unused inherited sockets */
> > +        if (fds[0] >= 0) {
> > +            closesocket(fds[0]);
> > +        }
> > +        if (ctrl_fds[0] >= 0) {
> > +            closesocket(ctrl_fds[0]);
> > +        }
> > +
> > +        i = STDERR_FILENO + 1;
> > +        if (fds[1] >= 0) {
> > +            data_fd = dup2(fds[1], i++);
> > +            if (data_fd < 0) {
> > +                error_report("tpm-emulator: dup2() failure - %s",
> > +                             strerror(errno));
> > +                goto exit_child;
> > +            }
> > +        }
> > +        if (ctrl_fds[1] >= 0) {
> > +            ctrl_fd = dup2(ctrl_fds[1], i++);
> > +            if (ctrl_fd < 0) {
> > +                error_report("tpm-emulator: dup2() failure - %s",
> > +                             strerror(errno));
> > +                goto exit_child;
> > +            }
> > +        }
> > +        for ( ; i < sysconf(_SC_OPEN_MAX); i++) {
> > +            close(i);
> > +        }
> > +
> > +        argv[PARAM_MAX] = NULL;
> > +        argv[PARAM_PATH] = g_strdup(tpm_pt->ops->path);
> > +        argv[PARAM_IFACE] = g_strdup("socket");
> > +        if (tpm_pt->ops->has_data_path) {
> > +            argv[PARAM_SERVER] = g_strdup("--server");
> > +            argv[PARAM_SERVER_ARGS] = g_strdup_printf("type=unixio,path=%s",
> > +                                               tpm_pt->ops->data_path);
> > +        } else {
> > +            argv[PARAM_SERVER] = g_strdup("--fd");
> > +            argv[PARAM_SERVER_ARGS] = g_strdup_printf("%d", data_fd);
> > +        }
> > +
> > +        argv[PARAM_CTRL] = g_strdup("--ctrl");
> > +        if (tpm_pt->ops->has_ctrl_path) {
> > +            argv[PARAM_CTRL_ARGS] = g_strdup_printf("type=unixio,path=%s",
> > +                                                    tpm_pt->ops->ctrl_path);
> > +        } else {
> > +            argv[PARAM_CTRL_ARGS] = g_strdup_printf("type=unixio,clientfd=%d",
> > +                                                    ctrl_fd);
> > +        }
> > +
> > +        argv[PARAM_STATE] = g_strdup("--tpmstate");
> > +        argv[PARAM_STATE_ARGS] = g_strdup_printf("dir=%s",
> > +                                        tpm_pt->ops->tpmstatedir);
> > +        argv[PARAM_PIDFILE] = g_strdup("--pid");
> > +        argv[PARAM_PIDFILE_ARGS] = g_strdup_printf("file=%s",
> > +                                            TPM_EMULATOR_PIDFILE);
> > +        if (tpm_pt->ops->has_logfile) {
> > +            argv[PARAM_LOG] = g_strdup("--log");
> > +            argv[PARAM_LOG_ARGS] = g_strdup_printf("file=%s,level=%d",
> > +                    tpm_pt->ops->logfile, (int)tpm_pt->ops->loglevel);
> > +        } else {
> > +            /* truncate logs */
> > +            argv[PARAM_LOG] = NULL;
> > +        }
> > +        DPRINTF("%s", "Running cmd: ")
> > +        for (i = 0; argv[i]; i++) {
> > +            DPRINT(" %s", argv[i])
> > +        }
> > +        DPRINT("\n")
> > +        if (execv(tpm_pt->ops->path, (char * const *)argv) < 0) {
> > +            error_report("execv() failure : %s", strerror(errno));
> > +        }
> > +
> > +exit_child:
> > +        g_strfreev(argv);
> > +        if (data_fd >= 0) {
> > +            closesocket(data_fd);
> > +        }
> > +        if (ctrl_fd >= 0) {
> > +            closesocket(ctrl_fd);
> > +        }
> > +
> > +        _exit(1);
> > +    } else { /* self */
> > +        struct stat st;
> > +        DPRINTF("child pid: %d", cpid);
> > +        int rc;
> > +        useconds_t usec = 100 * 1000L; /* wait for 100 milliseconds */
> > +        useconds_t timeout = 10; /* max 1 second */
> > +
> > +        /* close unused sockets */
> > +        if (fds[1] >= 0) {
> > +            closesocket(fds[1]);
> > +        }
> > +        if (ctrl_fds[1] >= 0) {
> > +            closesocket(ctrl_fds[1]);
> > +        }
> > +
> > +        tpm_pt->data_ioc = _iochannel_new(tpm_pt->ops->data_path, fds[0], NULL);
> > +        if (!tpm_pt->data_ioc) {
> > +            error_report("tpm-emulator: Unable to connect socket : %s",
> > +                          tpm_pt->ops->data_path);
> > +            goto err_kill_child;
> > +        }
> > +
> > +        tpm_pt->ctrl_ioc = _iochannel_new(tpm_pt->ops->ctrl_path, ctrl_fds[0],
> > +                                          NULL);
> > +        if (!tpm_pt->ctrl_ioc) {
> > +            error_report("tpm-emulator: Unable to connect socket : %s",
> > +                          tpm_pt->ops->ctrl_path);
> > +            goto err_kill_child;
> > +        }
> > +
> > +        qemu_add_child_watch(cpid);
> > +
> > +        qio_channel_add_watch(tpm_pt->data_ioc, G_IO_HUP | G_IO_ERR,
> > +                              tpm_emulator_fd_handler, tpm_pt, NULL);
> > +
> > +        while ((rc = stat(TPM_EMULATOR_PIDFILE, &st)) < 0 && timeout--) {
> > +            usleep(usec);
> > +        }
> > +
> > +        if (timeout == -1) {
> > +            error_report("tpm-emulator: pid file not ready: %s",
> > +                         strerror(errno));
> > +            goto err_kill_child;
> > +        }
> > +
> > +        /* check if child really running */
> > +        if (kill(cpid, 0) < 0 && errno == ESRCH) {
> > +            goto err_no_child;
> > +        }
> > +
> > +        tpm_pt->child_running = true;
> > +    }
> > +
> > +    return 0;
> > +
> > +err_kill_child:
> > +    kill(cpid, SIGTERM);
> > +    /* wait for 10 mill-seconds */
> > +    usleep(10 * 1000);
> > +    /* force kill if still reachable */
> > +    if (kill(cpid, 0) == 0) {
> > +        kill(cpid, SIGKILL);
> > +    }
> 
> You may want to loop on this as well checking whether it is still 
> reachable. It will  terminate faster once it's gone.
> 
> timeout = 10;
> while (kill(cpid, 0) == 0 && timeout--) {
>      usleep(1000):
> }
> if (timeout == -1) {
>      kill(cpid, SIGKILL);
> }
> 
> > +
> > +err_no_child:
> > +    tpm_pt->child_running = false;
> > +
> > +    return -1;
> > +}
> > +
> > +static void tpm_emulator_block_migration(TPMEmulator *tpm_pt)
> > +{
> > +   Error *err = NULL;
> > +
> > +   error_setg(&tpm_pt->migration_blocker,
> > +              "Migration disabled: TPM emulator not yet migratable");
> 
> indentation
> 
> > +    migrate_add_blocker(tpm_pt->migration_blocker, &err);
> > +    if (err) {
> > +        error_free(err);
> > +        error_free(tpm_pt->migration_blocker);
> > +        tpm_pt->migration_blocker = NULL;
> > +    }
> > +}
> > +
> > +static int tpm_emulator_handle_device_opts(TPMEmulator *tpm_pt, QemuOpts *opts)
> > +{
> > +    const char *value;
> > +
> > +    value = qemu_opt_get(opts, "tpmstatedir");
> > +    if (!value) {
> > +        error_report("tpm-emulator: Missing tpm state directory");
> > +        return -1;
> > +    }
> > +    tpm_pt->ops->tpmstatedir = g_strdup(value);
> > +
> > +    tpm_pt->ops->spawn = qemu_opt_get_bool(opts, "spawn", false);
> > +
> > +    value = qemu_opt_get(opts, "path");
> > +    if (!value) {
> > +        value = TPM_DEFAULT_EMULATOR;
> > +        tpm_pt->ops->has_path = false;
> > +    } else {
> > +        tpm_pt->ops->has_path = true;
> > +        if (value[0] == '/') {
> > +            struct stat st;
> > +            if (stat(value, &st) < 0 || !(S_ISREG(st.st_mode)
> > +                || S_ISLNK(st.st_mode))) {
> > +                error_report("tpm-emulator: Invalid emulator path: %s", value);
> > +                return -1;
> > +            }
> > +        }
> > +    }
> > +    tpm_pt->ops->path = g_strdup(value);
> > +
> > +    value = qemu_opt_get(opts, "data-path");
> > +    if (value) {
> > +        tpm_pt->ops->has_data_path = true;
> > +        tpm_pt->ops->data_path = g_strdup(value);
> > +    } else {
> > +        tpm_pt->ops->has_data_path = false;
> > +        if (!tpm_pt->ops->spawn) {
> > +            error_report("tpm-emulator: missing mandatory data-path");
> > +            return -1;
> > +        }
> > +    }
> > +
> > +    value = qemu_opt_get(opts, "ctrl-path");
> > +    if (value) {
> > +        tpm_pt->ops->has_ctrl_path = true;
> > +        tpm_pt->ops->ctrl_path = g_strdup(value);
> > +    } else {
> > +        tpm_pt->ops->has_ctrl_path = false;
> > +        if (!tpm_pt->ops->spawn) {
> > +            error_report("tpm-emulator: missing mandatory ctrl-path");
> > +            return -1;
> > +        }
> > +    }
> > +
> > +    value = qemu_opt_get(opts, "logfile");
> > +    if (value) {
> > +        tpm_pt->ops->has_logfile = true;
> > +        tpm_pt->ops->logfile = g_strdup(value);
> > +        tpm_pt->ops->loglevel = qemu_opt_get_number(opts, "loglevel",
> > +                                                   TPM_DEFAULT_LOGLEVEL);
> > +        tpm_pt->ops->has_loglevel = tpm_pt->ops->loglevel !=
> > +                                     TPM_DEFAULT_LOGLEVEL;
> > +    }
> > +
> > +    if (tpm_pt->ops->spawn) {
> > +        if (tpm_emulator_spawn_emulator(tpm_pt) < 0) {
> > +            goto err_close_dev;
> > +        }
> > +    } else {
> > +        tpm_pt->data_ioc = _iochannel_new(tpm_pt->ops->data_path, -1, NULL);
> > +        if (tpm_pt->data_ioc  == NULL) {
> > +            error_report("tpm-emulator: Failed to connect data socket: %s",
> > +                         tpm_pt->ops->data_path);
> > +            goto err_close_dev;
> > +        }
> > +        tpm_pt->ctrl_ioc = _iochannel_new(tpm_pt->ops->ctrl_path, -1, NULL);
> > +        if (tpm_pt->ctrl_ioc == NULL) {
> > +            DPRINTF("Failed to connect control socket: %s",
> > +                    strerror(errno));
> > +            goto err_close_dev;
> > +        }
> > +        tpm_pt->child_running = true;
> > +    }
> > +
> > +    /* FIXME: tpm_util_test_tpmdev() accepts only on socket fd, as it also used
> 
> on -> one
> 
> > +     * by passthrough driver, which not yet using GIOChannel.
> 
> -> which is not yet
> 
> > +     */
> > +    if (tpm_util_test_tpmdev(QIO_CHANNEL_SOCKET(tpm_pt->data_ioc)->fd,
> > +                             &tpm_pt->tpm_version)) {
> > +        error_report("'%s' is not emulating TPM device.", tpm_pt->ops->path);
> > +        goto err_close_dev;
> > +    }
> > +
> > +    DPRINTF("TPM Version %s", tpm_pt->tpm_version == TPM_VERSION_1_2 ? "1.2" :
> > +             (tpm_pt->tpm_version == TPM_VERSION_2_0 ?  "2.0" : "Unspecified"));
> > +
> > +    if (tpm_emulator_probe_caps(tpm_pt) ||
> > +        tpm_emulator_check_caps(tpm_pt)) {
> > +        goto err_close_dev;
> > +    }
> > +
> > +    tpm_emulator_block_migration(tpm_pt);
> > +
> > +    return 0;
> > +
> > +err_close_dev:
> 
> 'close_dev' seems a bit misleading here...
> 
> > +    DPRINT("Startup error\n");
> > +    return -1;
> > +}
> > +
> > +static TPMBackend *tpm_emulator_create(QemuOpts *opts, const char *id)
> > +{
> > +    TPMBackend *tb = TPM_BACKEND(object_new(TYPE_TPM_EMULATOR));
> > +
> > +    tb->id = g_strdup(id);
> > +
> > +    if (tpm_emulator_handle_device_opts(TPM_EMULATOR(tb), opts)) {
> > +        goto err_exit;
> > +    }
> > +
> > +    return tb;
> > +
> > +err_exit:
> > +    object_unref(OBJECT(tb));
> > +
> > +    return NULL;
> > +}
> > +
> > +static TpmTypeOptions *tpm_emulator_get_tpm_options(TPMBackend *tb)
> > +{
> > +    TPMEmulator *tpm_pt = TPM_EMULATOR(tb);
> > +    TpmTypeOptions *ops = NULL;
> > +    TPMEmulatorOptions *eops = NULL;
> > +
> > +    eops = g_new0(TPMEmulatorOptions, 1);
> > +    if (!eops) {
> > +        return NULL;
> > +    }
> > +    DPRINTF("%s", __func__);
> > +
> > +    eops->tpmstatedir = g_strdup(tpm_pt->ops->tpmstatedir);
> > +    eops->spawn = tpm_pt->ops->spawn;
> > +    if (tpm_pt->ops->has_path) {
> > +        eops->has_path = true;
> > +        eops->path = g_strdup(tpm_pt->ops->path);
> > +    }
> > +    if (tpm_pt->ops->has_data_path) {
> > +        eops->has_data_path = true;
> > +        eops->data_path = g_strdup(tpm_pt->ops->data_path);
> > +    }
> > +    if (tpm_pt->ops->has_ctrl_path) {
> > +        eops->has_ctrl_path = true;
> > +        eops->ctrl_path = g_strdup(tpm_pt->ops->ctrl_path);
> > +    }
> > +    if (tpm_pt->ops->has_logfile) {
> > +        eops->has_logfile = true;
> > +        eops->logfile = g_strdup(tpm_pt->ops->logfile);
> > +    }
> > +    if (tpm_pt->ops->has_loglevel) {
> > +        eops->has_loglevel = true;
> > +        eops->loglevel = tpm_pt->ops->loglevel;
> > +    }
> > +
> > +    ops = g_new0(TpmTypeOptions, 1);
> > +    if (!ops) {
> > +        qapi_free_TPMEmulatorOptions(eops);
> > +        return NULL;
> > +    }
> > +
> > +    ops->type = TPM_TYPE_EMULATOR;
> > +    ops->u.emulator.data = eops;
> > +
> > +    return ops;
> > +}
> > +
> > +static const QemuOptDesc tpm_emulator_cmdline_opts[] = {
> > +    TPM_STANDARD_CMDLINE_OPTS,
> > +    {
> > +        .name = "tpmstatedir",
> > +        .type = QEMU_OPT_STRING,
> > +        .help = "TPM state directroy",
> 
> directroy -> directory
> 
> > +    },
> > +    {
> > +        .name = "spawn",
> > +        .type = QEMU_OPT_BOOL,
> > +        .help = "Wether to spwan given emlatory binary",
> 
> emlatory -> emulator
> 
> > +    },
> > +    {
> > +        .name = "path",
> > +        .type = QEMU_OPT_STRING,
> > +        .help = "Path to TPM emulator binary",
> > +    },
> > +    {
> > +        .name = "data-path",
> > +        .type = QEMU_OPT_STRING,
> > +        .help = "Socket path to use for data exhange",
> 
> exhange -> exchange
> 
> > +    },
> > +    {
> > +        .name = "ctrl-path",
> > +        .type = QEMU_OPT_STRING,
> > +        .help = "Socket path to use for out-of-band control messages",
> > +    },
> > +    {
> > +        .name = "logfile",
> > +        .type = QEMU_OPT_STRING,
> > +        .help = "Path to log file",
> > +    },
> > +    {
> > +        .name = "loglevel",
> > +        .type = QEMU_OPT_NUMBER,
> > +        .help = "Log level number",
> > +    },
> > +    { /* end of list */ },
> > +};
> > +
> > +static const TPMDriverOps tpm_emulator_driver = {
> > +    .type                     = TPM_TYPE_EMULATOR,
> > +    .opts                     = tpm_emulator_cmdline_opts,
> > +    .desc                     = "TPM emulator backend driver",
> > +
> > +    .create                   = tpm_emulator_create,
> > +    .startup_tpm              = tpm_emulator_startup_tpm,
> > +    .reset                    = tpm_emulator_reset,
> > +    .had_startup_error        = tpm_emulator_had_startup_error,
> > +    .cancel_cmd               = tpm_emulator_cancel_cmd,
> > +    .get_tpm_established_flag = tpm_emulator_get_tpm_established_flag,
> > +    .reset_tpm_established_flag = tpm_emulator_reset_tpm_established_flag,
> > +    .get_tpm_version          = tpm_emulator_get_tpm_version,
> > +    .get_tpm_options          = tpm_emulator_get_tpm_options,
> > +};
> > +
> > +static void tpm_emulator_inst_init(Object *obj)
> > +{
> > +    TPMEmulator *tpm_pt = TPM_EMULATOR(obj);
> > +
> > +    DPRINTF("%s", __func__);
> > +    tpm_pt->ops = g_new0(TPMEmulatorOptions, 1);
> > +    tpm_pt->data_ioc = tpm_pt->ctrl_ioc = NULL;
> > +    tpm_pt->op_executing = tpm_pt->op_canceled = false;
> > +    tpm_pt->child_running = false;
> > +    tpm_pt->cur_locty_number = ~0;
> > +    qemu_mutex_init(&tpm_pt->state_lock);
> > +}
> > +
> > +static void tpm_emulator_inst_finalize(Object *obj)
> > +{
> > +    TPMEmulator *tpm_pt = TPM_EMULATOR(obj);
> > +
> > +    tpm_emulator_cancel_cmd(TPM_BACKEND(obj));
> > +    tpm_emulator_shutdown(tpm_pt);
> > +
> > +    if (tpm_pt->data_ioc) {
> > +        qio_channel_close(tpm_pt->data_ioc, NULL);
> > +    }
> > +    if (tpm_pt->ctrl_ioc) {
> > +        qio_channel_close(tpm_pt->ctrl_ioc, NULL);
> > +    }
> > +    if (tpm_pt->ops) {
> > +        qapi_free_TPMEmulatorOptions(tpm_pt->ops);
> > +    }
> > +
> > +    if (tpm_pt->migration_blocker) {
> > +        migrate_del_blocker(tpm_pt->migration_blocker);
> > +        error_free(tpm_pt->migration_blocker);
> > +    }
> > +}
> > +
> > +static void tpm_emulator_class_init(ObjectClass *klass, void *data)
> > +{
> > +    TPMBackendClass *tbc = TPM_BACKEND_CLASS(klass);
> > +    tbc->ops = &tpm_emulator_driver;
> > +    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);
> > +    tpm_register_driver(&tpm_emulator_driver);
> > +}
> > +
> > +type_init(tpm_emulator_register)
> > diff --git a/hw/tpm/tpm_ioctl.h b/hw/tpm/tpm_ioctl.h
> > new file mode 100644
> > index 0000000..af49708
> > --- /dev/null
> > +++ b/hw/tpm/tpm_ioctl.h
> > @@ -0,0 +1,243 @@
> > +/*
> > + * tpm_ioctl.h
> > + *
> > + * (c) Copyright IBM Corporation 2014, 2015.
> > + *
> > + * This file is licensed under the terms of the 3-clause BSD license
> > + */
> > +#ifndef _TPM_IOCTL_H_
> > +#define _TPM_IOCTL_H_
> > +
> > +#include <stdint.h>
> > +#include <sys/uio.h>
> > +#include <sys/types.h>
> > +#include <sys/ioctl.h>
> > +
> > +/*
> > + * Every response from a command involving a TPM command execution must hold
> > + * the ptm_res as the first element.
> > + * ptm_res corresponds to the error code of a command executed by the TPM.
> > + */
> > +
> > +typedef uint32_t ptm_res;
> > +
> > +/* PTM_GET_TPMESTABLISHED: get the establishment bit */
> > +struct ptm_est {
> > +    union {
> > +        struct {
> > +            ptm_res tpm_result;
> > +            unsigned char bit; /* TPM established bit */
> > +        } resp; /* response */
> > +    } u;
> > +};
> > +
> > +/* PTM_RESET_TPMESTABLISHED: reset establishment bit */
> > +struct ptm_reset_est {
> > +    union {
> > +        struct {
> > +            uint8_t loc; /* locality to use */
> > +        } req; /* request */
> > +        struct {
> > +            ptm_res tpm_result;
> > +        } resp; /* response */
> > +    } u;
> > +};
> > +
> > +/* PTM_INIT */
> > +struct ptm_init {
> > +    union {
> > +        struct {
> > +            uint32_t init_flags; /* see definitions below */
> > +        } req; /* request */
> > +        struct {
> > +            ptm_res tpm_result;
> > +        } resp; /* response */
> > +    } u;
> > +};
> > +
> > +/* above init_flags */
> > +#define PTM_INIT_FLAG_DELETE_VOLATILE (1 << 0)
> > +    /* delete volatile state file after reading it */
> > +
> > +/* PTM_SET_LOCALITY */
> > +struct ptm_loc {
> > +    union {
> > +        struct {
> > +            uint8_t loc; /* locality to set */
> > +        } req; /* request */
> > +        struct {
> > +            ptm_res tpm_result;
> > +        } resp; /* response */
> > +    } u;
> > +};
> > +
> > +/* PTM_HASH_DATA: hash given data */
> > +struct ptm_hdata {
> > +    union {
> > +        struct {
> > +            uint32_t length;
> > +            uint8_t data[4096];
> > +        } req; /* request */
> > +        struct {
> > +            ptm_res tpm_result;
> > +        } resp; /* response */
> > +    } u;
> > +};
> > +
> > +/*
> > + * size of the TPM state blob to transfer; x86_64 can handle 8k,
> > + * ppc64le only ~7k; keep the response below a 4k page size
> > + */
> > +#define PTM_STATE_BLOB_SIZE (3 * 1024)
> > +
> > +/*
> > + * The following is the data structure to get state blobs from the TPM.
> > + * If the size of the state blob exceeds the PTM_STATE_BLOB_SIZE, multiple reads
> > + * with this ioctl and with adjusted offset are necessary. All bytes
> > + * must be transferred and the transfer is done once the last byte has been
> > + * returned.
> > + * It is possible to use the read() interface for reading the data; however, the
> > + * first bytes of the state blob will be part of the response to the ioctl(); a
> > + * subsequent read() is only necessary if the total length (totlength) exceeds
> > + * the number of received bytes. seek() is not supported.
> > + */
> > +struct ptm_getstate {
> > +    union {
> > +        struct {
> > +            uint32_t state_flags; /* may be: PTM_STATE_FLAG_DECRYPTED */
> > +            uint32_t type;        /* which blob to pull */
> > +            uint32_t offset;      /* offset from where to read */
> > +        } req; /* request */
> > +        struct {
> > +            ptm_res tpm_result;
> > +            uint32_t state_flags; /* may be: PTM_STATE_FLAG_ENCRYPTED */
> > +            uint32_t totlength;   /* total length that will be transferred */
> > +            uint32_t length;      /* number of bytes in following buffer */
> > +            uint8_t  data[PTM_STATE_BLOB_SIZE];
> > +        } resp; /* response */
> > +    } u;
> > +};
> > +
> > +/* TPM state blob types */
> > +#define PTM_BLOB_TYPE_PERMANENT  1
> > +#define PTM_BLOB_TYPE_VOLATILE   2
> > +#define PTM_BLOB_TYPE_SAVESTATE  3
> > +
> > +/* state_flags above : */
> > +#define PTM_STATE_FLAG_DECRYPTED     1 /* on input:  get decrypted state */
> > +#define PTM_STATE_FLAG_ENCRYPTED     2 /* on output: state is encrypted */
> > +
> > +/*
> > + * The following is the data structure to set state blobs in the TPM.
> > + * If the size of the state blob exceeds the PTM_STATE_BLOB_SIZE, multiple
> > + * 'writes' using this ioctl are necessary. The last packet is indicated
> > + * by the length being smaller than the PTM_STATE_BLOB_SIZE.
> > + * The very first packet may have a length indicator of '0' enabling
> > + * a write() with all the bytes from a buffer. If the write() interface
> > + * is used, a final ioctl with a non-full buffer must be made to indicate
> > + * that all data were transferred (a write with 0 bytes would not work).
> > + */
> > +struct ptm_setstate {
> > +    union {
> > +        struct {
> > +            uint32_t state_flags; /* may be PTM_STATE_FLAG_ENCRYPTED */
> > +            uint32_t type;        /* which blob to set */
> > +            uint32_t length;      /* length of the data;
> > +                                     use 0 on the first packet to
> > +                                     transfer using write() */
> > +            uint8_t data[PTM_STATE_BLOB_SIZE];
> > +        } req; /* request */
> > +        struct {
> > +            ptm_res tpm_result;
> > +        } resp; /* response */
> > +    } u;
> > +};
> > +
> > +/*
> > + * PTM_GET_CONFIG: Data structure to get runtime configuration information
> > + * such as which keys are applied.
> > + */
> > +struct ptm_getconfig {
> > +    union {
> > +        struct {
> > +            ptm_res tpm_result;
> > +            uint32_t flags;
> > +        } resp; /* response */
> > +    } u;
> > +};
> > +
> > +#define PTM_CONFIG_FLAG_FILE_KEY        0x1
> > +#define PTM_CONFIG_FLAG_MIGRATION_KEY   0x2
> > +
> > +
> > +typedef uint64_t ptm_cap;
> > +typedef struct ptm_est ptm_est;
> > +typedef struct ptm_reset_est ptm_reset_est;
> > +typedef struct ptm_loc ptm_loc;
> > +typedef struct ptm_hdata ptm_hdata;
> > +typedef struct ptm_init ptm_init;
> > +typedef struct ptm_getstate ptm_getstate;
> > +typedef struct ptm_setstate ptm_setstate;
> > +typedef struct ptm_getconfig ptm_getconfig;
> > +
> > +/* capability flags returned by PTM_GET_CAPABILITY */
> > +#define PTM_CAP_INIT               (1)
> > +#define PTM_CAP_SHUTDOWN           (1 << 1)
> > +#define PTM_CAP_GET_TPMESTABLISHED (1 << 2)
> > +#define PTM_CAP_SET_LOCALITY       (1 << 3)
> > +#define PTM_CAP_HASHING            (1 << 4)
> > +#define PTM_CAP_CANCEL_TPM_CMD     (1 << 5)
> > +#define PTM_CAP_STORE_VOLATILE     (1 << 6)
> > +#define PTM_CAP_RESET_TPMESTABLISHED (1 << 7)
> > +#define PTM_CAP_GET_STATEBLOB      (1 << 8)
> > +#define PTM_CAP_SET_STATEBLOB      (1 << 9)
> > +#define PTM_CAP_STOP               (1 << 10)
> > +#define PTM_CAP_GET_CONFIG         (1 << 11)
> > +
> > +enum {
> > +    PTM_GET_CAPABILITY     = _IOR('P', 0, ptm_cap),
> > +    PTM_INIT               = _IOWR('P', 1, ptm_init),
> > +    PTM_SHUTDOWN           = _IOR('P', 2, ptm_res),
> > +    PTM_GET_TPMESTABLISHED = _IOR('P', 3, ptm_est),
> > +    PTM_SET_LOCALITY       = _IOWR('P', 4, ptm_loc),
> > +    PTM_HASH_START         = _IOR('P', 5, ptm_res),
> > +    PTM_HASH_DATA          = _IOWR('P', 6, ptm_hdata),
> > +    PTM_HASH_END           = _IOR('P', 7, ptm_res),
> > +    PTM_CANCEL_TPM_CMD     = _IOR('P', 8, ptm_res),
> > +    PTM_STORE_VOLATILE     = _IOR('P', 9, ptm_res),
> > +    PTM_RESET_TPMESTABLISHED = _IOWR('P', 10, ptm_reset_est),
> > +    PTM_GET_STATEBLOB      = _IOWR('P', 11, ptm_getstate),
> > +    PTM_SET_STATEBLOB      = _IOWR('P', 12, ptm_setstate),
> > +    PTM_STOP               = _IOR('P', 13, ptm_res),
> > +    PTM_GET_CONFIG         = _IOR('P', 14, ptm_getconfig),
> > +};
> > +
> > +/*
> > + * Commands used by the non-CUSE TPMs
> > + *
> > + * All messages container big-endian data.
> > + *
> > + * The return messages only contain the 'resp' part of the unions
> > + * in the data structures above. Besides that the limits in the
> > + * buffers above (ptm_hdata:u.req.data and ptm_get_state:u.resp.data
> > + * and ptm_set_state:u.req.data) are 0xffffffff.
> > + */
> > +enum {
> > +    CMD_GET_CAPABILITY = 1,
> > +    CMD_INIT,
> > +    CMD_SHUTDOWN,
> > +    CMD_GET_TPMESTABLISHED,
> > +    CMD_SET_LOCALITY,
> > +    CMD_HASH_START,
> > +    CMD_HASH_DATA,
> > +    CMD_HASH_END,
> > +    CMD_CANCEL_TPM_CMD,
> > +    CMD_STORE_VOLATILE,
> > +    CMD_RESET_TPMESTABLISHED,
> > +    CMD_GET_STATEBLOB,
> > +    CMD_SET_STATEBLOB,
> > +    CMD_STOP,
> > +    CMD_GET_CONFIG,
> > +};
> > +
> > +#endif /* _TPM_IOCTL_H */
> > diff --git a/qapi-schema.json b/qapi-schema.json
> > index 5728b7f..cfe0c94 100644
> > --- a/qapi-schema.json
> > +++ b/qapi-schema.json
> > @@ -5123,10 +5123,12 @@
> >   # An enumeration of TPM types
> >   #
> >   # @passthrough: TPM passthrough type
> > +# @emulator: Software Emulator TPM type
> > +#            Since: 2.10
> >   #
> >   # Since: 1.5
> >   ##
> > -{ 'enum': 'TpmType', 'data': [ 'passthrough' ] }
> > +{ 'enum': 'TpmType', 'data': [ 'passthrough', 'emulator' ] }
> >
> >   ##
> >   # @query-tpm-types:
> > @@ -5140,7 +5142,7 @@
> >   # Example:
> >   #
> >   # -> { "execute": "query-tpm-types" }
> > -# <- { "return": [ "passthrough" ] }
> > +# <- { "return": [ "passthrough", "emulator" ] }
> >   #
> >   ##
> >   { 'command': 'query-tpm-types', 'returns': ['TpmType'] }
> > @@ -5161,16 +5163,49 @@
> >                                                '*cancel-path' : 'str'} }
> >
> >   ##
> > +# @TPMEmulatorOptions:
> > +#
> > +# Information about the TPM emulator
> > +#
> > +# @tpmstatedir: TPM emulator state directory
> > +# @spawn: true if, qemu has to spawn a new emulator process with given @path,
> 
> qemu -> QEMU
> 
> > +#         otherwise it connects to already rinning emulator with given @data-path
> 
> rinning -> running
> 
> > +#         and @ctrl-path sockets. (default: 'false')
> > +# @path: TPM emulator binary path to spawn.(default: 'swtpm')
> > +# @data-path: path of the unix socket to use for exchanging data messages, if
> 
> replace ',' with ';'
> 
> > +#             not provided socket pairs are used when @sapwn is true.
> 
> @sapwn -> @spawn
> 
> > +# @ctrl-path: path of the unix socket file to use for exchagning out-of-band
> 
> exchanging
> 
> > +#             control messages, if not provided socket pairs are used when
> 
> replace ',' with ';'
> 
> > +#             @spawn is true.
> > +# @logfile: file to use to place TPM emulator logs, if not provided logging is
> 
> file to use for TPM emulator logs;
> 
> > +#           disabled.
> > +# @loglevel: optional log level number, loglevel is ignored if no logfile
> 
> logfile is provided
> 
> > +#            provided. (default: 5)
> > +#
> > +# Since: 2.10
> > +##
> > +{ 'struct': 'TPMEmulatorOptions',
> > +  'data': { 'tpmstatedir' : 'str',
> > +            'spawn': 'bool',
> > +            '*path': 'str',
> > +            '*data-path': 'str',
> > +            '*ctrl-path': 'str',
> > +            '*logfile': 'str',
> > +            '*loglevel': 'uint8' } }
> > +
> > +##
> >   # @TpmTypeOptions:
> >   #
> >   # A union referencing different TPM backend types' configuration options
> >   #
> >   # @type: 'passthrough' The configuration options for the TPM passthrough type
> > +#        'emulator' The configuration options for TPM emulator backend type
> >   #
> >   # Since: 1.5
> >   ##
> >   { 'union': 'TpmTypeOptions',
> > -   'data': { 'passthrough' : 'TPMPassthroughOptions' } }
> > +  'data': { 'passthrough': 'TPMPassthroughOptions',
> > +            'emulator': 'TPMEmulatorOptions' } }
> >
> >   ##
> >   # @TPMInfo:
> > diff --git a/qemu-options.hx b/qemu-options.hx
> > index f806af9..e4dbc33 100644
> > --- a/qemu-options.hx
> > +++ b/qemu-options.hx
> > @@ -2883,7 +2883,15 @@ DEF("tpmdev", HAS_ARG, QEMU_OPTION_tpmdev, \
> >       "-tpmdev passthrough,id=id[,path=path][,cancel-path=path]\n"
> >       "                use path to provide path to a character device; default is /dev/tpm0\n"
> >       "                use cancel-path to provide path to TPM's cancel sysfs entry; if\n"
> > -    "                not provided it will be searched for in /sys/class/misc/tpm?/device\n",
> > +    "                not provided it will be searched for in /sys/class/misc/tpm?/device\n"
> > +    "-tpmdev emulator,id=id,spawn=on|off,tpmstatedir=dir[,path=emulator-path,data-path=path,ctrl-path=path,logfile=path,loglevel=level]\n"
> > +    "                spawn=on|off controls spawning support\n"
> > +    "                use tpmstatedir to provide path to the tpm state dirctory\n"
> 
> -> TPM state directory
> 
> > +    "                use path to provide the emulator binary to launch; default is 'swtpm'\n"
> > +    "                use data-path to provide the socket path for exchanging data messages\n"
> > +    "                use ctrl-path to provide the socket path for sending control messages to software emulator\n"
> > +    "                use logfile to provide where to place the swtpm logs\n"
> 
> use logfile to provide a file for the swtpm logs
> 
> > +    "                use loglevel to controls the swtpm log level\n",
> 
> to control
> 
> >       QEMU_ARCH_ALL)
> >   STEXI
> >
> > @@ -2892,8 +2900,8 @@ The general form of a TPM device option is:
> >
> >   @item -tpmdev @var{backend} ,id=@var{id} [,@var{options}]
> >   @findex -tpmdev
> > -Backend type must be:
> > -@option{passthrough}.
> > +Backend type must be either one of the following:
> > +@option{passthrough}, @option{emulator}.
> >
> >   The specific backend type will determine the applicable options.
> >   The @code{-tpmdev} option creates the TPM backend and requires a
> > @@ -2943,6 +2951,45 @@ To create a passthrough TPM use the following two options:
> >   Note that the @code{-tpmdev} id is @code{tpm0} and is referenced by
> >   @code{tpmdev=tpm0} in the device option.
> >
> > +@item -tpmdev emulator, id=@var{id}, tpmstatedir=@var{path}, spawn=@var{on|off}, path=@var{emulator-binary-path}, data-path=@var{path}, ctrl-path=@var{path}, logfile=@var{path}, loglevel=@var{level}
> > +
> > +(Linux-host only) Enable access to a TPM emulator using unix domain sockets.
> > +
> 
> unix -> Unix
> 
> > +@option{tpmstatedir} specifies the tpm state directory
> > +
> 
> tpm -> TPM
> 
> > +@option{spawn} specifies if qemu should spawn new emulator process with given @option{path}
> > +
> 
> qemu -> QEMU
> 
> spawn a new
> 
> > +@option{path} specifies the emulator binary path to use for spawning
> 
> -> specifies the path to the emulator binary
> 
> > +
> > +@option{data-path} optional socket path to use for exchanging TPM data with emulator
> > +
> 
> socket path to use for exchanging TPM commands with emulator; required 
> when @option{spawn} is false
> 
> > +@option{ctrl-path} optional socket path to use for sending control data to emulator
> 
> socket path to use for sending control message to emulator; required 
> when @option{spawn} is false
> 
> > +
> > +@option{logfile} optional log file to use to place log messages
> > +
> 
> optional log file to use
> 
> > +@option{loglevel} specifies the log level to use
> > +
> > +To create TPM emulator backend device that spawns new swtpm binary and communicate with socket pairs:
> 
> To create a TPM emulator backend device that spawns a new swtpm binary 
> and communicates using socket pairs:
> 
> > +@example
> > +
> > +-tpmdev emulator,id=tpm0,tpmstatedir=/tmp/my-tpm,spawn=on,path=/usr/local/bin/swtpm,logfile=/tmp/qemu-tpm.log,loglevel=5 -device tpm-tis,tpmdev=tpm0
> > +
> > +@end example
> > +
> > +To create TPM emulator backend device that spawns new swtpm binary and communicate using unix file system sockets:
> 
> To create a TPM emulator backend device that spawns a new swtpm binary 
> and communicates using Unix domain sockets:
> 
> > +@example
> > +
> > +-tpmdev emulator,id=tpm0,tpmstatedir=/tmp/my-tpm,spawn=on,path=/usr/local/bin/swtpm,data-path=/tmp/swtpm-data.socket,ctrl-path=/tmp/swtpm-ctrl.socket,logfile=/tmp/qemu-tpm.log,loglevel=5 -device tpm-tis,tpmdev=tpm0
> > +
> > +@end example
> > +
> > +To create a TOM emulator backend device that connects to already running swtpm binary using file system sockets:
> 
> To create a TPM emulator backend device that connects to an already 
> running swtpm using Unix domain sockets:
> 
> > +@example
> > +
> > +-tpmdev emulator,id=tpm0,tpmstatedir=/tmp/my-tpm,spawn=off,data-path=/tmp/swtpm-data.socket,ctrl-path=/tmp/swtpm-ctrl.socket,logfile=/tmp/qemu-tpm.log,loglevel=5 -device tpm-tis,tpmdev=tpm0
> > +
> > +@end example
> > +
> >   @end table
> >
> >   ETEXI
> > diff --git a/tpm.c b/tpm.c
> > index 84e9667..6d2513c 100644
> > --- a/tpm.c
> > +++ b/tpm.c
> > @@ -25,7 +25,7 @@ static QLIST_HEAD(, TPMBackend) tpm_backends =
> >
> >
> >   #define TPM_MAX_MODELS      1
> > -#define TPM_MAX_DRIVERS     1
> > +#define TPM_MAX_DRIVERS     2
> >
> >   static TPMDriverOps const *be_drivers[TPM_MAX_DRIVERS] = {
> >       NULL,
> 
>

Patch

diff --git a/configure b/configure
index 39e727e..b010bfb 100755
--- a/configure
+++ b/configure
@@ -3404,10 +3404,15 @@  fi
 ##########################################
 # TPM passthrough is only on x86 Linux
 
-if test "$targetos" = Linux && test "$cpu" = i386 -o "$cpu" = x86_64; then
-  tpm_passthrough=$tpm
+if test "$targetos" = Linux; then
+  tpm_emulator=$tpm
+  if test "$cpu" = i386 -o "$cpu" = x86_64; then
+    tpm_passthrough=$tpm
+  else
+    tpm_passthrough=no
+  fi
 else
-  tpm_passthrough=no
+  tpm_emulator=no
 fi
 
 ##########################################
@@ -5214,6 +5219,7 @@  echo "gcov enabled      $gcov"
 echo "TPM support       $tpm"
 echo "libssh2 support   $libssh2"
 echo "TPM passthrough   $tpm_passthrough"
+echo "TPM emulator      $tpm_emulator"
 echo "QOM debugging     $qom_cast_debug"
 echo "lzo support       $lzo"
 echo "snappy support    $snappy"
@@ -5794,6 +5800,9 @@  if test "$tpm" = "yes"; then
   if test "$tpm_passthrough" = "yes"; then
     echo "CONFIG_TPM_PASSTHROUGH=y" >> $config_host_mak
   fi
+  if test "$tpm_emulator" = "yes"; then
+    echo "CONFIG_TPM_EMULATOR=y" >> $config_host_mak
+  fi
 fi
 
 echo "TRACE_BACKENDS=$trace_backends" >> $config_host_mak
diff --git a/hmp.c b/hmp.c
index 9338938..073faef 100644
--- a/hmp.c
+++ b/hmp.c
@@ -938,6 +938,7 @@  void hmp_info_tpm(Monitor *mon, const QDict *qdict)
     Error *err = NULL;
     unsigned int c = 0;
     TPMPassthroughOptions *tpo;
+    TPMEmulatorOptions *teo;
 
     info_list = qmp_query_tpm(&err);
     if (err) {
@@ -967,6 +968,26 @@  void hmp_info_tpm(Monitor *mon, const QDict *qdict)
                            tpo->has_cancel_path ? ",cancel-path=" : "",
                            tpo->has_cancel_path ? tpo->cancel_path : "");
             break;
+        case TPM_TYPE_EMULATOR:
+            teo = ti->options->u.emulator.data;
+            monitor_printf(mon, ",tmpstatedir=%s", teo->tpmstatedir);
+            monitor_printf(mon, ",spawn=%s", teo->spawn ? "on" : "off");
+            if (teo->has_path) {
+                monitor_printf(mon, ",path=%s", teo->path);
+            }
+            if (teo->has_data_path) {
+                monitor_printf(mon, ",data-path=%s", teo->data_path);
+            }
+            if (teo->has_ctrl_path) {
+                monitor_printf(mon, ",ctrl-path=%s", teo->ctrl_path);
+            }
+            if (teo->has_logfile) {
+                monitor_printf(mon, ",logfile=%s", teo->logfile);
+            }
+            if (teo->has_loglevel) {
+                monitor_printf(mon, ",loglevel=%u", teo->loglevel);
+            }
+            break;
         default:
             break;
         }
diff --git a/hw/tpm/Makefile.objs b/hw/tpm/Makefile.objs
index 64cecc3..41f0b7a 100644
--- a/hw/tpm/Makefile.objs
+++ b/hw/tpm/Makefile.objs
@@ -1,2 +1,3 @@ 
 common-obj-$(CONFIG_TPM_TIS) += tpm_tis.o
 common-obj-$(CONFIG_TPM_PASSTHROUGH) += tpm_passthrough.o tpm_util.o
+common-obj-$(CONFIG_TPM_EMULATOR) += tpm_emulator.o tpm_util.o
diff --git a/hw/tpm/tpm_emulator.c b/hw/tpm/tpm_emulator.c
new file mode 100644
index 0000000..c90914c
--- /dev/null
+++ b/hw/tpm/tpm_emulator.c
@@ -0,0 +1,973 @@ 
+/*
+ *  emulator TPM driver
+ *
+ *  Copyright (c) 2017 Intel Corporation
+ *  Author: Amarnath Valluri <[e-mail]>
+ *
+ *  Copyright (c) 2010 - 2013 IBM Corporation
+ *  Authors:
+ *    Stefan Berger <[e-mail]>
+ *
+ *  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 "hw/i386/pc.h"
+#include "tpm_util.h"
+#include "tpm_ioctl.h"
+#include "migration/migration.h"
+#include "qapi/error.h"
+
+#include <fcntl.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <stdio.h>
+
+#define DEBUG_TPM 0
+
+#define DPRINT(fmt, ...) do { \
+    if (DEBUG_TPM) { \
+        fprintf(stderr, fmt, ## __VA_ARGS__); \
+    } \
+} while (0);
+
+#define DPRINTF(fmt, ...) DPRINT("tpm-emulator: "fmt"\n", __VA_ARGS__)
+
+#define TYPE_TPM_EMULATOR "tpm-emulator"
+#define TPM_EMULATOR(obj) \
+    OBJECT_CHECK(TPMEmulator, (obj), TYPE_TPM_EMULATOR)
+
+static const TPMDriverOps tpm_emulator_driver;
+
+/* data structures */
+typedef struct TPMEmulator {
+    TPMBackend parent;
+
+    TPMEmulatorOptions *ops;
+    QIOChannel *data_ioc;
+    QIOChannel *ctrl_ioc;
+    bool op_executing;
+    bool op_canceled;
+    bool child_running;
+    TPMVersion tpm_version;
+    ptm_cap caps; /* capabilities of the TPM */
+    uint8_t cur_locty_number; /* last set locality */
+    QemuMutex state_lock;
+    Error *migration_blocker;
+} TPMEmulator;
+
+#define TPM_DEFAULT_EMULATOR "swtpm"
+#define TPM_DEFAULT_LOGLEVEL 5
+#define TPM_EMULATOR_PIDFILE "/tmp/qemu-tpm.pid"
+#define TPM_EMULATOR_IMPLEMENTS_ALL_CAPS(S, cap) (((S)->caps & (cap)) == (cap))
+
+static int tpm_emulator_ctrlcmd(QIOChannel *ioc, unsigned long cmd, void *msg,
+                                size_t msg_len_in, size_t msg_len_out)
+{
+    ssize_t n;
+
+    uint32_t cmd_no = cpu_to_be32(cmd);
+    struct iovec iov[2] = {
+        { .iov_base = &cmd_no, .iov_len = sizeof(cmd_no), },
+        { .iov_base = msg, .iov_len = msg_len_in, },
+    };
+
+    n = qio_channel_writev(ioc, iov, 2, NULL);
+    if (n > 0) {
+        if (msg_len_out > 0) {
+            n = qio_channel_read(ioc, (char *)msg, msg_len_out, NULL);
+            /* simulate ioctl return value */
+            if (n > 0) {
+                n = 0;
+            }
+        } else {
+            n = 0;
+        }
+    }
+    return n;
+}
+
+static int tpm_emulator_unix_tx_bufs(TPMEmulator *tpm_pt,
+                                     const uint8_t *in, uint32_t in_len,
+                                     uint8_t *out, uint32_t out_len,
+                                     bool *selftest_done)
+{
+    ssize_t ret;
+    bool is_selftest;
+    const struct tpm_resp_hdr *hdr;
+
+    if (!tpm_pt->child_running) {
+        return -1;
+    }
+
+    tpm_pt->op_canceled = false;
+    tpm_pt->op_executing = true;
+    *selftest_done = false;
+
+    is_selftest = tpm_util_is_selftest(in, in_len);
+
+    ret = qio_channel_write(tpm_pt->data_ioc, (const char *)in, (size_t)in_len,
+                            NULL);
+    if (ret != in_len) {
+        if (!tpm_pt->op_canceled || errno != ECANCELED) {
+            error_report("tpm-emulator: error while transmitting data "
+                         "to TPM: %s (%i)", strerror(errno), errno);
+        }
+        goto err_exit;
+    }
+
+    tpm_pt->op_executing = false;
+
+    ret = qio_channel_read(tpm_pt->data_ioc, (char *)out, (size_t)out_len,
+                           NULL);
+    if (ret < 0) {
+        if (!tpm_pt->op_canceled || errno != ECANCELED) {
+            error_report("tpm-emulator: error while reading data from "
+                         "TPM: %s (%i)", strerror(errno), errno);
+        }
+    } else if (ret < sizeof(struct tpm_resp_hdr) ||
+               be32_to_cpu(((struct tpm_resp_hdr *)out)->len) != ret) {
+        ret = -1;
+        error_report("tpm-emulator: received invalid response "
+                     "packet from TPM");
+    }
+
+    if (is_selftest && (ret >= sizeof(struct tpm_resp_hdr))) {
+        hdr = (struct tpm_resp_hdr *)out;
+        *selftest_done = (be32_to_cpu(hdr->errcode) == 0);
+    }
+
+err_exit:
+    if (ret < 0) {
+        tpm_util_write_fatal_error_response(out, out_len);
+    }
+
+    tpm_pt->op_executing = false;
+
+    return ret;
+}
+
+static int tpm_emulator_set_locality(TPMEmulator *tpm_pt,
+                                     uint8_t locty_number)
+{
+    ptm_loc loc;
+
+    if (!tpm_pt->child_running) {
+        return -1;
+    }
+
+    DPRINTF("%s : locality: 0x%x", __func__, locty_number);
+
+    if (tpm_pt->cur_locty_number != locty_number) {
+        DPRINTF("setting locality : 0x%x", locty_number);
+        loc.u.req.loc = locty_number;
+        if (tpm_emulator_ctrlcmd(tpm_pt->ctrl_ioc, CMD_SET_LOCALITY, &loc,
+                             sizeof(loc), sizeof(loc)) < 0) {
+            error_report("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_report("tpm-emulator: TPM result for set locality : 0x%x",
+                         loc.u.resp.tpm_result);
+            return -1;
+        }
+        tpm_pt->cur_locty_number = locty_number;
+    }
+    return 0;
+}
+
+static void tpm_emulator_handle_request(TPMBackend *tb, TPMBackendCmd cmd)
+{
+    TPMEmulator *tpm_pt = TPM_EMULATOR(tb);
+    TPMLocality *locty = NULL;
+    bool selftest_done = false;
+
+    DPRINTF("processing command type %d", cmd);
+
+    switch (cmd) {
+    case TPM_BACKEND_CMD_PROCESS_CMD:
+        qemu_mutex_lock(&tpm_pt->state_lock);
+        locty = tb->tpm_state->locty_data;
+        if (tpm_emulator_set_locality(tpm_pt,
+                                      tb->tpm_state->locty_number) < 0) {
+            tpm_util_write_fatal_error_response(locty->r_buffer.buffer,
+                                           locty->r_buffer.size);
+        } else {
+            tpm_emulator_unix_tx_bufs(tpm_pt, locty->w_buffer.buffer,
+                                  locty->w_offset, locty->r_buffer.buffer,
+                                  locty->r_buffer.size, &selftest_done);
+        }
+        tb->recv_data_callback(tb->tpm_state, tb->tpm_state->locty_number,
+                               selftest_done);
+        qemu_mutex_unlock(&tpm_pt->state_lock);
+        break;
+    case TPM_BACKEND_CMD_INIT:
+    case TPM_BACKEND_CMD_END:
+    case TPM_BACKEND_CMD_TPM_RESET:
+        /* nothing to do */
+        break;
+    }
+}
+
+/*
+ * Gracefully shut down the external unixio TPM
+ */
+static void tpm_emulator_shutdown(TPMEmulator *tpm_pt)
+{
+    ptm_res res;
+
+    if (!tpm_pt->child_running) {
+        return;
+    }
+
+    if (tpm_emulator_ctrlcmd(tpm_pt->ctrl_ioc, 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 int tpm_emulator_probe_caps(TPMEmulator *tpm_pt)
+{
+    if (!tpm_pt->child_running) {
+        return -1;
+    }
+
+    DPRINTF("%s", __func__);
+    if (tpm_emulator_ctrlcmd(tpm_pt->ctrl_ioc, CMD_GET_CAPABILITY,
+                         &tpm_pt->caps, 0, sizeof(tpm_pt->caps)) < 0) {
+        error_report("tpm-emulator: probing failed : %s", strerror(errno));
+        return -1;
+    }
+
+    tpm_pt->caps = be64_to_cpu(tpm_pt->caps);
+
+    DPRINTF("capbilities : 0x%lx", tpm_pt->caps);
+
+    return 0;
+}
+
+static int tpm_emulator_check_caps(TPMEmulator *tpm_pt)
+{
+    ptm_cap caps = 0;
+    const char *tpm = NULL;
+
+    /* check for min. required capabilities */
+    switch (tpm_pt->tpm_version) {
+    case TPM_VERSION_1_2:
+        caps = PTM_CAP_INIT | PTM_CAP_SHUTDOWN | PTM_CAP_GET_TPMESTABLISHED |
+               PTM_CAP_SET_LOCALITY;
+        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;
+        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_pt, 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_init_tpm(TPMEmulator *tpm_pt)
+{
+    ptm_init init;
+    ptm_res res;
+
+    if (!tpm_pt->child_running) {
+        return -1;
+    }
+
+    DPRINTF("%s", __func__);
+    if (tpm_emulator_ctrlcmd(tpm_pt->ctrl_ioc, CMD_INIT, &init, sizeof(init),
+                         sizeof(init)) < 0) {
+        error_report("tpm-emulator: could not send INIT: %s",
+                     strerror(errno));
+        return -1;
+    }
+
+    res = be32_to_cpu(init.u.resp.tpm_result);
+    if (res) {
+        error_report("tpm-emulator: TPM result for CMD_INIT: 0x%x", res);
+        return -1;
+    }
+
+    return 0;
+}
+
+static int tpm_emulator_startup_tpm(TPMBackend *tb)
+{
+    TPMEmulator *tpm_pt = TPM_EMULATOR(tb);
+
+    DPRINTF("%s", __func__);
+
+    tpm_emulator_init_tpm(tpm_pt) ;
+
+    return 0;
+}
+
+static bool tpm_emulator_get_tpm_established_flag(TPMBackend *tb)
+{
+    TPMEmulator *tpm_pt = TPM_EMULATOR(tb);
+    ptm_est est;
+
+    DPRINTF("%s", __func__);
+    if (tpm_emulator_ctrlcmd(tpm_pt->ctrl_ioc, 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("established flag: %0x", est.u.resp.bit);
+
+    return (est.u.resp.bit != 0);
+}
+
+static int tpm_emulator_reset_tpm_established_flag(TPMBackend *tb,
+                                                   uint8_t locty)
+{
+    TPMEmulator *tpm_pt = TPM_EMULATOR(tb);
+    ptm_reset_est reset_est;
+    ptm_res res;
+
+    /* only a TPM 2.0 will support this */
+    if (tpm_pt->tpm_version == TPM_VERSION_2_0) {
+        reset_est.u.req.loc = tpm_pt->cur_locty_number;
+
+        if (tpm_emulator_ctrlcmd(tpm_pt->ctrl_ioc, 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;
+        }
+    }
+
+    return 0;
+}
+
+static bool tpm_emulator_had_startup_error(TPMBackend *tb)
+{
+    TPMEmulator *tpm_pt = TPM_EMULATOR(tb);
+
+    return !tpm_pt->child_running;
+}
+
+static void tpm_emulator_cancel_cmd(TPMBackend *tb)
+{
+    TPMEmulator *tpm_pt = TPM_EMULATOR(tb);
+    ptm_res res;
+
+    /*
+     * As of Linux 3.7 the tpm_tis driver does not properly cancel
+     * commands on all TPM manufacturers' TPMs.
+     * Only cancel if we're busy so we don't cancel someone else's
+     * command, e.g., a command executed on the host.
+     */
+    if (tpm_pt->op_executing) {
+        if (TPM_EMULATOR_IMPLEMENTS_ALL_CAPS(tpm_pt, PTM_CAP_CANCEL_TPM_CMD)) {
+            if (tpm_emulator_ctrlcmd(tpm_pt->ctrl_ioc, 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));
+            } else {
+                tpm_pt->op_canceled = true;
+            }
+        }
+    }
+}
+
+static void tpm_emulator_reset(TPMBackend *tb)
+{
+    DPRINTF("%s", __func__);
+
+    tpm_emulator_cancel_cmd(tb);
+}
+
+static TPMVersion tpm_emulator_get_tpm_version(TPMBackend *tb)
+{
+    TPMEmulator *tpm_pt = TPM_EMULATOR(tb);
+
+    return tpm_pt->tpm_version;
+}
+
+static gboolean tpm_emulator_fd_handler(QIOChannel *ioc, GIOCondition cnd,
+                                        void *opaque)
+{
+    TPMEmulator *tpm_pt = opaque;
+
+    if (cnd & G_IO_ERR || cnd & G_IO_HUP) {
+        error_report("TPM backend disappeared");
+        tpm_pt->child_running = false;
+        return false;
+    }
+
+    return true;
+}
+
+static QIOChannel *_iochannel_new(const char *path, int fd, Error **err)
+{
+    int socket = path ?  unix_connect(path, err) : fd;
+    if (socket < 0) {
+        return NULL;
+    }
+
+    return QIO_CHANNEL(qio_channel_socket_new_fd(socket, err));
+}
+
+static int tpm_emulator_spawn_emulator(TPMEmulator *tpm_pt)
+{
+    int fds[2] = { -1, -1 };
+    int ctrl_fds[2] = { -1, -1 };
+    pid_t cpid;
+
+    if (!tpm_pt->ops->has_data_path) {
+        if (socketpair(AF_UNIX, SOCK_SEQPACKET, 0, fds) < 0) {
+            return -1;
+        }
+    }
+
+    if (!tpm_pt->ops->has_ctrl_path) {
+        if (socketpair(AF_UNIX, SOCK_SEQPACKET, 0, ctrl_fds) < 0) {
+            if (!tpm_pt->ops->has_data_path) {
+                closesocket(fds[0]);
+                closesocket(fds[1]);
+            }
+            return -1;
+        }
+    }
+
+    cpid = qemu_fork(NULL);
+    if (cpid < 0) {
+        error_report("tpm-emulator: Fork failure: %s", strerror(errno));
+        if (!tpm_pt->ops->has_data_path) {
+            closesocket(fds[0]);
+            closesocket(fds[1]);
+        }
+        if (!tpm_pt->ops->has_ctrl_path) {
+            closesocket(ctrl_fds[0]);
+            closesocket(ctrl_fds[1]);
+        }
+        return -1;
+    }
+
+    unlink(TPM_EMULATOR_PIDFILE);
+
+    if (cpid == 0) { /* CHILD */
+        enum {
+            PARAM_PATH,
+            PARAM_IFACE,
+            PARAM_SERVER,  PARAM_SERVER_ARGS,
+            PARAM_CTRL,    PARAM_CTRL_ARGS,
+            PARAM_STATE,   PARAM_STATE_ARGS,
+            PARAM_PIDFILE, PARAM_PIDFILE_ARGS,
+            PARAM_LOG,     PARAM_LOG_ARGS,
+            PARAM_MAX
+        };
+
+        int i;
+        int data_fd = -1, ctrl_fd = -1;
+        char *argv[PARAM_MAX + 1];
+
+        /* close all unused inherited sockets */
+        if (fds[0] >= 0) {
+            closesocket(fds[0]);
+        }
+        if (ctrl_fds[0] >= 0) {
+            closesocket(ctrl_fds[0]);
+        }
+
+        i = STDERR_FILENO + 1;
+        if (fds[1] >= 0) {
+            data_fd = dup2(fds[1], i++);
+            if (data_fd < 0) {
+                error_report("tpm-emulator: dup2() failure - %s",
+                             strerror(errno));
+                goto exit_child;
+            }
+        }
+        if (ctrl_fds[1] >= 0) {
+            ctrl_fd = dup2(ctrl_fds[1], i++);
+            if (ctrl_fd < 0) {
+                error_report("tpm-emulator: dup2() failure - %s",
+                             strerror(errno));
+                goto exit_child;
+            }
+        }
+        for ( ; i < sysconf(_SC_OPEN_MAX); i++) {
+            close(i);
+        }
+
+        argv[PARAM_MAX] = NULL;
+        argv[PARAM_PATH] = g_strdup(tpm_pt->ops->path);
+        argv[PARAM_IFACE] = g_strdup("socket");
+        if (tpm_pt->ops->has_data_path) {
+            argv[PARAM_SERVER] = g_strdup("--server");
+            argv[PARAM_SERVER_ARGS] = g_strdup_printf("type=unixio,path=%s",
+                                               tpm_pt->ops->data_path);
+        } else {
+            argv[PARAM_SERVER] = g_strdup("--fd");
+            argv[PARAM_SERVER_ARGS] = g_strdup_printf("%d", data_fd);
+        }
+
+        argv[PARAM_CTRL] = g_strdup("--ctrl");
+        if (tpm_pt->ops->has_ctrl_path) {
+            argv[PARAM_CTRL_ARGS] = g_strdup_printf("type=unixio,path=%s",
+                                                    tpm_pt->ops->ctrl_path);
+        } else {
+            argv[PARAM_CTRL_ARGS] = g_strdup_printf("type=unixio,clientfd=%d",
+                                                    ctrl_fd);
+        }
+
+        argv[PARAM_STATE] = g_strdup("--tpmstate");
+        argv[PARAM_STATE_ARGS] = g_strdup_printf("dir=%s",
+                                        tpm_pt->ops->tpmstatedir);
+        argv[PARAM_PIDFILE] = g_strdup("--pid");
+        argv[PARAM_PIDFILE_ARGS] = g_strdup_printf("file=%s",
+                                            TPM_EMULATOR_PIDFILE);
+        if (tpm_pt->ops->has_logfile) {
+            argv[PARAM_LOG] = g_strdup("--log");
+            argv[PARAM_LOG_ARGS] = g_strdup_printf("file=%s,level=%d",
+                    tpm_pt->ops->logfile, (int)tpm_pt->ops->loglevel);
+        } else {
+            /* truncate logs */
+            argv[PARAM_LOG] = NULL;
+        }
+        DPRINTF("%s", "Running cmd: ")
+        for (i = 0; argv[i]; i++) {
+            DPRINT(" %s", argv[i])
+        }
+        DPRINT("\n")
+        if (execv(tpm_pt->ops->path, (char * const *)argv) < 0) {
+            error_report("execv() failure : %s", strerror(errno));
+        }
+
+exit_child:
+        g_strfreev(argv);
+        if (data_fd >= 0) {
+            closesocket(data_fd);
+        }
+        if (ctrl_fd >= 0) {
+            closesocket(ctrl_fd);
+        }
+
+        _exit(1);
+    } else { /* self */
+        struct stat st;
+        DPRINTF("child pid: %d", cpid);
+        int rc;
+        useconds_t usec = 100 * 1000L; /* wait for 100 milliseconds */
+        useconds_t timeout = 10; /* max 1 second */
+
+        /* close unused sockets */
+        if (fds[1] >= 0) {
+            closesocket(fds[1]);
+        }
+        if (ctrl_fds[1] >= 0) {
+            closesocket(ctrl_fds[1]);
+        }
+
+        tpm_pt->data_ioc = _iochannel_new(tpm_pt->ops->data_path, fds[0], NULL);
+        if (!tpm_pt->data_ioc) {
+            error_report("tpm-emulator: Unable to connect socket : %s",
+                          tpm_pt->ops->data_path);
+            goto err_kill_child;
+        }
+
+        tpm_pt->ctrl_ioc = _iochannel_new(tpm_pt->ops->ctrl_path, ctrl_fds[0],
+                                          NULL);
+        if (!tpm_pt->ctrl_ioc) {
+            error_report("tpm-emulator: Unable to connect socket : %s",
+                          tpm_pt->ops->ctrl_path);
+            goto err_kill_child;
+        }
+
+        qemu_add_child_watch(cpid);
+
+        qio_channel_add_watch(tpm_pt->data_ioc, G_IO_HUP | G_IO_ERR,
+                              tpm_emulator_fd_handler, tpm_pt, NULL);
+
+        while ((rc = stat(TPM_EMULATOR_PIDFILE, &st)) < 0 && timeout--) {
+            usleep(usec);
+        }
+
+        if (timeout == -1) {
+            error_report("tpm-emulator: pid file not ready: %s",
+                         strerror(errno));
+            goto err_kill_child;
+        }
+
+        /* check if child really running */
+        if (kill(cpid, 0) < 0 && errno == ESRCH) {
+            goto err_no_child;
+        }
+
+        tpm_pt->child_running = true;
+    }
+
+    return 0;
+
+err_kill_child:
+    kill(cpid, SIGTERM);
+    /* wait for 10 mill-seconds */
+    usleep(10 * 1000);
+    /* force kill if still reachable */
+    if (kill(cpid, 0) == 0) {
+        kill(cpid, SIGKILL);
+    }
+
+err_no_child:
+    tpm_pt->child_running = false;
+
+    return -1;
+}
+
+static void tpm_emulator_block_migration(TPMEmulator *tpm_pt)
+{
+   Error *err = NULL;
+
+   error_setg(&tpm_pt->migration_blocker,
+              "Migration disabled: TPM emulator not yet migratable");
+    migrate_add_blocker(tpm_pt->migration_blocker, &err);
+    if (err) {
+        error_free(err);
+        error_free(tpm_pt->migration_blocker);
+        tpm_pt->migration_blocker = NULL;
+    }
+}
+
+static int tpm_emulator_handle_device_opts(TPMEmulator *tpm_pt, QemuOpts *opts)
+{
+    const char *value;
+
+    value = qemu_opt_get(opts, "tpmstatedir");
+    if (!value) {
+        error_report("tpm-emulator: Missing tpm state directory");
+        return -1;
+    }
+    tpm_pt->ops->tpmstatedir = g_strdup(value);
+
+    tpm_pt->ops->spawn = qemu_opt_get_bool(opts, "spawn", false);
+
+    value = qemu_opt_get(opts, "path");
+    if (!value) {
+        value = TPM_DEFAULT_EMULATOR;
+        tpm_pt->ops->has_path = false;
+    } else {
+        tpm_pt->ops->has_path = true;
+        if (value[0] == '/') {
+            struct stat st;
+            if (stat(value, &st) < 0 || !(S_ISREG(st.st_mode)
+                || S_ISLNK(st.st_mode))) {
+                error_report("tpm-emulator: Invalid emulator path: %s", value);
+                return -1;
+            }
+        }
+    }
+    tpm_pt->ops->path = g_strdup(value);
+
+    value = qemu_opt_get(opts, "data-path");
+    if (value) {
+        tpm_pt->ops->has_data_path = true;
+        tpm_pt->ops->data_path = g_strdup(value);
+    } else {
+        tpm_pt->ops->has_data_path = false;
+        if (!tpm_pt->ops->spawn) {
+            error_report("tpm-emulator: missing mandatory data-path");
+            return -1;
+        }
+    }
+
+    value = qemu_opt_get(opts, "ctrl-path");
+    if (value) {
+        tpm_pt->ops->has_ctrl_path = true;
+        tpm_pt->ops->ctrl_path = g_strdup(value);
+    } else {
+        tpm_pt->ops->has_ctrl_path = false;
+        if (!tpm_pt->ops->spawn) {
+            error_report("tpm-emulator: missing mandatory ctrl-path");
+            return -1;
+        }
+    }
+
+    value = qemu_opt_get(opts, "logfile");
+    if (value) {
+        tpm_pt->ops->has_logfile = true;
+        tpm_pt->ops->logfile = g_strdup(value);
+        tpm_pt->ops->loglevel = qemu_opt_get_number(opts, "loglevel",
+                                                   TPM_DEFAULT_LOGLEVEL);
+        tpm_pt->ops->has_loglevel = tpm_pt->ops->loglevel !=
+                                     TPM_DEFAULT_LOGLEVEL;
+    }
+
+    if (tpm_pt->ops->spawn) {
+        if (tpm_emulator_spawn_emulator(tpm_pt) < 0) {
+            goto err_close_dev;
+        }
+    } else {
+        tpm_pt->data_ioc = _iochannel_new(tpm_pt->ops->data_path, -1, NULL);
+        if (tpm_pt->data_ioc  == NULL) {
+            error_report("tpm-emulator: Failed to connect data socket: %s",
+                         tpm_pt->ops->data_path);
+            goto err_close_dev;
+        }
+        tpm_pt->ctrl_ioc = _iochannel_new(tpm_pt->ops->ctrl_path, -1, NULL);
+        if (tpm_pt->ctrl_ioc == NULL) {
+            DPRINTF("Failed to connect control socket: %s",
+                    strerror(errno));
+            goto err_close_dev;
+        }
+        tpm_pt->child_running = true;
+    }
+
+    /* 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_pt->data_ioc)->fd,
+                             &tpm_pt->tpm_version)) {
+        error_report("'%s' is not emulating TPM device.", tpm_pt->ops->path);
+        goto err_close_dev;
+    }
+
+    DPRINTF("TPM Version %s", tpm_pt->tpm_version == TPM_VERSION_1_2 ? "1.2" :
+             (tpm_pt->tpm_version == TPM_VERSION_2_0 ?  "2.0" : "Unspecified"));
+
+    if (tpm_emulator_probe_caps(tpm_pt) ||
+        tpm_emulator_check_caps(tpm_pt)) {
+        goto err_close_dev;
+    }
+
+    tpm_emulator_block_migration(tpm_pt);
+
+    return 0;
+
+err_close_dev:
+    DPRINT("Startup error\n");
+    return -1;
+}
+
+static TPMBackend *tpm_emulator_create(QemuOpts *opts, const char *id)
+{
+    TPMBackend *tb = TPM_BACKEND(object_new(TYPE_TPM_EMULATOR));
+
+    tb->id = g_strdup(id);
+
+    if (tpm_emulator_handle_device_opts(TPM_EMULATOR(tb), opts)) {
+        goto err_exit;
+    }
+
+    return tb;
+
+err_exit:
+    object_unref(OBJECT(tb));
+
+    return NULL;
+}
+
+static TpmTypeOptions *tpm_emulator_get_tpm_options(TPMBackend *tb)
+{
+    TPMEmulator *tpm_pt = TPM_EMULATOR(tb);
+    TpmTypeOptions *ops = NULL;
+    TPMEmulatorOptions *eops = NULL;
+
+    eops = g_new0(TPMEmulatorOptions, 1);
+    if (!eops) {
+        return NULL;
+    }
+    DPRINTF("%s", __func__);
+
+    eops->tpmstatedir = g_strdup(tpm_pt->ops->tpmstatedir);
+    eops->spawn = tpm_pt->ops->spawn;
+    if (tpm_pt->ops->has_path) {
+        eops->has_path = true;
+        eops->path = g_strdup(tpm_pt->ops->path);
+    }
+    if (tpm_pt->ops->has_data_path) {
+        eops->has_data_path = true;
+        eops->data_path = g_strdup(tpm_pt->ops->data_path);
+    }
+    if (tpm_pt->ops->has_ctrl_path) {
+        eops->has_ctrl_path = true;
+        eops->ctrl_path = g_strdup(tpm_pt->ops->ctrl_path);
+    }
+    if (tpm_pt->ops->has_logfile) {
+        eops->has_logfile = true;
+        eops->logfile = g_strdup(tpm_pt->ops->logfile);
+    }
+    if (tpm_pt->ops->has_loglevel) {
+        eops->has_loglevel = true;
+        eops->loglevel = tpm_pt->ops->loglevel;
+    }
+
+    ops = g_new0(TpmTypeOptions, 1);
+    if (!ops) {
+        qapi_free_TPMEmulatorOptions(eops);
+        return NULL;
+    }
+
+    ops->type = TPM_TYPE_EMULATOR;
+    ops->u.emulator.data = eops;
+
+    return ops;
+}
+
+static const QemuOptDesc tpm_emulator_cmdline_opts[] = {
+    TPM_STANDARD_CMDLINE_OPTS,
+    {
+        .name = "tpmstatedir",
+        .type = QEMU_OPT_STRING,
+        .help = "TPM state directroy",
+    },
+    {
+        .name = "spawn",
+        .type = QEMU_OPT_BOOL,
+        .help = "Wether to spwan given emlatory binary",
+    },
+    {
+        .name = "path",
+        .type = QEMU_OPT_STRING,
+        .help = "Path to TPM emulator binary",
+    },
+    {
+        .name = "data-path",
+        .type = QEMU_OPT_STRING,
+        .help = "Socket path to use for data exhange",
+    },
+    {
+        .name = "ctrl-path",
+        .type = QEMU_OPT_STRING,
+        .help = "Socket path to use for out-of-band control messages",
+    },
+    {
+        .name = "logfile",
+        .type = QEMU_OPT_STRING,
+        .help = "Path to log file",
+    },
+    {
+        .name = "loglevel",
+        .type = QEMU_OPT_NUMBER,
+        .help = "Log level number",
+    },
+    { /* end of list */ },
+};
+
+static const TPMDriverOps tpm_emulator_driver = {
+    .type                     = TPM_TYPE_EMULATOR,
+    .opts                     = tpm_emulator_cmdline_opts,
+    .desc                     = "TPM emulator backend driver",
+
+    .create                   = tpm_emulator_create,
+    .startup_tpm              = tpm_emulator_startup_tpm,
+    .reset                    = tpm_emulator_reset,
+    .had_startup_error        = tpm_emulator_had_startup_error,
+    .cancel_cmd               = tpm_emulator_cancel_cmd,
+    .get_tpm_established_flag = tpm_emulator_get_tpm_established_flag,
+    .reset_tpm_established_flag = tpm_emulator_reset_tpm_established_flag,
+    .get_tpm_version          = tpm_emulator_get_tpm_version,
+    .get_tpm_options          = tpm_emulator_get_tpm_options,
+};
+
+static void tpm_emulator_inst_init(Object *obj)
+{
+    TPMEmulator *tpm_pt = TPM_EMULATOR(obj);
+
+    DPRINTF("%s", __func__);
+    tpm_pt->ops = g_new0(TPMEmulatorOptions, 1);
+    tpm_pt->data_ioc = tpm_pt->ctrl_ioc = NULL;
+    tpm_pt->op_executing = tpm_pt->op_canceled = false;
+    tpm_pt->child_running = false;
+    tpm_pt->cur_locty_number = ~0;
+    qemu_mutex_init(&tpm_pt->state_lock);
+}
+
+static void tpm_emulator_inst_finalize(Object *obj)
+{
+    TPMEmulator *tpm_pt = TPM_EMULATOR(obj);
+
+    tpm_emulator_cancel_cmd(TPM_BACKEND(obj));
+    tpm_emulator_shutdown(tpm_pt);
+
+    if (tpm_pt->data_ioc) {
+        qio_channel_close(tpm_pt->data_ioc, NULL);
+    }
+    if (tpm_pt->ctrl_ioc) {
+        qio_channel_close(tpm_pt->ctrl_ioc, NULL);
+    }
+    if (tpm_pt->ops) {
+        qapi_free_TPMEmulatorOptions(tpm_pt->ops);
+    }
+
+    if (tpm_pt->migration_blocker) {
+        migrate_del_blocker(tpm_pt->migration_blocker);
+        error_free(tpm_pt->migration_blocker);
+    }
+}
+
+static void tpm_emulator_class_init(ObjectClass *klass, void *data)
+{
+    TPMBackendClass *tbc = TPM_BACKEND_CLASS(klass);
+    tbc->ops = &tpm_emulator_driver;
+    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);
+    tpm_register_driver(&tpm_emulator_driver);
+}
+
+type_init(tpm_emulator_register)
diff --git a/hw/tpm/tpm_ioctl.h b/hw/tpm/tpm_ioctl.h
new file mode 100644
index 0000000..af49708
--- /dev/null
+++ b/hw/tpm/tpm_ioctl.h
@@ -0,0 +1,243 @@ 
+/*
+ * tpm_ioctl.h
+ *
+ * (c) Copyright IBM Corporation 2014, 2015.
+ *
+ * This file is licensed under the terms of the 3-clause BSD license
+ */
+#ifndef _TPM_IOCTL_H_
+#define _TPM_IOCTL_H_
+
+#include <stdint.h>
+#include <sys/uio.h>
+#include <sys/types.h>
+#include <sys/ioctl.h>
+
+/*
+ * Every response from a command involving a TPM command execution must hold
+ * the ptm_res as the first element.
+ * ptm_res corresponds to the error code of a command executed by the TPM.
+ */
+
+typedef uint32_t ptm_res;
+
+/* PTM_GET_TPMESTABLISHED: get the establishment bit */
+struct ptm_est {
+    union {
+        struct {
+            ptm_res tpm_result;
+            unsigned char bit; /* TPM established bit */
+        } resp; /* response */
+    } u;
+};
+
+/* PTM_RESET_TPMESTABLISHED: reset establishment bit */
+struct ptm_reset_est {
+    union {
+        struct {
+            uint8_t loc; /* locality to use */
+        } req; /* request */
+        struct {
+            ptm_res tpm_result;
+        } resp; /* response */
+    } u;
+};
+
+/* PTM_INIT */
+struct ptm_init {
+    union {
+        struct {
+            uint32_t init_flags; /* see definitions below */
+        } req; /* request */
+        struct {
+            ptm_res tpm_result;
+        } resp; /* response */
+    } u;
+};
+
+/* above init_flags */
+#define PTM_INIT_FLAG_DELETE_VOLATILE (1 << 0)
+    /* delete volatile state file after reading it */
+
+/* PTM_SET_LOCALITY */
+struct ptm_loc {
+    union {
+        struct {
+            uint8_t loc; /* locality to set */
+        } req; /* request */
+        struct {
+            ptm_res tpm_result;
+        } resp; /* response */
+    } u;
+};
+
+/* PTM_HASH_DATA: hash given data */
+struct ptm_hdata {
+    union {
+        struct {
+            uint32_t length;
+            uint8_t data[4096];
+        } req; /* request */
+        struct {
+            ptm_res tpm_result;
+        } resp; /* response */
+    } u;
+};
+
+/*
+ * size of the TPM state blob to transfer; x86_64 can handle 8k,
+ * ppc64le only ~7k; keep the response below a 4k page size
+ */
+#define PTM_STATE_BLOB_SIZE (3 * 1024)
+
+/*
+ * The following is the data structure to get state blobs from the TPM.
+ * If the size of the state blob exceeds the PTM_STATE_BLOB_SIZE, multiple reads
+ * with this ioctl and with adjusted offset are necessary. All bytes
+ * must be transferred and the transfer is done once the last byte has been
+ * returned.
+ * It is possible to use the read() interface for reading the data; however, the
+ * first bytes of the state blob will be part of the response to the ioctl(); a
+ * subsequent read() is only necessary if the total length (totlength) exceeds
+ * the number of received bytes. seek() is not supported.
+ */
+struct ptm_getstate {
+    union {
+        struct {
+            uint32_t state_flags; /* may be: PTM_STATE_FLAG_DECRYPTED */
+            uint32_t type;        /* which blob to pull */
+            uint32_t offset;      /* offset from where to read */
+        } req; /* request */
+        struct {
+            ptm_res tpm_result;
+            uint32_t state_flags; /* may be: PTM_STATE_FLAG_ENCRYPTED */
+            uint32_t totlength;   /* total length that will be transferred */
+            uint32_t length;      /* number of bytes in following buffer */
+            uint8_t  data[PTM_STATE_BLOB_SIZE];
+        } resp; /* response */
+    } u;
+};
+
+/* TPM state blob types */
+#define PTM_BLOB_TYPE_PERMANENT  1
+#define PTM_BLOB_TYPE_VOLATILE   2
+#define PTM_BLOB_TYPE_SAVESTATE  3
+
+/* state_flags above : */
+#define PTM_STATE_FLAG_DECRYPTED     1 /* on input:  get decrypted state */
+#define PTM_STATE_FLAG_ENCRYPTED     2 /* on output: state is encrypted */
+
+/*
+ * The following is the data structure to set state blobs in the TPM.
+ * If the size of the state blob exceeds the PTM_STATE_BLOB_SIZE, multiple
+ * 'writes' using this ioctl are necessary. The last packet is indicated
+ * by the length being smaller than the PTM_STATE_BLOB_SIZE.
+ * The very first packet may have a length indicator of '0' enabling
+ * a write() with all the bytes from a buffer. If the write() interface
+ * is used, a final ioctl with a non-full buffer must be made to indicate
+ * that all data were transferred (a write with 0 bytes would not work).
+ */
+struct ptm_setstate {
+    union {
+        struct {
+            uint32_t state_flags; /* may be PTM_STATE_FLAG_ENCRYPTED */
+            uint32_t type;        /* which blob to set */
+            uint32_t length;      /* length of the data;
+                                     use 0 on the first packet to
+                                     transfer using write() */
+            uint8_t data[PTM_STATE_BLOB_SIZE];
+        } req; /* request */
+        struct {
+            ptm_res tpm_result;
+        } resp; /* response */
+    } u;
+};
+
+/*
+ * PTM_GET_CONFIG: Data structure to get runtime configuration information
+ * such as which keys are applied.
+ */
+struct ptm_getconfig {
+    union {
+        struct {
+            ptm_res tpm_result;
+            uint32_t flags;
+        } resp; /* response */
+    } u;
+};
+
+#define PTM_CONFIG_FLAG_FILE_KEY        0x1
+#define PTM_CONFIG_FLAG_MIGRATION_KEY   0x2
+
+
+typedef uint64_t ptm_cap;
+typedef struct ptm_est ptm_est;
+typedef struct ptm_reset_est ptm_reset_est;
+typedef struct ptm_loc ptm_loc;
+typedef struct ptm_hdata ptm_hdata;
+typedef struct ptm_init ptm_init;
+typedef struct ptm_getstate ptm_getstate;
+typedef struct ptm_setstate ptm_setstate;
+typedef struct ptm_getconfig ptm_getconfig;
+
+/* capability flags returned by PTM_GET_CAPABILITY */
+#define PTM_CAP_INIT               (1)
+#define PTM_CAP_SHUTDOWN           (1 << 1)
+#define PTM_CAP_GET_TPMESTABLISHED (1 << 2)
+#define PTM_CAP_SET_LOCALITY       (1 << 3)
+#define PTM_CAP_HASHING            (1 << 4)
+#define PTM_CAP_CANCEL_TPM_CMD     (1 << 5)
+#define PTM_CAP_STORE_VOLATILE     (1 << 6)
+#define PTM_CAP_RESET_TPMESTABLISHED (1 << 7)
+#define PTM_CAP_GET_STATEBLOB      (1 << 8)
+#define PTM_CAP_SET_STATEBLOB      (1 << 9)
+#define PTM_CAP_STOP               (1 << 10)
+#define PTM_CAP_GET_CONFIG         (1 << 11)
+
+enum {
+    PTM_GET_CAPABILITY     = _IOR('P', 0, ptm_cap),
+    PTM_INIT               = _IOWR('P', 1, ptm_init),
+    PTM_SHUTDOWN           = _IOR('P', 2, ptm_res),
+    PTM_GET_TPMESTABLISHED = _IOR('P', 3, ptm_est),
+    PTM_SET_LOCALITY       = _IOWR('P', 4, ptm_loc),
+    PTM_HASH_START         = _IOR('P', 5, ptm_res),
+    PTM_HASH_DATA          = _IOWR('P', 6, ptm_hdata),
+    PTM_HASH_END           = _IOR('P', 7, ptm_res),
+    PTM_CANCEL_TPM_CMD     = _IOR('P', 8, ptm_res),
+    PTM_STORE_VOLATILE     = _IOR('P', 9, ptm_res),
+    PTM_RESET_TPMESTABLISHED = _IOWR('P', 10, ptm_reset_est),
+    PTM_GET_STATEBLOB      = _IOWR('P', 11, ptm_getstate),
+    PTM_SET_STATEBLOB      = _IOWR('P', 12, ptm_setstate),
+    PTM_STOP               = _IOR('P', 13, ptm_res),
+    PTM_GET_CONFIG         = _IOR('P', 14, ptm_getconfig),
+};
+
+/*
+ * Commands used by the non-CUSE TPMs
+ *
+ * All messages container big-endian data.
+ *
+ * The return messages only contain the 'resp' part of the unions
+ * in the data structures above. Besides that the limits in the
+ * buffers above (ptm_hdata:u.req.data and ptm_get_state:u.resp.data
+ * and ptm_set_state:u.req.data) are 0xffffffff.
+ */
+enum {
+    CMD_GET_CAPABILITY = 1,
+    CMD_INIT,
+    CMD_SHUTDOWN,
+    CMD_GET_TPMESTABLISHED,
+    CMD_SET_LOCALITY,
+    CMD_HASH_START,
+    CMD_HASH_DATA,
+    CMD_HASH_END,
+    CMD_CANCEL_TPM_CMD,
+    CMD_STORE_VOLATILE,
+    CMD_RESET_TPMESTABLISHED,
+    CMD_GET_STATEBLOB,
+    CMD_SET_STATEBLOB,
+    CMD_STOP,
+    CMD_GET_CONFIG,
+};
+
+#endif /* _TPM_IOCTL_H */
diff --git a/qapi-schema.json b/qapi-schema.json
index 5728b7f..cfe0c94 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -5123,10 +5123,12 @@ 
 # An enumeration of TPM types
 #
 # @passthrough: TPM passthrough type
+# @emulator: Software Emulator TPM type
+#            Since: 2.10
 #
 # Since: 1.5
 ##
-{ 'enum': 'TpmType', 'data': [ 'passthrough' ] }
+{ 'enum': 'TpmType', 'data': [ 'passthrough', 'emulator' ] }
 
 ##
 # @query-tpm-types:
@@ -5140,7 +5142,7 @@ 
 # Example:
 #
 # -> { "execute": "query-tpm-types" }
-# <- { "return": [ "passthrough" ] }
+# <- { "return": [ "passthrough", "emulator" ] }
 #
 ##
 { 'command': 'query-tpm-types', 'returns': ['TpmType'] }
@@ -5161,16 +5163,49 @@ 
                                              '*cancel-path' : 'str'} }
 
 ##
+# @TPMEmulatorOptions:
+#
+# Information about the TPM emulator
+#
+# @tpmstatedir: TPM emulator state directory
+# @spawn: true if, qemu has to spawn a new emulator process with given @path,
+#         otherwise it connects to already rinning emulator with given @data-path
+#         and @ctrl-path sockets. (default: 'false')
+# @path: TPM emulator binary path to spawn.(default: 'swtpm')
+# @data-path: path of the unix socket to use for exchanging data messages, if
+#             not provided socket pairs are used when @sapwn is true.
+# @ctrl-path: path of the unix socket file to use for exchagning out-of-band
+#             control messages, if not provided socket pairs are used when
+#             @spawn is true.
+# @logfile: file to use to place TPM emulator logs, if not provided logging is
+#           disabled.
+# @loglevel: optional log level number, loglevel is ignored if no logfile
+#            provided. (default: 5)
+#
+# Since: 2.10
+##
+{ 'struct': 'TPMEmulatorOptions',
+  'data': { 'tpmstatedir' : 'str',
+            'spawn': 'bool',
+            '*path': 'str',
+            '*data-path': 'str',
+            '*ctrl-path': 'str',
+            '*logfile': 'str',
+            '*loglevel': 'uint8' } }
+
+##
 # @TpmTypeOptions:
 #
 # A union referencing different TPM backend types' configuration options
 #
 # @type: 'passthrough' The configuration options for the TPM passthrough type
+#        'emulator' The configuration options for TPM emulator backend type
 #
 # Since: 1.5
 ##
 { 'union': 'TpmTypeOptions',
-   'data': { 'passthrough' : 'TPMPassthroughOptions' } }
+  'data': { 'passthrough': 'TPMPassthroughOptions',
+            'emulator': 'TPMEmulatorOptions' } }
 
 ##
 # @TPMInfo:
diff --git a/qemu-options.hx b/qemu-options.hx
index f806af9..e4dbc33 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -2883,7 +2883,15 @@  DEF("tpmdev", HAS_ARG, QEMU_OPTION_tpmdev, \
     "-tpmdev passthrough,id=id[,path=path][,cancel-path=path]\n"
     "                use path to provide path to a character device; default is /dev/tpm0\n"
     "                use cancel-path to provide path to TPM's cancel sysfs entry; if\n"
-    "                not provided it will be searched for in /sys/class/misc/tpm?/device\n",
+    "                not provided it will be searched for in /sys/class/misc/tpm?/device\n"
+    "-tpmdev emulator,id=id,spawn=on|off,tpmstatedir=dir[,path=emulator-path,data-path=path,ctrl-path=path,logfile=path,loglevel=level]\n"
+    "                spawn=on|off controls spawning support\n"
+    "                use tpmstatedir to provide path to the tpm state dirctory\n"
+    "                use path to provide the emulator binary to launch; default is 'swtpm'\n"
+    "                use data-path to provide the socket path for exchanging data messages\n"
+    "                use ctrl-path to provide the socket path for sending control messages to software emulator\n"
+    "                use logfile to provide where to place the swtpm logs\n"
+    "                use loglevel to controls the swtpm log level\n",
     QEMU_ARCH_ALL)
 STEXI
 
@@ -2892,8 +2900,8 @@  The general form of a TPM device option is:
 
 @item -tpmdev @var{backend} ,id=@var{id} [,@var{options}]
 @findex -tpmdev
-Backend type must be:
-@option{passthrough}.
+Backend type must be either one of the following:
+@option{passthrough}, @option{emulator}.
 
 The specific backend type will determine the applicable options.
 The @code{-tpmdev} option creates the TPM backend and requires a
@@ -2943,6 +2951,45 @@  To create a passthrough TPM use the following two options:
 Note that the @code{-tpmdev} id is @code{tpm0} and is referenced by
 @code{tpmdev=tpm0} in the device option.
 
+@item -tpmdev emulator, id=@var{id}, tpmstatedir=@var{path}, spawn=@var{on|off}, path=@var{emulator-binary-path}, data-path=@var{path}, ctrl-path=@var{path}, logfile=@var{path}, loglevel=@var{level}
+
+(Linux-host only) Enable access to a TPM emulator using unix domain sockets.
+
+@option{tpmstatedir} specifies the tpm state directory
+
+@option{spawn} specifies if qemu should spawn new emulator process with given @option{path}
+
+@option{path} specifies the emulator binary path to use for spawning
+
+@option{data-path} optional socket path to use for exchanging TPM data with emulator
+
+@option{ctrl-path} optional socket path to use for sending control data to emulator
+
+@option{logfile} optional log file to use to place log messages
+
+@option{loglevel} specifies the log level to use
+
+To create TPM emulator backend device that spawns new swtpm binary and communicate with socket pairs:
+@example
+
+-tpmdev emulator,id=tpm0,tpmstatedir=/tmp/my-tpm,spawn=on,path=/usr/local/bin/swtpm,logfile=/tmp/qemu-tpm.log,loglevel=5 -device tpm-tis,tpmdev=tpm0
+
+@end example
+
+To create TPM emulator backend device that spawns new swtpm binary and communicate using unix file system sockets:
+@example
+
+-tpmdev emulator,id=tpm0,tpmstatedir=/tmp/my-tpm,spawn=on,path=/usr/local/bin/swtpm,data-path=/tmp/swtpm-data.socket,ctrl-path=/tmp/swtpm-ctrl.socket,logfile=/tmp/qemu-tpm.log,loglevel=5 -device tpm-tis,tpmdev=tpm0
+
+@end example
+
+To create a TOM emulator backend device that connects to already running swtpm binary using file system sockets:
+@example
+
+-tpmdev emulator,id=tpm0,tpmstatedir=/tmp/my-tpm,spawn=off,data-path=/tmp/swtpm-data.socket,ctrl-path=/tmp/swtpm-ctrl.socket,logfile=/tmp/qemu-tpm.log,loglevel=5 -device tpm-tis,tpmdev=tpm0
+
+@end example
+
 @end table
 
 ETEXI
diff --git a/tpm.c b/tpm.c
index 84e9667..6d2513c 100644
--- a/tpm.c
+++ b/tpm.c
@@ -25,7 +25,7 @@  static QLIST_HEAD(, TPMBackend) tpm_backends =
 
 
 #define TPM_MAX_MODELS      1
-#define TPM_MAX_DRIVERS     1
+#define TPM_MAX_DRIVERS     2
 
 static TPMDriverOps const *be_drivers[TPM_MAX_DRIVERS] = {
     NULL,