diff mbox series

[v4,1/2] tpm: convert tpmdev options processing to new visitor format

Message ID 20221230152415.27375-2-jejb@linux.ibm.com (mailing list archive)
State New, archived
Headers show
Series tpm: add mssim backend | expand

Commit Message

James Bottomley Dec. 30, 2022, 3:24 p.m. UTC
From: James Bottomley <James.Bottomley@HansenPartnership.com>

Instead of processing the tpmdev options using the old qemu options,
convert to the new visitor format which also allows the passing of
json on the command line.

Signed-off-by: James Bottomley <jejb@linux.ibm.com>

---
v4: add TpmConfiOptions
---
 backends/tpm/tpm_emulator.c    | 24 ++++-----
 backends/tpm/tpm_passthrough.c | 27 +++-------
 include/sysemu/tpm.h           |  4 +-
 include/sysemu/tpm_backend.h   |  2 +-
 qapi/tpm.json                  | 19 +++++++
 softmmu/tpm.c                  | 90 ++++++++++++++--------------------
 softmmu/vl.c                   | 19 +------
 7 files changed, 76 insertions(+), 109 deletions(-)

Comments

Stefan Berger Dec. 30, 2022, 5:01 p.m. UTC | #1
On 12/30/22 10:24, James Bottomley wrote:
> From: James Bottomley <James.Bottomley@HansenPartnership.com>
> 
> Instead of processing the tpmdev options using the old qemu options,
> convert to the new visitor format which also allows the passing of
> json on the command line.
> 
> Signed-off-by: James Bottomley <jejb@linux.ibm.com>
> 
> ---
> v4: add TpmConfiOptions
> ---
>   backends/tpm/tpm_emulator.c    | 24 ++++-----
>   backends/tpm/tpm_passthrough.c | 27 +++-------
>   include/sysemu/tpm.h           |  4 +-
>   include/sysemu/tpm_backend.h   |  2 +-
>   qapi/tpm.json                  | 19 +++++++
>   softmmu/tpm.c                  | 90 ++++++++++++++--------------------
>   softmmu/vl.c                   | 19 +------
>   7 files changed, 76 insertions(+), 109 deletions(-)
> 
> diff --git a/backends/tpm/tpm_emulator.c b/backends/tpm/tpm_emulator.c
> index 49cc3d749d..cb6bf9d7c2 100644
> --- a/backends/tpm/tpm_emulator.c
> +++ b/backends/tpm/tpm_emulator.c
> @@ -584,33 +584,28 @@ err_exit:
>       return -1;
>   }
>   
> -static int tpm_emulator_handle_device_opts(TPMEmulator *tpm_emu, QemuOpts *opts)
> +static int tpm_emulator_handle_device_opts(TPMEmulator *tpm_emu, TpmCreateOptions *opts)
>   {
> -    const char *value;
>       Error *err = NULL;
>       Chardev *dev;
>   
> -    value = qemu_opt_get(opts, "chardev");
> -    if (!value) {
> -        error_report("tpm-emulator: parameter 'chardev' is missing");
> -        goto err;
> -    }
> +    tpm_emu->options = QAPI_CLONE(TPMEmulatorOptions, &opts->u.emulator);
> +    tpm_emu->data_ioc = NULL;
>   
> -    dev = qemu_chr_find(value);
> +    dev = qemu_chr_find(opts->u.emulator.chardev);
>       if (!dev) {
> -        error_report("tpm-emulator: tpm chardev '%s' not found", value);
> +        error_report("tpm-emulator: tpm chardev '%s' not found",
> +                opts->u.emulator.chardev);
>           goto err;
>       }
>   
>       if (!qemu_chr_fe_init(&tpm_emu->ctrl_chr, dev, &err)) {
>           error_prepend(&err, "tpm-emulator: No valid chardev found at '%s':",
> -                      value);
> +                      opts->u.emulator.chardev);
>           error_report_err(err);
>           goto err;
>       }
>   
> -    tpm_emu->options->chardev = g_strdup(value);
> -
>       if (tpm_emulator_prepare_data_fd(tpm_emu) < 0) {
>           goto err;
>       }
> @@ -649,7 +644,7 @@ err:
>       return -1;
>   }
>   
> -static TPMBackend *tpm_emulator_create(QemuOpts *opts)
> +static TPMBackend *tpm_emulator_create(TpmCreateOptions *opts)
>   {
>       TPMBackend *tb = TPM_BACKEND(object_new(TYPE_TPM_EMULATOR));
>   
> @@ -972,7 +967,6 @@ static void tpm_emulator_inst_init(Object *obj)
>   
>       trace_tpm_emulator_inst_init();
>   
> -    tpm_emu->options = g_new0(TPMEmulatorOptions, 1);
>       tpm_emu->cur_locty_number = ~0;
>       qemu_mutex_init(&tpm_emu->mutex);
>       tpm_emu->vmstate =
> @@ -990,7 +984,7 @@ static void tpm_emulator_shutdown(TPMEmulator *tpm_emu)
>   {
>       ptm_res res;
>   
> -    if (!tpm_emu->options->chardev) {
> +    if (!tpm_emu->data_ioc) {
>           /* was never properly initialized */
>           return;
>       }
> diff --git a/backends/tpm/tpm_passthrough.c b/backends/tpm/tpm_passthrough.c
> index 5a2f74db1b..f9771eaf1f 100644
> --- a/backends/tpm/tpm_passthrough.c
> +++ b/backends/tpm/tpm_passthrough.c
> @@ -252,23 +252,11 @@ static int tpm_passthrough_open_sysfs_cancel(TPMPassthruState *tpm_pt)
>   }
>   
>   static int
> -tpm_passthrough_handle_device_opts(TPMPassthruState *tpm_pt, QemuOpts *opts)
> +tpm_passthrough_handle_device_opts(TPMPassthruState *tpm_pt, TpmCreateOptions *opts)
>   {
> -    const char *value;
> +    tpm_pt->options = QAPI_CLONE(TPMPassthroughOptions, &opts->u.passthrough);
>   
> -    value = qemu_opt_get(opts, "cancel-path");
> -    if (value) {
> -        tpm_pt->options->cancel_path = g_strdup(value);
> -        tpm_pt->options->has_cancel_path = true;
> -    }
> -
> -    value = qemu_opt_get(opts, "path");
> -    if (value) {
> -        tpm_pt->options->has_path = true;
> -        tpm_pt->options->path = g_strdup(value);
> -    }
> -
> -    tpm_pt->tpm_dev = value ? value : TPM_PASSTHROUGH_DEFAULT_DEVICE;
> +    tpm_pt->tpm_dev = opts->u.passthrough.has_path ? opts->u.passthrough.path : TPM_PASSTHROUGH_DEFAULT_DEVICE;
>       tpm_pt->tpm_fd = qemu_open_old(tpm_pt->tpm_dev, O_RDWR);
>       if (tpm_pt->tpm_fd < 0) {
>           error_report("Cannot access TPM device using '%s': %s",
> @@ -290,11 +278,11 @@ tpm_passthrough_handle_device_opts(TPMPassthruState *tpm_pt, QemuOpts *opts)
>       return 0;
>   }
>   
> -static TPMBackend *tpm_passthrough_create(QemuOpts *opts)
> +static TPMBackend *tpm_passthrough_create(TpmCreateOptions *tco)
>   {
>       Object *obj = object_new(TYPE_TPM_PASSTHROUGH);
>   
> -    if (tpm_passthrough_handle_device_opts(TPM_PASSTHROUGH(obj), opts)) {
> +    if (tpm_passthrough_handle_device_opts(TPM_PASSTHROUGH(obj), tco)) {
>           object_unref(obj);
>           return NULL;
>       }
> @@ -321,8 +309,8 @@ static TpmTypeOptions *tpm_passthrough_get_tpm_options(TPMBackend *tb)
>       TpmTypeOptions *options = g_new0(TpmTypeOptions, 1);
>   
>       options->type = TPM_TYPE_PASSTHROUGH;
> -    options->u.passthrough.data = QAPI_CLONE(TPMPassthroughOptions,
> -                                             TPM_PASSTHROUGH(tb)->options);
> +
> +    options->u.passthrough.data = QAPI_CLONE(TPMPassthroughOptions, TPM_PASSTHROUGH(tb)->options);
>   
>       return options;
>   }
> @@ -346,7 +334,6 @@ static void tpm_passthrough_inst_init(Object *obj)
>   {
>       TPMPassthruState *tpm_pt = TPM_PASSTHROUGH(obj);
>   
> -    tpm_pt->options = g_new0(TPMPassthroughOptions, 1);
>       tpm_pt->tpm_fd = -1;
>       tpm_pt->cancel_fd = -1;
>   }
> diff --git a/include/sysemu/tpm.h b/include/sysemu/tpm.h
> index fb40e30ff6..d00a833a21 100644
> --- a/include/sysemu/tpm.h
> +++ b/include/sysemu/tpm.h
> @@ -17,8 +17,8 @@
>   
>   #ifdef CONFIG_TPM
>   
> -int tpm_config_parse(QemuOptsList *opts_list, const char *optarg);
> -int tpm_init(void);
> +void tpm_config_parse(const char *optarg);
> +void tpm_init(void);
>   void tpm_cleanup(void);
>   
>   typedef enum TPMVersion {
> diff --git a/include/sysemu/tpm_backend.h b/include/sysemu/tpm_backend.h
> index 8fd3269c11..846a9e39fa 100644
> --- a/include/sysemu/tpm_backend.h
> +++ b/include/sysemu/tpm_backend.h
> @@ -57,7 +57,7 @@ struct TPMBackendClass {
>       /* get a descriptive text of the backend to display to the user */
>       const char *desc;
>   
> -    TPMBackend *(*create)(QemuOpts *opts);
> +    TPMBackend *(*create)(TpmCreateOptions *tco);
>   
>       /* start up the TPM on the backend - optional */
>       int (*startup_tpm)(TPMBackend *t, size_t buffersize);
> diff --git a/qapi/tpm.json b/qapi/tpm.json
> index 4e2ea9756a..2b491c28b4 100644
> --- a/qapi/tpm.json
> +++ b/qapi/tpm.json
> @@ -134,6 +134,25 @@
>               'emulator': 'TPMEmulatorOptionsWrapper' },
>     'if': 'CONFIG_TPM' }
>   
> +##
> +# @TpmCreateOptions:
> +#
> +# A union referencing different TPM backend types' configuration options
> +#   without the wrapper to be usable by visitors.
> +#
> +# @type: - 'passthrough' The configuration options for the TPM passthrough type
> +#        - 'emulator' The configuration options for TPM emulator backend type
> +#
> +# Since: 7.2
> +##
> +{ 'union': 'TpmCreateOptions',
> +  'base': { 'type': 'TpmType',
> +            'id' : 'str' },
> +  'discriminator': 'type',
> +  'data': { 'passthrough' : 'TPMPassthroughOptions',
> +            'emulator': 'TPMEmulatorOptions' },
> +  'if': 'CONFIG_TPM' }
> +
>   ##
>   # @TPMInfo:
>   #
> diff --git a/softmmu/tpm.c b/softmmu/tpm.c
> index 578563f05a..699c46d3ae 100644
> --- a/softmmu/tpm.c
> +++ b/softmmu/tpm.c
> @@ -17,14 +17,26 @@
>   #include "qapi/error.h"
>   #include "qapi/qapi-commands-tpm.h"
>   #include "qapi/qmp/qerror.h"
> +#include "qapi/qobject-input-visitor.h"
> +#include "qapi/qapi-visit-tpm.h"
>   #include "sysemu/tpm_backend.h"
>   #include "sysemu/tpm.h"
>   #include "qemu/config-file.h"
>   #include "qemu/error-report.h"
> +#include "qemu/help_option.h"
>   
>   static QLIST_HEAD(, TPMBackend) tpm_backends =
>       QLIST_HEAD_INITIALIZER(tpm_backends);
>   
> +typedef struct TpmCreateOptionsQueueEntry {
> +        TpmCreateOptions *tco;
> +        QSIMPLEQ_ENTRY(TpmCreateOptionsQueueEntry) entry;
> +} TpmCreateOptionsQueueEntry;
> +
> +typedef QSIMPLEQ_HEAD(, TpmCreateOptionsQueueEntry) TpmCreateOptionsQueue;
> +
> +static TpmCreateOptionsQueue tco_queue = QSIMPLEQ_HEAD_INITIALIZER(tco_queue);
> +
>   static const TPMBackendClass *
>   tpm_be_find_by_type(enum TpmType type)
>   {
> @@ -84,63 +96,31 @@ TPMBackend *qemu_find_tpm_be(const char *id)
>       return NULL;
>   }
>   
> -static int tpm_init_tpmdev(void *dummy, QemuOpts *opts, Error **errp)
> +static void tpm_init_tpmdev(TpmCreateOptions *tco)
>   {
> -    /*
> -     * Use of error_report() in a function with an Error ** parameter
> -     * is suspicious.  It is okay here.  The parameter only exists to
> -     * make the function usable with qemu_opts_foreach().  It is not
> -     * actually used.
> -     */
> -    const char *value;
> -    const char *id;
>       const TPMBackendClass *be;
>       TPMBackend *drv;
> -    Error *local_err = NULL;
> -    int i;
>   
>       if (!QLIST_EMPTY(&tpm_backends)) {
>           error_report("Only one TPM is allowed.");
> -        return 1;
> +        exit(1);
>       }
>   
> -    id = qemu_opts_id(opts);
> -    if (id == NULL) {
> -        error_report(QERR_MISSING_PARAMETER, "id");
> -        return 1;
> -    }
> -
> -    value = qemu_opt_get(opts, "type");
> -    if (!value) {
> -        error_report(QERR_MISSING_PARAMETER, "type");
> -        tpm_display_backend_drivers();
> -        return 1;
> -    }
> -
> -    i = qapi_enum_parse(&TpmType_lookup, value, -1, NULL);
> -    be = i >= 0 ? tpm_be_find_by_type(i) : NULL;
> +    be = tco->type >= 0 ? tpm_be_find_by_type(tco->type) : NULL;
>       if (be == NULL) {
>           error_report(QERR_INVALID_PARAMETER_VALUE,
>                        "type", "a TPM backend type");
>           tpm_display_backend_drivers();
> -        return 1;
> -    }
> -
> -    /* validate backend specific opts */
> -    if (!qemu_opts_validate(opts, be->opts, &local_err)) {
> -        error_report_err(local_err);
> -        return 1;
> +        exit(1);
>       }
>   
> -    drv = be->create(opts);
> +    drv = be->create(tco);
>       if (!drv) {
> -        return 1;
> +        exit(1);
>       }
>   
> -    drv->id = g_strdup(id);
> +    drv->id = g_strdup(tco->id);
>       QLIST_INSERT_HEAD(&tpm_backends, drv, list);
> -
> -    return 0;
>   }
>   
>   /*
> @@ -161,33 +141,35 @@ void tpm_cleanup(void)
>    * Initialize the TPM. Process the tpmdev command line options describing the
>    * TPM backend.
>    */
> -int tpm_init(void)
> +void tpm_init(void)
>   {
> -    if (qemu_opts_foreach(qemu_find_opts("tpmdev"),
> -                          tpm_init_tpmdev, NULL, NULL)) {
> -        return -1;
> -    }
> +    while (!QSIMPLEQ_EMPTY(&tco_queue)) {
> +        TpmCreateOptionsQueueEntry *tcoqe = QSIMPLEQ_FIRST(&tco_queue);
>   
> -    return 0;
> +        QSIMPLEQ_REMOVE_HEAD(&tco_queue, entry);
> +        tpm_init_tpmdev(tcoqe->tco);
> +        g_free(tcoqe);
> +    }
>   }
>   
>   /*
>    * Parse the TPM configuration options.
>    * To display all available TPM backends the user may use '-tpmdev help'
>    */
> -int tpm_config_parse(QemuOptsList *opts_list, const char *optarg)
> +void tpm_config_parse(const char *optarg)
>   {
> -    QemuOpts *opts;
> +    Visitor *v;
> +    TpmCreateOptionsQueueEntry *tcqe;
>   
> -    if (!strcmp(optarg, "help")) {
> +    if (is_help_option(optarg)) {
>           tpm_display_backend_drivers();
> -        return -1;
> -    }
> -    opts = qemu_opts_parse_noisily(opts_list, optarg, true);
> -    if (!opts) {
> -        return -1;
> +        return;
>       }
> -    return 0;
> +    v = qobject_input_visitor_new_str(optarg, "type", &error_fatal);
> +    tcqe = g_new(TpmCreateOptionsQueueEntry, 1);
> +    visit_type_TpmCreateOptions(v, NULL, &tcqe->tco, &error_fatal);
> +    visit_free(v);
> +    QSIMPLEQ_INSERT_TAIL(&tco_queue, tcqe, entry);
>   }
>   
>   /*
> diff --git a/softmmu/vl.c b/softmmu/vl.c
> index 5115221efe..980f998c35 100644
> --- a/softmmu/vl.c
> +++ b/softmmu/vl.c
> @@ -328,16 +328,6 @@ static QemuOptsList qemu_object_opts = {
>       },
>   };
>   
> -static QemuOptsList qemu_tpmdev_opts = {
> -    .name = "tpmdev",
> -    .implied_opt_name = "type",
> -    .head = QTAILQ_HEAD_INITIALIZER(qemu_tpmdev_opts.head),
> -    .desc = {
> -        /* options are defined in the TPM backends */
> -        { /* end of list */ }
> -    },
> -};
> -
>   static QemuOptsList qemu_overcommit_opts = {
>       .name = "overcommit",
>       .head = QTAILQ_HEAD_INITIALIZER(qemu_overcommit_opts.head),
> @@ -1934,9 +1924,7 @@ static void qemu_create_late_backends(void)
>   
>       object_option_foreach_add(object_create_late);
>   
> -    if (tpm_init() < 0) {
> -        exit(1);
> -    }
> +    tpm_init();
>   
>       qemu_opts_foreach(qemu_find_opts("mon"),
>                         mon_init_func, NULL, &error_fatal);
> @@ -2658,7 +2646,6 @@ void qemu_init(int argc, char **argv)
>       qemu_add_opts(&qemu_boot_opts);
>       qemu_add_opts(&qemu_add_fd_opts);
>       qemu_add_opts(&qemu_object_opts);
> -    qemu_add_opts(&qemu_tpmdev_opts);
>       qemu_add_opts(&qemu_overcommit_opts);
>       qemu_add_opts(&qemu_msg_opts);
>       qemu_add_opts(&qemu_name_opts);
> @@ -2906,9 +2893,7 @@ void qemu_init(int argc, char **argv)
>                   break;
>   #ifdef CONFIG_TPM
>               case QEMU_OPTION_tpmdev:
> -                if (tpm_config_parse(qemu_find_opts("tpmdev"), optarg) < 0) {
> -                    exit(1);
> -                }
> +                tpm_config_parse(optarg);

The patches don't apply to upstream's master.

This used to exit() on failure but doesn't do this anymore, though it probably should.


    Stefan

>                   break;
>   #endif
>               case QEMU_OPTION_mempath:
James Bottomley Dec. 31, 2022, 3:40 a.m. UTC | #2
On Fri, 2022-12-30 at 12:01 -0500, Stefan Berger wrote:
> On 12/30/22 10:24, James Bottomley wrote:
[...]
> > @@ -2906,9 +2893,7 @@ void qemu_init(int argc, char **argv)
> >                   break;
> >   #ifdef CONFIG_TPM
> >               case QEMU_OPTION_tpmdev:
> > -                if (tpm_config_parse(qemu_find_opts("tpmdev"),
> > optarg) < 0) {
> > -                    exit(1);
> > -                }
> > +                tpm_config_parse(optarg);
> 
> The patches don't apply to upstream's master.

I think it depends how you apply them.  If you use git, they do except
a minor merge conflict in tpm_passthrough.c

More seriously there's now a compile failure in tpm_mssim.c because of
the lost has_X for X pointer options, but it's also easily fixable.

> This used to exit() on failure but doesn't do this anymore, though it
> probably should.

Actually it still does.  I converted it to the standard &error_fatal
way of doing this, which will cause an exit(1) if we get an error.  The
error_fatal construct seems to have been done precisely to cure this
type of return value threading.

James
Stefan Berger Jan. 3, 2023, 12:49 a.m. UTC | #3
On 12/30/22 22:40, James Bottomley wrote:
> On Fri, 2022-12-30 at 12:01 -0500, Stefan Berger wrote:
>> On 12/30/22 10:24, James Bottomley wrote:
> [...]
>>> @@ -2906,9 +2893,7 @@ void qemu_init(int argc, char **argv)
>>>                    break;
>>>    #ifdef CONFIG_TPM
>>>                case QEMU_OPTION_tpmdev:
>>> -                if (tpm_config_parse(qemu_find_opts("tpmdev"),
>>> optarg) < 0) {
>>> -                    exit(1);
>>> -                }
>>> +                tpm_config_parse(optarg);
>>
>> The patches don't apply to upstream's master.
> 
> I think it depends how you apply them.  If you use git, they do except
> a minor merge conflict in tpm_passthrough.c

It has changed quite a bit there, so I let you rebase the series.

    Stefan
diff mbox series

Patch

diff --git a/backends/tpm/tpm_emulator.c b/backends/tpm/tpm_emulator.c
index 49cc3d749d..cb6bf9d7c2 100644
--- a/backends/tpm/tpm_emulator.c
+++ b/backends/tpm/tpm_emulator.c
@@ -584,33 +584,28 @@  err_exit:
     return -1;
 }
 
-static int tpm_emulator_handle_device_opts(TPMEmulator *tpm_emu, QemuOpts *opts)
+static int tpm_emulator_handle_device_opts(TPMEmulator *tpm_emu, TpmCreateOptions *opts)
 {
-    const char *value;
     Error *err = NULL;
     Chardev *dev;
 
-    value = qemu_opt_get(opts, "chardev");
-    if (!value) {
-        error_report("tpm-emulator: parameter 'chardev' is missing");
-        goto err;
-    }
+    tpm_emu->options = QAPI_CLONE(TPMEmulatorOptions, &opts->u.emulator);
+    tpm_emu->data_ioc = NULL;
 
-    dev = qemu_chr_find(value);
+    dev = qemu_chr_find(opts->u.emulator.chardev);
     if (!dev) {
-        error_report("tpm-emulator: tpm chardev '%s' not found", value);
+        error_report("tpm-emulator: tpm chardev '%s' not found",
+                opts->u.emulator.chardev);
         goto err;
     }
 
     if (!qemu_chr_fe_init(&tpm_emu->ctrl_chr, dev, &err)) {
         error_prepend(&err, "tpm-emulator: No valid chardev found at '%s':",
-                      value);
+                      opts->u.emulator.chardev);
         error_report_err(err);
         goto err;
     }
 
-    tpm_emu->options->chardev = g_strdup(value);
-
     if (tpm_emulator_prepare_data_fd(tpm_emu) < 0) {
         goto err;
     }
@@ -649,7 +644,7 @@  err:
     return -1;
 }
 
-static TPMBackend *tpm_emulator_create(QemuOpts *opts)
+static TPMBackend *tpm_emulator_create(TpmCreateOptions *opts)
 {
     TPMBackend *tb = TPM_BACKEND(object_new(TYPE_TPM_EMULATOR));
 
@@ -972,7 +967,6 @@  static void tpm_emulator_inst_init(Object *obj)
 
     trace_tpm_emulator_inst_init();
 
-    tpm_emu->options = g_new0(TPMEmulatorOptions, 1);
     tpm_emu->cur_locty_number = ~0;
     qemu_mutex_init(&tpm_emu->mutex);
     tpm_emu->vmstate =
@@ -990,7 +984,7 @@  static void tpm_emulator_shutdown(TPMEmulator *tpm_emu)
 {
     ptm_res res;
 
-    if (!tpm_emu->options->chardev) {
+    if (!tpm_emu->data_ioc) {
         /* was never properly initialized */
         return;
     }
diff --git a/backends/tpm/tpm_passthrough.c b/backends/tpm/tpm_passthrough.c
index 5a2f74db1b..f9771eaf1f 100644
--- a/backends/tpm/tpm_passthrough.c
+++ b/backends/tpm/tpm_passthrough.c
@@ -252,23 +252,11 @@  static int tpm_passthrough_open_sysfs_cancel(TPMPassthruState *tpm_pt)
 }
 
 static int
-tpm_passthrough_handle_device_opts(TPMPassthruState *tpm_pt, QemuOpts *opts)
+tpm_passthrough_handle_device_opts(TPMPassthruState *tpm_pt, TpmCreateOptions *opts)
 {
-    const char *value;
+    tpm_pt->options = QAPI_CLONE(TPMPassthroughOptions, &opts->u.passthrough);
 
-    value = qemu_opt_get(opts, "cancel-path");
-    if (value) {
-        tpm_pt->options->cancel_path = g_strdup(value);
-        tpm_pt->options->has_cancel_path = true;
-    }
-
-    value = qemu_opt_get(opts, "path");
-    if (value) {
-        tpm_pt->options->has_path = true;
-        tpm_pt->options->path = g_strdup(value);
-    }
-
-    tpm_pt->tpm_dev = value ? value : TPM_PASSTHROUGH_DEFAULT_DEVICE;
+    tpm_pt->tpm_dev = opts->u.passthrough.has_path ? opts->u.passthrough.path : TPM_PASSTHROUGH_DEFAULT_DEVICE;
     tpm_pt->tpm_fd = qemu_open_old(tpm_pt->tpm_dev, O_RDWR);
     if (tpm_pt->tpm_fd < 0) {
         error_report("Cannot access TPM device using '%s': %s",
@@ -290,11 +278,11 @@  tpm_passthrough_handle_device_opts(TPMPassthruState *tpm_pt, QemuOpts *opts)
     return 0;
 }
 
-static TPMBackend *tpm_passthrough_create(QemuOpts *opts)
+static TPMBackend *tpm_passthrough_create(TpmCreateOptions *tco)
 {
     Object *obj = object_new(TYPE_TPM_PASSTHROUGH);
 
-    if (tpm_passthrough_handle_device_opts(TPM_PASSTHROUGH(obj), opts)) {
+    if (tpm_passthrough_handle_device_opts(TPM_PASSTHROUGH(obj), tco)) {
         object_unref(obj);
         return NULL;
     }
@@ -321,8 +309,8 @@  static TpmTypeOptions *tpm_passthrough_get_tpm_options(TPMBackend *tb)
     TpmTypeOptions *options = g_new0(TpmTypeOptions, 1);
 
     options->type = TPM_TYPE_PASSTHROUGH;
-    options->u.passthrough.data = QAPI_CLONE(TPMPassthroughOptions,
-                                             TPM_PASSTHROUGH(tb)->options);
+
+    options->u.passthrough.data = QAPI_CLONE(TPMPassthroughOptions, TPM_PASSTHROUGH(tb)->options);
 
     return options;
 }
@@ -346,7 +334,6 @@  static void tpm_passthrough_inst_init(Object *obj)
 {
     TPMPassthruState *tpm_pt = TPM_PASSTHROUGH(obj);
 
-    tpm_pt->options = g_new0(TPMPassthroughOptions, 1);
     tpm_pt->tpm_fd = -1;
     tpm_pt->cancel_fd = -1;
 }
diff --git a/include/sysemu/tpm.h b/include/sysemu/tpm.h
index fb40e30ff6..d00a833a21 100644
--- a/include/sysemu/tpm.h
+++ b/include/sysemu/tpm.h
@@ -17,8 +17,8 @@ 
 
 #ifdef CONFIG_TPM
 
-int tpm_config_parse(QemuOptsList *opts_list, const char *optarg);
-int tpm_init(void);
+void tpm_config_parse(const char *optarg);
+void tpm_init(void);
 void tpm_cleanup(void);
 
 typedef enum TPMVersion {
diff --git a/include/sysemu/tpm_backend.h b/include/sysemu/tpm_backend.h
index 8fd3269c11..846a9e39fa 100644
--- a/include/sysemu/tpm_backend.h
+++ b/include/sysemu/tpm_backend.h
@@ -57,7 +57,7 @@  struct TPMBackendClass {
     /* get a descriptive text of the backend to display to the user */
     const char *desc;
 
-    TPMBackend *(*create)(QemuOpts *opts);
+    TPMBackend *(*create)(TpmCreateOptions *tco);
 
     /* start up the TPM on the backend - optional */
     int (*startup_tpm)(TPMBackend *t, size_t buffersize);
diff --git a/qapi/tpm.json b/qapi/tpm.json
index 4e2ea9756a..2b491c28b4 100644
--- a/qapi/tpm.json
+++ b/qapi/tpm.json
@@ -134,6 +134,25 @@ 
             'emulator': 'TPMEmulatorOptionsWrapper' },
   'if': 'CONFIG_TPM' }
 
+##
+# @TpmCreateOptions:
+#
+# A union referencing different TPM backend types' configuration options
+#   without the wrapper to be usable by visitors.
+#
+# @type: - 'passthrough' The configuration options for the TPM passthrough type
+#        - 'emulator' The configuration options for TPM emulator backend type
+#
+# Since: 7.2
+##
+{ 'union': 'TpmCreateOptions',
+  'base': { 'type': 'TpmType',
+            'id' : 'str' },
+  'discriminator': 'type',
+  'data': { 'passthrough' : 'TPMPassthroughOptions',
+            'emulator': 'TPMEmulatorOptions' },
+  'if': 'CONFIG_TPM' }
+
 ##
 # @TPMInfo:
 #
diff --git a/softmmu/tpm.c b/softmmu/tpm.c
index 578563f05a..699c46d3ae 100644
--- a/softmmu/tpm.c
+++ b/softmmu/tpm.c
@@ -17,14 +17,26 @@ 
 #include "qapi/error.h"
 #include "qapi/qapi-commands-tpm.h"
 #include "qapi/qmp/qerror.h"
+#include "qapi/qobject-input-visitor.h"
+#include "qapi/qapi-visit-tpm.h"
 #include "sysemu/tpm_backend.h"
 #include "sysemu/tpm.h"
 #include "qemu/config-file.h"
 #include "qemu/error-report.h"
+#include "qemu/help_option.h"
 
 static QLIST_HEAD(, TPMBackend) tpm_backends =
     QLIST_HEAD_INITIALIZER(tpm_backends);
 
+typedef struct TpmCreateOptionsQueueEntry {
+        TpmCreateOptions *tco;
+        QSIMPLEQ_ENTRY(TpmCreateOptionsQueueEntry) entry;
+} TpmCreateOptionsQueueEntry;
+
+typedef QSIMPLEQ_HEAD(, TpmCreateOptionsQueueEntry) TpmCreateOptionsQueue;
+
+static TpmCreateOptionsQueue tco_queue = QSIMPLEQ_HEAD_INITIALIZER(tco_queue);
+
 static const TPMBackendClass *
 tpm_be_find_by_type(enum TpmType type)
 {
@@ -84,63 +96,31 @@  TPMBackend *qemu_find_tpm_be(const char *id)
     return NULL;
 }
 
-static int tpm_init_tpmdev(void *dummy, QemuOpts *opts, Error **errp)
+static void tpm_init_tpmdev(TpmCreateOptions *tco)
 {
-    /*
-     * Use of error_report() in a function with an Error ** parameter
-     * is suspicious.  It is okay here.  The parameter only exists to
-     * make the function usable with qemu_opts_foreach().  It is not
-     * actually used.
-     */
-    const char *value;
-    const char *id;
     const TPMBackendClass *be;
     TPMBackend *drv;
-    Error *local_err = NULL;
-    int i;
 
     if (!QLIST_EMPTY(&tpm_backends)) {
         error_report("Only one TPM is allowed.");
-        return 1;
+        exit(1);
     }
 
-    id = qemu_opts_id(opts);
-    if (id == NULL) {
-        error_report(QERR_MISSING_PARAMETER, "id");
-        return 1;
-    }
-
-    value = qemu_opt_get(opts, "type");
-    if (!value) {
-        error_report(QERR_MISSING_PARAMETER, "type");
-        tpm_display_backend_drivers();
-        return 1;
-    }
-
-    i = qapi_enum_parse(&TpmType_lookup, value, -1, NULL);
-    be = i >= 0 ? tpm_be_find_by_type(i) : NULL;
+    be = tco->type >= 0 ? tpm_be_find_by_type(tco->type) : NULL;
     if (be == NULL) {
         error_report(QERR_INVALID_PARAMETER_VALUE,
                      "type", "a TPM backend type");
         tpm_display_backend_drivers();
-        return 1;
-    }
-
-    /* validate backend specific opts */
-    if (!qemu_opts_validate(opts, be->opts, &local_err)) {
-        error_report_err(local_err);
-        return 1;
+        exit(1);
     }
 
-    drv = be->create(opts);
+    drv = be->create(tco);
     if (!drv) {
-        return 1;
+        exit(1);
     }
 
-    drv->id = g_strdup(id);
+    drv->id = g_strdup(tco->id);
     QLIST_INSERT_HEAD(&tpm_backends, drv, list);
-
-    return 0;
 }
 
 /*
@@ -161,33 +141,35 @@  void tpm_cleanup(void)
  * Initialize the TPM. Process the tpmdev command line options describing the
  * TPM backend.
  */
-int tpm_init(void)
+void tpm_init(void)
 {
-    if (qemu_opts_foreach(qemu_find_opts("tpmdev"),
-                          tpm_init_tpmdev, NULL, NULL)) {
-        return -1;
-    }
+    while (!QSIMPLEQ_EMPTY(&tco_queue)) {
+        TpmCreateOptionsQueueEntry *tcoqe = QSIMPLEQ_FIRST(&tco_queue);
 
-    return 0;
+        QSIMPLEQ_REMOVE_HEAD(&tco_queue, entry);
+        tpm_init_tpmdev(tcoqe->tco);
+        g_free(tcoqe);
+    }
 }
 
 /*
  * Parse the TPM configuration options.
  * To display all available TPM backends the user may use '-tpmdev help'
  */
-int tpm_config_parse(QemuOptsList *opts_list, const char *optarg)
+void tpm_config_parse(const char *optarg)
 {
-    QemuOpts *opts;
+    Visitor *v;
+    TpmCreateOptionsQueueEntry *tcqe;
 
-    if (!strcmp(optarg, "help")) {
+    if (is_help_option(optarg)) {
         tpm_display_backend_drivers();
-        return -1;
-    }
-    opts = qemu_opts_parse_noisily(opts_list, optarg, true);
-    if (!opts) {
-        return -1;
+        return;
     }
-    return 0;
+    v = qobject_input_visitor_new_str(optarg, "type", &error_fatal);
+    tcqe = g_new(TpmCreateOptionsQueueEntry, 1);
+    visit_type_TpmCreateOptions(v, NULL, &tcqe->tco, &error_fatal);
+    visit_free(v);
+    QSIMPLEQ_INSERT_TAIL(&tco_queue, tcqe, entry);
 }
 
 /*
diff --git a/softmmu/vl.c b/softmmu/vl.c
index 5115221efe..980f998c35 100644
--- a/softmmu/vl.c
+++ b/softmmu/vl.c
@@ -328,16 +328,6 @@  static QemuOptsList qemu_object_opts = {
     },
 };
 
-static QemuOptsList qemu_tpmdev_opts = {
-    .name = "tpmdev",
-    .implied_opt_name = "type",
-    .head = QTAILQ_HEAD_INITIALIZER(qemu_tpmdev_opts.head),
-    .desc = {
-        /* options are defined in the TPM backends */
-        { /* end of list */ }
-    },
-};
-
 static QemuOptsList qemu_overcommit_opts = {
     .name = "overcommit",
     .head = QTAILQ_HEAD_INITIALIZER(qemu_overcommit_opts.head),
@@ -1934,9 +1924,7 @@  static void qemu_create_late_backends(void)
 
     object_option_foreach_add(object_create_late);
 
-    if (tpm_init() < 0) {
-        exit(1);
-    }
+    tpm_init();
 
     qemu_opts_foreach(qemu_find_opts("mon"),
                       mon_init_func, NULL, &error_fatal);
@@ -2658,7 +2646,6 @@  void qemu_init(int argc, char **argv)
     qemu_add_opts(&qemu_boot_opts);
     qemu_add_opts(&qemu_add_fd_opts);
     qemu_add_opts(&qemu_object_opts);
-    qemu_add_opts(&qemu_tpmdev_opts);
     qemu_add_opts(&qemu_overcommit_opts);
     qemu_add_opts(&qemu_msg_opts);
     qemu_add_opts(&qemu_name_opts);
@@ -2906,9 +2893,7 @@  void qemu_init(int argc, char **argv)
                 break;
 #ifdef CONFIG_TPM
             case QEMU_OPTION_tpmdev:
-                if (tpm_config_parse(qemu_find_opts("tpmdev"), optarg) < 0) {
-                    exit(1);
-                }
+                tpm_config_parse(optarg);
                 break;
 #endif
             case QEMU_OPTION_mempath: