Commit a9a72aee authored by Marc-André Lureau's avatar Marc-André Lureau Committed by Markus Armbruster
Browse files

tpm: Clean up driver registration & lookup 



We have a strict separation between enum TpmType and be_drivers[]:

* TpmType may have any number of members.  It just happens to have one.

* tpm_register_driver() uses the first empty slot in be_drivers[].

  If you register more than tpm_models[] has space,
  tpm_register_driver() fails.  Its caller silently ignores the
  failure.

  If you register more than one with a given TpmType,
  tpm_display_backend_drivers() will shows all of them, but
  tpm_driver_find_by_type() and tpm_get_backend_driver() will find
  only the one one that registered first.

Since we only ever register one driver, and be_drivers[] has space for
just that one, this contraption even works.

Turn be_drivers[] into a straight map from enum TpmType to driver.
Much simpler, and has a decent chance to actually work should we ever
acquire additional drivers.

While there, use qapi_enum_parse() in tpm_get_backend_driver().

Signed-off-by: default avatarMarc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20170822132255.23945-8-marcandre.lureau@redhat.com>
Reviewed-by: default avatarMarkus Armbruster <armbru@redhat.com>
[Rebased, superfluous initializer dropped, commit message rewritten]
Cc: Stefan Berger <stefanb@us.ibm.com>
Signed-off-by: default avatarMarkus Armbruster <armbru@redhat.com>
Message-Id: <1503564371-26090-4-git-send-email-armbru@redhat.com>
parent 06c60b6c

include/sysemu/tpm_backend.h

+1 −1
Original line number Diff line number Diff line
@@ -227,6 +227,6 @@ TPMBackend *qemu_find_tpm(const char *id); 


const TPMDriverOps *tpm_get_backend_driver(const char *type);

int tpm_register_model(enum TpmModel model);

int tpm_register_driver(const TPMDriverOps *tdo);

void tpm_register_driver(const TPMDriverOps *tdo);



#endif

tpm.c

+13 −32
Original line number Diff line number Diff line
@@ -14,6 +14,7 @@ 
#include "qemu/osdep.h"



#include "qapi/qmp/qerror.h"

#include "qapi/util.h"

#include "sysemu/tpm_backend.h"

#include "sysemu/tpm.h"

#include "qemu/config-file.h"
@@ -25,11 +26,8 @@ static QLIST_HEAD(, TPMBackend) tpm_backends = 




#define TPM_MAX_MODELS      1

#define TPM_MAX_DRIVERS     1



static TPMDriverOps const *be_drivers[TPM_MAX_DRIVERS] = {

    NULL,

};

static TPMDriverOps const *be_drivers[TPM_TYPE__MAX];



static enum TpmModel tpm_models[TPM_MAX_MODELS] = {

    TPM_MODEL__MAX,
@@ -63,31 +61,18 @@ static bool tpm_model_is_registered(enum TpmModel model) 


const TPMDriverOps *tpm_get_backend_driver(const char *type)

{

    int i;



    for (i = 0; i < TPM_MAX_DRIVERS && be_drivers[i] != NULL; i++) {

        if (!strcmp(TpmType_lookup[be_drivers[i]->type], type)) {

            return be_drivers[i];

        }

    }

    int i = qapi_enum_parse(TpmType_lookup, type, -1, NULL);



    return NULL;

    return i >= 0 ? be_drivers[i] : NULL;

}



#ifdef CONFIG_TPM



int tpm_register_driver(const TPMDriverOps *tdo)

void tpm_register_driver(const TPMDriverOps *tdo)

{

    int i;

    assert(!be_drivers[tdo->type]);



    for (i = 0; i < TPM_MAX_DRIVERS; i++) {

        if (!be_drivers[i]) {

            be_drivers[i] = tdo;

            return 0;

        }

    }

    error_report("Could not register TPM driver");

    return 1;

    be_drivers[tdo->type] = tdo;

}



/*
@@ -100,9 +85,12 @@ static void tpm_display_backend_drivers(void) 


    fprintf(stderr, "Supported TPM types (choose only one):\n");



    for (i = 0; i < TPM_MAX_DRIVERS && be_drivers[i] != NULL; i++) {

    for (i = 0; i < TPM_TYPE__MAX; i++) {

        if (be_drivers[i] == NULL) {

            continue;

        }

        fprintf(stderr, "%12s   %s\n",

                TpmType_lookup[be_drivers[i]->type], be_drivers[i]->desc());

                TpmType_lookup[i], be_drivers[i]->desc());

    }

    fprintf(stderr, "\n");

}
@@ -239,14 +227,7 @@ int tpm_config_parse(QemuOptsList *opts_list, const char *optarg) 


static const TPMDriverOps *tpm_driver_find_by_type(enum TpmType type)

{

    int i;



    for (i = 0; i < TPM_MAX_DRIVERS && be_drivers[i] != NULL; i++) {

        if (be_drivers[i]->type == type) {

            return be_drivers[i];

        }

    }

    return NULL;

    return be_drivers[type];

}



static TPMInfo *qmp_query_tpm_inst(TPMBackend *drv)