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: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20170822132255.23945-8-marcandre.lureau@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Rebased, superfluous initializer dropped, commit message rewritten]
Cc: Stefan Berger <stefanb@us.ibm.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1503564371-26090-4-git-send-email-armbru@redhat.com>
diff --git a/include/sysemu/tpm_backend.h b/include/sysemu/tpm_backend.h
index b58f52d..1d21c6b 100644
--- a/include/sysemu/tpm_backend.h
+++ b/include/sysemu/tpm_backend.h
@@ -227,6 +227,6 @@
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
diff --git a/tpm.c b/tpm.c
index 9a7c711..6f39ec9 100644
--- a/tpm.c
+++ b/tpm.c
@@ -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 @@
#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 @@
const TPMDriverOps *tpm_get_backend_driver(const char *type)
{
- int i;
+ int i = qapi_enum_parse(TpmType_lookup, type, -1, NULL);
- 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];
- }
- }
-
- 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 @@
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 @@
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)
