tpm-backend: store TPMIf interface, improve backend_init()

Store the TPM interface, the actual object may be different from
TPMState. Keep a reference on the interface, and check the backend
wasn't already initialized.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>

backends/tpm.c

@@ -43,9 +43,15 @@ enum TpmType tpm_backend_get_type(TPMBackend *s)
     return k->type;
 }
 
-int tpm_backend_init(TPMBackend *s, TPMState *state)
+int tpm_backend_init(TPMBackend *s, TPMIf *tpmif)
 {
-    s->tpm_state = state;
+    if (s->tpmif) {
+        return -1;
+    }
+
+    s->tpmif = tpmif;
+    object_ref(OBJECT(tpmif));
+
     s->had_startup_error = false;
 
     return 0;
@@ -193,6 +199,7 @@ static void tpm_backend_instance_finalize(Object *obj)
 {
     TPMBackend *s = TPM_BACKEND(obj);
 
+    object_unref(OBJECT(s->tpmif));
     g_free(s->id);
     tpm_backend_thread_end(s);
 }

hw/tpm/tpm_emulator.c

@@ -186,7 +186,7 @@ static int tpm_emulator_set_locality(TPMEmulator *tpm_emu, uint8_t locty_number,
 static void tpm_emulator_handle_request(TPMBackend *tb, TPMBackendCmd *cmd)
 {
     TPMEmulator *tpm_emu = TPM_EMULATOR(tb);
-    TPMIfClass *tic = TPM_IF_GET_CLASS(tb->tpm_state);
+    TPMIfClass *tic = TPM_IF_GET_CLASS(tb->tpmif);
     Error *err = NULL;
 
     DPRINTF("processing TPM command");
@@ -201,7 +201,7 @@ static void tpm_emulator_handle_request(TPMBackend *tb, TPMBackendCmd *cmd)
         goto error;
     }
 
-    tic->request_completed(TPM_IF(tb->tpm_state));
+    tic->request_completed(tb->tpmif);
     return;
 
 error:

hw/tpm/tpm_passthrough.c

@@ -139,14 +139,14 @@ err_exit:
 static void tpm_passthrough_handle_request(TPMBackend *tb, TPMBackendCmd *cmd)
 {
     TPMPassthruState *tpm_pt = TPM_PASSTHROUGH(tb);
-    TPMIfClass *tic = TPM_IF_GET_CLASS(tb->tpm_state);
+    TPMIfClass *tic = TPM_IF_GET_CLASS(tb->tpmif);
 
     DPRINTF("tpm_passthrough: processing command %p\n", cmd);
 
     tpm_passthrough_unix_tx_bufs(tpm_pt, cmd->in, cmd->in_len,
                                  cmd->out, cmd->out_len, &cmd->selftest_done);
 
-    tic->request_completed(TPM_IF(tb->tpm_state));
+    tic->request_completed(tb->tpmif);
 }
 
 static void tpm_passthrough_reset(TPMBackend *tb)

hw/tpm/tpm_tis.c

@@ -1082,7 +1082,7 @@ static void tpm_tis_realizefn(DeviceState *dev, Error **errp)
 
     s->be_driver->fe_model = TPM_MODEL_TPM_TIS;
 
-    if (tpm_backend_init(s->be_driver, s)) {
+    if (tpm_backend_init(s->be_driver, TPM_IF(s))) {
         error_setg(errp, "tpm_tis: backend driver with id %s could not be "
                    "initialized", s->backend);
         return;

include/sysemu/tpm.h

@@ -12,8 +12,8 @@
 #ifndef QEMU_TPM_H
 #define QEMU_TPM_H
 
-#include "qemu/option.h"
 #include "qom/object.h"
+#include "qapi-types.h"
 
 typedef struct TPMState TPMState;
 

include/sysemu/tpm_backend.h

@@ -43,8 +43,8 @@ struct TPMBackend {
     Object parent;
 
     /*< protected >*/
+    TPMIf *tpmif;
     bool opened;
-    TPMState *tpm_state;
     GThreadPool *thread_pool;
     bool had_startup_error;
 
@@ -96,14 +96,14 @@ enum TpmType tpm_backend_get_type(TPMBackend *s);
 /**
  * tpm_backend_init:
  * @s: the backend to initialized
- * @state: TPMState
+ * @tpmif: TPM interface
  * @datacb: callback for sending data to frontend
  *
  * Initialize the backend with the given variables.
  *
  * Returns 0 on success.
  */
-int tpm_backend_init(TPMBackend *s, TPMState *state);
+int tpm_backend_init(TPMBackend *s, TPMIf *tpmif);
 
 /**
  * tpm_backend_startup_tpm: