[Qemu-devel] [PATCH 2/7] tpm-backend: Move thread handling inside TPMBackend

[Amarnath Valluri <amarnath.valluri@intel.com>]

Move thread handling inside TPMBackend, this way backend implementations need
not to maintain their own thread life cycle, instead they needs to implement
'handle_request()' class method that always been called from a thread.

This change also demands to move TPMBackendClass definition to
tpm_backend_int.h. As handle_request() method is internal to TPMBackend and its
derived classes, and shall not be visible for others.

Signed-off-by: Amarnath Valluri <amarnath.valluri@intel.com>
---
 backends/tpm.c                   | 66 ++++++++++++++++++++++++++--------------
 hw/tpm/tpm_passthrough.c         | 57 +++++-----------------------------
 include/sysemu/tpm_backend.h     | 19 +++---------
 include/sysemu/tpm_backend_int.h | 19 ++++++------
 4 files changed, 67 insertions(+), 94 deletions(-)

diff --git a/backends/tpm.c b/backends/tpm.c
index 536f262..50a7809 100644
--- a/backends/tpm.c
+++ b/backends/tpm.c
@@ -20,6 +20,25 @@
 #include "qemu/thread.h"
 #include "sysemu/tpm_backend_int.h"
 
+static void tpm_backend_worker_thread(gpointer data, gpointer user_data)
+{
+    TPMBackend *s = TPM_BACKEND(user_data);
+    TPMBackendClass *k  = TPM_BACKEND_GET_CLASS(s);
+
+    if (k->handle_request) {
+        k->handle_request(s, (TPMBackendCmd)data);
+    }
+}
+
+static void tpm_backend_thread_end(TPMBackend *s)
+{
+    if (s->thread_pool) {
+        g_thread_pool_push(s->thread_pool, (gpointer)TPM_BACKEND_CMD_END, NULL);
+        g_thread_pool_free(s->thread_pool, FALSE, TRUE);
+        s->thread_pool = NULL;
+    }
+}
+
 enum TpmType tpm_backend_get_type(TPMBackend *s)
 {
     TPMBackendClass *k = TPM_BACKEND_GET_CLASS(s);
@@ -39,6 +58,8 @@ void tpm_backend_destroy(TPMBackend *s)
     TPMBackendClass *k = TPM_BACKEND_GET_CLASS(s);
 
     k->ops->destroy(s);
+
+    tpm_backend_thread_end(s);
 }
 
 int tpm_backend_init(TPMBackend *s, TPMState *state,
@@ -46,13 +67,26 @@ int tpm_backend_init(TPMBackend *s, TPMState *state,
 {
     TPMBackendClass *k = TPM_BACKEND_GET_CLASS(s);
 
-    return k->ops->init(s, state, datacb);
+    s->tpm_state = state;
+    s->recv_data_callback = datacb;
+
+    return k->ops->init(s);
 }
 
 int tpm_backend_startup_tpm(TPMBackend *s)
 {
     TPMBackendClass *k = TPM_BACKEND_GET_CLASS(s);
 
+    /* terminate a running TPM */
+    tpm_backend_thread_end(s);
+
+    if (!s->thread_pool) {
+        s->thread_pool = g_thread_pool_new(tpm_backend_worker_thread, s, 1,
+                                           TRUE, NULL);
+        g_thread_pool_push(s->thread_pool, (gpointer)TPM_BACKEND_CMD_INIT,
+                           NULL);
+    }
+
     return k->ops->startup_tpm(s);
 }
 
@@ -72,9 +106,8 @@ size_t tpm_backend_realloc_buffer(TPMBackend *s, TPMSizedBuffer *sb)
 
 void tpm_backend_deliver_request(TPMBackend *s)
 {
-    TPMBackendClass *k = TPM_BACKEND_GET_CLASS(s);
-
-    k->ops->deliver_request(s);
+    g_thread_pool_push(s->thread_pool, (gpointer)TPM_BACKEND_CMD_PROCESS_CMD,
+                       NULL);
 }
 
 void tpm_backend_reset(TPMBackend *s)
@@ -82,6 +115,8 @@ void tpm_backend_reset(TPMBackend *s)
     TPMBackendClass *k = TPM_BACKEND_GET_CLASS(s);
 
     k->ops->reset(s);
+
+    tpm_backend_thread_end(s);
 }
 
 void tpm_backend_cancel_cmd(TPMBackend *s)
@@ -156,29 +191,15 @@ static void tpm_backend_instance_init(Object *obj)
                              tpm_backend_prop_get_opened,
                              tpm_backend_prop_set_opened,
                              NULL);
-}
 
-void tpm_backend_thread_deliver_request(TPMBackendThread *tbt)
-{
-   g_thread_pool_push(tbt->pool, (gpointer)TPM_BACKEND_CMD_PROCESS_CMD, NULL);
 }
 
-void tpm_backend_thread_create(TPMBackendThread *tbt,
-                               GFunc func, gpointer user_data)
+static void tpm_backend_instance_finalize(Object *obj)
 {
-    if (!tbt->pool) {
-        tbt->pool = g_thread_pool_new(func, user_data, 1, TRUE, NULL);
-        g_thread_pool_push(tbt->pool, (gpointer)TPM_BACKEND_CMD_INIT, NULL);
-    }
-}
+    TPMBackend *s = TPM_BACKEND(obj);
 
-void tpm_backend_thread_end(TPMBackendThread *tbt)
-{
-    if (tbt->pool) {
-        g_thread_pool_push(tbt->pool, (gpointer)TPM_BACKEND_CMD_END, NULL);
-        g_thread_pool_free(tbt->pool, FALSE, TRUE);
-        tbt->pool = NULL;
-    }
+    g_free(s->id);
+    tpm_backend_thread_end(s);
 }
 
 static const TypeInfo tpm_backend_info = {
@@ -186,6 +207,7 @@ static const TypeInfo tpm_backend_info = {
     .parent = TYPE_OBJECT,
     .instance_size = sizeof(TPMBackend),
     .instance_init = tpm_backend_instance_init,
+    .instance_finalize = tpm_backend_instance_finalize,
     .class_size = sizeof(TPMBackendClass),
     .abstract = true,
 };
diff --git a/hw/tpm/tpm_passthrough.c b/hw/tpm/tpm_passthrough.c
index a0baf5f..606e064 100644
--- a/hw/tpm/tpm_passthrough.c
+++ b/hw/tpm/tpm_passthrough.c
@@ -47,20 +47,9 @@
     OBJECT_CHECK(TPMPassthruState, (obj), TYPE_TPM_PASSTHROUGH)
 
 /* data structures */
-typedef struct TPMPassthruThreadParams {
-    TPMState *tpm_state;
-
-    TPMRecvDataCB *recv_data_callback;
-    TPMBackend *tb;
-} TPMPassthruThreadParams;
-
 struct TPMPassthruState {
     TPMBackend parent;
 
-    TPMBackendThread tbt;
-
-    TPMPassthruThreadParams tpm_thread_params;
-
     char *tpm_dev;
     int tpm_fd;
     bool tpm_executing;
@@ -214,12 +203,9 @@ static int tpm_passthrough_unix_transfer(TPMPassthruState *tpm_pt,
                                         selftest_done);
 }
 
-static void tpm_passthrough_worker_thread(gpointer data,
-                                          gpointer user_data)
+static void tpm_passthrough_handle_request(TPMBackend *tb, TPMBackendCmd cmd)
 {
-    TPMPassthruThreadParams *thr_parms = user_data;
-    TPMPassthruState *tpm_pt = TPM_PASSTHROUGH(thr_parms->tb);
-    TPMBackendCmd cmd = (TPMBackendCmd)data;
+    TPMPassthruState *tpm_pt = TPM_PASSTHROUGH(tb);
     bool selftest_done = false;
 
     DPRINTF("tpm_passthrough: processing command type %d\n", cmd);
@@ -227,12 +213,12 @@ static void tpm_passthrough_worker_thread(gpointer data,
     switch (cmd) {
     case TPM_BACKEND_CMD_PROCESS_CMD:
         tpm_passthrough_unix_transfer(tpm_pt,
-                                      thr_parms->tpm_state->locty_data,
+                                      tb->tpm_state->locty_data,
                                       &selftest_done);
 
-        thr_parms->recv_data_callback(thr_parms->tpm_state,
-                                      thr_parms->tpm_state->locty_number,
-                                      selftest_done);
+        tb->recv_data_callback(tb->tpm_state,
+                               tb->tpm_state->locty_number,
+                               selftest_done);
         break;
     case TPM_BACKEND_CMD_INIT:
     case TPM_BACKEND_CMD_END:
@@ -248,15 +234,6 @@ static void tpm_passthrough_worker_thread(gpointer data,
  */
 static int tpm_passthrough_startup_tpm(TPMBackend *tb)
 {
-    TPMPassthruState *tpm_pt = TPM_PASSTHROUGH(tb);
-
-    /* terminate a running TPM */
-    tpm_backend_thread_end(&tpm_pt->tbt);
-
-    tpm_backend_thread_create(&tpm_pt->tbt,
-                              tpm_passthrough_worker_thread,
-                              &tpm_pt->tpm_thread_params);
-
     return 0;
 }
 
@@ -268,20 +245,11 @@ static void tpm_passthrough_reset(TPMBackend *tb)
 
     tpm_passthrough_cancel_cmd(tb);
 
-    tpm_backend_thread_end(&tpm_pt->tbt);
-
     tpm_pt->had_startup_error = false;
 }
 
-static int tpm_passthrough_init(TPMBackend *tb, TPMState *s,
-                                TPMRecvDataCB *recv_data_cb)
+static int tpm_passthrough_init(TPMBackend *tb)
 {
-    TPMPassthruState *tpm_pt = TPM_PASSTHROUGH(tb);
-
-    tpm_pt->tpm_thread_params.tpm_state = s;
-    tpm_pt->tpm_thread_params.recv_data_callback = recv_data_cb;
-    tpm_pt->tpm_thread_params.tb = tb;
-
     return 0;
 }
 
@@ -315,13 +283,6 @@ static size_t tpm_passthrough_realloc_buffer(TPMSizedBuffer *sb)
     return sb->size;
 }
 
-static void tpm_passthrough_deliver_request(TPMBackend *tb)
-{
-    TPMPassthruState *tpm_pt = TPM_PASSTHROUGH(tb);
-
-    tpm_backend_thread_deliver_request(&tpm_pt->tbt);
-}
-
 static void tpm_passthrough_cancel_cmd(TPMBackend *tb)
 {
     TPMPassthruState *tpm_pt = TPM_PASSTHROUGH(tb);
@@ -483,8 +444,6 @@ static void tpm_passthrough_destroy(TPMBackend *tb)
 
     tpm_passthrough_cancel_cmd(tb);
 
-    tpm_backend_thread_end(&tpm_pt->tbt);
-
     qemu_close(tpm_pt->tpm_fd);
     qemu_close(tpm_pt->cancel_fd);
 
@@ -520,7 +479,6 @@ static const TPMDriverOps tpm_passthrough_driver = {
     .realloc_buffer           = tpm_passthrough_realloc_buffer,
     .reset                    = tpm_passthrough_reset,
     .had_startup_error        = tpm_passthrough_get_startup_error,
-    .deliver_request          = tpm_passthrough_deliver_request,
     .cancel_cmd               = tpm_passthrough_cancel_cmd,
     .get_tpm_established_flag = tpm_passthrough_get_tpm_established_flag,
     .reset_tpm_established_flag = tpm_passthrough_reset_tpm_established_flag,
@@ -540,6 +498,7 @@ static void tpm_passthrough_class_init(ObjectClass *klass, void *data)
     TPMBackendClass *tbc = TPM_BACKEND_CLASS(klass);
 
     tbc->ops = &tpm_passthrough_driver;
+    tbc->handle_request = tpm_passthrough_handle_request;
 }
 
 static const TypeInfo tpm_passthrough_info = {
diff --git a/include/sysemu/tpm_backend.h b/include/sysemu/tpm_backend.h
index e7f590d..98b6112 100644
--- a/include/sysemu/tpm_backend.h
+++ b/include/sysemu/tpm_backend.h
@@ -29,22 +29,17 @@
 
 typedef struct TPMBackendClass TPMBackendClass;
 typedef struct TPMBackend TPMBackend;
-
 typedef struct TPMDriverOps TPMDriverOps;
-
-struct TPMBackendClass {
-    ObjectClass parent_class;
-
-    const TPMDriverOps *ops;
-
-    void (*opened)(TPMBackend *s, Error **errp);
-};
+typedef void (TPMRecvDataCB)(TPMState *, uint8_t locty, bool selftest_done);
 
 struct TPMBackend {
     Object parent;
 
     /*< protected >*/
     bool opened;
+    TPMState *tpm_state;
+    GThreadPool *thread_pool;
+    TPMRecvDataCB *recv_data_callback;
 
     char *id;
     enum TpmModel fe_model;
@@ -54,8 +49,6 @@ struct TPMBackend {
     QLIST_ENTRY(TPMBackend) list;
 };
 
-typedef void (TPMRecvDataCB)(TPMState *, uint8_t locty, bool selftest_done);
-
 typedef struct TPMSizedBuffer {
     uint32_t size;
     uint8_t  *buffer;
@@ -71,7 +64,7 @@ struct TPMDriverOps {
     void (*destroy)(TPMBackend *t);
 
     /* initialize the backend */
-    int (*init)(TPMBackend *t, TPMState *s, TPMRecvDataCB *datacb);
+    int (*init)(TPMBackend *t);
     /* start up the TPM on the backend */
     int (*startup_tpm)(TPMBackend *t);
     /* returns true if nothing will ever answer TPM requests */
@@ -79,8 +72,6 @@ struct TPMDriverOps {
 
     size_t (*realloc_buffer)(TPMSizedBuffer *sb);
 
-    void (*deliver_request)(TPMBackend *t);
-
     void (*reset)(TPMBackend *t);
 
     void (*cancel_cmd)(TPMBackend *t);
diff --git a/include/sysemu/tpm_backend_int.h b/include/sysemu/tpm_backend_int.h
index 00639dd..9b48a35 100644
--- a/include/sysemu/tpm_backend_int.h
+++ b/include/sysemu/tpm_backend_int.h
@@ -22,15 +22,6 @@
 #ifndef TPM_BACKEND_INT_H
 #define TPM_BACKEND_INT_H
 
-typedef struct TPMBackendThread {
-    GThreadPool *pool;
-} TPMBackendThread;
-
-void tpm_backend_thread_deliver_request(TPMBackendThread *tbt);
-void tpm_backend_thread_create(TPMBackendThread *tbt,
-                               GFunc func, gpointer user_data);
-void tpm_backend_thread_end(TPMBackendThread *tbt);
-
 typedef enum TPMBackendCmd {
     TPM_BACKEND_CMD_INIT = 1,
     TPM_BACKEND_CMD_PROCESS_CMD,
@@ -38,4 +29,14 @@ typedef enum TPMBackendCmd {
     TPM_BACKEND_CMD_TPM_RESET,
 } TPMBackendCmd;
 
+struct TPMBackendClass {
+    ObjectClass parent_class;
+
+    const TPMDriverOps *ops;
+
+    void (*opened)(TPMBackend *s, Error **errp);
+
+    void (*handle_request)(TPMBackend *s, TPMBackendCmd cmd);
+};
+
 #endif /* TPM_BACKEND_INT_H */
-- 
2.7.4