vhost: readded return codes for dpdk callbacks

Added spdk_vhost_dev_backend_event_done function
that sets the return code for the callback and
transparently calls sem_post.

Change-Id: Iba27af780cd1753056c1607177c945e13c95c712
Signed-off-by: Dariusz Stojaczyk <dariuszx.stojaczyk@intel.com>
Reviewed-on: https://review.gerrithub.io/377585
Tested-by: SPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Daniel Verkamp <daniel.verkamp@intel.com>

lib/vhost/vhost.c

@@ -61,6 +61,9 @@ struct spdk_vhost_dev_event_ctx {
 
 	/** Semaphore used to signal that event is done. */
 	sem_t sem;
+
+	/** Response to be written by enqueued event. */
+	int response;
 };
 
 static int new_connection(int vid);
@@ -536,12 +539,21 @@ spdk_vhost_allocate_reactor(uint64_t cpumask)
 	return selected_core;
 }
 
+void
+spdk_vhost_dev_backend_event_done(void *event_ctx, int response)
+{
+	struct spdk_vhost_dev_event_ctx *ctx = event_ctx;
+
+	ctx->response = response;
+	sem_post(&ctx->sem);
+}
+
 static void
 spdk_vhost_event_cb(void *arg1, void *arg2)
 {
 	struct spdk_vhost_dev_event_ctx *ctx = arg1;
 
-	ctx->cb_fn(ctx->vdev, &ctx->sem);
+	ctx->cb_fn(ctx->vdev, ctx);
 }
 
 static void
@@ -599,7 +611,7 @@ spdk_vhost_event_send(struct spdk_vhost_dev *vdev, spdk_vhost_event_fn cb_fn,
 	sem_destroy(&ev_ctx.sem);
 	free(ev_ctx.ctrlr_name);
 
-	return rc;
+	return ev_ctx.response;
 }
 
 static int

lib/vhost/vhost_blk.c

@@ -484,10 +484,9 @@ alloc_task_pool(struct spdk_vhost_blk_dev *bvdev)
  *
  */
 static int
-new_device(struct spdk_vhost_dev *vdev, void *arg)
+new_device(struct spdk_vhost_dev *vdev, void *event_ctx)
 {
 	struct spdk_vhost_blk_dev *bvdev;
-	sem_t *sem = arg;
 	int rc = 0;
 
 	bvdev = to_blk_dev(vdev);
@@ -522,14 +521,14 @@ new_device(struct spdk_vhost_dev *vdev, void *arg)
 			     bvdev, vdev->lcore, 0);
 	SPDK_NOTICELOG("Started poller for vhost controller %s on lcore %d\n", vdev->name, vdev->lcore);
 out:
-	sem_post(sem);
+	spdk_vhost_dev_backend_event_done(event_ctx, rc);
 	return rc;
 }
 
 struct spdk_vhost_dev_destroy_ctx {
 	struct spdk_vhost_blk_dev *bvdev;
 	struct spdk_poller *poller;
-	sem_t *sem;
+	void *event_ctx;
 };
 
 static void
@@ -553,15 +552,14 @@ destroy_device_poller_cb(void *arg)
 	spdk_vhost_dev_mem_unregister(&bvdev->vdev);
 
 	spdk_poller_unregister(&ctx->poller, NULL);
-	sem_post(ctx->sem);
+	spdk_vhost_dev_backend_event_done(ctx->event_ctx, 0);
 }
 
 static int
-destroy_device(struct spdk_vhost_dev *vdev, void *arg)
+destroy_device(struct spdk_vhost_dev *vdev, void *event_ctx)
 {
 	struct spdk_vhost_blk_dev *bvdev;
 	struct spdk_vhost_dev_destroy_ctx *destroy_ctx;
-	sem_t *sem = arg;
 
 	bvdev = to_blk_dev(vdev);
 	if (bvdev == NULL) {
@@ -576,7 +574,7 @@ destroy_device(struct spdk_vhost_dev *vdev, void *arg)
 	}
 
 	destroy_ctx->bvdev = bvdev;
-	destroy_ctx->sem = arg;
+	destroy_ctx->event_ctx = event_ctx;
 
 	spdk_poller_unregister(&bvdev->requestq_poller, NULL);
 	spdk_poller_register(&destroy_ctx->poller, destroy_device_poller_cb, destroy_ctx, vdev->lcore,
@@ -584,7 +582,7 @@ destroy_device(struct spdk_vhost_dev *vdev, void *arg)
 	return 0;
 
 err:
-	sem_post(sem);
+	spdk_vhost_dev_backend_event_done(event_ctx, -1);
 	return -1;
 }
 

lib/vhost/vhost_internal.h

@@ -88,11 +88,12 @@ struct spdk_vhost_dev_backend {
 
 	/**
 	 * Callbacks for starting and pausing the device.
-	 * The first param is struct spdk_vhost_dev *,
-	 * The second one is sem_t* passed as a void*.
-	 * The callback must call sem_post with given sem.
-	 * If sem_post won't be called within an arbitrary
-	 * limit of 3 seconds, this will time out.
+	 * The first param is struct spdk_vhost_dev *.
+	 * The second one is event context that has to be
+	 * passed to spdk_vhost_dev_backend_event_done().
+	 * If spdk_vhost_dev_backend_event_done isn't called
+	 * within an arbitrary limit of 3 seconds, these
+	 * callbacks will time out.
 	 */
 	spdk_vhost_event_fn new_device;
 	spdk_vhost_event_fn destroy_device;
@@ -147,5 +148,6 @@ int spdk_vhost_dev_remove(struct spdk_vhost_dev *vdev);
 
 int spdk_vhost_blk_controller_construct(void);
 void spdk_vhost_dump_config_json(struct spdk_vhost_dev *vdev, struct spdk_json_write_ctx *w);
+void spdk_vhost_dev_backend_event_done(void *event_ctx, int response);
 
 #endif /* SPDK_VHOST_INTERNAL_H */

lib/vhost/vhost_scsi.c

@@ -1052,10 +1052,9 @@ alloc_task_pool(struct spdk_vhost_scsi_dev *svdev)
  * and then allocated to a specific data core.
  */
 static int
-new_device(struct spdk_vhost_dev *vdev, void *arg)
+new_device(struct spdk_vhost_dev *vdev, void *event_ctx)
 {
 	struct spdk_vhost_scsi_dev *svdev;
-	sem_t *sem = arg;
 	uint32_t i;
 	int rc = 0;
 
@@ -1094,14 +1093,14 @@ new_device(struct spdk_vhost_dev *vdev, void *arg)
 	spdk_poller_register(&svdev->mgmt_poller, vdev_mgmt_worker, svdev, vdev->lcore,
 			     MGMT_POLL_PERIOD_US);
 out:
-	sem_post(sem);
+	spdk_vhost_dev_backend_event_done(event_ctx, rc);
 	return rc;
 }
 
 struct spdk_vhost_dev_destroy_ctx {
 	struct spdk_vhost_scsi_dev *svdev;
 	struct spdk_poller *poller;
-	sem_t *sem;
+	void *event_ctx;
 };
 
 static void
@@ -1138,15 +1137,14 @@ destroy_device_poller_cb(void *arg)
 	free_task_pool(svdev);
 
 	spdk_poller_unregister(&ctx->poller, NULL);
-	sem_post(ctx->sem);
+	spdk_vhost_dev_backend_event_done(ctx->event_ctx, 0);
 }
 
 static int
-destroy_device(struct spdk_vhost_dev *vdev, void *arg)
+destroy_device(struct spdk_vhost_dev *vdev, void *event_ctx)
 {
 	struct spdk_vhost_scsi_dev *svdev;
 	struct spdk_vhost_dev_destroy_ctx *destroy_ctx;
-	sem_t *sem = arg;
 
 	svdev = to_scsi_dev(vdev);
 	if (svdev == NULL) {
@@ -1161,7 +1159,7 @@ destroy_device(struct spdk_vhost_dev *vdev, void *arg)
 	}
 
 	destroy_ctx->svdev = svdev;
-	destroy_ctx->sem = arg;
+	destroy_ctx->event_ctx = event_ctx;
 
 	spdk_poller_unregister(&svdev->requestq_poller, NULL);
 	spdk_poller_unregister(&svdev->mgmt_poller, NULL);
@@ -1171,7 +1169,7 @@ destroy_device(struct spdk_vhost_dev *vdev, void *arg)
 	return 0;
 
 err:
-	sem_post(sem);
+	spdk_vhost_dev_backend_event_done(event_ctx, -1);
 	return -1;
 }
 

test/unit/lib/vhost/vhost_blk.c/vhost_blk_ut.c

@@ -121,6 +121,7 @@ DEFINE_STUB(spdk_json_write_array_end, int, (struct spdk_json_write_ctx *w), 0);
 DEFINE_STUB_P(spdk_bdev_get_io_channel, struct spdk_io_channel, (struct spdk_bdev_desc *desc), {0});
 DEFINE_STUB_V(spdk_vhost_call_external_event, (const char *ctrlr_name, spdk_vhost_event_fn fn,
 		void *arg));
+DEFINE_STUB_V(spdk_vhost_dev_backend_event_done, (void *event_ctx, int response));
 
 /* This sets spdk_vhost_dev_remove to either to fail or success */
 DEFINE_STUB(spdk_vhost_dev_remove_fail, bool, (void), false);

test/unit/lib/vhost/vhost_scsi.c/vhost_scsi_ut.c

@@ -117,6 +117,7 @@ DEFINE_STUB(spdk_json_write_string, int, (struct spdk_json_write_ctx *w, const c
 DEFINE_STUB(spdk_json_write_array_begin, int, (struct spdk_json_write_ctx *w), 0);
 DEFINE_STUB(spdk_json_write_object_end, int, (struct spdk_json_write_ctx *w), 0);
 DEFINE_STUB(spdk_json_write_array_end, int, (struct spdk_json_write_ctx *w), 0);
+DEFINE_STUB_V(spdk_vhost_dev_backend_event_done, (void *event_ctx, int response));
 
 /* This sets spdk_vhost_dev_remove to either to fail or success */
 DEFINE_STUB(spdk_vhost_dev_remove_fail, bool, (void), false);