vhost: dump interrupt coalescing parameters in RPC info/config

Change-Id: I7fec9a5fe30bb64f6c76fc951a40e27cf86ecdee
Signed-off-by: Pawel Wodkowski <pawelx.wodkowski@intel.com>
Reviewed-on: https://review.gerrithub.io/415461
Tested-by: SPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: Karol Latecki <karol.latecki@intel.com>
Reviewed-by: Daniel Verkamp <daniel.verkamp@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>

include/spdk/vhost.h

@@ -162,6 +162,18 @@ const struct spdk_cpuset *spdk_vhost_dev_get_cpumask(struct spdk_vhost_dev *vdev
 int spdk_vhost_set_coalescing(struct spdk_vhost_dev *vdev, uint32_t delay_base_us,
 			      uint32_t iops_threshold);
 
+/**
+ * Get coalescing parameters.
+ *
+ * \see spdk_vhost_set_coalescing
+ *
+ * \param vdev vhost device.
+ * \param delay_base_us Optional pointer to store base delay time.
+ * \param iops_threshold Optional pointer to store IOPS threshold.
+ */
+void spdk_vhost_get_coalescing(struct spdk_vhost_dev *vdev, uint32_t *delay_base_us,
+			       uint32_t *iops_threshold);
+
 /**
  * Construct an empty vhost SCSI device.  This will create a
  * Unix domain socket together with a vhost-user slave server waiting

lib/vhost/vhost.c

@@ -338,7 +338,7 @@ spdk_vhost_set_coalescing(struct spdk_vhost_dev *vdev, uint32_t delay_base_us,
 			  uint32_t iops_threshold)
 {
 	uint64_t delay_time_base = delay_base_us * spdk_get_ticks_hz() / 1000000ULL;
-	uint32_t io_rate = iops_threshold * SPDK_VHOST_DEV_STATS_CHECK_INTERVAL_MS / 1000;
+	uint32_t io_rate = iops_threshold * SPDK_VHOST_DEV_STATS_CHECK_INTERVAL_MS / 1000U;
 
 	if (delay_time_base >= UINT32_MAX) {
 		SPDK_ERRLOG("Delay time of %"PRIu32" is to big\n", delay_base_us);
@@ -351,9 +351,25 @@ spdk_vhost_set_coalescing(struct spdk_vhost_dev *vdev, uint32_t delay_base_us,
 
 	vdev->coalescing_delay_time_base = delay_time_base;
 	vdev->coalescing_io_rate_threshold = io_rate;
+
+	vdev->coalescing_delay_us = delay_base_us;
+	vdev->coalescing_iops_threshold = iops_threshold;
 	return 0;
 }
 
+void
+spdk_vhost_get_coalescing(struct spdk_vhost_dev *vdev, uint32_t *delay_base_us,
+			  uint32_t *iops_threshold)
+{
+	if (delay_base_us) {
+		*delay_base_us = vdev->coalescing_delay_us;
+	}
+
+	if (iops_threshold) {
+		*iops_threshold = vdev->coalescing_iops_threshold;
+	}
+}
+
 /*
  * Enqueue id and len to used ring.
  */
@@ -1386,6 +1402,8 @@ static int
 spdk_vhost_config_json_cb(struct spdk_vhost_dev *vdev, void *arg)
 {
 	struct spdk_vhost_write_config_json_ctx *ctx = arg;
+	uint32_t delay_base_us;
+	uint32_t iops_threshold;
 
 	if (vdev == NULL) {
 		spdk_json_write_array_end(ctx->w);
@@ -1395,6 +1413,21 @@ spdk_vhost_config_json_cb(struct spdk_vhost_dev *vdev, void *arg)
 	}
 
 	vdev->backend->write_config_json(vdev, ctx->w);
+
+	spdk_vhost_get_coalescing(vdev, &delay_base_us, &iops_threshold);
+	if (delay_base_us) {
+		spdk_json_write_object_begin(ctx->w);
+		spdk_json_write_named_string(ctx->w, "method", "set_vhost_controller_coalescing");
+
+		spdk_json_write_named_object_begin(ctx->w, "params");
+		spdk_json_write_named_string(ctx->w, "ctrlr", vdev->name);
+		spdk_json_write_named_uint32(ctx->w, "delay_base_us", delay_base_us);
+		spdk_json_write_named_uint32(ctx->w, "iops_threshold", iops_threshold);
+		spdk_json_write_object_end(ctx->w);
+
+		spdk_json_write_object_end(ctx->w);
+	}
+
 	return 0;
 }
 

lib/vhost/vhost_internal.h

@@ -150,6 +150,12 @@ struct spdk_vhost_dev {
 
 	const struct spdk_vhost_dev_backend *backend;
 
+	/* Saved orginal values used to setup coalescing to avoid integer
+	 * rounding issues during save/load config.
+	 */
+	uint32_t coalescing_delay_us;
+	uint32_t coalescing_iops_threshold;
+
 	uint32_t coalescing_delay_time_base;
 
 	/* Threshold when event coalescing for virtqueue will be turned on. */

lib/vhost/vhost_rpc.c

@@ -459,6 +459,8 @@ static int
 spdk_rpc_get_vhost_controllers_cb(struct spdk_vhost_dev *vdev, void *arg)
 {
 	struct rpc_get_vhost_ctrlrs *ctx = arg;
+	uint32_t delay_base_us, iops_threshold;
+
 
 	if (vdev == NULL) {
 		spdk_json_write_array_end(ctx->w);
@@ -467,10 +469,14 @@ spdk_rpc_get_vhost_controllers_cb(struct spdk_vhost_dev *vdev, void *arg)
 		return 0;
 	}
 
+	spdk_vhost_get_coalescing(vdev, &delay_base_us, &iops_threshold);
+
 	spdk_json_write_object_begin(ctx->w);
 
 	spdk_json_write_named_string(ctx->w, "ctrlr", spdk_vhost_dev_get_name(vdev));
 	spdk_json_write_named_string_fmt(ctx->w, "cpumask", "0x%s", spdk_cpuset_fmt(vdev->cpumask));
+	spdk_json_write_named_uint32(ctx->w, "delay_base_us", delay_base_us);
+	spdk_json_write_named_uint32(ctx->w, "iops_threshold", iops_threshold);
 
 	spdk_json_write_named_object_begin(ctx->w, "backend_specific");
 	spdk_vhost_dump_info_json(vdev, ctx->w);