[PATCH v2 3/5] net/virtio-user: add rxq interrupt mode support

[Jianfeng Tan <jianfeng.tan@intel.com>]

For rxq interrupt, the device (backend driver) will notify driver
through callfd. Each virtqueue has a callfd. To keep compatible
with the existing framework, we will give these callfds to
interrupt thread for listening for interrupts.

Signed-off-by: Jianfeng Tan <jianfeng.tan@intel.com>
---
 doc/guides/rel_notes/release_17_05.rst           |  7 +++++++
 drivers/net/virtio/virtio_user/virtio_user_dev.c | 25 +++++++++++++++++++++++-
 drivers/net/virtio/virtio_user/virtio_user_dev.h |  2 +-
 drivers/net/virtio/virtio_user_ethdev.c          | 12 +++++++++++-
 4 files changed, 43 insertions(+), 3 deletions(-)

diff --git a/doc/guides/rel_notes/release_17_05.rst b/doc/guides/rel_notes/release_17_05.rst
index bb64428..2b5eaab 100644
--- a/doc/guides/rel_notes/release_17_05.rst
+++ b/doc/guides/rel_notes/release_17_05.rst
@@ -57,6 +57,13 @@ New Features
   * Enable Vhost PMD's MTU get feature.
   * Get max MTU value from host in Virtio PMD
 
+* **Added interrupt mode support for virtio-user.**
+
+  Implemented Rxq interrupt mode support for virtio-user as a virtual
+  device. Supported cases:
+
+  * Rxq interrupt for virtio-user + vhost-user as the backend.
+  * Rxq interrupt for virtio-user + vhost-kernel as the backend.
 
 Resolved Issues
 ---------------
diff --git a/drivers/net/virtio/virtio_user/virtio_user_dev.c b/drivers/net/virtio/virtio_user/virtio_user_dev.c
index 9dcdac8..e269ad1 100644
--- a/drivers/net/virtio/virtio_user/virtio_user_dev.c
+++ b/drivers/net/virtio/virtio_user/virtio_user_dev.c
@@ -140,8 +140,28 @@ virtio_user_queue_setup(struct virtio_user_dev *dev,
 	return 0;
 }
 
+static void
+virtio_user_fill_intr_handle(struct virtio_user_dev *dev, uint8_t portid)
+{
+	uint32_t i;
+	struct rte_eth_dev *eth_dev = &rte_eth_devices[portid];
+
+	if (!eth_dev->intr_handle) {
+		eth_dev->intr_handle = malloc(sizeof(*eth_dev->intr_handle));
+		if (!eth_dev->intr_handle)
+			return;
+		memset(eth_dev->intr_handle, 0, sizeof(*eth_dev->intr_handle));
+	}
+
+	for (i = 0; i < dev->max_queue_pairs; ++i)
+		eth_dev->intr_handle->efds[i] = dev->callfds[i];
+	eth_dev->intr_handle->nb_efd = dev->max_queue_pairs;
+	eth_dev->intr_handle->max_intr = dev->max_queue_pairs + 1;
+	eth_dev->intr_handle->type = RTE_INTR_HANDLE_VDEV;
+}
+
 int
-virtio_user_start_device(struct virtio_user_dev *dev)
+virtio_user_start_device(struct virtio_user_dev *dev, uint8_t portid)
 {
 	uint64_t features;
 	int ret;
@@ -175,6 +195,9 @@ virtio_user_start_device(struct virtio_user_dev *dev)
 	 */
 	dev->ops->enable_qp(dev, 0, 1);
 
+	/* Step 5: prepare for interrupt mode */
+	virtio_user_fill_intr_handle(dev, portid);
+
 	return 0;
 error:
 	/* TODO: free resource here or caller to check */
diff --git a/drivers/net/virtio/virtio_user/virtio_user_dev.h b/drivers/net/virtio/virtio_user/virtio_user_dev.h
index bd2e4ca..de4bb5c 100644
--- a/drivers/net/virtio/virtio_user/virtio_user_dev.h
+++ b/drivers/net/virtio/virtio_user/virtio_user_dev.h
@@ -66,7 +66,7 @@ struct virtio_user_dev {
 	struct virtio_user_backend_ops *ops;
 };
 
-int virtio_user_start_device(struct virtio_user_dev *dev);
+int virtio_user_start_device(struct virtio_user_dev *dev, uint8_t portid);
 int virtio_user_stop_device(struct virtio_user_dev *dev);
 int virtio_user_dev_init(struct virtio_user_dev *dev, char *path, int queues,
 			 int cq, int queue_size, const char *mac);
diff --git a/drivers/net/virtio/virtio_user_ethdev.c b/drivers/net/virtio/virtio_user_ethdev.c
index 2961e6b..e4d4c03 100644
--- a/drivers/net/virtio/virtio_user_ethdev.c
+++ b/drivers/net/virtio/virtio_user_ethdev.c
@@ -101,7 +101,7 @@ virtio_user_set_status(struct virtio_hw *hw, uint8_t status)
 	struct virtio_user_dev *dev = virtio_user_get_dev(hw);
 
 	if (status & VIRTIO_CONFIG_STATUS_DRIVER_OK)
-		virtio_user_start_device(dev);
+		virtio_user_start_device(dev, hw->port_id);
 	else if (status == VIRTIO_CONFIG_STATUS_RESET)
 		virtio_user_reset(hw);
 	dev->status = status;
@@ -148,6 +148,15 @@ virtio_user_set_config_irq(struct virtio_hw *hw __rte_unused,
 	return VIRTIO_MSI_NO_VECTOR;
 }
 
+static uint16_t
+virtio_user_set_queue_irq(struct virtio_hw *hw __rte_unused,
+			  struct virtqueue *vq __rte_unused,
+			  uint16_t vec)
+{
+	/* pretend we have done that */
+	return vec;
+}
+
 /* This function is to get the queue size, aka, number of descs, of a specified
  * queue. Different with the VHOST_USER_GET_QUEUE_NUM, which is used to get the
  * max supported queues.
@@ -226,6 +235,7 @@ const struct virtio_pci_ops virtio_user_ops = {
 	.set_features	= virtio_user_set_features,
 	.get_isr	= virtio_user_get_isr,
 	.set_config_irq	= virtio_user_set_config_irq,
+	.set_queue_irq	= virtio_user_set_queue_irq,
 	.get_queue_num	= virtio_user_get_queue_num,
 	.setup_queue	= virtio_user_setup_queue,
 	.del_queue	= virtio_user_del_queue,
-- 
2.7.4