[PATCH v3 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.

Before that, we need to allocate intr_handle, and fill callfds
into it so that driver can use it to set up rxq interrupt mode.

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 | 27 ++++++++++++++++++++++++
 drivers/net/virtio/virtio_user/virtio_user_dev.h |  1 +
 drivers/net/virtio/virtio_user_ethdev.c          | 12 ++++++++++-
 4 files changed, 46 insertions(+), 1 deletion(-)

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 8ff23c5..ce4ead0 100644
--- a/drivers/net/virtio/virtio_user/virtio_user_dev.c
+++ b/drivers/net/virtio/virtio_user/virtio_user_dev.c
@@ -254,6 +254,30 @@ virtio_user_dev_init_notify(struct virtio_user_dev *dev)
 }
 
 static int
+virtio_user_fill_intr_handle(struct virtio_user_dev *dev)
+{
+	uint32_t i;
+	struct rte_eth_dev *eth_dev = &rte_eth_devices[dev->portid];
+
+	if (!eth_dev->intr_handle) {
+		eth_dev->intr_handle = malloc(sizeof(*eth_dev->intr_handle));
+		if (!eth_dev->intr_handle) {
+			PMD_DRV_LOG(ERR, "fail to allocate intr_handle");
+			return -1;
+		}
+		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;
+
+	return 0;
+}
+
+static int
 virtio_user_dev_setup(struct virtio_user_dev *dev)
 {
 	uint32_t q;
@@ -265,6 +289,9 @@ virtio_user_dev_setup(struct virtio_user_dev *dev)
 	if (virtio_user_dev_init_notify(dev) < 0)
 		return -1;
 
+	if (virtio_user_fill_intr_handle(dev) < 0)
+		return -1;
+
 	if (is_vhost_user_by_type(dev->path)) {
 		dev->ops = &ops_user;
 	} else {
diff --git a/drivers/net/virtio/virtio_user/virtio_user_dev.h b/drivers/net/virtio/virtio_user/virtio_user_dev.h
index bd2e4ca..44c4e68 100644
--- a/drivers/net/virtio/virtio_user/virtio_user_dev.h
+++ b/drivers/net/virtio/virtio_user/virtio_user_dev.h
@@ -60,6 +60,7 @@ struct virtio_user_dev {
 				   */
 	uint64_t	device_features; /* supported features by device */
 	uint8_t		status;
+	uint8_t		portid;
 	uint8_t		mac_addr[ETHER_ADDR_LEN];
 	char		path[PATH_MAX];
 	struct vring	vrings[VIRTIO_MAX_VIRTQUEUES];
diff --git a/drivers/net/virtio/virtio_user_ethdev.c b/drivers/net/virtio/virtio_user_ethdev.c
index 2961e6b..335d70d 100644
--- a/drivers/net/virtio/virtio_user_ethdev.c
+++ b/drivers/net/virtio/virtio_user_ethdev.c
@@ -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,
@@ -307,7 +317,7 @@ virtio_user_eth_dev_alloc(const char *name)
 		return NULL;
 	}
 
-	hw->port_id = data->port_id;
+	dev->portid = hw->port_id = data->port_id;
 	virtio_hw_internal[hw->port_id].vtpci_ops = &virtio_user_ops;
 	hw->use_msix = 0;
 	hw->modern   = 0;
-- 
2.7.4