[dpdk-dev] [PATCH v2] net/virtio: packed ring notification data feature support

[Cheng Jiang <Cheng1.jiang@intel.com>]

This patch supports the feature that the driver passes extra data
(besides identifying the virtqueue) in its device notifications.

Signed-off-by: Cheng Jiang <Cheng1.jiang@intel.com>
---

v2:
* Removed rte_unused attribute in *hw.
* Added some comments on notify_data.

 drivers/net/virtio/virtio_ethdev.h |  3 ++-
 drivers/net/virtio/virtio_pci.c    | 27 +++++++++++++++++++++++++--
 drivers/net/virtio/virtio_pci.h    |  6 ++++++
 3 files changed, 33 insertions(+), 3 deletions(-)

diff --git a/drivers/net/virtio/virtio_ethdev.h b/drivers/net/virtio/virtio_ethdev.h
index a10111758..cd8947656 100644
--- a/drivers/net/virtio/virtio_ethdev.h
+++ b/drivers/net/virtio/virtio_ethdev.h
@@ -36,7 +36,8 @@
 	 1ULL << VIRTIO_F_IN_ORDER        |	\
 	 1ULL << VIRTIO_F_RING_PACKED	  |	\
 	 1ULL << VIRTIO_F_IOMMU_PLATFORM  |	\
-	 1ULL << VIRTIO_F_ORDER_PLATFORM)
+	 1ULL << VIRTIO_F_ORDER_PLATFORM  |	\
+	 1ULL << VIRTIO_F_NOTIFICATION_DATA)
 
 #define VIRTIO_PMD_SUPPORTED_GUEST_FEATURES	\
 	(VIRTIO_PMD_DEFAULT_GUEST_FEATURES |	\
diff --git a/drivers/net/virtio/virtio_pci.c b/drivers/net/virtio/virtio_pci.c
index 4468e89cb..8b4e001a1 100644
--- a/drivers/net/virtio/virtio_pci.c
+++ b/drivers/net/virtio/virtio_pci.c
@@ -416,9 +416,32 @@ modern_del_queue(struct virtio_hw *hw, struct virtqueue *vq)
 }
 
 static void
-modern_notify_queue(struct virtio_hw *hw __rte_unused, struct virtqueue *vq)
+modern_notify_queue(struct virtio_hw *hw, struct virtqueue *vq)
 {
-	rte_write16(vq->vq_queue_index, vq->notify_addr);
+	uint32_t notify_data;
+
+	if (!vtpci_with_feature(hw, VIRTIO_F_NOTIFICATION_DATA)) {
+		rte_write16(vq->vq_queue_index, vq->notify_addr);
+		return;
+	}
+
+	if (vtpci_with_feature(hw, VIRTIO_F_RING_PACKED)) {
+		/*
+		 * Bit[0:15]: vq queue index
+		 * Bit[16:30]: avail index
+		 * Bit[31]: avail wrap counter
+		 */
+		notify_data = ((((uint32_t)vq->vq_packed.used_wrap_counter << 15) |
+				vq->vq_avail_idx) << 16) | vq->vq_queue_index;
+	} else {
+		/*
+		 * Bit[0:15]: vq queue index
+		 * Bit[16:31]: avail index
+		 */
+		notify_data = ((uint32_t)vq->vq_avail_idx << 16) |
+				vq->vq_queue_index;
+	}
+	rte_write32(notify_data, vq->notify_addr);
 }
 
 const struct virtio_pci_ops modern_ops = {
diff --git a/drivers/net/virtio/virtio_pci.h b/drivers/net/virtio/virtio_pci.h
index a38cb45ad..7433d2f08 100644
--- a/drivers/net/virtio/virtio_pci.h
+++ b/drivers/net/virtio/virtio_pci.h
@@ -135,6 +135,12 @@ struct virtnet_ctl;
  */
 #define VIRTIO_F_ORDER_PLATFORM 36
 
+/*
+ * This feature indicates that the driver passes extra data (besides
+ * identifying the virtqueue) in its device notifications.
+ */
+#define VIRTIO_F_NOTIFICATION_DATA 38
+
 /* The Guest publishes the used index for which it expects an interrupt
  * at the end of the avail ring. Host should ignore the avail->flags field. */
 /* The Host publishes the avail index for which it expects a kick
-- 
2.17.1