[dpdk-dev] [PATCH v2 07/22] vhost: export vhost vring info

[Yuanhan Liu <yuanhan.liu@linux.intel.com>]

Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
---

v2: - fix off-by-one check
    - add API comments
---
 lib/librte_vhost/rte_vhost_version.map |  1 +
 lib/librte_vhost/rte_virtio_net.h      | 26 ++++++++++++++++++++++++++
 lib/librte_vhost/vhost.c               | 30 ++++++++++++++++++++++++++++++
 lib/librte_vhost/vhost.h               |  2 ++
 4 files changed, 59 insertions(+)

diff --git a/lib/librte_vhost/rte_vhost_version.map b/lib/librte_vhost/rte_vhost_version.map
index e21b788..28664a4 100644
--- a/lib/librte_vhost/rte_vhost_version.map
+++ b/lib/librte_vhost/rte_vhost_version.map
@@ -39,5 +39,6 @@ DPDK_17.05 {
 	rte_vhost_get_mtu;
 	rte_vhost_get_negotiated_features
 	rte_vhost_get_vhost_memory;
+	rte_vhost_get_vhost_vring;
 
 } DPDK_16.07;
diff --git a/lib/librte_vhost/rte_virtio_net.h b/lib/librte_vhost/rte_virtio_net.h
index 57e57e3..5142337 100644
--- a/lib/librte_vhost/rte_virtio_net.h
+++ b/lib/librte_vhost/rte_virtio_net.h
@@ -80,6 +80,17 @@ struct rte_vhost_memory {
 	struct rte_vhost_mem_region regions[0];
 };
 
+struct rte_vhost_vring {
+	struct vring_desc	*desc;
+	struct vring_avail	*avail;
+	struct vring_used	*used;
+	uint64_t		log_guest_addr;
+
+	int			callfd;
+	int			kickfd;
+	uint16_t		size;
+};
+
 /**
  * Device and vring operations.
  */
@@ -292,4 +303,19 @@ uint16_t rte_vhost_dequeue_burst(int vid, uint16_t queue_id,
  */
 int rte_vhost_get_mem_table(int vid, struct rte_vhost_memory **mem);
 
+/**
+ * Get guest vring info, including the vring address, vring size, etc.
+ *
+ * @param vid
+ *  vhost device ID
+ * @param vring_idx
+ *  vring index
+ * @param vring
+ *  the structure to hold the requested vring info
+ * @return
+ *  0 on success, -1 on failure
+ */
+int rte_vhost_get_vhost_vring(int vid, uint16_t vring_idx,
+			      struct rte_vhost_vring *vring);
+
 #endif /* _VIRTIO_NET_H_ */
diff --git a/lib/librte_vhost/vhost.c b/lib/librte_vhost/vhost.c
index 08dccfb..6fe613b 100644
--- a/lib/librte_vhost/vhost.c
+++ b/lib/librte_vhost/vhost.c
@@ -394,6 +394,36 @@ struct virtio_net *
 	return 0;
 }
 
+int
+rte_vhost_get_vhost_vring(int vid, uint16_t vring_idx,
+			  struct rte_vhost_vring *vring)
+{
+	struct virtio_net *dev;
+	struct vhost_virtqueue *vq;
+
+	dev = get_device(vid);
+	if (!dev)
+		return -1;
+
+	if (vring_idx >= VHOST_MAX_VRING)
+		return -1;
+
+	vq = dev->virtqueue[vring_idx];
+	if (!vq)
+		return -1;
+
+	vring->desc  = vq->desc;
+	vring->avail = vq->avail;
+	vring->used  = vq->used;
+	vring->log_guest_addr  = vq->log_guest_addr;
+
+	vring->callfd  = vq->callfd;
+	vring->kickfd  = vq->kickfd;
+	vring->size    = vq->size;
+
+	return 0;
+}
+
 uint16_t
 rte_vhost_avail_entries(int vid, uint16_t queue_id)
 {
diff --git a/lib/librte_vhost/vhost.h b/lib/librte_vhost/vhost.h
index 6d1986a..68ca197 100644
--- a/lib/librte_vhost/vhost.h
+++ b/lib/librte_vhost/vhost.h
@@ -120,6 +120,8 @@ struct vhost_virtqueue {
 #ifndef VIRTIO_NET_F_MQ
  #define VIRTIO_NET_F_MQ		22
 #endif
+
+#define VHOST_MAX_VRING			0x100
 #define VHOST_MAX_QUEUE_PAIRS		0x80
 
 #ifndef VIRTIO_NET_F_MTU
-- 
1.9.0