[dpdk-dev] [PATCH v6 17/25] lib/librte_vhost: vhost APIs

[Huawei Xie <huawei.xie@intel.com>]

rte_vring_available_entries returns the available number of vring entries.
gpa_to_vva translates guest physical address to vhost virtual address.
rte_vhost_feature_disable/enable disables or enables VHOST features.
rte_vhost_feature_get returns currently supported VHOST features.
rte_vhost_enqueue_burst copies host packets to guest.
rte_vhost_dequeue_burst gets to-be-sent packets from guest.

Signed-off-by: Huawei Xie <huawei.xie@intel.com>
---
 lib/librte_vhost/rte_virtio_net.h | 70 +++++++++++++++++++++++++++++++++++++++
 lib/librte_vhost/virtio-net.c     | 31 +++++++++++++++++
 2 files changed, 101 insertions(+)

diff --git a/lib/librte_vhost/rte_virtio_net.h b/lib/librte_vhost/rte_virtio_net.h
index 2766133..de2ced6 100644
--- a/lib/librte_vhost/rte_virtio_net.h
+++ b/lib/librte_vhost/rte_virtio_net.h
@@ -119,7 +119,49 @@ struct virtio_net_device_ops {
 	void (* destroy_device)	(volatile struct virtio_net *);	/* Remove device. */
 };
 
+static inline uint16_t __attribute__((always_inline))
+rte_vring_available_entries(struct virtio_net *dev, uint16_t queue_id)
+{
+	struct vhost_virtqueue *vq = dev->virtqueue[queue_id];
+	return *(volatile uint16_t *)&vq->avail->idx - vq->last_used_idx_res;
+}
+
+/**
+ * Function to convert guest physical addresses to vhost virtual addresses.
+ * This is used to convert guest virtio buffer addresses.
+ */
+static inline uint64_t __attribute__((always_inline))
+gpa_to_vva(struct virtio_net *dev, uint64_t guest_pa)
+{
+	struct virtio_memory_regions *region;
+	uint32_t regionidx;
+	uint64_t vhost_va = 0;
+
+	for (regionidx = 0; regionidx < dev->mem->nregions; regionidx++) {
+		region = &dev->mem->regions[regionidx];
+		if ((guest_pa >= region->guest_phys_address) &&
+			(guest_pa <= region->guest_phys_address_end)) {
+			vhost_va = region->address_offset + guest_pa;
+			break;
+		}
+	}
+	return vhost_va;
+}
+
+/**
+ *  Disable features in feature_mask. Returns 0 on success.
+ */
+int rte_vhost_feature_disable(uint64_t feature_mask);
+
+/**
+ *  Enable features in feature_mask. Returns 0 on success.
+ */
+int rte_vhost_feature_enable(uint64_t feature_mask);
+
+/* Returns currently supported vhost features */
+uint64_t rte_vhost_feature_get(void);
 
+int rte_vhost_enable_guest_notification(struct virtio_net *dev, uint16_t queue_id, int enable);
 
 /* Register vhost driver. dev_name could be different for multiple instance support. */
 int rte_vhost_driver_register(const char *dev_name);
@@ -128,4 +170,32 @@ int rte_vhost_driver_register(const char *dev_name);
 int rte_vhost_driver_callback_register(struct virtio_net_device_ops const * const);
 /* Start vhost driver session blocking loop. */
 int rte_vhost_driver_session_start(void);
+
+/**
+ * This function adds buffers to the virtio devices RX virtqueue. Buffers can
+ * be received from the physical port or from another virtual device. A packet
+ * count is returned to indicate the number of packets that were succesfully
+ * added to the RX queue.
+ * @param queue_id
+ *  virtio queue index in mq case
+ * @return
+ *  num of packets enqueued
+ */
+uint16_t rte_vhost_enqueue_burst(struct virtio_net *dev, uint16_t queue_id,
+	struct rte_mbuf **pkts, uint16_t count);
+
+/**
+ * This function gets guest buffers from the virtio device TX virtqueue,
+ * construct host mbufs, copies guest buffer content to host mbufs and
+ * store them in pkts to be processed.
+ * @param mbuf_pool
+ *  mbuf_pool where host mbuf is allocated.
+ * @param queue_id
+ *  virtio queue index in mq case.
+ * @return
+ *  num of packets dequeued
+ */
+uint16_t rte_vhost_dequeue_burst(struct virtio_net *dev, uint16_t queue_id,
+	struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts, uint16_t count);
+
 #endif /* _VIRTIO_NET_H_ */
diff --git a/lib/librte_vhost/virtio-net.c b/lib/librte_vhost/virtio-net.c
index 14e657b..de505c5 100644
--- a/lib/librte_vhost/virtio-net.c
+++ b/lib/librte_vhost/virtio-net.c
@@ -960,6 +960,37 @@ get_virtio_net_callbacks(void)
 	return &vhost_device_ops;
 }
 
+int rte_vhost_enable_guest_notification(struct virtio_net *dev, uint16_t queue_id, int enable)
+{
+	if (enable) {
+		RTE_LOG(ERR, VHOST_CONFIG, "guest notification isn't supported.\n");
+		return -1;
+	}
+
+	dev->virtqueue[queue_id]->used->flags = enable ? 0 : VRING_USED_F_NO_NOTIFY;
+	return 0;
+}
+
+uint64_t rte_vhost_feature_get(void)
+{
+	return VHOST_FEATURES;
+}
+
+int rte_vhost_feature_disable(uint64_t feature_mask)
+{
+	VHOST_FEATURES = VHOST_FEATURES & ~feature_mask;
+	return 0;
+}
+
+int rte_vhost_feature_enable(uint64_t feature_mask)
+{
+	if ((feature_mask & VHOST_SUPPORTED_FEATURES) == feature_mask) {
+		VHOST_FEATURES = VHOST_FEATURES | feature_mask;
+		return 0;
+	}
+	return -1;
+}
+
 /*
  * Register ops so that we can add/remove device to data core.
  */
-- 
1.8.1.4