[v4,08/14] vhost: buffer vhost dequeue shadow ring
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Commit Message
Buffer used ring updates as many as possible in vhost dequeue function
for coordinating with virtio driver. For supporting buffer, shadow used
ring element should contain descriptor index and its wrap counter. First
shadowed ring index is recorded for calculating buffered number.
Signed-off-by: Marvin Liu <yong.liu@intel.com>
@@ -42,6 +42,8 @@
#define PACKED_RX_USED_FLAG (0ULL | VRING_DESC_F_AVAIL | VRING_DESC_F_USED \
| VRING_DESC_F_WRITE)
#define PACKED_RX_USED_WRAP_FLAG (VRING_DESC_F_WRITE)
+#define PACKED_TX_USED_FLAG (0ULL | VRING_DESC_F_AVAIL | VRING_DESC_F_USED)
+#define PACKED_TX_USED_WRAP_FLAG (0x0)
#define PACKED_BATCH_SIZE (RTE_CACHE_LINE_SIZE / \
sizeof(struct vring_packed_desc))
#define PACKED_BATCH_MASK (PACKED_BATCH_SIZE - 1)
@@ -110,9 +112,11 @@ struct log_cache_entry {
};
struct vring_used_elem_packed {
+ uint16_t used_idx;
uint16_t id;
uint32_t len;
uint32_t count;
+ uint16_t used_wrap_counter;
};
/**
@@ -167,6 +171,7 @@ struct vhost_virtqueue {
};
uint16_t shadow_used_idx;
uint16_t enqueue_shadow_count;
+ uint16_t dequeue_shadow_head;
struct vhost_vring_addr ring_addrs;
struct batch_copy_elem *batch_copy_elems;
@@ -230,6 +230,41 @@ update_enqueue_shadow_used_ring_packed(struct vhost_virtqueue *vq,
vq->enqueue_shadow_count += count;
}
+static __rte_always_inline void
+update_dequeue_shadow_used_ring_packed(struct vhost_virtqueue *vq,
+ uint16_t buf_id, uint16_t count)
+{
+ if (!vq->shadow_used_idx) {
+ vq->dequeue_shadow_head = vq->last_used_idx;
+
+ vq->shadow_used_packed[0].id = buf_id;
+ vq->shadow_used_packed[0].len = 0;
+ vq->shadow_used_packed[0].count = count;
+ vq->shadow_used_packed[0].used_idx = vq->last_used_idx;
+ vq->shadow_used_packed[0].used_wrap_counter =
+ vq->used_wrap_counter;
+
+ vq->shadow_used_idx = 1;
+ } else {
+ vq->desc_packed[vq->last_used_idx].id = buf_id;
+ vq->desc_packed[vq->last_used_idx].len = 0;
+
+ if (vq->used_wrap_counter)
+ vq->desc_packed[vq->last_used_idx].flags =
+ PACKED_TX_USED_FLAG;
+ else
+ vq->desc_packed[vq->last_used_idx].flags =
+ PACKED_TX_USED_WRAP_FLAG;
+ }
+
+ vq->last_used_idx += count;
+
+ if (vq->last_used_idx >= vq->size) {
+ vq->used_wrap_counter ^= 1;
+ vq->last_used_idx -= vq->size;
+ }
+}
+
static inline void
do_data_copy_enqueue(struct virtio_net *dev, struct vhost_virtqueue *vq)
{
@@ -1822,6 +1857,8 @@ virtio_dev_tx_single_packed(struct virtio_net *dev, struct vhost_virtqueue *vq,
&desc_count))
return -1;
+ update_dequeue_shadow_used_ring_packed(vq, buf_id, desc_count);
+
vq->last_avail_idx += desc_count;
if (vq->last_avail_idx >= vq->size) {
vq->last_avail_idx -= vq->size;