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authorDamjan Marion <damarion@cisco.com>2018-11-21 10:03:44 +0100
committerOle Trøan <otroan@employees.org>2018-11-23 11:41:14 +0000
commit9282538f0984590369d8096704de61301889d8b0 (patch)
tree2affacfd796315ec3c492b2b560a9fed708faf21
parent7f8a8dba96a78a0c67756df0b2fabaab313c3f2d (diff)
vhost-user: simplify input loop
Change-Id: I6e6963882825e83d8da3a460be35c7349e107777 Signed-off-by: Damjan Marion <damarion@cisco.com>
-rw-r--r--src/vnet/devices/virtio/vhost_user_input.c355
1 files changed, 174 insertions, 181 deletions
diff --git a/src/vnet/devices/virtio/vhost_user_input.c b/src/vnet/devices/virtio/vhost_user_input.c
index 87a01cefd5b..4fdfbd5d6e0 100644
--- a/src/vnet/devices/virtio/vhost_user_input.c
+++ b/src/vnet/devices/virtio/vhost_user_input.c
@@ -382,223 +382,216 @@ vhost_user_if_input (vlib_main_t * vm,
&next_index, 0);
}
+ vlib_get_new_next_frame (vm, node, next_index, to_next, n_left_to_next);
+
+ if (next_index == VNET_DEVICE_INPUT_NEXT_ETHERNET_INPUT)
+ {
+ /* give some hints to ethernet-input */
+ vlib_next_frame_t *nf;
+ vlib_frame_t *f;
+ ethernet_input_frame_t *ef;
+ nf = vlib_node_runtime_get_next_frame (vm, node, next_index);
+ f = vlib_get_frame (vm, nf->frame_index);
+ f->flags = ETH_INPUT_FRAME_F_SINGLE_SW_IF_IDX;
+
+ ef = vlib_frame_scalar_args (f);
+ ef->sw_if_index = vui->sw_if_index;
+ ef->hw_if_index = vui->hw_if_index;
+ }
+
while (n_left > 0)
{
- vlib_get_new_next_frame (vm, node, next_index, to_next, n_left_to_next);
+ vlib_buffer_t *b_head, *b_current;
+ u32 bi_current;
+ u16 desc_current;
+ u32 desc_data_offset;
+ vring_desc_t *desc_table = txvq->desc;
- if (next_index == VNET_DEVICE_INPUT_NEXT_ETHERNET_INPUT)
+ if (PREDICT_FALSE (cpu->rx_buffers_len <= 1))
{
- /* give some hints to ethernet-input */
- vlib_next_frame_t *nf;
- vlib_frame_t *f;
- ethernet_input_frame_t *ef;
- nf = vlib_node_runtime_get_next_frame (vm, node, next_index);
- f = vlib_get_frame (vm, nf->frame_index);
- f->flags = ETH_INPUT_FRAME_F_SINGLE_SW_IF_IDX;
-
- ef = vlib_frame_scalar_args (f);
- ef->sw_if_index = vui->sw_if_index;
- ef->hw_if_index = vui->hw_if_index;
+ /* Not enough rx_buffers
+ * Note: We yeld on 1 so we don't need to do an additional
+ * check for the next buffer prefetch.
+ */
+ n_left = 0;
+ break;
}
- while (n_left > 0 && n_left_to_next > 0)
+ desc_current = txvq->avail->ring[txvq->last_avail_idx & txvq->qsz_mask];
+ cpu->rx_buffers_len--;
+ bi_current = cpu->rx_buffers[cpu->rx_buffers_len];
+ b_head = b_current = vlib_get_buffer (vm, bi_current);
+ to_next[0] = bi_current; //We do that now so we can forget about bi_current
+ to_next++;
+ n_left_to_next--;
+
+ vlib_prefetch_buffer_with_index
+ (vm, cpu->rx_buffers[cpu->rx_buffers_len - 1], LOAD);
+
+ /* Just preset the used descriptor id and length for later */
+ txvq->used->ring[txvq->last_used_idx & txvq->qsz_mask].id =
+ desc_current;
+ txvq->used->ring[txvq->last_used_idx & txvq->qsz_mask].len = 0;
+ vhost_user_log_dirty_ring (vui, txvq,
+ ring[txvq->last_used_idx & txvq->qsz_mask]);
+
+ /* The buffer should already be initialized */
+ b_head->total_length_not_including_first_buffer = 0;
+ b_head->flags |= VLIB_BUFFER_TOTAL_LENGTH_VALID;
+
+ if (PREDICT_FALSE (n_trace))
{
- vlib_buffer_t *b_head, *b_current;
- u32 bi_current;
- u16 desc_current;
- u32 desc_data_offset;
- vring_desc_t *desc_table = txvq->desc;
+ //TODO: next_index is not exactly known at that point
+ vlib_trace_buffer (vm, node, next_index, b_head,
+ /* follow_chain */ 0);
+ vhost_trace_t *t0 =
+ vlib_add_trace (vm, node, b_head, sizeof (t0[0]));
+ vhost_user_rx_trace (t0, vui, qid, b_head, txvq);
+ n_trace--;
+ vlib_set_trace_count (vm, node, n_trace);
+ }
- if (PREDICT_FALSE (cpu->rx_buffers_len <= 1))
+ /* This depends on the setup but is very consistent
+ * So I think the CPU branch predictor will make a pretty good job
+ * at optimizing the decision. */
+ if (txvq->desc[desc_current].flags & VIRTQ_DESC_F_INDIRECT)
+ {
+ desc_table = map_guest_mem (vui, txvq->desc[desc_current].addr,
+ &map_hint);
+ desc_current = 0;
+ if (PREDICT_FALSE (desc_table == 0))
{
- /* Not enough rx_buffers
- * Note: We yeld on 1 so we don't need to do an additional
- * check for the next buffer prefetch.
- */
- n_left = 0;
- break;
+ vlib_error_count (vm, node->node_index,
+ VHOST_USER_INPUT_FUNC_ERROR_MMAP_FAIL, 1);
+ goto out;
}
+ }
- desc_current =
- txvq->avail->ring[txvq->last_avail_idx & txvq->qsz_mask];
- cpu->rx_buffers_len--;
- bi_current = cpu->rx_buffers[cpu->rx_buffers_len];
- b_head = b_current = vlib_get_buffer (vm, bi_current);
- to_next[0] = bi_current; //We do that now so we can forget about bi_current
- to_next++;
- n_left_to_next--;
-
- vlib_prefetch_buffer_with_index
- (vm, cpu->rx_buffers[cpu->rx_buffers_len - 1], LOAD);
-
- /* Just preset the used descriptor id and length for later */
- txvq->used->ring[txvq->last_used_idx & txvq->qsz_mask].id =
- desc_current;
- txvq->used->ring[txvq->last_used_idx & txvq->qsz_mask].len = 0;
- vhost_user_log_dirty_ring (vui, txvq,
- ring[txvq->last_used_idx &
- txvq->qsz_mask]);
-
- /* The buffer should already be initialized */
- b_head->total_length_not_including_first_buffer = 0;
- b_head->flags |= VLIB_BUFFER_TOTAL_LENGTH_VALID;
-
- if (PREDICT_FALSE (n_trace))
- {
- //TODO: next_index is not exactly known at that point
- vlib_trace_buffer (vm, node, next_index, b_head,
- /* follow_chain */ 0);
- vhost_trace_t *t0 =
- vlib_add_trace (vm, node, b_head, sizeof (t0[0]));
- vhost_user_rx_trace (t0, vui, qid, b_head, txvq);
- n_trace--;
- vlib_set_trace_count (vm, node, n_trace);
- }
+ if (PREDICT_TRUE (vui->is_any_layout) ||
+ (!(desc_table[desc_current].flags & VIRTQ_DESC_F_NEXT)))
+ {
+ /* ANYLAYOUT or single buffer */
+ desc_data_offset = vui->virtio_net_hdr_sz;
+ }
+ else
+ {
+ /* CSR case without ANYLAYOUT, skip 1st buffer */
+ desc_data_offset = desc_table[desc_current].len;
+ }
- /* This depends on the setup but is very consistent
- * So I think the CPU branch predictor will make a pretty good job
- * at optimizing the decision. */
- if (txvq->desc[desc_current].flags & VIRTQ_DESC_F_INDIRECT)
+ while (1)
+ {
+ /* Get more input if necessary. Or end of packet. */
+ if (desc_data_offset == desc_table[desc_current].len)
{
- desc_table = map_guest_mem (vui, txvq->desc[desc_current].addr,
- &map_hint);
- desc_current = 0;
- if (PREDICT_FALSE (desc_table == 0))
+ if (PREDICT_FALSE (desc_table[desc_current].flags &
+ VIRTQ_DESC_F_NEXT))
+ {
+ desc_current = desc_table[desc_current].next;
+ desc_data_offset = 0;
+ }
+ else
{
- vlib_error_count (vm, node->node_index,
- VHOST_USER_INPUT_FUNC_ERROR_MMAP_FAIL, 1);
goto out;
}
}
- if (PREDICT_TRUE (vui->is_any_layout) ||
- (!(desc_table[desc_current].flags & VIRTQ_DESC_F_NEXT)))
- {
- /* ANYLAYOUT or single buffer */
- desc_data_offset = vui->virtio_net_hdr_sz;
- }
- else
- {
- /* CSR case without ANYLAYOUT, skip 1st buffer */
- desc_data_offset = desc_table[desc_current].len;
- }
-
- while (1)
+ /* Get more output if necessary. Or end of packet. */
+ if (PREDICT_FALSE
+ (b_current->current_length == VLIB_BUFFER_DATA_SIZE))
{
- /* Get more input if necessary. Or end of packet. */
- if (desc_data_offset == desc_table[desc_current].len)
- {
- if (PREDICT_FALSE (desc_table[desc_current].flags &
- VIRTQ_DESC_F_NEXT))
- {
- desc_current = desc_table[desc_current].next;
- desc_data_offset = 0;
- }
- else
- {
- goto out;
- }
- }
-
- /* Get more output if necessary. Or end of packet. */
- if (PREDICT_FALSE
- (b_current->current_length == VLIB_BUFFER_DATA_SIZE))
+ if (PREDICT_FALSE (cpu->rx_buffers_len == 0))
{
- if (PREDICT_FALSE (cpu->rx_buffers_len == 0))
- {
- /* Cancel speculation */
- to_next--;
- n_left_to_next++;
-
- /*
- * Checking if there are some left buffers.
- * If not, just rewind the used buffers and stop.
- * Note: Scheduled copies are not cancelled. This is
- * not an issue as they would still be valid. Useless,
- * but valid.
- */
- vhost_user_input_rewind_buffers (vm, cpu, b_head);
- n_left = 0;
- goto stop;
- }
-
- /* Get next output */
- cpu->rx_buffers_len--;
- u32 bi_next = cpu->rx_buffers[cpu->rx_buffers_len];
- b_current->next_buffer = bi_next;
- b_current->flags |= VLIB_BUFFER_NEXT_PRESENT;
- bi_current = bi_next;
- b_current = vlib_get_buffer (vm, bi_current);
+ /* Cancel speculation */
+ to_next--;
+ n_left_to_next++;
+
+ /*
+ * Checking if there are some left buffers.
+ * If not, just rewind the used buffers and stop.
+ * Note: Scheduled copies are not cancelled. This is
+ * not an issue as they would still be valid. Useless,
+ * but valid.
+ */
+ vhost_user_input_rewind_buffers (vm, cpu, b_head);
+ n_left = 0;
+ goto stop;
}
- /* Prepare a copy order executed later for the data */
- vhost_copy_t *cpy = &cpu->copy[copy_len];
- copy_len++;
- u32 desc_data_l =
- desc_table[desc_current].len - desc_data_offset;
- cpy->len = VLIB_BUFFER_DATA_SIZE - b_current->current_length;
- cpy->len = (cpy->len > desc_data_l) ? desc_data_l : cpy->len;
- cpy->dst = (uword) (vlib_buffer_get_current (b_current) +
- b_current->current_length);
- cpy->src = desc_table[desc_current].addr + desc_data_offset;
-
- desc_data_offset += cpy->len;
-
- b_current->current_length += cpy->len;
- b_head->total_length_not_including_first_buffer += cpy->len;
+ /* Get next output */
+ cpu->rx_buffers_len--;
+ u32 bi_next = cpu->rx_buffers[cpu->rx_buffers_len];
+ b_current->next_buffer = bi_next;
+ b_current->flags |= VLIB_BUFFER_NEXT_PRESENT;
+ bi_current = bi_next;
+ b_current = vlib_get_buffer (vm, bi_current);
}
- out:
- CLIB_PREFETCH (&n_left, sizeof (n_left), LOAD);
+ /* Prepare a copy order executed later for the data */
+ vhost_copy_t *cpy = &cpu->copy[copy_len];
+ copy_len++;
+ u32 desc_data_l = desc_table[desc_current].len - desc_data_offset;
+ cpy->len = VLIB_BUFFER_DATA_SIZE - b_current->current_length;
+ cpy->len = (cpy->len > desc_data_l) ? desc_data_l : cpy->len;
+ cpy->dst = (uword) (vlib_buffer_get_current (b_current) +
+ b_current->current_length);
+ cpy->src = desc_table[desc_current].addr + desc_data_offset;
- n_rx_bytes += b_head->total_length_not_including_first_buffer;
- n_rx_packets++;
+ desc_data_offset += cpy->len;
- b_head->total_length_not_including_first_buffer -=
- b_head->current_length;
+ b_current->current_length += cpy->len;
+ b_head->total_length_not_including_first_buffer += cpy->len;
+ }
- /* consume the descriptor and return it as used */
- txvq->last_avail_idx++;
- txvq->last_used_idx++;
+ out:
- VLIB_BUFFER_TRACE_TRAJECTORY_INIT (b_head);
+ n_rx_bytes += b_head->total_length_not_including_first_buffer;
+ n_rx_packets++;
- vnet_buffer (b_head)->sw_if_index[VLIB_RX] = vui->sw_if_index;
- vnet_buffer (b_head)->sw_if_index[VLIB_TX] = (u32) ~ 0;
- b_head->error = 0;
+ b_head->total_length_not_including_first_buffer -=
+ b_head->current_length;
- if (current_config_index != ~(u32) 0)
- {
- b_head->current_config_index = current_config_index;
- vnet_buffer (b_head)->feature_arc_index = feature_arc_idx;
- }
+ /* consume the descriptor and return it as used */
+ txvq->last_avail_idx++;
+ txvq->last_used_idx++;
- n_left--;
+ VLIB_BUFFER_TRACE_TRAJECTORY_INIT (b_head);
- /*
- * Although separating memory copies from virtio ring parsing
- * is beneficial, we can offer to perform the copies from time
- * to time in order to free some space in the ring.
- */
- if (PREDICT_FALSE (copy_len >= VHOST_USER_RX_COPY_THRESHOLD))
- {
- if (PREDICT_FALSE (vhost_user_input_copy (vui, cpu->copy,
- copy_len, &map_hint)))
- {
- vlib_error_count (vm, node->node_index,
- VHOST_USER_INPUT_FUNC_ERROR_MMAP_FAIL, 1);
- }
- copy_len = 0;
+ vnet_buffer (b_head)->sw_if_index[VLIB_RX] = vui->sw_if_index;
+ vnet_buffer (b_head)->sw_if_index[VLIB_TX] = (u32) ~ 0;
+ b_head->error = 0;
+
+ if (current_config_index != ~(u32) 0)
+ {
+ b_head->current_config_index = current_config_index;
+ vnet_buffer (b_head)->feature_arc_index = feature_arc_idx;
+ }
- /* give buffers back to driver */
- CLIB_MEMORY_BARRIER ();
- txvq->used->idx = txvq->last_used_idx;
- vhost_user_log_dirty_ring (vui, txvq, idx);
+ n_left--;
+
+ /*
+ * Although separating memory copies from virtio ring parsing
+ * is beneficial, we can offer to perform the copies from time
+ * to time in order to free some space in the ring.
+ */
+ if (PREDICT_FALSE (copy_len >= VHOST_USER_RX_COPY_THRESHOLD))
+ {
+ if (PREDICT_FALSE (vhost_user_input_copy (vui, cpu->copy,
+ copy_len, &map_hint)))
+ {
+ vlib_error_count (vm, node->node_index,
+ VHOST_USER_INPUT_FUNC_ERROR_MMAP_FAIL, 1);
}
+ copy_len = 0;
+
+ /* give buffers back to driver */
+ CLIB_MEMORY_BARRIER ();
+ txvq->used->idx = txvq->last_used_idx;
+ vhost_user_log_dirty_ring (vui, txvq, idx);
}
- stop:
- vlib_put_next_frame (vm, node, next_index, n_left_to_next);
}
+stop:
+ vlib_put_next_frame (vm, node, next_index, n_left_to_next);
/* Do the memory copies */
if (PREDICT_FALSE (vhost_user_input_copy (vui, cpu->copy, copy_len,