From: Damjan Marion Date: Thu, 22 Nov 2018 21:16:19 +0000 (+0100) Subject: vhost-user: avoid global storage access X-Git-Tag: v19.04-rc0~343 X-Git-Url: https://gerrit.fd.io/r/gitweb?p=vpp.git;a=commitdiff_plain;h=ba1afaae5179a756cdedd37a837127ee248c1ad6 vhost-user: avoid global storage access Change-Id: I9dbeff51d3ede6db3cd5a097623aa580e5e25042 Signed-off-by: Damjan Marion --- diff --git a/src/vnet/devices/virtio/vhost_user_input.c b/src/vnet/devices/virtio/vhost_user_input.c index 4fdfbd5d6e0..720119db2fb 100644 --- a/src/vnet/devices/virtio/vhost_user_input.c +++ b/src/vnet/devices/virtio/vhost_user_input.c @@ -92,10 +92,10 @@ static __clib_unused char *vhost_user_input_func_error_strings[] = { static_always_inline void vhost_user_rx_trace (vhost_trace_t * t, vhost_user_intf_t * vui, u16 qid, - vlib_buffer_t * b, vhost_user_vring_t * txvq) + vlib_buffer_t * b, vhost_user_vring_t * txvq, + u16 last_avail_idx) { vhost_user_main_t *vum = &vhost_user_main; - u32 last_avail_idx = txvq->last_avail_idx; u32 desc_current = txvq->avail->ring[last_avail_idx & txvq->qsz_mask]; vring_desc_t *hdr_desc = 0; virtio_net_hdr_mrg_rxbuf_t *hdr; @@ -195,24 +195,26 @@ vhost_user_rx_discard_packet (vlib_main_t * vm, */ u32 discarded_packets = 0; u32 avail_idx = txvq->avail->idx; + u16 mask = txvq->qsz_mask; + u16 last_avail_idx = txvq->last_avail_idx; + u16 last_used_idx = txvq->last_used_idx; while (discarded_packets != discard_max) { if (avail_idx == txvq->last_avail_idx) goto out; - u16 desc_chain_head = - txvq->avail->ring[txvq->last_avail_idx & txvq->qsz_mask]; - txvq->last_avail_idx++; - txvq->used->ring[txvq->last_used_idx & txvq->qsz_mask].id = - desc_chain_head; - 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]); - txvq->last_used_idx++; + u16 desc_chain_head = txvq->avail->ring[last_avail_idx & mask]; + last_avail_idx++; + txvq->used->ring[last_used_idx & mask].id = desc_chain_head; + txvq->used->ring[last_used_idx & mask].len = 0; + vhost_user_log_dirty_ring (vui, txvq, ring[last_used_idx & mask]); + last_used_idx++; discarded_packets++; } out: + txvq->last_avail_idx = last_avail_idx; + txvq->last_used_idx = last_used_idx; CLIB_MEMORY_BARRIER (); txvq->used->idx = txvq->last_used_idx; vhost_user_log_dirty_ring (vui, txvq, idx); @@ -261,10 +263,11 @@ vhost_user_if_input (vlib_main_t * vm, u16 copy_len = 0; u8 feature_arc_idx = fm->device_input_feature_arc_index; u32 current_config_index = ~(u32) 0; + u16 mask = txvq->qsz_mask; /* The descriptor table is not ready yet */ if (PREDICT_FALSE (txvq->avail == 0)) - return 0; + goto done; { /* do we have pending interrupts ? */ @@ -299,13 +302,13 @@ vhost_user_if_input (vlib_main_t * vm, } if (PREDICT_FALSE (txvq->avail->flags & 0xFFFE)) - return 0; + goto done; n_left = (u16) (txvq->avail->idx - txvq->last_avail_idx); /* nothing to do */ if (PREDICT_FALSE (n_left == 0)) - return 0; + goto done; if (PREDICT_FALSE (!vui->admin_up || !(txvq->enabled))) { @@ -318,10 +321,10 @@ vhost_user_if_input (vlib_main_t * vm, */ vhost_user_rx_discard_packet (vm, vui, txvq, VHOST_USER_DOWN_DISCARD_COUNT); - return 0; + goto done; } - if (PREDICT_FALSE (n_left == (txvq->qsz_mask + 1))) + if (PREDICT_FALSE (n_left == (mask + 1))) { /* * Informational error logging when VPP is not @@ -382,6 +385,9 @@ vhost_user_if_input (vlib_main_t * vm, &next_index, 0); } + u16 last_avail_idx = txvq->last_avail_idx; + u16 last_used_idx = txvq->last_used_idx; + vlib_get_new_next_frame (vm, node, next_index, to_next, n_left_to_next); if (next_index == VNET_DEVICE_INPUT_NEXT_ETHERNET_INPUT) @@ -417,7 +423,7 @@ vhost_user_if_input (vlib_main_t * vm, break; } - desc_current = txvq->avail->ring[txvq->last_avail_idx & txvq->qsz_mask]; + desc_current = txvq->avail->ring[last_avail_idx & mask]; cpu->rx_buffers_len--; bi_current = cpu->rx_buffers[cpu->rx_buffers_len]; b_head = b_current = vlib_get_buffer (vm, bi_current); @@ -429,11 +435,9 @@ vhost_user_if_input (vlib_main_t * vm, (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]); + txvq->used->ring[last_used_idx & mask].id = desc_current; + txvq->used->ring[last_used_idx & mask].len = 0; + vhost_user_log_dirty_ring (vui, txvq, ring[last_used_idx & mask]); /* The buffer should already be initialized */ b_head->total_length_not_including_first_buffer = 0; @@ -446,7 +450,7 @@ vhost_user_if_input (vlib_main_t * vm, /* 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); + vhost_user_rx_trace (t0, vui, qid, b_head, txvq, last_avail_idx); n_trace--; vlib_set_trace_count (vm, node, n_trace); } @@ -552,8 +556,8 @@ vhost_user_if_input (vlib_main_t * vm, b_head->current_length; /* consume the descriptor and return it as used */ - txvq->last_avail_idx++; - txvq->last_used_idx++; + last_avail_idx++; + last_used_idx++; VLIB_BUFFER_TRACE_TRAJECTORY_INIT (b_head); @@ -586,13 +590,16 @@ vhost_user_if_input (vlib_main_t * vm, /* give buffers back to driver */ CLIB_MEMORY_BARRIER (); - txvq->used->idx = txvq->last_used_idx; + txvq->used->idx = last_used_idx; vhost_user_log_dirty_ring (vui, txvq, idx); } } stop: vlib_put_next_frame (vm, node, next_index, n_left_to_next); + txvq->last_used_idx = last_used_idx; + txvq->last_avail_idx = last_avail_idx; + /* Do the memory copies */ if (PREDICT_FALSE (vhost_user_input_copy (vui, cpu->copy, copy_len, &map_hint))) @@ -624,6 +631,7 @@ stop: vnet_device_increment_rx_packets (vm->thread_index, n_rx_packets); +done: return n_rx_packets; }