#define DBG_VQ(args...)
#endif
+/*
+ * When an RX queue is down but active, received packets
+ * must be discarded. This value controls up to how many
+ * packets will be discarded during each round.
+ */
+#define VHOST_USER_DOWN_DISCARD_COUNT 256
+
+/*
+ * When the number of available buffers gets under this threshold,
+ * RX node will start discarding packets.
+ */
+#define VHOST_USER_RX_BUFFER_STARVATION 32
+
+/*
+ * On the receive side, the host should free descriptors as soon
+ * as possible in order to avoid TX drop in the VM.
+ * This value controls the number of copy operations that are stacked
+ * before copy is done for all and descriptors are given back to
+ * the guest.
+ * The value 64 was obtained by testing (48 and 128 were not as good).
+ */
+#define VHOST_USER_RX_COPY_THRESHOLD 64
+
#define UNIX_GET_FD(unixfd_idx) \
(unixfd_idx != ~0) ? \
pool_elt_at_index (unix_main.file_pool, \
#define foreach_vhost_user_tx_func_error \
_(NONE, "no error") \
- _(NOT_READY, "vhost user state error") \
+ _(NOT_READY, "vhost vring not ready") \
+ _(DOWN, "vhost interface is down") \
_(PKT_DROP_NOBUF, "tx packet drops (no available descriptors)") \
_(PKT_DROP_NOMRG, "tx packet drops (cannot merge descriptors)") \
_(MMAP_FAIL, "mmap failure") \
}
#define VHOST_LOG_PAGE 0x1000
-always_inline void
-vhost_user_log_dirty_pages (vhost_user_intf_t * vui, u64 addr, u64 len)
+static_always_inline void
+vhost_user_log_dirty_pages_2 (vhost_user_intf_t * vui,
+ u64 addr, u64 len, u8 is_host_address)
{
if (PREDICT_TRUE (vui->log_base_addr == 0
|| !(vui->features & (1 << FEAT_VHOST_F_LOG_ALL))))
{
return;
}
+ if (is_host_address)
+ {
+ addr = (u64) map_user_mem (vui, (uword) addr);
+ }
if (PREDICT_FALSE ((addr + len - 1) / VHOST_LOG_PAGE / 8 >= vui->log_size))
{
DBG_SOCK ("vhost_user_log_dirty_pages(): out of range\n");
}
}
+static_always_inline void
+vhost_user_log_dirty_pages (vhost_user_intf_t * vui, u64 addr, u64 len)
+{
+ vhost_user_log_dirty_pages_2 (vui, addr, len, 0);
+}
+
#define vhost_user_log_dirty_ring(vui, vq, member) \
if (PREDICT_FALSE(vq->log_used)) { \
vhost_user_log_dirty_pages(vui, vq->log_guest_addr + STRUCT_OFFSET_OF(vring_used_t, member), \
vum->coalesce_frames = 32;
vum->coalesce_time = 1e-3;
- vec_validate_aligned (vum->rx_buffers, tm->n_vlib_mains - 1,
- CLIB_CACHE_LINE_BYTES);
vec_validate (vum->cpus, tm->n_vlib_mains - 1);
+ vhost_cpu_t *cpu;
+ vec_foreach (cpu, vum->cpus)
+ {
+ /* This is actually not necessary as validate already zeroes it
+ * Just keeping the loop here for later because I am lazy. */
+ cpu->rx_buffers_len = 0;
+ }
+
/* find out which cpus will be used for input */
vum->input_cpu_first_index = 0;
vum->input_cpu_count = 1;
VLIB_MAIN_LOOP_EXIT_FUNCTION (vhost_user_exit);
-typedef struct
-{
- u16 qid; /** The interface queue index (Not the virtio vring idx) */
- u16 device_index; /** The device index */
- u32 virtio_ring_flags; /** Runtime queue flags **/
- u16 first_desc_len; /** Length of the first data descriptor **/
- virtio_net_hdr_mrg_rxbuf_t hdr; /** Virtio header **/
-} vhost_trace_t;
-
static u8 *
format_vhost_trace (u8 * s, va_list * va)
{
if (txvq->desc[desc_current].flags & VIRTQ_DESC_F_INDIRECT)
{
t->virtio_ring_flags |= 1 << VIRTIO_TRACE_F_INDIRECT;
- //Header is the first here
+ /* Header is the first here */
hdr_desc = map_guest_mem (vui, txvq->desc[desc_current].addr, &hint);
}
if (txvq->desc[desc_current].flags & VIRTQ_DESC_F_NEXT)
vq->int_deadline = vlib_time_now (vm) + vum->coalesce_time;
}
+static_always_inline u32
+vhost_user_input_copy (vhost_user_intf_t * vui, vhost_copy_t * cpy,
+ u16 copy_len, u32 * map_hint)
+{
+ void *src0, *src1, *src2, *src3;
+ if (PREDICT_TRUE (copy_len >= 4))
+ {
+ if (PREDICT_FALSE (!(src2 = map_guest_mem (vui, cpy[0].src, map_hint))))
+ return 1;
+ if (PREDICT_FALSE (!(src3 = map_guest_mem (vui, cpy[1].src, map_hint))))
+ return 1;
+
+ while (PREDICT_TRUE (copy_len >= 4))
+ {
+ src0 = src2;
+ src1 = src3;
+
+ if (PREDICT_FALSE
+ (!(src2 = map_guest_mem (vui, cpy[2].src, map_hint))))
+ return 1;
+ if (PREDICT_FALSE
+ (!(src3 = map_guest_mem (vui, cpy[3].src, map_hint))))
+ return 1;
+
+ CLIB_PREFETCH (src2, 64, LOAD);
+ CLIB_PREFETCH (src3, 64, LOAD);
+
+ clib_memcpy ((void *) cpy[0].dst, src0, cpy[0].len);
+ clib_memcpy ((void *) cpy[1].dst, src1, cpy[1].len);
+ copy_len -= 2;
+ cpy += 2;
+ }
+ }
+ while (copy_len)
+ {
+ if (PREDICT_FALSE (!(src0 = map_guest_mem (vui, cpy->src, map_hint))))
+ return 1;
+ clib_memcpy ((void *) cpy->dst, src0, cpy->len);
+ copy_len -= 1;
+ cpy += 1;
+ }
+ return 0;
+}
+
+/**
+ * Try to discard packets from the tx ring (VPP RX path).
+ * Returns the number of discarded packets.
+ */
+u32
+vhost_user_rx_discard_packet (vlib_main_t * vm,
+ vhost_user_intf_t * vui,
+ vhost_user_vring_t * txvq, u32 discard_max)
+{
+ /*
+ * On the RX side, each packet corresponds to one descriptor
+ * (it is the same whether it is a shallow descriptor, chained, or indirect).
+ * Therefore, discarding a packet is like discarding a descriptor.
+ */
+ u32 discarded_packets = 0;
+ u32 avail_idx = txvq->avail->idx;
+ u16 qsz_mask = txvq->qsz - 1;
+ 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 & qsz_mask];
+ txvq->last_avail_idx++;
+ txvq->used->ring[txvq->last_used_idx & qsz_mask].id = desc_chain_head;
+ txvq->used->ring[txvq->last_used_idx & qsz_mask].len = 0;
+ vhost_user_log_dirty_ring (vui, txvq,
+ ring[txvq->last_used_idx & qsz_mask]);
+ txvq->last_used_idx++;
+ discarded_packets++;
+ }
+
+out:
+ CLIB_MEMORY_BARRIER ();
+ txvq->used->idx = txvq->last_used_idx;
+ vhost_user_log_dirty_ring (vui, txvq, idx);
+ return discarded_packets;
+}
+
+/*
+ * In case of overflow, we need to rewind the array of allocated buffers.
+ */
+static void
+vhost_user_input_rewind_buffers (vlib_main_t * vm,
+ vhost_cpu_t * cpu, vlib_buffer_t * b_head)
+{
+ u32 bi_current = cpu->rx_buffers[cpu->rx_buffers_len];
+ vlib_buffer_t *b_current = vlib_get_buffer (vm, bi_current);
+ b_current->current_length = 0;
+ b_current->flags = 0;
+ while (b_current != b_head)
+ {
+ cpu->rx_buffers_len++;
+ bi_current = cpu->rx_buffers[cpu->rx_buffers_len];
+ b_current = vlib_get_buffer (vm, bi_current);
+ b_current->current_length = 0;
+ b_current->flags = 0;
+ }
+}
static u32
vhost_user_if_input (vlib_main_t * vm,
u16 qid, vlib_node_runtime_t * node)
{
vhost_user_vring_t *txvq = &vui->vrings[VHOST_VRING_IDX_TX (qid)];
- vhost_user_vring_t *rxvq = &vui->vrings[VHOST_VRING_IDX_RX (qid)];
- uword n_rx_packets = 0, n_rx_bytes = 0;
- uword n_left;
+ u16 n_rx_packets = 0;
+ u32 n_rx_bytes = 0;
+ u16 n_left;
u32 n_left_to_next, *to_next;
- u32 next_index = 0;
- u32 next0;
- uword n_trace = vlib_get_trace_count (vm, node);
+ u32 next_index = VNET_DEVICE_INPUT_NEXT_ETHERNET_INPUT;
+ u32 n_trace = vlib_get_trace_count (vm, node);
u16 qsz_mask;
- u32 cpu_index, rx_len, drops, flush;
- f64 now = vlib_time_now (vm);
- u32 map_guest_hint_desc = 0;
- u32 map_guest_hint_indirect = 0;
- u32 *map_guest_hint_p = &map_guest_hint_desc;
+ u32 map_hint = 0;
+ u16 cpu_index = os_get_cpu_number ();
+ u16 copy_len = 0;
- /* do we have pending interrupts ? */
- if ((txvq->n_since_last_int) && (txvq->int_deadline < now))
- vhost_user_send_call (vm, txvq);
+ {
+ /* do we have pending interrupts ? */
+ vhost_user_vring_t *rxvq = &vui->vrings[VHOST_VRING_IDX_RX (qid)];
+ f64 now = vlib_time_now (vm);
+
+ if ((txvq->n_since_last_int) && (txvq->int_deadline < now))
+ vhost_user_send_call (vm, txvq);
- if ((rxvq->n_since_last_int) && (rxvq->int_deadline < now))
- vhost_user_send_call (vm, rxvq);
+ if ((rxvq->n_since_last_int) && (rxvq->int_deadline < now))
+ vhost_user_send_call (vm, rxvq);
+ }
if (PREDICT_FALSE (txvq->avail->flags & 0xFFFE))
return 0;
* client must not supply any new RX packets, but must process
* and discard any TX packets."
*/
-
- txvq->last_avail_idx = txvq->last_used_idx = txvq->avail->idx;
- CLIB_MEMORY_BARRIER ();
- txvq->used->idx = txvq->last_used_idx;
- vhost_user_log_dirty_ring (vui, txvq, idx);
- vhost_user_send_call (vm, txvq);
+ vhost_user_rx_discard_packet (vm, vui, txvq,
+ VHOST_USER_DOWN_DISCARD_COUNT);
return 0;
}
if (PREDICT_FALSE (n_left == txvq->qsz))
{
- //Informational error logging when VPP is not receiving packets fast enough
+ /*
+ * Informational error logging when VPP is not
+ * receiving packets fast enough.
+ */
vlib_error_count (vm, node->node_index,
VHOST_USER_INPUT_FUNC_ERROR_FULL_RX_QUEUE, 1);
}
qsz_mask = txvq->qsz - 1;
- cpu_index = os_get_cpu_number ();
- drops = 0;
- flush = 0;
if (n_left > VLIB_FRAME_SIZE)
n_left = VLIB_FRAME_SIZE;
- /* Allocate some buffers.
- * Note that buffers that are chained for jumbo
- * frames are allocated separately using a slower path.
- * The idea is to be certain to have enough buffers at least
- * to cycle through the descriptors without having to check for errors.
- * For jumbo frames, the bottleneck is memory copy anyway.
+ /*
+ * For small packets (<2kB), we will not need more than one vlib buffer
+ * per packet. In case packets are bigger, we will just yeld at some point
+ * in the loop and come back later. This is not an issue as for big packet,
+ * processing cost really comes from the memory copy.
*/
- if (PREDICT_FALSE (!vum->rx_buffers[cpu_index]))
+ if (PREDICT_FALSE (vum->cpus[cpu_index].rx_buffers_len < n_left + 1))
{
- vec_alloc (vum->rx_buffers[cpu_index], 2 * VLIB_FRAME_SIZE);
-
- if (PREDICT_FALSE (!vum->rx_buffers[cpu_index]))
- flush = n_left; //Drop all input
- }
-
- if (PREDICT_FALSE (_vec_len (vum->rx_buffers[cpu_index]) < n_left))
- {
- u32 curr_len = _vec_len (vum->rx_buffers[cpu_index]);
- _vec_len (vum->rx_buffers[cpu_index]) +=
+ u32 curr_len = vum->cpus[cpu_index].rx_buffers_len;
+ vum->cpus[cpu_index].rx_buffers_len +=
vlib_buffer_alloc_from_free_list (vm,
- vum->rx_buffers[cpu_index] +
+ vum->cpus[cpu_index].rx_buffers +
curr_len,
- 2 * VLIB_FRAME_SIZE - curr_len,
+ VHOST_USER_RX_BUFFERS_N - curr_len,
VLIB_BUFFER_DEFAULT_FREE_LIST_INDEX);
- if (PREDICT_FALSE (n_left > _vec_len (vum->rx_buffers[cpu_index])))
- flush = n_left - _vec_len (vum->rx_buffers[cpu_index]);
- }
-
- if (PREDICT_FALSE (flush))
- {
- //Remove some input buffers
- drops += flush;
- n_left -= flush;
- vlib_error_count (vm, vhost_user_input_node.index,
- VHOST_USER_INPUT_FUNC_ERROR_NO_BUFFER, flush);
- while (flush)
+ if (PREDICT_FALSE
+ (vum->cpus[cpu_index].rx_buffers_len <
+ VHOST_USER_RX_BUFFER_STARVATION))
{
- u16 desc_chain_head =
- txvq->avail->ring[txvq->last_avail_idx & qsz_mask];
- txvq->last_avail_idx++;
- txvq->used->ring[txvq->last_used_idx & qsz_mask].id =
- desc_chain_head;
- txvq->used->ring[txvq->last_used_idx & qsz_mask].len = 0;
- vhost_user_log_dirty_ring (vui, txvq,
- ring[txvq->last_used_idx & qsz_mask]);
- txvq->last_used_idx++;
- flush--;
+ /* In case of buffer starvation, discard some packets from the queue
+ * and log the event.
+ * We keep doing best effort for the remaining packets. */
+ u32 flush = (n_left + 1 > vum->cpus[cpu_index].rx_buffers_len) ?
+ n_left + 1 - vum->cpus[cpu_index].rx_buffers_len : 1;
+ flush = vhost_user_rx_discard_packet (vm, vui, txvq, flush);
+
+ n_left -= flush;
+ vlib_increment_simple_counter (vnet_main.
+ interface_main.sw_if_counters +
+ VNET_INTERFACE_COUNTER_DROP,
+ os_get_cpu_number (),
+ vui->sw_if_index, flush);
+
+ vlib_error_count (vm, vhost_user_input_node.index,
+ VHOST_USER_INPUT_FUNC_ERROR_NO_BUFFER, flush);
}
}
- rx_len = vec_len (vum->rx_buffers[cpu_index]); //vector might be null
while (n_left > 0)
{
vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
while (n_left > 0 && n_left_to_next > 0)
{
vlib_buffer_t *b_head, *b_current;
- u32 bi_head, bi_current;
- u16 desc_chain_head, desc_current;
- u8 error = VHOST_USER_INPUT_FUNC_ERROR_NO_ERROR;
+ u32 bi_current;
+ u16 desc_current;
+ u32 desc_data_offset;
+ vring_desc_t *desc_table = txvq->desc;
- if (PREDICT_TRUE (n_left > 1))
+ if (PREDICT_FALSE (vum->cpus[cpu_index].rx_buffers_len <= 1))
{
- u32 next_desc =
- txvq->avail->ring[(txvq->last_avail_idx + 1) & qsz_mask];
- void *buffer_addr =
- map_guest_mem (vui, txvq->desc[next_desc].addr,
- &map_guest_hint_desc);
- if (PREDICT_TRUE (buffer_addr != 0))
- CLIB_PREFETCH (buffer_addr, 64, STORE);
-
- u32 bi = vum->rx_buffers[cpu_index][rx_len - 2];
- vlib_prefetch_buffer_with_index (vm, bi, STORE);
- CLIB_PREFETCH (vlib_get_buffer (vm, bi)->data, 128, STORE);
+ /* 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;
}
- desc_chain_head = desc_current =
- txvq->avail->ring[txvq->last_avail_idx & qsz_mask];
- bi_head = bi_current = vum->rx_buffers[cpu_index][--rx_len];
- b_head = b_current = vlib_get_buffer (vm, bi_head);
- vlib_buffer_chain_init (b_head);
+ desc_current = txvq->avail->ring[txvq->last_avail_idx & qsz_mask];
+ vum->cpus[cpu_index].rx_buffers_len--;
+ bi_current = (vum->cpus[cpu_index].rx_buffers)
+ [vum->cpus[cpu_index].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,
+ (vum->cpus[cpu_index].rx_buffers)
+ [vum->cpus[cpu_index].
+ rx_buffers_len - 1], LOAD);
+
+ /* Just preset the used descriptor id and length for later */
+ txvq->used->ring[txvq->last_used_idx & qsz_mask].id = desc_current;
+ txvq->used->ring[txvq->last_used_idx & qsz_mask].len = 0;
+ vhost_user_log_dirty_ring (vui, txvq,
+ ring[txvq->last_used_idx & 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_set_trace_count (vm, node, n_trace);
}
- uword offset;
- if (PREDICT_TRUE (vui->is_any_layout) ||
- (!(txvq->desc[desc_current].flags & VIRTQ_DESC_F_NEXT) &&
- !(txvq->desc[desc_current].flags & VIRTQ_DESC_F_INDIRECT)))
- {
- /* ANYLAYOUT or single buffer */
- offset = vui->virtio_net_hdr_sz;
- }
- else
- {
- /* CSR case without ANYLAYOUT, skip 1st buffer */
- offset = txvq->desc[desc_current].len;
- }
-
- vring_desc_t *desc_table = txvq->desc;
- u32 desc_index = desc_current;
- map_guest_hint_p = &map_guest_hint_desc;
-
+ /* 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_guest_hint_desc);
- desc_index = 0;
- map_guest_hint_p = &map_guest_hint_indirect;
+ &map_hint);
+ desc_current = 0;
if (PREDICT_FALSE (desc_table == 0))
{
- error = VHOST_USER_INPUT_FUNC_ERROR_MMAP_FAIL;
+ //FIXME: Handle error by shutdown the queue
goto out;
}
}
- while (1)
+ if (PREDICT_TRUE (vui->is_any_layout) ||
+ (!(desc_table[desc_current].flags & VIRTQ_DESC_F_NEXT)))
{
- void *buffer_addr =
- map_guest_mem (vui, desc_table[desc_index].addr,
- map_guest_hint_p);
- if (PREDICT_FALSE (buffer_addr == 0))
- {
- error = VHOST_USER_INPUT_FUNC_ERROR_MMAP_FAIL;
- goto out;
- }
+ /* 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;
+ }
- if (PREDICT_TRUE
- (desc_table[desc_index].flags & VIRTQ_DESC_F_NEXT))
+ while (1)
+ {
+ /* Get more input if necessary. Or end of packet. */
+ if (desc_data_offset == desc_table[desc_current].len)
{
- CLIB_PREFETCH (&desc_table[desc_table[desc_index].next],
- sizeof (vring_desc_t), STORE);
+ 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;
+ }
}
- if (desc_table[desc_index].len > offset)
+ /* Get more output if necessary. Or end of packet. */
+ if (PREDICT_FALSE
+ (b_current->current_length == VLIB_BUFFER_DATA_SIZE))
{
- u16 len = desc_table[desc_index].len - offset;
- u16 copied = vlib_buffer_chain_append_data_with_alloc (vm,
- VLIB_BUFFER_DEFAULT_FREE_LIST_INDEX,
- b_head,
- &b_current,
- buffer_addr
- +
- offset,
- len);
- if (copied != len)
+ if (PREDICT_FALSE
+ (vum->cpus[cpu_index].rx_buffers_len == 0))
{
- error = VHOST_USER_INPUT_FUNC_ERROR_NO_BUFFER;
- break;
+ /*
+ * 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,
+ &vum->cpus[cpu_index],
+ b_head);
+ n_left = 0;
+ goto stop;
}
+
+ /* Get next output */
+ vum->cpus[cpu_index].rx_buffers_len--;
+ u32 bi_next =
+ (vum->cpus[cpu_index].rx_buffers)[vum->cpus
+ [cpu_index].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);
}
- offset = 0;
- /* if next flag is set, take next desc in the chain */
- if ((desc_table[desc_index].flags & VIRTQ_DESC_F_NEXT))
- desc_index = desc_table[desc_index].next;
- else
- goto out;
+ /* Prepare a copy order executed later for the data */
+ vhost_copy_t *cpy = &vum->cpus[cpu_index].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);
+ 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;
}
+
out:
+ CLIB_PREFETCH (&n_left, sizeof (n_left), LOAD);
+
+ n_rx_bytes += b_head->total_length_not_including_first_buffer;
+ n_rx_packets++;
+
+ b_head->total_length_not_including_first_buffer -=
+ b_head->current_length;
/* consume the descriptor and return it as used */
txvq->last_avail_idx++;
- txvq->used->ring[txvq->last_used_idx & qsz_mask].id =
- desc_chain_head;
- txvq->used->ring[txvq->last_used_idx & qsz_mask].len = 0;
- vhost_user_log_dirty_ring (vui, txvq,
- ring[txvq->last_used_idx & qsz_mask]);
txvq->last_used_idx++;
- //It is important to free RX as fast as possible such that the TX
- //process does not drop packets
- if ((txvq->last_used_idx & 0x3f) == 0) // Every 64 packets
- txvq->used->idx = txvq->last_used_idx;
-
- if (PREDICT_FALSE (b_head->current_length < 14 &&
- error == VHOST_USER_INPUT_FUNC_ERROR_NO_ERROR))
- error = VHOST_USER_INPUT_FUNC_ERROR_UNDERSIZED_FRAME;
-
VLIB_BUFFER_TRACE_TRAJECTORY_INIT (b_head);
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 = node->errors[error];
+ b_head->error = 0;
- if (PREDICT_FALSE (error))
- {
- drops++;
- next0 = VNET_DEVICE_INPUT_NEXT_DROP;
- }
- else
- {
- n_rx_bytes +=
- b_head->current_length +
- b_head->total_length_not_including_first_buffer;
- n_rx_packets++;
- next0 = VNET_DEVICE_INPUT_NEXT_ETHERNET_INPUT;
- }
+ {
+ u32 next0 = VNET_DEVICE_INPUT_NEXT_ETHERNET_INPUT;
- to_next[0] = bi_head;
- to_next++;
- n_left_to_next--;
+ /* redirect if feature path enabled */
+ vnet_feature_start_device_input_x1 (vui->sw_if_index, &next0,
+ b_head, 0);
- /* redirect if feature path enabled */
- vnet_feature_start_device_input_x1 (vui->sw_if_index, &next0,
- b_head, 0);
+ u32 bi = to_next[-1]; //Cannot use to_next[-1] in the macro
+ vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
+ to_next, n_left_to_next,
+ bi, next0);
+ }
- vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
- to_next, n_left_to_next,
- bi_head, next0);
n_left--;
- if (PREDICT_FALSE (!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))
{
- // I NEED SOME MORE !
- u32 remain = (u16) (txvq->avail->idx - txvq->last_avail_idx);
- remain = (remain > VLIB_FRAME_SIZE - n_rx_packets) ?
- VLIB_FRAME_SIZE - n_rx_packets : remain;
- remain = (remain > rx_len) ? rx_len : remain;
- n_left = remain;
+ if (PREDICT_FALSE
+ (vhost_user_input_copy (vui, vum->cpus[cpu_index].copy,
+ copy_len, &map_hint)))
+ {
+ clib_warning
+ ("Memory mapping error on interface hw_if_index=%d "
+ "(Shutting down - Switch interface down and up to restart)",
+ vui->hw_if_index);
+ vui->admin_up = 0;
+ copy_len = 0;
+ break;
+ }
+ 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);
}
- if (PREDICT_TRUE (vum->rx_buffers[cpu_index] != 0))
- _vec_len (vum->rx_buffers[cpu_index]) = rx_len;
+ /* Do the memory copies */
+ if (PREDICT_FALSE
+ (vhost_user_input_copy (vui, vum->cpus[cpu_index].copy,
+ copy_len, &map_hint)))
+ {
+ clib_warning ("Memory mapping error on interface hw_if_index=%d "
+ "(Shutting down - Switch interface down and up to restart)",
+ vui->hw_if_index);
+ vui->admin_up = 0;
+ }
/* give buffers back to driver */
CLIB_MEMORY_BARRIER ();
vhost_user_send_call (vm, txvq);
}
- if (PREDICT_FALSE (drops))
- {
- vlib_increment_simple_counter
- (vnet_main.interface_main.sw_if_counters
- + VNET_INTERFACE_COUNTER_DROP, os_get_cpu_number (),
- vui->sw_if_index, drops);
- }
-
/* increase rx counters */
vlib_increment_combined_counter
(vnet_main.interface_main.combined_sw_if_counters
n_rx_packets += vhost_user_if_input (vm, vum, vui, vhiq->qid, node);
}
- //TODO: One call might return more than 256 packets here.
- //But this is supposed to be the vector size.
return n_rx_packets;
}
if (rxvq->desc[desc_current].flags & VIRTQ_DESC_F_INDIRECT)
{
t->virtio_ring_flags |= 1 << VIRTIO_TRACE_F_INDIRECT;
- //Header is the first here
+ /* Header is the first here */
hdr_desc = map_guest_mem (vui, rxvq->desc[desc_current].addr, &hint);
}
if (rxvq->desc[desc_current].flags & VIRTQ_DESC_F_NEXT)
t->first_desc_len = hdr_desc ? hdr_desc->len : 0;
}
+static_always_inline u32
+vhost_user_tx_copy (vhost_user_intf_t * vui, vhost_copy_t * cpy,
+ u16 copy_len, u32 * map_hint)
+{
+ void *dst0, *dst1, *dst2, *dst3;
+ if (PREDICT_TRUE (copy_len >= 4))
+ {
+ if (PREDICT_FALSE (!(dst2 = map_guest_mem (vui, cpy[0].dst, map_hint))))
+ return 1;
+ if (PREDICT_FALSE (!(dst3 = map_guest_mem (vui, cpy[1].dst, map_hint))))
+ return 1;
+ while (PREDICT_TRUE (copy_len >= 4))
+ {
+ dst0 = dst2;
+ dst1 = dst3;
+
+ if (PREDICT_FALSE
+ (!(dst2 = map_guest_mem (vui, cpy[2].dst, map_hint))))
+ return 1;
+ if (PREDICT_FALSE
+ (!(dst3 = map_guest_mem (vui, cpy[3].dst, map_hint))))
+ return 1;
+
+ CLIB_PREFETCH ((void *) cpy[2].src, 64, LOAD);
+ CLIB_PREFETCH ((void *) cpy[3].src, 64, LOAD);
+
+ clib_memcpy (dst0, (void *) cpy[0].src, cpy[0].len);
+ clib_memcpy (dst1, (void *) cpy[1].src, cpy[1].len);
+
+ vhost_user_log_dirty_pages_2 (vui, cpy[0].dst, cpy[0].len, 1);
+ vhost_user_log_dirty_pages_2 (vui, cpy[1].dst, cpy[1].len, 1);
+ copy_len -= 2;
+ cpy += 2;
+ }
+ }
+ while (copy_len)
+ {
+ if (PREDICT_FALSE (!(dst0 = map_guest_mem (vui, cpy->dst, map_hint))))
+ return 1;
+ clib_memcpy (dst0, (void *) cpy->src, cpy->len);
+ vhost_user_log_dirty_pages_2 (vui, cpy->dst, cpy->len, 1);
+ copy_len -= 1;
+ cpy += 1;
+ }
+ return 0;
+}
+
+
static uword
vhost_user_tx (vlib_main_t * vm,
vlib_node_runtime_t * node, vlib_frame_t * frame)
{
u32 *buffers = vlib_frame_args (frame);
- u32 n_left = 0;
+ u32 n_left = frame->n_vectors;
vhost_user_main_t *vum = &vhost_user_main;
- uword n_packets = 0;
vnet_interface_output_runtime_t *rd = (void *) node->runtime_data;
vhost_user_intf_t *vui =
pool_elt_at_index (vum->vhost_user_interfaces, rd->dev_instance);
u32 qid = ~0;
vhost_user_vring_t *rxvq;
u16 qsz_mask;
- u8 error = VHOST_USER_TX_FUNC_ERROR_NONE;
+ u8 error;
u32 cpu_index = os_get_cpu_number ();
- n_left = n_packets = frame->n_vectors;
- u32 map_guest_hint_desc = 0;
- u32 map_guest_hint_indirect = 0;
- u32 *map_guest_hint_p = &map_guest_hint_desc;
- vhost_trace_t *current_trace = 0;
- int n_retry;
+ u32 map_hint = 0;
+ u8 retry = 8;
+ u16 copy_len;
+ u16 tx_headers_len;
+
+ if (PREDICT_FALSE (!vui->admin_up))
+ {
+ error = VHOST_USER_TX_FUNC_ERROR_DOWN;
+ goto done3;
+ }
- if (PREDICT_FALSE (!vui->is_up || !vui->admin_up))
+ if (PREDICT_FALSE (!vui->is_up))
{
error = VHOST_USER_TX_FUNC_ERROR_NOT_READY;
goto done3;
}
qid =
- VHOST_VRING_IDX_RX (*vec_elt_at_index (vui->per_cpu_tx_qid, cpu_index));
+ VHOST_VRING_IDX_RX (*vec_elt_at_index
+ (vui->per_cpu_tx_qid, os_get_cpu_number ()));
rxvq = &vui->vrings[qid];
if (PREDICT_FALSE (vui->use_tx_spinlock))
vhost_user_vring_lock (vui, qid);
- if (PREDICT_FALSE ((rxvq->avail->idx == rxvq->last_avail_idx)))
- {
- error = VHOST_USER_TX_FUNC_ERROR_PKT_DROP_NOBUF;
- goto done2;
- }
-
qsz_mask = rxvq->qsz - 1; /* qsz is always power of 2 */
- n_retry = 8;
- while (n_left > 0 && n_retry--)
+retry:
+ error = VHOST_USER_TX_FUNC_ERROR_NONE;
+ tx_headers_len = 0;
+ copy_len = 0;
+ while (n_left > 0)
{
+ vlib_buffer_t *b0, *current_b0;
+ u16 desc_head, desc_index, desc_len;
+ vring_desc_t *desc_table;
+ uword buffer_map_addr;
+ u32 buffer_len;
+ u16 bytes_left;
- while (n_left > 0)
+ if (PREDICT_TRUE (n_left > 1))
+ vlib_prefetch_buffer_with_index (vm, buffers[1], LOAD);
+
+ b0 = vlib_get_buffer (vm, buffers[0]);
+
+ if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
{
- vlib_buffer_t *b0, *current_b0;
- u16 desc_head, desc_index, desc_len;
- vring_desc_t *desc_table;
- void *buffer_addr;
- u32 buffer_len;
+ vum->cpus[cpu_index].current_trace =
+ vlib_add_trace (vm, node, b0,
+ sizeof (*vum->cpus[cpu_index].current_trace));
+ vhost_user_tx_trace (vum->cpus[cpu_index].current_trace,
+ vui, qid / 2, b0, rxvq);
+ }
- b0 = vlib_get_buffer (vm, buffers[0]);
+ if (PREDICT_FALSE (rxvq->last_avail_idx == rxvq->avail->idx))
+ {
+ error = VHOST_USER_TX_FUNC_ERROR_PKT_DROP_NOBUF;
+ goto done;
+ }
- if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
- {
- current_trace = vlib_add_trace (vm, node, b0,
- sizeof (*current_trace));
- vhost_user_tx_trace (current_trace, vui, qid / 2, b0, rxvq);
- }
+ desc_table = rxvq->desc;
+ desc_head = desc_index =
+ rxvq->avail->ring[rxvq->last_avail_idx & qsz_mask];
- if (PREDICT_FALSE (rxvq->last_avail_idx == rxvq->avail->idx))
+ /* Go deeper in case of indirect descriptor
+ * I don't know of any driver providing indirect for RX. */
+ if (PREDICT_FALSE (rxvq->desc[desc_head].flags & VIRTQ_DESC_F_INDIRECT))
+ {
+ if (PREDICT_FALSE
+ (rxvq->desc[desc_head].len < sizeof (vring_desc_t)))
{
- error = VHOST_USER_TX_FUNC_ERROR_PKT_DROP_NOBUF;
+ error = VHOST_USER_TX_FUNC_ERROR_INDIRECT_OVERFLOW;
goto done;
}
-
- desc_table = rxvq->desc;
- map_guest_hint_p = &map_guest_hint_desc;
- desc_head = desc_index =
- rxvq->avail->ring[rxvq->last_avail_idx & qsz_mask];
- if (rxvq->desc[desc_head].flags & VIRTQ_DESC_F_INDIRECT)
- {
- if (PREDICT_FALSE
- (rxvq->desc[desc_head].len < sizeof (vring_desc_t)))
- {
- error = VHOST_USER_TX_FUNC_ERROR_INDIRECT_OVERFLOW;
- goto done;
- }
- if (PREDICT_FALSE
- (!(desc_table =
- map_guest_mem (vui, rxvq->desc[desc_index].addr,
- &map_guest_hint_desc))))
- {
- error = VHOST_USER_TX_FUNC_ERROR_MMAP_FAIL;
- goto done;
- }
- desc_index = 0;
- map_guest_hint_p = &map_guest_hint_indirect;
- }
-
- desc_len = vui->virtio_net_hdr_sz;
-
if (PREDICT_FALSE
- (!(buffer_addr =
- map_guest_mem (vui, desc_table[desc_index].addr,
- map_guest_hint_p))))
+ (!(desc_table =
+ map_guest_mem (vui, rxvq->desc[desc_index].addr,
+ &map_hint))))
{
error = VHOST_USER_TX_FUNC_ERROR_MMAP_FAIL;
goto done;
}
- buffer_len = desc_table[desc_index].len;
-
- CLIB_PREFETCH (buffer_addr, CLIB_CACHE_LINE_BYTES, STORE);
+ desc_index = 0;
+ }
- virtio_net_hdr_mrg_rxbuf_t *hdr =
- (virtio_net_hdr_mrg_rxbuf_t *) buffer_addr;
- hdr->hdr.flags = 0;
- hdr->hdr.gso_type = 0;
- if (vui->virtio_net_hdr_sz == 12)
- hdr->num_buffers = 1;
+ desc_len = vui->virtio_net_hdr_sz;
+ buffer_map_addr = desc_table[desc_index].addr;
+ buffer_len = desc_table[desc_index].len;
- vhost_user_log_dirty_pages (vui, desc_table[desc_index].addr,
- vui->virtio_net_hdr_sz);
+ {
+ // Get a header from the header array
+ virtio_net_hdr_mrg_rxbuf_t *hdr =
+ &vum->cpus[cpu_index].tx_headers[tx_headers_len];
+ tx_headers_len++;
+ hdr->hdr.flags = 0;
+ hdr->hdr.gso_type = 0;
+ hdr->num_buffers = 1; //This is local, no need to check
+
+ // Prepare a copy order executed later for the header
+ vhost_copy_t *cpy = &vum->cpus[cpu_index].copy[copy_len];
+ copy_len++;
+ cpy->len = vui->virtio_net_hdr_sz;
+ cpy->dst = buffer_map_addr;
+ cpy->src = (uword) hdr;
+ }
- u16 bytes_left = b0->current_length;
- buffer_addr += vui->virtio_net_hdr_sz;
- buffer_len -= vui->virtio_net_hdr_sz;
- current_b0 = b0;
- while (1)
- {
- if (!bytes_left)
- { //Get new input
- if (current_b0->flags & VLIB_BUFFER_NEXT_PRESENT)
- {
- current_b0 =
- vlib_get_buffer (vm, current_b0->next_buffer);
- bytes_left = current_b0->current_length;
- }
- else
- {
- //End of packet
- break;
- }
+ buffer_map_addr += vui->virtio_net_hdr_sz;
+ buffer_len -= vui->virtio_net_hdr_sz;
+ bytes_left = b0->current_length;
+ current_b0 = b0;
+ while (1)
+ {
+ if (buffer_len == 0)
+ { //Get new output
+ if (desc_table[desc_index].flags & VIRTQ_DESC_F_NEXT)
+ {
+ //Next one is chained
+ desc_index = desc_table[desc_index].next;
+ buffer_map_addr = desc_table[desc_index].addr;
+ buffer_len = desc_table[desc_index].len;
}
-
- if (buffer_len == 0)
- { //Get new output
- if (desc_table[desc_index].flags & VIRTQ_DESC_F_NEXT)
+ else if (vui->virtio_net_hdr_sz == 12) //MRG is available
+ {
+ virtio_net_hdr_mrg_rxbuf_t *hdr =
+ &vum->cpus[cpu_index].tx_headers[tx_headers_len - 1];
+
+ //Move from available to used buffer
+ rxvq->used->ring[rxvq->last_used_idx & qsz_mask].id =
+ desc_head;
+ rxvq->used->ring[rxvq->last_used_idx & qsz_mask].len =
+ desc_len;
+ vhost_user_log_dirty_ring (vui, rxvq,
+ ring[rxvq->last_used_idx &
+ qsz_mask]);
+
+ rxvq->last_avail_idx++;
+ rxvq->last_used_idx++;
+ hdr->num_buffers++;
+ desc_len = 0;
+
+ if (PREDICT_FALSE
+ (rxvq->last_avail_idx == rxvq->avail->idx))
{
- //Next one is chained
- desc_index = desc_table[desc_index].next;
- if (PREDICT_FALSE
- (!(buffer_addr =
- map_guest_mem (vui, desc_table[desc_index].addr,
- map_guest_hint_p))))
- {
- rxvq->last_used_idx -= hdr->num_buffers - 1;
- rxvq->last_avail_idx -= hdr->num_buffers - 1;
- error = VHOST_USER_TX_FUNC_ERROR_MMAP_FAIL;
- goto done;
- }
- buffer_len = desc_table[desc_index].len;
+ //Dequeue queued descriptors for this packet
+ rxvq->last_used_idx -= hdr->num_buffers - 1;
+ rxvq->last_avail_idx -= hdr->num_buffers - 1;
+ error = VHOST_USER_TX_FUNC_ERROR_PKT_DROP_NOBUF;
+ goto done;
}
- else if (vui->virtio_net_hdr_sz == 12) //MRG is available
- {
- //Move from available to used buffer
- rxvq->used->ring[rxvq->last_used_idx & qsz_mask].id =
- desc_head;
- rxvq->used->ring[rxvq->last_used_idx & qsz_mask].len =
- desc_len;
- vhost_user_log_dirty_ring (vui, rxvq,
- ring[rxvq->last_used_idx &
- qsz_mask]);
- rxvq->last_avail_idx++;
- rxvq->last_used_idx++;
- hdr->num_buffers++;
+ desc_table = rxvq->desc;
+ desc_head = desc_index =
+ rxvq->avail->ring[rxvq->last_avail_idx & qsz_mask];
+ if (PREDICT_FALSE
+ (rxvq->desc[desc_head].flags & VIRTQ_DESC_F_INDIRECT))
+ {
+ //It is seriously unlikely that a driver will put indirect descriptor
+ //after non-indirect descriptor.
if (PREDICT_FALSE
- (rxvq->last_avail_idx == rxvq->avail->idx))
+ (rxvq->desc[desc_head].len < sizeof (vring_desc_t)))
{
- //Dequeue queued descriptors for this packet
- rxvq->last_used_idx -= hdr->num_buffers - 1;
- rxvq->last_avail_idx -= hdr->num_buffers - 1;
- error = VHOST_USER_TX_FUNC_ERROR_PKT_DROP_NOBUF;
+ error = VHOST_USER_TX_FUNC_ERROR_INDIRECT_OVERFLOW;
goto done;
}
-
- desc_table = rxvq->desc;
- map_guest_hint_p = &map_guest_hint_desc;
- desc_head = desc_index =
- rxvq->avail->ring[rxvq->last_avail_idx & qsz_mask];
- if (PREDICT_FALSE
- (rxvq->
- desc[desc_head].flags & VIRTQ_DESC_F_INDIRECT))
- {
- //It is seriously unlikely that a driver will put indirect descriptor
- //after non-indirect descriptor.
- if (PREDICT_FALSE
- (rxvq->desc[desc_head].len <
- sizeof (vring_desc_t)))
- {
- error =
- VHOST_USER_TX_FUNC_ERROR_INDIRECT_OVERFLOW;
- goto done;
- }
- if (PREDICT_FALSE
- (!(desc_table =
- map_guest_mem (vui,
- rxvq->desc[desc_index].addr,
- &map_guest_hint_desc))))
- {
- error = VHOST_USER_TX_FUNC_ERROR_MMAP_FAIL;
- goto done;
- }
- desc_index = 0;
- map_guest_hint_p = &map_guest_hint_indirect;
- }
-
if (PREDICT_FALSE
- (!(buffer_addr =
- map_guest_mem (vui, desc_table[desc_index].addr,
- map_guest_hint_p))))
+ (!(desc_table =
+ map_guest_mem (vui,
+ rxvq->desc[desc_index].addr,
+ &map_hint))))
{
error = VHOST_USER_TX_FUNC_ERROR_MMAP_FAIL;
goto done;
}
- buffer_len = desc_table[desc_index].len;
- CLIB_PREFETCH (buffer_addr, CLIB_CACHE_LINE_BYTES,
- STORE);
- }
- else
- {
- error = VHOST_USER_TX_FUNC_ERROR_PKT_DROP_NOMRG;
- goto done;
+ desc_index = 0;
}
+ buffer_map_addr = desc_table[desc_index].addr;
+ buffer_len = desc_table[desc_index].len;
+ }
+ else
+ {
+ error = VHOST_USER_TX_FUNC_ERROR_PKT_DROP_NOMRG;
+ goto done;
}
-
- u16 bytes_to_copy = bytes_left;
- bytes_to_copy =
- (bytes_to_copy > buffer_len) ? buffer_len : bytes_to_copy;
- clib_memcpy (buffer_addr,
- vlib_buffer_get_current (current_b0) +
- current_b0->current_length - bytes_left,
- bytes_to_copy);
-
- vhost_user_log_dirty_pages (vui,
- desc_table[desc_index].addr +
- desc_table[desc_index].len -
- bytes_left - bytes_to_copy,
- bytes_to_copy);
-
- CLIB_PREFETCH (rxvq, sizeof (*rxvq), STORE);
- bytes_left -= bytes_to_copy;
- buffer_len -= bytes_to_copy;
- buffer_addr += bytes_to_copy;
- desc_len += bytes_to_copy;
}
- //Move from available to used ring
- rxvq->used->ring[rxvq->last_used_idx & qsz_mask].id = desc_head;
- rxvq->used->ring[rxvq->last_used_idx & qsz_mask].len = desc_len;
- vhost_user_log_dirty_ring (vui, rxvq,
- ring[rxvq->last_used_idx & qsz_mask]);
+ {
+ vhost_copy_t *cpy = &vum->cpus[cpu_index].copy[copy_len];
+ copy_len++;
+ cpy->len = bytes_left;
+ cpy->len = (cpy->len > buffer_len) ? buffer_len : cpy->len;
+ cpy->dst = buffer_map_addr;
+ cpy->src = (uword) vlib_buffer_get_current (current_b0) +
+ current_b0->current_length - bytes_left;
+
+ bytes_left -= cpy->len;
+ buffer_len -= cpy->len;
+ buffer_map_addr += cpy->len;
+ desc_len += cpy->len;
+
+ CLIB_PREFETCH (&rxvq->desc, sizeof (&rxvq->desc), LOAD);
+ }
- rxvq->last_avail_idx++;
- rxvq->last_used_idx++;
+ // Check if vlib buffer has more data. If not, get more or break.
+ if (PREDICT_TRUE (!bytes_left))
+ {
+ if (PREDICT_FALSE
+ (current_b0->flags & VLIB_BUFFER_NEXT_PRESENT))
+ {
+ current_b0 = vlib_get_buffer (vm, current_b0->next_buffer);
+ bytes_left = current_b0->current_length;
+ }
+ else
+ {
+ //End of packet
+ break;
+ }
+ }
+ }
- if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
- current_trace->hdr = *hdr;
+ //Move from available to used ring
+ rxvq->used->ring[rxvq->last_used_idx & qsz_mask].id = desc_head;
+ rxvq->used->ring[rxvq->last_used_idx & qsz_mask].len = desc_len;
+ vhost_user_log_dirty_ring (vui, rxvq,
+ ring[rxvq->last_used_idx & qsz_mask]);
+ rxvq->last_avail_idx++;
+ rxvq->last_used_idx++;
- buffers++;
- n_left--; //At the end for error counting when 'goto done' is invoked
+ if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
+ {
+ vum->cpus[cpu_index].current_trace->hdr =
+ vum->cpus[cpu_index].tx_headers[tx_headers_len - 1];
}
- done:
- CLIB_MEMORY_BARRIER ();
- rxvq->used->idx = rxvq->last_used_idx;
- vhost_user_log_dirty_ring (vui, rxvq, idx);
+ n_left--; //At the end for error counting when 'goto done' is invoked
+ buffers++;
+ }
+
+done:
+ //Do the memory copies
+ if (PREDICT_FALSE
+ (vhost_user_tx_copy (vui, vum->cpus[cpu_index].copy,
+ copy_len, &map_hint)))
+ {
+ clib_warning ("Memory mapping error on interface hw_if_index=%d "
+ "(Shutting down - Switch interface down and up to restart)",
+ vui->hw_if_index);
+ vui->admin_up = 0;
+ }
+
+ CLIB_MEMORY_BARRIER ();
+ rxvq->used->idx = rxvq->last_used_idx;
+ vhost_user_log_dirty_ring (vui, rxvq, idx);
+
+ /*
+ * When n_left is set, error is always set to something too.
+ * In case error is due to lack of remaining buffers, we go back up and
+ * retry.
+ * The idea is that it is better to waste some time on packets
+ * that have been processed already than dropping them and get
+ * more fresh packets with a good likelyhood that they will be dropped too.
+ * This technique also gives more time to VM driver to pick-up packets.
+ * In case the traffic flows from physical to virtual interfaces, this
+ * technique will end-up leveraging the physical NIC buffer in order to
+ * absorb the VM's CPU jitter.
+ */
+ if (n_left && (error == VHOST_USER_TX_FUNC_ERROR_PKT_DROP_NOBUF) && retry)
+ {
+ retry--;
+ goto retry;
}
/* interrupt (call) handling */
if ((rxvq->callfd_idx != ~0) && !(rxvq->avail->flags & 1))
{
- rxvq->n_since_last_int += n_packets - n_left;
+ rxvq->n_since_last_int += frame->n_vectors - n_left;
if (rxvq->n_since_last_int > vum->coalesce_frames)
vhost_user_send_call (vm, rxvq);
}
-done2:
vhost_user_vring_unlock (vui, qid);
done3:
Code Review / vpp.git / commitdiff