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gerrit.nordix.org / fdio / vpp / 36f7a6aeb021a549f2d684868303c9891bc0dd00 / . / src / vnet / devices / virtio / vhost_user_output.c
blob: 59ea8104d5b3a95c21f044a636da66aaccafa9ef [file] [log] [blame]
/*
*------------------------------------------------------------------
* vhost-user-output
*
* Copyright (c) 2014-2018 Cisco and/or its affiliates.
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at:
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*------------------------------------------------------------------
*/
#include <stddef.h>
#include <fcntl.h> /* for open */
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/uio.h> /* for iovec */
#include <netinet/in.h>
#include <sys/vfs.h>
#include <linux/if_arp.h>
#include <linux/if_tun.h>
#include <vlib/vlib.h>
#include <vlib/unix/unix.h>
#include <vnet/ethernet/ethernet.h>
#include <vnet/devices/devices.h>
#include <vnet/feature/feature.h>
#include <vnet/devices/virtio/vhost_user.h>
#include <vnet/devices/virtio/vhost_user_inline.h>
#include <vnet/gso/hdr_offset_parser.h>
/*
* On the transmit side, we keep processing the buffers from vlib in the while
* loop and prepare the copy order to be executed later. However, the static
* array which we keep the copy order is limited to VHOST_USER_COPY_ARRAY_N
* entries. In order to not corrupt memory, we have to do the copy when the
* static array reaches the copy threshold. We subtract 40 in case the code
* goes into the inner loop for a maximum of 64k frames which may require
* more array entries. We subtract 200 because our default buffer size is
* 2048 and the default desc len is likely 1536. While it takes less than 40
* vlib buffers for the jumbo frame, it may take twice as much descriptors
* for the same jumbo frame. Use 200 for the extra head room.
*/
#define VHOST_USER_TX_COPY_THRESHOLD (VHOST_USER_COPY_ARRAY_N - 200)
extern vnet_device_class_t vhost_user_device_class;
#define foreach_vhost_user_tx_func_error \
_(NONE, "no 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") \
_(INDIRECT_OVERFLOW, "indirect descriptor table overflow")
typedef enum
{
#define _(f,s) VHOST_USER_TX_FUNC_ERROR_##f,
foreach_vhost_user_tx_func_error
#undef _
VHOST_USER_TX_FUNC_N_ERROR,
} vhost_user_tx_func_error_t;
static __clib_unused char *vhost_user_tx_func_error_strings[] = {
#define _(n,s) s,
foreach_vhost_user_tx_func_error
#undef _
};
static __clib_unused u8 *
format_vhost_user_interface_name (u8 * s, va_list * args)
{
u32 i = va_arg (*args, u32);
u32 show_dev_instance = ~0;
vhost_user_main_t *vum = &vhost_user_main;
if (i < vec_len (vum->show_dev_instance_by_real_dev_instance))
show_dev_instance = vum->show_dev_instance_by_real_dev_instance[i];
if (show_dev_instance != ~0)
i = show_dev_instance;
s = format (s, "VirtualEthernet0/0/%d", i);
return s;
}
static __clib_unused int
vhost_user_name_renumber (vnet_hw_interface_t * hi, u32 new_dev_instance)
{
// FIXME: check if the new dev instance is already used
vhost_user_main_t *vum = &vhost_user_main;
vhost_user_intf_t *vui = pool_elt_at_index (vum->vhost_user_interfaces,
hi->dev_instance);
vec_validate_init_empty (vum->show_dev_instance_by_real_dev_instance,
hi->dev_instance, ~0);
vum->show_dev_instance_by_real_dev_instance[hi->dev_instance] =
new_dev_instance;
vu_log_debug (vui, "renumbered vhost-user interface dev_instance %d to %d",
hi->dev_instance, new_dev_instance);
return 0;
}
/**
* @brief Spin until the vring is successfully locked
*/
static_always_inline void
vhost_user_vring_lock (vhost_user_intf_t * vui, u32 qid)
{
clib_spinlock_lock_if_init (&vui->vrings[qid].vring_lock);
}
/**
* @brief Unlock the vring lock
*/
static_always_inline void
vhost_user_vring_unlock (vhost_user_intf_t * vui, u32 qid)
{
clib_spinlock_unlock_if_init (&vui->vrings[qid].vring_lock);
}
static_always_inline void
vhost_user_tx_trace (vhost_trace_t * t,
vhost_user_intf_t * vui, u16 qid,
vlib_buffer_t * b, vhost_user_vring_t * rxvq)
{
vhost_user_main_t *vum = &vhost_user_main;
u32 last_avail_idx = rxvq->last_avail_idx;
u32 desc_current = rxvq->avail->ring[last_avail_idx & rxvq->qsz_mask];
vring_desc_t *hdr_desc = 0;
u32 hint = 0;
clib_memset (t, 0, sizeof (*t));
t->device_index = vui - vum->vhost_user_interfaces;
t->qid = qid;
hdr_desc = &rxvq->desc[desc_current];
if (rxvq->desc[desc_current].flags & VRING_DESC_F_INDIRECT)
{
t->virtio_ring_flags |= 1 << VIRTIO_TRACE_F_INDIRECT;
/* Header is the first here */
hdr_desc = map_guest_mem (vui, rxvq->desc[desc_current].addr, &hint);
}
if (rxvq->desc[desc_current].flags & VRING_DESC_F_NEXT)
{
t->virtio_ring_flags |= 1 << VIRTIO_TRACE_F_SIMPLE_CHAINED;
}
if (!(rxvq->desc[desc_current].flags & VRING_DESC_F_NEXT) &&
!(rxvq->desc[desc_current].flags & VRING_DESC_F_INDIRECT))
{
t->virtio_ring_flags |= 1 << VIRTIO_TRACE_F_SINGLE_DESC;
}
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_fast (dst0, (void *) cpy[0].src, cpy[0].len);
clib_memcpy_fast (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_fast (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_always_inline void
vhost_user_handle_tx_offload (vhost_user_intf_t * vui, vlib_buffer_t * b,
virtio_net_hdr_t * hdr)
{
generic_header_offset_t gho = { 0 };
int is_ip4 = b->flags & VNET_BUFFER_F_IS_IP4;
int is_ip6 = b->flags & VNET_BUFFER_F_IS_IP6;
vnet_buffer_oflags_t oflags = vnet_buffer (b)->oflags;
ASSERT (!(is_ip4 && is_ip6));
vnet_generic_header_offset_parser (b, &gho, 1 /* l2 */ , is_ip4, is_ip6);
if (oflags & VNET_BUFFER_OFFLOAD_F_IP_CKSUM)
{
ip4_header_t *ip4;
ip4 =
(ip4_header_t *) (vlib_buffer_get_current (b) + gho.l3_hdr_offset);
ip4->checksum = ip4_header_checksum (ip4);
}
/* checksum offload */
if (oflags & VNET_BUFFER_OFFLOAD_F_UDP_CKSUM)
{
hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
hdr->csum_start = gho.l4_hdr_offset;
hdr->csum_offset = offsetof (udp_header_t, checksum);
}
else if (oflags & VNET_BUFFER_OFFLOAD_F_TCP_CKSUM)
{
hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
hdr->csum_start = gho.l4_hdr_offset;
hdr->csum_offset = offsetof (tcp_header_t, checksum);
}
/* GSO offload */
if (b->flags & VNET_BUFFER_F_GSO)
{
if (oflags & VNET_BUFFER_OFFLOAD_F_TCP_CKSUM)
{
if (is_ip4 &&
(vui->features & VIRTIO_FEATURE (VIRTIO_NET_F_GUEST_TSO4)))
{
hdr->gso_size = vnet_buffer2 (b)->gso_size;
hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
}
else if (is_ip6 &&
(vui->features & VIRTIO_FEATURE (VIRTIO_NET_F_GUEST_TSO6)))
{
hdr->gso_size = vnet_buffer2 (b)->gso_size;
hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
}
}
else if ((vui->features & VIRTIO_FEATURE (VIRTIO_NET_F_GUEST_UFO)) &&
(oflags & VNET_BUFFER_OFFLOAD_F_UDP_CKSUM))
{
hdr->gso_size = vnet_buffer2 (b)->gso_size;
hdr->gso_type = VIRTIO_NET_HDR_GSO_UDP;
}
}
}
static_always_inline void
vhost_user_mark_desc_available (vlib_main_t * vm, vhost_user_intf_t * vui,
vhost_user_vring_t * rxvq,
u16 * n_descs_processed, u8 chained,
vlib_frame_t * frame, u32 n_left)
{
u16 desc_idx, flags;
vring_packed_desc_t *desc_table = rxvq->packed_desc;
u16 last_used_idx = rxvq->last_used_idx;
if (PREDICT_FALSE (*n_descs_processed == 0))
return;
if (rxvq->used_wrap_counter)
flags = desc_table[last_used_idx & rxvq->qsz_mask].flags |
(VRING_DESC_F_AVAIL | VRING_DESC_F_USED);
else
flags = desc_table[last_used_idx & rxvq->qsz_mask].flags &
~(VRING_DESC_F_AVAIL | VRING_DESC_F_USED);
vhost_user_advance_last_used_idx (rxvq);
for (desc_idx = 1; desc_idx < *n_descs_processed; desc_idx++)
{
if (rxvq->used_wrap_counter)
desc_table[rxvq->last_used_idx & rxvq->qsz_mask].flags |=
(VRING_DESC_F_AVAIL | VRING_DESC_F_USED);
else
desc_table[rxvq->last_used_idx & rxvq->qsz_mask].flags &=
~(VRING_DESC_F_AVAIL | VRING_DESC_F_USED);
vhost_user_advance_last_used_idx (rxvq);
}
desc_table[last_used_idx & rxvq->qsz_mask].flags = flags;
*n_descs_processed = 0;
if (chained)
{
vring_packed_desc_t *desc_table = rxvq->packed_desc;
while (desc_table[rxvq->last_used_idx & rxvq->qsz_mask].flags &
VRING_DESC_F_NEXT)
vhost_user_advance_last_used_idx (rxvq);
/* Advance past the current chained table entries */
vhost_user_advance_last_used_idx (rxvq);
}
/* interrupt (call) handling */
if ((rxvq->callfd_idx != ~0) &&
(rxvq->avail_event->flags != VRING_EVENT_F_DISABLE))
{
vhost_user_main_t *vum = &vhost_user_main;
rxvq->n_since_last_int += frame->n_vectors - n_left;
if (rxvq->n_since_last_int > vum->coalesce_frames)
vhost_user_send_call (vm, vui, rxvq);
}
}
static_always_inline void
vhost_user_tx_trace_packed (vhost_trace_t * t, vhost_user_intf_t * vui,
u16 qid, vlib_buffer_t * b,
vhost_user_vring_t * rxvq)
{
vhost_user_main_t *vum = &vhost_user_main;
u32 last_avail_idx = rxvq->last_avail_idx;
u32 desc_current = last_avail_idx & rxvq->qsz_mask;
vring_packed_desc_t *hdr_desc = 0;
u32 hint = 0;
clib_memset (t, 0, sizeof (*t));
t->device_index = vui - vum->vhost_user_interfaces;
t->qid = qid;
hdr_desc = &rxvq->packed_desc[desc_current];
if (rxvq->packed_desc[desc_current].flags & VRING_DESC_F_INDIRECT)
{
t->virtio_ring_flags |= 1 << VIRTIO_TRACE_F_INDIRECT;
/* Header is the first here */
hdr_desc = map_guest_mem (vui, rxvq->packed_desc[desc_current].addr,
&hint);
}
if (rxvq->packed_desc[desc_current].flags & VRING_DESC_F_NEXT)
{
t->virtio_ring_flags |= 1 << VIRTIO_TRACE_F_SIMPLE_CHAINED;
}
if (!(rxvq->packed_desc[desc_current].flags & VRING_DESC_F_NEXT) &&
!(rxvq->packed_desc[desc_current].flags & VRING_DESC_F_INDIRECT))
{
t->virtio_ring_flags |= 1 << VIRTIO_TRACE_F_SINGLE_DESC;
}
t->first_desc_len = hdr_desc ? hdr_desc->len : 0;
}
static_always_inline uword
vhost_user_device_class_packed (vlib_main_t * vm, vlib_node_runtime_t * node,
vlib_frame_t * frame)
{
u32 *buffers = vlib_frame_vector_args (frame);
u32 n_left = frame->n_vectors;
vhost_user_main_t *vum = &vhost_user_main;
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;
vhost_user_vring_t *rxvq;
u8 error;
u32 thread_index = vm->thread_index;
vhost_cpu_t *cpu = &vum->cpus[thread_index];
u32 map_hint = 0;
u8 retry = 8;
u16 copy_len;
u16 tx_headers_len;
vring_packed_desc_t *desc_table;
u32 or_flags;
u16 desc_head, desc_index, desc_len;
u16 n_descs_processed;
u8 indirect, chained;
qid = VHOST_VRING_IDX_RX (*vec_elt_at_index (vui->per_cpu_tx_qid,
thread_index));
rxvq = &vui->vrings[qid];
retry:
error = VHOST_USER_TX_FUNC_ERROR_NONE;
tx_headers_len = 0;
copy_len = 0;
n_descs_processed = 0;
while (n_left > 0)
{
vlib_buffer_t *b0, *current_b0;
uword buffer_map_addr;
u32 buffer_len;
u16 bytes_left;
u32 total_desc_len = 0;
u16 n_entries = 0;
indirect = 0;
chained = 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))
{
cpu->current_trace = vlib_add_trace (vm, node, b0,
sizeof (*cpu->current_trace));
vhost_user_tx_trace_packed (cpu->current_trace, vui, qid / 2, b0,
rxvq);
}
desc_table = rxvq->packed_desc;
desc_head = desc_index = rxvq->last_avail_idx & rxvq->qsz_mask;
if (PREDICT_FALSE (!vhost_user_packed_desc_available (rxvq, desc_head)))
{
error = VHOST_USER_TX_FUNC_ERROR_PKT_DROP_NOBUF;
goto done;
}
/*
* Go deeper in case of indirect descriptor.
* To test it, turn off mrg_rxbuf.
*/
if (desc_table[desc_head].flags & VRING_DESC_F_INDIRECT)
{
indirect = 1;
if (PREDICT_FALSE (desc_table[desc_head].len <
sizeof (vring_packed_desc_t)))
{
error = VHOST_USER_TX_FUNC_ERROR_INDIRECT_OVERFLOW;
goto done;
}
n_entries = desc_table[desc_head].len >> 4;
desc_table = map_guest_mem (vui, desc_table[desc_index].addr,
&map_hint);
if (PREDICT_FALSE (desc_table == 0))
{
error = VHOST_USER_TX_FUNC_ERROR_MMAP_FAIL;
goto done;
}
desc_index = 0;
}
else if (rxvq->packed_desc[desc_head].flags & VRING_DESC_F_NEXT)
chained = 1;
desc_len = vui->virtio_net_hdr_sz;
buffer_map_addr = desc_table[desc_index].addr;
buffer_len = desc_table[desc_index].len;
/* Get a header from the header array */
virtio_net_hdr_mrg_rxbuf_t *hdr = &cpu->tx_headers[tx_headers_len];
tx_headers_len++;
hdr->hdr.flags = 0;
hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE;
hdr->num_buffers = 1;
or_flags = (b0->flags & VNET_BUFFER_F_OFFLOAD);
/* Guest supports csum offload and buffer requires checksum offload? */
if (or_flags &&
(vui->features & VIRTIO_FEATURE (VIRTIO_NET_F_GUEST_CSUM)))
vhost_user_handle_tx_offload (vui, b0, &hdr->hdr);
/* Prepare a copy order executed later for the header */
ASSERT (copy_len < VHOST_USER_COPY_ARRAY_N);
vhost_copy_t *cpy = &cpu->copy[copy_len];
copy_len++;
cpy->len = vui->virtio_net_hdr_sz;
cpy->dst = buffer_map_addr;
cpy->src = (uword) hdr;
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 (chained)
{
/*
* Next one is chained
* Test it with both indirect and mrg_rxbuf off
*/
if (PREDICT_FALSE (!(desc_table[desc_index].flags &
VRING_DESC_F_NEXT)))
{
/*
* Last descriptor in chain.
* Dequeue queued descriptors for this packet
*/
vhost_user_dequeue_chained_descs (rxvq,
&n_descs_processed);
error = VHOST_USER_TX_FUNC_ERROR_PKT_DROP_NOBUF;
goto done;
}
vhost_user_advance_last_avail_idx (rxvq);
desc_index = rxvq->last_avail_idx & rxvq->qsz_mask;
n_descs_processed++;
buffer_map_addr = desc_table[desc_index].addr;
buffer_len = desc_table[desc_index].len;
total_desc_len += desc_len;
desc_len = 0;
}
else if (indirect)
{
/*
* Indirect table
* Test it with mrg_rxnuf off
*/
if (PREDICT_TRUE (n_entries > 0))
n_entries--;
else
{
/* Dequeue queued descriptors for this packet */
vhost_user_dequeue_chained_descs (rxvq,
&n_descs_processed);
error = VHOST_USER_TX_FUNC_ERROR_INDIRECT_OVERFLOW;
goto done;
}
total_desc_len += desc_len;
desc_index = (desc_index + 1) & rxvq->qsz_mask;
buffer_map_addr = desc_table[desc_index].addr;
buffer_len = desc_table[desc_index].len;
desc_len = 0;
}
else if (vui->virtio_net_hdr_sz == 12)
{
/*
* MRG is available
* This is the default setting for the guest VM
*/
virtio_net_hdr_mrg_rxbuf_t *hdr =
&cpu->tx_headers[tx_headers_len - 1];
desc_table[desc_index].len = desc_len;
vhost_user_advance_last_avail_idx (rxvq);
desc_head = desc_index =
rxvq->last_avail_idx & rxvq->qsz_mask;
hdr->num_buffers++;
n_descs_processed++;
desc_len = 0;
if (PREDICT_FALSE (!vhost_user_packed_desc_available
(rxvq, desc_index)))
{
/* Dequeue queued descriptors for this packet */
vhost_user_dequeue_descs (rxvq, hdr,
&n_descs_processed);
error = VHOST_USER_TX_FUNC_ERROR_PKT_DROP_NOBUF;
goto done;
}
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;
}
}
ASSERT (copy_len < VHOST_USER_COPY_ARRAY_N);
vhost_copy_t *cpy = &cpu->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->packed_desc, CLIB_CACHE_LINE_BYTES, LOAD);
/* 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;
}
}
}
/* Move from available to used ring */
total_desc_len += desc_len;
rxvq->packed_desc[desc_head].len = total_desc_len;
vhost_user_advance_last_avail_table_idx (vui, rxvq, chained);
n_descs_processed++;
if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
cpu->current_trace->hdr = cpu->tx_headers[tx_headers_len - 1];
n_left--;
/*
* Do the copy periodically to prevent
* cpu->copy array overflow and corrupt memory
*/
if (PREDICT_FALSE (copy_len >= VHOST_USER_TX_COPY_THRESHOLD) || chained)
{
if (PREDICT_FALSE (vhost_user_tx_copy (vui, cpu->copy, copy_len,
&map_hint)))
vlib_error_count (vm, node->node_index,
VHOST_USER_TX_FUNC_ERROR_MMAP_FAIL, 1);
copy_len = 0;
/* give buffers back to driver */
vhost_user_mark_desc_available (vm, vui, rxvq, &n_descs_processed,
chained, frame, n_left);
}
buffers++;
}
done:
if (PREDICT_TRUE (copy_len))
{
if (PREDICT_FALSE (vhost_user_tx_copy (vui, cpu->copy, copy_len,
&map_hint)))
vlib_error_count (vm, node->node_index,
VHOST_USER_TX_FUNC_ERROR_MMAP_FAIL, 1);
vhost_user_mark_desc_available (vm, vui, rxvq, &n_descs_processed,
chained, frame, n_left);
}
/*
* 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;
}
vhost_user_vring_unlock (vui, qid);
if (PREDICT_FALSE (n_left && error != VHOST_USER_TX_FUNC_ERROR_NONE))
{
vlib_error_count (vm, node->node_index, error, n_left);
vlib_increment_simple_counter
(vnet_main.interface_main.sw_if_counters +
VNET_INTERFACE_COUNTER_DROP, thread_index, vui->sw_if_index, n_left);
}
vlib_buffer_free (vm, vlib_frame_vector_args (frame), frame->n_vectors);
return frame->n_vectors;
}
VNET_DEVICE_CLASS_TX_FN (vhost_user_device_class) (vlib_main_t * vm,
vlib_node_runtime_t *
node, vlib_frame_t * frame)
{
u32 *buffers = vlib_frame_vector_args (frame);
u32 n_left = frame->n_vectors;
vhost_user_main_t *vum = &vhost_user_main;
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;
u8 error;
u32 thread_index = vm->thread_index;
vhost_cpu_t *cpu = &vum->cpus[thread_index];
u32 map_hint = 0;
u8 retry = 8;
u16 copy_len;
u16 tx_headers_len;
u32 or_flags;
if (PREDICT_FALSE (!vui->admin_up))
{
error = VHOST_USER_TX_FUNC_ERROR_DOWN;
goto done3;
}
if (PREDICT_FALSE (!vui->is_ready))
{
error = VHOST_USER_TX_FUNC_ERROR_NOT_READY;
goto done3;
}
qid = VHOST_VRING_IDX_RX (*vec_elt_at_index (vui->per_cpu_tx_qid,
thread_index));
rxvq = &vui->vrings[qid];
if (PREDICT_FALSE (rxvq->avail == 0))
{
error = VHOST_USER_TX_FUNC_ERROR_MMAP_FAIL;
goto done3;
}
if (PREDICT_FALSE (vui->use_tx_spinlock))
vhost_user_vring_lock (vui, qid);
if (vhost_user_is_packed_ring_supported (vui))
return (vhost_user_device_class_packed (vm, node, frame));
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;
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))
{
cpu->current_trace = vlib_add_trace (vm, node, b0,
sizeof (*cpu->current_trace));
vhost_user_tx_trace (cpu->current_trace, vui, qid / 2, b0, rxvq);
}
if (PREDICT_FALSE (rxvq->last_avail_idx == rxvq->avail->idx))
{
error = VHOST_USER_TX_FUNC_ERROR_PKT_DROP_NOBUF;
goto done;
}
desc_table = rxvq->desc;
desc_head = desc_index =
rxvq->avail->ring[rxvq->last_avail_idx & rxvq->qsz_mask];
/* 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 & VRING_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_hint))))
{
error = VHOST_USER_TX_FUNC_ERROR_MMAP_FAIL;
goto done;
}
desc_index = 0;
}
desc_len = vui->virtio_net_hdr_sz;
buffer_map_addr = desc_table[desc_index].addr;
buffer_len = desc_table[desc_index].len;
{
// Get a header from the header array
virtio_net_hdr_mrg_rxbuf_t *hdr = &cpu->tx_headers[tx_headers_len];
tx_headers_len++;
hdr->hdr.flags = 0;
hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE;
hdr->num_buffers = 1; //This is local, no need to check
or_flags = (b0->flags & VNET_BUFFER_F_OFFLOAD);
/* Guest supports csum offload and buffer requires checksum offload? */
if (or_flags
&& (vui->features & VIRTIO_FEATURE (VIRTIO_NET_F_GUEST_CSUM)))
vhost_user_handle_tx_offload (vui, b0, &hdr->hdr);
// Prepare a copy order executed later for the header
ASSERT (copy_len < VHOST_USER_COPY_ARRAY_N);
vhost_copy_t *cpy = &cpu->copy[copy_len];
copy_len++;
cpy->len = vui->virtio_net_hdr_sz;
cpy->dst = buffer_map_addr;
cpy->src = (uword) hdr;
}
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 & VRING_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;
}
else if (vui->virtio_net_hdr_sz == 12) //MRG is available
{
virtio_net_hdr_mrg_rxbuf_t *hdr =
&cpu->tx_headers[tx_headers_len - 1];
//Move from available to used buffer
rxvq->used->ring[rxvq->last_used_idx & rxvq->qsz_mask].id =
desc_head;
rxvq->used->ring[rxvq->last_used_idx & rxvq->qsz_mask].len =
desc_len;
vhost_user_log_dirty_ring (vui, rxvq,
ring[rxvq->last_used_idx &
rxvq->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))
{
//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;
}
desc_table = rxvq->desc;
desc_head = desc_index =
rxvq->avail->ring[rxvq->last_avail_idx & rxvq->qsz_mask];
if (PREDICT_FALSE
(rxvq->desc[desc_head].flags & VRING_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_hint))))
{
error = VHOST_USER_TX_FUNC_ERROR_MMAP_FAIL;
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;
}
}
{
ASSERT (copy_len < VHOST_USER_COPY_ARRAY_N);
vhost_copy_t *cpy = &cpu->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, CLIB_CACHE_LINE_BYTES, LOAD);
}
// 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;
}
}
}
//Move from available to used ring
rxvq->used->ring[rxvq->last_used_idx & rxvq->qsz_mask].id = desc_head;
rxvq->used->ring[rxvq->last_used_idx & rxvq->qsz_mask].len = desc_len;
vhost_user_log_dirty_ring (vui, rxvq,
ring[rxvq->last_used_idx & rxvq->qsz_mask]);
rxvq->last_avail_idx++;
rxvq->last_used_idx++;
if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
{
cpu->current_trace->hdr = cpu->tx_headers[tx_headers_len - 1];
}
n_left--; //At the end for error counting when 'goto done' is invoked
/*
* Do the copy periodically to prevent
* cpu->copy array overflow and corrupt memory
*/
if (PREDICT_FALSE (copy_len >= VHOST_USER_TX_COPY_THRESHOLD))
{
if (PREDICT_FALSE (vhost_user_tx_copy (vui, cpu->copy, copy_len,
&map_hint)))
{
vlib_error_count (vm, node->node_index,
VHOST_USER_TX_FUNC_ERROR_MMAP_FAIL, 1);
}
copy_len = 0;
/* give buffers back to driver */
CLIB_MEMORY_BARRIER ();
rxvq->used->idx = rxvq->last_used_idx;
vhost_user_log_dirty_ring (vui, rxvq, idx);
}
buffers++;
}
done:
//Do the memory copies
if (PREDICT_FALSE (vhost_user_tx_copy (vui, cpu->copy, copy_len,
&map_hint)))
{
vlib_error_count (vm, node->node_index,
VHOST_USER_TX_FUNC_ERROR_MMAP_FAIL, 1);
}
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 likelihood 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 & VRING_AVAIL_F_NO_INTERRUPT))
{
rxvq->n_since_last_int += frame->n_vectors - n_left;
if (rxvq->n_since_last_int > vum->coalesce_frames)
vhost_user_send_call (vm, vui, rxvq);
}
vhost_user_vring_unlock (vui, qid);
done3:
if (PREDICT_FALSE (n_left && error != VHOST_USER_TX_FUNC_ERROR_NONE))
{
vlib_error_count (vm, node->node_index, error, n_left);
vlib_increment_simple_counter
(vnet_main.interface_main.sw_if_counters
+ VNET_INTERFACE_COUNTER_DROP,
thread_index, vui->sw_if_index, n_left);
}
vlib_buffer_free (vm, vlib_frame_vector_args (frame), frame->n_vectors);
return frame->n_vectors;
}
static __clib_unused clib_error_t *
vhost_user_interface_rx_mode_change (vnet_main_t * vnm, u32 hw_if_index,
u32 qid, vnet_hw_if_rx_mode mode)
{
vlib_main_t *vm = vnm->vlib_main;
vnet_hw_interface_t *hif = vnet_get_hw_interface (vnm, hw_if_index);
vhost_user_main_t *vum = &vhost_user_main;
vhost_user_intf_t *vui =
pool_elt_at_index (vum->vhost_user_interfaces, hif->dev_instance);
vhost_user_vring_t *txvq = &vui->vrings[VHOST_VRING_IDX_TX (qid)];
if ((mode == VNET_HW_IF_RX_MODE_INTERRUPT) ||
(mode == VNET_HW_IF_RX_MODE_ADAPTIVE))
{
if (txvq->kickfd_idx == ~0)
{
// We cannot support interrupt mode if the driver opts out
return clib_error_return (0, "Driver does not support interrupt");
}
if (txvq->mode == VNET_HW_IF_RX_MODE_POLLING)
{
vum->ifq_count++;
// Start the timer if this is the first encounter on interrupt
// interface/queue
if ((vum->ifq_count == 1) &&
(vum->coalesce_time > 0.0) && (vum->coalesce_frames > 0))
vlib_process_signal_event (vm,
vhost_user_send_interrupt_node.index,
VHOST_USER_EVENT_START_TIMER, 0);
}
}
else if (mode == VNET_HW_IF_RX_MODE_POLLING)
{
if (((txvq->mode == VNET_HW_IF_RX_MODE_INTERRUPT) ||
(txvq->mode == VNET_HW_IF_RX_MODE_ADAPTIVE)) && vum->ifq_count)
{
vum->ifq_count--;
// Stop the timer if there is no more interrupt interface/queue
if ((vum->ifq_count == 0) &&
(vum->coalesce_time > 0.0) && (vum->coalesce_frames > 0))
vlib_process_signal_event (vm,
vhost_user_send_interrupt_node.index,
VHOST_USER_EVENT_STOP_TIMER, 0);
}
}
txvq->mode = mode;
if (mode == VNET_HW_IF_RX_MODE_POLLING)
txvq->used->flags = VRING_USED_F_NO_NOTIFY;
else if ((mode == VNET_HW_IF_RX_MODE_ADAPTIVE) ||
(mode == VNET_HW_IF_RX_MODE_INTERRUPT))
txvq->used->flags = 0;
else
{
vu_log_err (vui, "unhandled mode %d changed for if %d queue %d", mode,
hw_if_index, qid);
return clib_error_return (0, "unsupported");
}
return 0;
}
static __clib_unused clib_error_t *
vhost_user_interface_admin_up_down (vnet_main_t * vnm, u32 hw_if_index,
u32 flags)
{
vnet_hw_interface_t *hif = vnet_get_hw_interface (vnm, hw_if_index);
vhost_user_main_t *vum = &vhost_user_main;
vhost_user_intf_t *vui =
pool_elt_at_index (vum->vhost_user_interfaces, hif->dev_instance);
u8 link_old, link_new;
link_old = vui_is_link_up (vui);
vui->admin_up = (flags & VNET_SW_INTERFACE_FLAG_ADMIN_UP) != 0;
link_new = vui_is_link_up (vui);
if (link_old != link_new)
vnet_hw_interface_set_flags (vnm, vui->hw_if_index, link_new ?
VNET_HW_INTERFACE_FLAG_LINK_UP : 0);
return /* no error */ 0;
}
/* *INDENT-OFF* */
VNET_DEVICE_CLASS (vhost_user_device_class) = {
.name = "vhost-user",
.tx_function_n_errors = VHOST_USER_TX_FUNC_N_ERROR,
.tx_function_error_strings = vhost_user_tx_func_error_strings,
.format_device_name = format_vhost_user_interface_name,
.name_renumber = vhost_user_name_renumber,
.admin_up_down_function = vhost_user_interface_admin_up_down,
.rx_mode_change_function = vhost_user_interface_rx_mode_change,
.format_tx_trace = format_vhost_trace,
};
/* *INDENT-ON* */
/*
* fd.io coding-style-patch-verification: ON
*
* Local Variables:
* eval: (c-set-style "gnu")
* End:
*/