aboutsummaryrefslogtreecommitdiffstats
path: root/src/plugins/vhost/vhost_user_output.c
diff options
context:
space:
mode:
authorSteven Luong <sluong@cisco.com>2022-10-19 12:46:29 -0700
committerDamjan Marion <dmarion@0xa5.net>2022-12-02 13:43:11 +0000
commit7eba44d1ec54982636f830a4859027218ca56832 (patch)
tree6447cda45a430c8a735b92be2b13b41b18e1f8a1 /src/plugins/vhost/vhost_user_output.c
parenta6d16b71308f1badf4b362d26d2326a2977fe462 (diff)
vhost: convert vhost device driver to a plugin
convert vhost device driver to a plugin as described in https://jira.fd.io/browse/VPP-2065 Type: improvement Signed-off-by: Steven Luong <sluong@cisco.com> Change-Id: Ibfe2f351bcaed36a04b136d082ae414145dd37b5
Diffstat (limited to 'src/plugins/vhost/vhost_user_output.c')
-rw-r--r--src/plugins/vhost/vhost_user_output.c1145
1 files changed, 1145 insertions, 0 deletions
diff --git a/src/plugins/vhost/vhost_user_output.c b/src/plugins/vhost/vhost_user_output.c
new file mode 100644
index 00000000000..9b52fc6265c
--- /dev/null
+++ b/src/plugins/vhost/vhost_user_output.c
@@ -0,0 +1,1145 @@
+/*
+ *------------------------------------------------------------------
+ * 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/ip/ip_psh_cksum.h>
+
+#include <vhost/vhost_user.h>
+#include <vhost/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;
+}
+
+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];
+ vnet_virtio_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_load ((void *) cpy[2].src);
+ clib_prefetch_load ((void *) cpy[3].src);
+
+ 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,
+ vnet_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;
+ u16 psh_cksum = 0;
+ ip4_header_t *ip4 = 0;
+ ip6_header_t *ip6 = 0;
+
+ 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 =
+ (ip4_header_t *) (vlib_buffer_get_current (b) + gho.l3_hdr_offset);
+ ip4->checksum = ip4_header_checksum (ip4);
+ psh_cksum = ip4_pseudo_header_cksum (ip4);
+ }
+ else
+ {
+ ip6 = (ip6_header_t *) (vlib_buffer_get_current (b) + gho.l3_hdr_offset);
+ psh_cksum = ip6_pseudo_header_cksum (ip6);
+ }
+
+ /* checksum offload */
+ if (oflags & VNET_BUFFER_OFFLOAD_F_UDP_CKSUM)
+ {
+ udp_header_t *udp =
+ (udp_header_t *) (vlib_buffer_get_current (b) + gho.l4_hdr_offset);
+ udp->checksum = psh_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)
+ {
+ tcp_header_t *tcp =
+ (tcp_header_t *) (vlib_buffer_get_current (b) + gho.l4_hdr_offset);
+ tcp->checksum = psh_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;
+ vnet_virtio_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)
+ {
+ vnet_virtio_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;
+ vnet_virtio_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, vhost_user_intf_t *vui,
+ vhost_user_vring_t *rxvq)
+{
+ u32 *buffers = vlib_frame_vector_args (frame);
+ u32 n_left = frame->n_vectors;
+ vhost_user_main_t *vum = &vhost_user_main;
+ u32 qid = rxvq->qid;
+ 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;
+ vnet_virtio_vring_packed_desc_t *desc_table;
+ u32 or_flags;
+ u16 desc_head, desc_index, desc_len;
+ u16 n_descs_processed;
+ u8 indirect, chained;
+
+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 (vnet_virtio_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 */
+ vnet_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
+ */
+ vnet_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_load (&rxvq->packed_desc);
+
+ /* 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;
+ }
+
+ clib_spinlock_unlock (&rxvq->vring_lock);
+
+ 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;
+ 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;
+ vnet_hw_if_tx_frame_t *tf = vlib_frame_scalar_args (frame);
+
+ 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 (tf->queue_id);
+ rxvq = &vui->vrings[qid];
+ ASSERT (tf->queue_id == rxvq->qid);
+
+ if (PREDICT_FALSE (rxvq->avail == 0))
+ {
+ error = VHOST_USER_TX_FUNC_ERROR_MMAP_FAIL;
+ goto done3;
+ }
+ if (tf->shared_queue)
+ clib_spinlock_lock (&rxvq->vring_lock);
+
+ if (vhost_user_is_packed_ring_supported (vui))
+ return (vhost_user_device_class_packed (vm, node, frame, vui, rxvq));
+
+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;
+ vnet_virtio_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 (vnet_virtio_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
+ vnet_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
+ {
+ vnet_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 (vnet_virtio_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_load (&rxvq->desc);
+ }
+
+ // 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);
+ }
+
+ clib_spinlock_unlock (&rxvq->vring_lock);
+
+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)];
+ vhost_cpu_t *cpu;
+
+ if (mode == txvq->mode)
+ return 0;
+
+ if ((mode != VNET_HW_IF_RX_MODE_POLLING) &&
+ (mode != VNET_HW_IF_RX_MODE_ADAPTIVE) &&
+ (mode != VNET_HW_IF_RX_MODE_INTERRUPT))
+ {
+ vu_log_err (vui, "unhandled mode %d changed for if %d queue %d", mode,
+ hw_if_index, qid);
+ return clib_error_return (0, "unsupported");
+ }
+
+ if (txvq->thread_index == ~0)
+ return clib_error_return (0, "Queue initialization is not finished yet");
+
+ cpu = vec_elt_at_index (vum->cpus, txvq->thread_index);
+ 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)
+ {
+ ASSERT (cpu->polling_q_count != 0);
+ if (cpu->polling_q_count)
+ cpu->polling_q_count--;
+ 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)
+ {
+ cpu->polling_q_count++;
+ vum->ifq_count--;
+ // Stop the timer if there is no more interrupt interface/queue
+ if (vum->ifq_count == 0)
+ vlib_process_signal_event (vm,
+ vhost_user_send_interrupt_node.index,
+ VHOST_USER_EVENT_STOP_TIMER, 0);
+ }
+ }
+
+ txvq->mode = mode;
+ vhost_user_set_operation_mode (vui, txvq);
+
+ 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:
+ */