Now DPDK vhost lib has been generic enough, that it can be used to
implement any vhost-user drivers.
For example, this patch implements a very simple vhost-user net driver,
mainly for demonstrating how to use those generic vhost APIs.
And when the --builtin-net-driver option is used, the example virtio-net
driver code will be invoked, instead of the one provided from the vhost
library.
Signed-off-by: Yuanhan Liu <yuanhan....@linux.intel.com>
---
examples/vhost/Makefile | 2 +-
examples/vhost/main.c | 36 +++-
examples/vhost/main.h | 29 +++-
examples/vhost/virtio_net.c | 405 ++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 465 insertions(+), 7 deletions(-)
create mode 100644 examples/vhost/virtio_net.c
diff --git a/examples/vhost/Makefile b/examples/vhost/Makefile
index e95c68a..af7be99 100644
--- a/examples/vhost/Makefile
+++ b/examples/vhost/Makefile
@@ -48,7 +48,7 @@ else
APP = vhost-switch
# all source are stored in SRCS-y
-SRCS-y := main.c
+SRCS-y := main.c virtio_net.c
CFLAGS += -O2 -D_FILE_OFFSET_BITS=64
CFLAGS += $(WERROR_FLAGS)
diff --git a/examples/vhost/main.c b/examples/vhost/main.c
index a9b5352..bebfb7f 100644
--- a/examples/vhost/main.c
+++ b/examples/vhost/main.c
@@ -1,7 +1,7 @@
/*-
* BSD LICENSE
*
- * Copyright(c) 2010-2016 Intel Corporation. All rights reserved.
+ * Copyright(c) 2010-2017 Intel Corporation. All rights reserved.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
@@ -65,7 +65,6 @@
#define MBUF_CACHE_SIZE 128
#define MBUF_DATA_SIZE RTE_MBUF_DEFAULT_BUF_SIZE
-#define MAX_PKT_BURST 32 /* Max burst size for RX/TX */
#define BURST_TX_DRAIN_US 100 /* TX drain every ~100us */
#define BURST_RX_WAIT_US 15 /* Defines how long we wait between retries on
RX */
@@ -129,6 +128,8 @@
static int client_mode;
static int dequeue_zero_copy;
+static int builtin_net_driver;
+
/* Specify timeout (in useconds) between retries on RX. */
static uint32_t burst_rx_delay_time = BURST_RX_WAIT_US;
/* Specify the number of retries on RX. */
@@ -499,6 +500,7 @@ struct mbuf_table {
{"tso", required_argument, NULL, 0},
{"client", no_argument, &client_mode, 1},
{"dequeue-zero-copy", no_argument, &dequeue_zero_copy, 1},
+ {"builtin-net-driver", no_argument, &builtin_net_driver, 1},
{NULL, 0, 0, 0},
};
@@ -795,7 +797,12 @@ static inline void __attribute__((always_inline))
{
uint16_t ret;
- ret = rte_vhost_enqueue_burst(dst_vdev->vid, VIRTIO_RXQ, &m, 1);
+ if (builtin_net_driver) {
+ ret = vs_enqueue_pkts(dst_vdev, VIRTIO_RXQ, &m, 1);
+ } else {
+ ret = rte_vhost_enqueue_burst(dst_vdev->vid, VIRTIO_RXQ, &m, 1);
+ }
+
if (enable_stats) {
rte_atomic64_inc(&dst_vdev->stats.rx_total_atomic);
rte_atomic64_add(&dst_vdev->stats.rx_atomic, ret);
@@ -1066,8 +1073,13 @@ static inline void __attribute__((always_inline))
}
}
- enqueue_count = rte_vhost_enqueue_burst(vdev->vid, VIRTIO_RXQ,
+ if (builtin_net_driver) {
+ enqueue_count = vs_enqueue_pkts(vdev, VIRTIO_RXQ,
pkts, rx_count);
+ } else {
+ enqueue_count = rte_vhost_enqueue_burst(vdev->vid, VIRTIO_RXQ,
+ pkts, rx_count);
+ }
if (enable_stats) {
rte_atomic64_add(&vdev->stats.rx_total_atomic, rx_count);
rte_atomic64_add(&vdev->stats.rx_atomic, enqueue_count);
@@ -1083,8 +1095,13 @@ static inline void __attribute__((always_inline))
uint16_t count;
uint16_t i;
- count = rte_vhost_dequeue_burst(vdev->vid, VIRTIO_TXQ, mbuf_pool,
+ if (builtin_net_driver) {
+ count = vs_dequeue_pkts(vdev, VIRTIO_TXQ, mbuf_pool,
pkts, MAX_PKT_BURST);
+ } else {
+ count = rte_vhost_dequeue_burst(vdev->vid, VIRTIO_TXQ,
+ mbuf_pool, pkts, MAX_PKT_BURST);
+ }
/* setup VMDq for the first packet */
if (unlikely(vdev->ready == DEVICE_MAC_LEARNING) && count) {
@@ -1187,6 +1204,9 @@ static inline void __attribute__((always_inline))
rte_pause();
}
+ if (builtin_net_driver)
+ vs_vhost_net_remove(vdev);
+
TAILQ_REMOVE(&lcore_info[vdev->coreid].vdev_list, vdev,
lcore_vdev_entry);
TAILQ_REMOVE(&vhost_dev_list, vdev, global_vdev_entry);
@@ -1235,6 +1255,9 @@ static inline void __attribute__((always_inline))
}
vdev->vid = vid;
+ if (builtin_net_driver)
+ vs_vhost_net_setup(vdev);
+
TAILQ_INSERT_TAIL(&vhost_dev_list, vdev, global_vdev_entry);
vdev->vmdq_rx_q = vid * queues_per_pool + vmdq_queue_base;
@@ -1513,6 +1536,9 @@ static inline void __attribute__((always_inline))
rte_exit(EXIT_FAILURE,
"vhost driver register failure.\n");
}
+
+ ret = rte_vhost_driver_set_features(file, VIRTIO_NET_FEATURES);
+
if (mergeable == 0) {
rte_vhost_driver_disable_features(file,
1ULL << VIRTIO_NET_F_MRG_RXBUF);
diff --git a/examples/vhost/main.h b/examples/vhost/main.h
index ddcd858..5ba7d38 100644
--- a/examples/vhost/main.h
+++ b/examples/vhost/main.h
@@ -1,7 +1,7 @@
/*-
* BSD LICENSE
*
- * Copyright(c) 2010-2016 Intel Corporation. All rights reserved.
+ * Copyright(c) 2010-2017 Intel Corporation. All rights reserved.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
@@ -43,8 +43,11 @@
#define RTE_LOGTYPE_VHOST_DATA RTE_LOGTYPE_USER2
#define RTE_LOGTYPE_VHOST_PORT RTE_LOGTYPE_USER3
+
enum {VIRTIO_RXQ, VIRTIO_TXQ, VIRTIO_QNUM};
+#define MAX_PKT_BURST 32 /* Max burst size for RX/TX */
+
struct device_statistics {
uint64_t tx;
uint64_t tx_total;
@@ -52,6 +55,12 @@ struct device_statistics {
rte_atomic64_t rx_total_atomic;
};
+struct vhost_queue {
+ struct rte_vhost_vring vr;
+ uint16_t last_avail_idx;
+ uint16_t last_used_idx;
+};
+
struct vhost_dev {
/**< Number of memory regions for gpa to hpa translation. */
uint32_t nregions_hpa;
@@ -69,9 +78,16 @@ struct vhost_dev {
volatile uint8_t remove;
int vid;
+ uint64_t features;
+ size_t hdr_len;
+ uint16_t nr_vrings;
+ struct rte_vhost_memory *mem;
struct device_statistics stats;
TAILQ_ENTRY(vhost_dev) global_vdev_entry;
TAILQ_ENTRY(vhost_dev) lcore_vdev_entry;
+
+#define MAX_QUEUE_PAIRS 4
+ struct vhost_queue queues[MAX_QUEUE_PAIRS * 2];
} __rte_cache_aligned;
TAILQ_HEAD(vhost_dev_tailq_list, vhost_dev);
@@ -92,4 +108,15 @@ struct lcore_info {
struct vhost_dev_tailq_list vdev_list;
};
+/* we implement non-extra virtio net features */
+#define VIRTIO_NET_FEATURES 0
+
+void vs_vhost_net_setup(struct vhost_dev *dev);
+void vs_vhost_net_remove(struct vhost_dev *dev);
+uint16_t vs_enqueue_pkts(struct vhost_dev *dev, uint16_t queue_id,
+ struct rte_mbuf **pkts, uint32_t count);
+
+uint16_t vs_dequeue_pkts(struct vhost_dev *dev, uint16_t queue_id,
+ struct rte_mempool *mbuf_pool,
+ struct rte_mbuf **pkts, uint16_t count);
#endif /* _MAIN_H_ */
diff --git a/examples/vhost/virtio_net.c b/examples/vhost/virtio_net.c
new file mode 100644
index 0000000..6dbf8aa
--- /dev/null
+++ b/examples/vhost/virtio_net.c
@@ -0,0 +1,405 @@
+/*-
+ * BSD LICENSE
+ *
+ * Copyright(c) 2010-2017 Intel Corporation. All rights reserved.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the
+ * distribution.
+ * * Neither the name of Intel Corporation nor the names of its
+ * contributors may be used to endorse or promote products derived
+ * from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <stdint.h>
+#include <stdbool.h>
+#include <linux/virtio_net.h>
+
+#include <rte_mbuf.h>
+#include <rte_memcpy.h>
+#include <rte_vhost.h>
+
+#include "main.h"
+
+/*
+ * A very simple vhost-user net driver implementation, without
+ * any extra features being enabled, such as TSO and mrg-Rx.
+ */
+
+void
+vs_vhost_net_setup(struct vhost_dev *dev)
+{
+ uint16_t i;
+ int vid = dev->vid;
+ struct vhost_queue *queue;
+
+ RTE_LOG(INFO, VHOST_CONFIG,
+ "setting builtin vhost-user net driver\n");
+
+ dev->features = rte_vhost_get_negotiated_features(vid);
+ if (dev->features &
+ ((1 << VIRTIO_NET_F_MRG_RXBUF) | (1ULL << VIRTIO_F_VERSION_1)))
{
+ dev->hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
+ } else {
+ dev->hdr_len = sizeof(struct virtio_net_hdr);
+ }
+
+ rte_vhost_get_vhost_memory(vid, &dev->mem);
+
+ dev->nr_vrings = rte_vhost_get_vring_num(vid);
+ for (i = 0; i < dev->nr_vrings; i++) {
+ queue = &dev->queues[i];
+
+ queue->last_used_idx = 0;
+ queue->last_avail_idx = 0;
+ rte_vhost_get_vhost_vring(vid, i, &queue->vr);
+ }
+}
+
+void
+vs_vhost_net_remove(struct vhost_dev *dev)
+{
+ free(dev->mem);
+}
+
+static inline int __attribute__((always_inline))
+enqueue_pkt(struct vhost_dev *dev, struct rte_vhost_vring *vr,
+ struct rte_mbuf *m, uint16_t desc_idx)
+{
+ uint32_t desc_avail, desc_offset;
+ uint32_t mbuf_avail, mbuf_offset;
+ uint32_t cpy_len;
+ struct vring_desc *desc;
+ uint64_t desc_addr;
+ struct virtio_net_hdr virtio_hdr = {0, 0, 0, 0, 0, 0};
+ /* A counter to avoid desc dead loop chain */
+ uint16_t nr_desc = 1;
+
+ desc = &vr->desc[desc_idx];
+ desc_addr = rte_vhost_gpa_to_vva(dev->mem, desc->addr);
+ /*
+ * Checking of 'desc_addr' placed outside of 'unlikely' macro to avoid
+ * performance issue with some versions of gcc (4.8.4 and 5.3.0) which
+ * otherwise stores offset on the stack instead of in a register.
+ */
+ if (unlikely(desc->len < dev->hdr_len) || !desc_addr)
+ return -1;
+
+ rte_prefetch0((void *)(uintptr_t)desc_addr);
+
+ /* write virtio-net header */
+ *(struct virtio_net_hdr *)(uintptr_t)desc_addr = virtio_hdr;
+
+ desc_offset = dev->hdr_len;
+ desc_avail = desc->len - dev->hdr_len;
+
+ mbuf_avail = rte_pktmbuf_data_len(m);
+ mbuf_offset = 0;
+ while (mbuf_avail != 0 || m->next != NULL) {
+ /* done with current mbuf, fetch next */
+ if (mbuf_avail == 0) {
+ m = m->next;
+
+ mbuf_offset = 0;
+ mbuf_avail = rte_pktmbuf_data_len(m);
+ }
+
+ /* done with current desc buf, fetch next */
+ if (desc_avail == 0) {
+ if ((desc->flags & VRING_DESC_F_NEXT) == 0) {
+ /* Room in vring buffer is not enough */
+ return -1;
+ }
+ if (unlikely(desc->next >= vr->size ||
+ ++nr_desc > vr->size))
+ return -1;
+
+ desc = &vr->desc[desc->next];
+ desc_addr = rte_vhost_gpa_to_vva(dev->mem, desc->addr);
+ if (unlikely(!desc_addr))
+ return -1;
+
+ desc_offset = 0;
+ desc_avail = desc->len;
+ }
+
+ cpy_len = RTE_MIN(desc_avail, mbuf_avail);
+ rte_memcpy((void *)((uintptr_t)(desc_addr + desc_offset)),
+ rte_pktmbuf_mtod_offset(m, void *, mbuf_offset),
+ cpy_len);
+
+ mbuf_avail -= cpy_len;
+ mbuf_offset += cpy_len;
+ desc_avail -= cpy_len;
+ desc_offset += cpy_len;
+ }
+
+ return 0;
+}
+
+uint16_t
+vs_enqueue_pkts(struct vhost_dev *dev, uint16_t queue_id,
+ struct rte_mbuf **pkts, uint32_t count)
+{
+ struct vhost_queue *queue;
+ struct rte_vhost_vring *vr;
+ uint16_t avail_idx, free_entries, start_idx;
+ uint16_t desc_indexes[MAX_PKT_BURST];
+ uint16_t used_idx;
+ uint32_t i;
+
+ queue = &dev->queues[queue_id];
+ vr = &queue->vr;
+
+ avail_idx = *((volatile uint16_t *)&vr->avail->idx);
+ start_idx = queue->last_used_idx;
+ free_entries = avail_idx - start_idx;
+ count = RTE_MIN(count, free_entries);
+ count = RTE_MIN(count, (uint32_t)MAX_PKT_BURST);
+ if (count == 0)
+ return 0;
+
+ /* Retrieve all of the desc indexes first to avoid caching issues. */
+ rte_prefetch0(&vr->avail->ring[start_idx & (vr->size - 1)]);
+ for (i = 0; i < count; i++) {
+ used_idx = (start_idx + i) & (vr->size - 1);
+ desc_indexes[i] = vr->avail->ring[used_idx];
+ vr->used->ring[used_idx].id = desc_indexes[i];
+ vr->used->ring[used_idx].len = pkts[i]->pkt_len +
+ dev->hdr_len;
+ }
+
+ rte_prefetch0(&vr->desc[desc_indexes[0]]);
+ for (i = 0; i < count; i++) {
+ uint16_t desc_idx = desc_indexes[i];
+ int err;
+
+ err = enqueue_pkt(dev, vr, pkts[i], desc_idx);
+ if (unlikely(err)) {
+ used_idx = (start_idx + i) & (vr->size - 1);
+ vr->used->ring[used_idx].len = dev->hdr_len;
+ }
+
+ if (i + 1 < count)
+ rte_prefetch0(&vr->desc[desc_indexes[i+1]]);
+ }
+
+ rte_smp_wmb();
+
+ *(volatile uint16_t *)&vr->used->idx += count;
+ queue->last_used_idx += count;
+
+ /* flush used->idx update before we read avail->flags. */
+ rte_mb();
+
+ /* Kick the guest if necessary. */
+ if (!(vr->avail->flags & VRING_AVAIL_F_NO_INTERRUPT)
+ && (vr->callfd >= 0))
+ eventfd_write(vr->callfd, (eventfd_t)1);
+ return count;
+}
+
+static inline int __attribute__((always_inline))
+dequeue_pkt(struct vhost_dev *dev, struct rte_vhost_vring *vr,
+ struct rte_mbuf *m, uint16_t desc_idx,
+ struct rte_mempool *mbuf_pool)
+{
+ struct vring_desc *desc;
+ uint64_t desc_addr;
+ uint32_t desc_avail, desc_offset;
+ uint32_t mbuf_avail, mbuf_offset;
+ uint32_t cpy_len;
+ struct rte_mbuf *cur = m, *prev = m;
+ /* A counter to avoid desc dead loop chain */
+ uint32_t nr_desc = 1;
+
+ desc = &vr->desc[desc_idx];
+ if (unlikely((desc->len < dev->hdr_len)) ||
+ (desc->flags & VRING_DESC_F_INDIRECT))
+ return -1;
+
+ desc_addr = rte_vhost_gpa_to_vva(dev->mem, desc->addr);
+ if (unlikely(!desc_addr))
+ return -1;
+
+ /*
+ * We don't support ANY_LAYOUT, neither VERSION_1, meaning
+ * a Tx packet from guest must have 2 desc buffers at least:
+ * the first for storing the header and the others for
+ * storing the data.
+ *
+ * And since we don't support TSO, we could simply skip the
+ * header.
+ */
+ desc = &vr->desc[desc->next];
+ desc_addr = rte_vhost_gpa_to_vva(dev->mem, desc->addr);
+ if (unlikely(!desc_addr))
+ return -1;
+ rte_prefetch0((void *)(uintptr_t)desc_addr);
+
+ desc_offset = 0;
+ desc_avail = desc->len;
+ nr_desc += 1;
+
+ mbuf_offset = 0;
+ mbuf_avail = m->buf_len - RTE_PKTMBUF_HEADROOM;
+ while (1) {
+ cpy_len = RTE_MIN(desc_avail, mbuf_avail);
+ rte_memcpy(rte_pktmbuf_mtod_offset(cur, void *,
+ mbuf_offset),
+ (void *)((uintptr_t)(desc_addr + desc_offset)),
+ cpy_len);
+
+ mbuf_avail -= cpy_len;
+ mbuf_offset += cpy_len;
+ desc_avail -= cpy_len;
+ desc_offset += cpy_len;
+
+ /* This desc reaches to its end, get the next one */
+ if (desc_avail == 0) {
+ if ((desc->flags & VRING_DESC_F_NEXT) == 0)
+ break;
+
+ if (unlikely(desc->next >= vr->size ||
+ ++nr_desc > vr->size))
+ return -1;
+ desc = &vr->desc[desc->next];
+
+ desc_addr = rte_vhost_gpa_to_vva(dev->mem, desc->addr);
+ if (unlikely(!desc_addr))
+ return -1;
+ rte_prefetch0((void *)(uintptr_t)desc_addr);
+
+ desc_offset = 0;
+ desc_avail = desc->len;
+ }
+
+ /*
+ * This mbuf reaches to its end, get a new one
+ * to hold more data.
+ */
+ if (mbuf_avail == 0) {
+ cur = rte_pktmbuf_alloc(mbuf_pool);
+ if (unlikely(cur == NULL)) {
+ RTE_LOG(ERR, VHOST_DATA, "Failed to "
+ "allocate memory for mbuf.\n");
+ return -1;
+ }
+
+ prev->next = cur;
+ prev->data_len = mbuf_offset;
+ m->nb_segs += 1;
+ m->pkt_len += mbuf_offset;
+ prev = cur;
+
+ mbuf_offset = 0;
+ mbuf_avail = cur->buf_len - RTE_PKTMBUF_HEADROOM;
+ }
+ }
+
+ prev->data_len = mbuf_offset;
+ m->pkt_len += mbuf_offset;
+
+ return 0;
+}
+
+uint16_t
+vs_dequeue_pkts(struct vhost_dev *dev, uint16_t queue_id,
+ struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts, uint16_t count)
+{
+ struct vhost_queue *queue;
+ struct rte_vhost_vring *vr;
+ uint32_t desc_indexes[MAX_PKT_BURST];
+ uint32_t used_idx;
+ uint32_t i = 0;
+ uint16_t free_entries;
+ uint16_t avail_idx;
+
+ queue = &dev->queues[queue_id];
+ vr = &queue->vr;
+
+ free_entries = *((volatile uint16_t *)&vr->avail->idx) -
+ queue->last_avail_idx;
+ if (free_entries == 0)
+ return 0;
+
+ /* Prefetch available and used ring */
+ avail_idx = queue->last_avail_idx & (vr->size - 1);
+ used_idx = queue->last_used_idx & (vr->size - 1);
+ rte_prefetch0(&vr->avail->ring[avail_idx]);
+ rte_prefetch0(&vr->used->ring[used_idx]);
+
+ count = RTE_MIN(count, MAX_PKT_BURST);
+ count = RTE_MIN(count, free_entries);
+
+ /*
+ * Retrieve all of the head indexes first and pre-update used entries
+ * to avoid caching issues.
+ */
+ for (i = 0; i < count; i++) {
+ avail_idx = (queue->last_avail_idx + i) & (vr->size - 1);
+ used_idx = (queue->last_used_idx + i) & (vr->size - 1);
+ desc_indexes[i] = vr->avail->ring[avail_idx];
+
+ vr->used->ring[used_idx].id = desc_indexes[i];
+ vr->used->ring[used_idx].len = 0;
+ }
+
+ /* Prefetch descriptor index. */
+ rte_prefetch0(&vr->desc[desc_indexes[0]]);
+ for (i = 0; i < count; i++) {
+ int err;
+
+ if (likely(i + 1 < count))
+ rte_prefetch0(&vr->desc[desc_indexes[i + 1]]);
+
+ pkts[i] = rte_pktmbuf_alloc(mbuf_pool);
+ if (unlikely(pkts[i] == NULL)) {
+ RTE_LOG(ERR, VHOST_DATA,
+ "Failed to allocate memory for mbuf.\n");
+ break;
+ }
+
+ err = dequeue_pkt(dev, vr, pkts[i], desc_indexes[i], mbuf_pool);
+ if (unlikely(err)) {
+ rte_pktmbuf_free(pkts[i]);
+ break;
+ }
+
+ }
+ if (!i)
+ return 0;
+
+ queue->last_avail_idx += i;
+ queue->last_used_idx += i;
+ rte_smp_wmb();
+ rte_smp_rmb();
+
+ vr->used->idx += i;
+
+ if (!(vr->avail->flags & VRING_AVAIL_F_NO_INTERRUPT)
+ && (vr->callfd >= 0))
+ eventfd_write(vr->callfd, (eventfd_t)1);
+
+ return i;
+}
--
1.9.0
