Re: [PATCH 3/3] vhost: Add VHOST PMD

[Tetsuya Mukawa <mukawa@igel.co.jp>]

On 2015/11/10 7:25, Stephen Hemminger wrote:
> On Tue, 27 Oct 2015 15:12:55 +0900
> Tetsuya Mukawa <mukawa@igel.co.jp> wrote:
>
>> The patch introduces a new PMD. This PMD is implemented as thin wrapper
>> of librte_vhost. It means librte_vhost is also needed to compile the PMD.
>> The vhost messages will be handled only when a port is started. So start
>> a port first, then invoke QEMU.
>>
>> The PMD has 2 parameters.
>>  - iface:  The parameter is used to specify a path to connect to a
>>            virtio-net device.
>>  - queues: The parameter is used to specify the number of the queues
>>            virtio-net device has.
>>            (Default: 1)
>>
>> Here is an example.
>> $ ./testpmd -c f -n 4 --vdev 'eth_vhost0,iface=/tmp/sock0,queues=1' -- -i
>>
>> To connect above testpmd, here is qemu command example.
>>
>> $ qemu-system-x86_64 \
>>         <snip>
>>         -chardev socket,id=chr0,path=/tmp/sock0 \
>>         -netdev vhost-user,id=net0,chardev=chr0,vhostforce,queues=1 \
>>         -device virtio-net-pci,netdev=net0
>>
>> Signed-off-by: Tetsuya Mukawa <mukawa@igel.co.jp>
> Brocade developed a much simpler vhost PMD, without all the atomics and
> locking.
>

Hi Stephen,

With your PMD, it seems we need to call some vhost library APIs before
start sending and receiving.
It means we need to manage virtio-net device connections in DPDK
application anyway.

Also, I guess all PMDs should provide feature to be replaced by one of
other PMD without heavy modification for DPDK application.
This is because I tried to manage virtio-net device connections in vhost
PMD.

Thanks,
Tetsuya

> /*-
>  *   BSD LICENSE
>  *
>  *   Copyright (C) Brocade Communications Systems, Inc.
>  *   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 Brocade Communications Systems, Inc.
>  *       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 <rte_mbuf.h>
> #include <rte_ether.h>
> #include <rte_ethdev.h>
> #include <rte_malloc.h>
> #include <rte_memcpy.h>
> #include <rte_dev.h>
> #include <rte_log.h>
>
> #include "../librte_vhost/rte_virtio_net.h"
> #include "../librte_vhost/virtio-net.h"
>
> struct pmd_internals;
>
> struct vhost_queue {
> 	struct pmd_internals *internals;
>
> 	struct rte_mempool *mb_pool;
>
> 	uint64_t	pkts;
> 	uint64_t	bytes;
> };
>
> struct pmd_internals {
> 	struct virtio_net *dev;
> 	unsigned numa_node;
> 	struct eth_driver *eth_drv;
>
> 	unsigned nb_rx_queues;
> 	unsigned nb_tx_queues;
>
> 	struct vhost_queue rx_queues[1];
> 	struct vhost_queue tx_queues[1];
> 	uint8_t port_id;
> };
>
>
> static const char *drivername = "Vhost PMD";
>
> static struct rte_eth_link pmd_link = {
> 	.link_speed = 10000,
> 	.link_duplex = ETH_LINK_FULL_DUPLEX,
> 	.link_status = 0
> };
>
> static uint16_t
> eth_vhost_rx(void *q, struct rte_mbuf **bufs, uint16_t nb_bufs)
> {
> 	int ret, i;
> 	struct vhost_queue *h = q;
>
> 	ret = rte_vhost_dequeue_burst(h->internals->dev,
> 		VIRTIO_TXQ, h->mb_pool, bufs, nb_bufs);
>
> 	for (i = 0; i < ret ; i++) {
> 		struct rte_mbuf *m = bufs[i];
>
> 		m->port = h->internals->port_id;
> 		++h->pkts;
> 		h->bytes += rte_pktmbuf_pkt_len(m);
> 	}
> 	return ret;
> }
>
> static uint16_t
> eth_vhost_tx(void *q, struct rte_mbuf **bufs, uint16_t nb_bufs)
> {
> 	int ret, i;
> 	struct vhost_queue *h = q;
>
> 	ret = rte_vhost_enqueue_burst(h->internals->dev,
> 		VIRTIO_RXQ, bufs, nb_bufs);
>
> 	for (i = 0; i < ret; i++) {
> 		struct rte_mbuf *m = bufs[i];
>
> 		++h->pkts;
> 		h->bytes += rte_pktmbuf_pkt_len(m);
> 		rte_pktmbuf_free(m);
> 	}
>
> 	return ret;
> }
>
> static int
> eth_dev_configure(struct rte_eth_dev *dev __rte_unused)
> {
> 	return 0;
> }
>
> static int
> eth_dev_start(struct rte_eth_dev *dev)
> {
> 	struct pmd_internals *internals = dev->data->dev_private;
>
> 	dev->data->dev_link.link_status = 1;
> 	RTE_LOG(INFO, PMD, "vhost(%s): link up\n", internals->dev->ifname);
> 	return 0;
> }
>
> static void
> eth_dev_stop(struct rte_eth_dev *dev)
> {
> 	struct pmd_internals *internals = dev->data->dev_private;
>
> 	dev->data->dev_link.link_status = 0;
> 	RTE_LOG(INFO, PMD, "vhost(%s): link down\n", internals->dev->ifname);
> }
>
> static int
> eth_rx_queue_setup(struct rte_eth_dev *dev, uint16_t rx_queue_id,
> 		uint16_t nb_rx_desc __rte_unused,
> 		unsigned int socket_id __rte_unused,
> 		const struct rte_eth_rxconf *rx_conf __rte_unused,
> 		struct rte_mempool *mb_pool)
> {
> 	struct pmd_internals *internals = dev->data->dev_private;
>
> 	internals->rx_queues[rx_queue_id].mb_pool = mb_pool;
> 	dev->data->rx_queues[rx_queue_id] =
> 		&internals->rx_queues[rx_queue_id];
> 	internals->rx_queues[rx_queue_id].internals = internals;
>
> 	return 0;
> }
>
> static int
> eth_tx_queue_setup(struct rte_eth_dev *dev, uint16_t tx_queue_id,
> 		uint16_t nb_tx_desc __rte_unused,
> 		unsigned int socket_id __rte_unused,
> 		const struct rte_eth_txconf *tx_conf __rte_unused)
> {
> 	struct pmd_internals *internals = dev->data->dev_private;
>
> 	dev->data->tx_queues[tx_queue_id] =
> 		&internals->tx_queues[tx_queue_id];
> 	internals->tx_queues[tx_queue_id].internals = internals;
>
> 	return 0;
> }
>
>
> static void
> eth_dev_info(struct rte_eth_dev *dev,
> 		struct rte_eth_dev_info *dev_info)
> {
> 	struct pmd_internals *internals = dev->data->dev_private;
>
> 	dev_info->driver_name = drivername;
> 	dev_info->max_mac_addrs = 1;
> 	dev_info->max_rx_pktlen = -1;
> 	dev_info->max_rx_queues = (uint16_t)internals->nb_rx_queues;
> 	dev_info->max_tx_queues = (uint16_t)internals->nb_tx_queues;
> 	dev_info->min_rx_bufsize = 0;
> 	dev_info->pci_dev = NULL;
> }
>
> static void
> eth_stats_get(struct rte_eth_dev *dev, struct rte_eth_stats *stats)
> {
> 	const struct pmd_internals *internal = dev->data->dev_private;
> 	unsigned i;
>
> 	for (i = 0; i < internal->nb_rx_queues; i++) {
> 		const struct vhost_queue *h = &internal->rx_queues[i];
>
> 		stats->ipackets += h->pkts;
> 		stats->ibytes += h->bytes;
>
> 		if (i < RTE_ETHDEV_QUEUE_STAT_CNTRS) {
> 			stats->q_ibytes[i] = h->bytes;
> 			stats->q_ipackets[i] = h->pkts;
> 		}
> 	}
>
> 	for (i = 0; i < internal->nb_tx_queues; i++) {
> 		const struct vhost_queue *h = &internal->tx_queues[i];
>
> 		stats->opackets += h->pkts;
> 		stats->obytes += h->bytes;
>
> 		if (i < RTE_ETHDEV_QUEUE_STAT_CNTRS) {
> 			stats->q_obytes[i] = h->bytes;
> 			stats->q_opackets[i] = h->pkts;
> 		}
> 	}
> }
>
> static void
> eth_stats_reset(struct rte_eth_dev *dev)
> {
> 	unsigned i;
> 	struct pmd_internals *internal = dev->data->dev_private;
>
> 	for (i = 0; i < internal->nb_rx_queues; i++) {
> 		internal->rx_queues[i].pkts = 0;
> 		internal->rx_queues[i].bytes = 0;
> 	}
>
> 	for (i = 0; i < internal->nb_tx_queues; i++) {
> 		internal->tx_queues[i].pkts = 0;
> 		internal->tx_queues[i].bytes = 0;
> 	}
> }
>
> static struct eth_driver rte_vhost_pmd = {
> 	.pci_drv = {
> 		.name = "rte_vhost_pmd",
> 		.drv_flags = RTE_PCI_DRV_DETACHABLE,
> 	},
> };
>
> static void
> eth_queue_release(void *q __rte_unused)
> {
> }
>
> static int
> eth_link_update(struct rte_eth_dev *dev __rte_unused,
> 		int wait_to_complete __rte_unused)
> {
> 	return 0;
> }
>
> static struct eth_dev_ops eth_ops = {
> 	.dev_start = eth_dev_start,
> 	.dev_stop = eth_dev_stop,
> 	.dev_configure = eth_dev_configure,
> 	.dev_infos_get = eth_dev_info,
> 	.rx_queue_setup = eth_rx_queue_setup,
> 	.tx_queue_setup = eth_tx_queue_setup,
> 	.rx_queue_release = eth_queue_release,
> 	.tx_queue_release = eth_queue_release,
> 	.link_update = eth_link_update,
> 	.stats_get = eth_stats_get,
> 	.stats_reset = eth_stats_reset,
> };
>
> static int
> eth_dev_vhost_create(const char *name, const unsigned numa_node)
> {
> 	const unsigned nb_rx_queues = 1;
> 	const unsigned nb_tx_queues = 1;
> 	struct rte_eth_dev_data *data = NULL;
> 	struct rte_pci_device *pci_dev = NULL;
> 	struct pmd_internals *internals = NULL;
> 	struct rte_eth_dev *eth_dev = NULL;
> 	struct virtio_net *vhost_dev = NULL;
> 	struct eth_driver *eth_drv = NULL;
> 	struct rte_pci_id *id_table = NULL;
> 	struct ether_addr *eth_addr = NULL;
>
> 	if (name == NULL)
> 		return -EINVAL;
>
> 	vhost_dev = get_device_by_name(name);
>
> 	if (vhost_dev == NULL)
> 		return -EINVAL;
>
> 	RTE_LOG(INFO, PMD, "Creating vhost ethdev on numa socket %u\n",
> 			numa_node);
>
> 	data = rte_zmalloc_socket(name, sizeof(*data), 0, numa_node);
> 	if (data == NULL)
> 		goto error;
>
> 	pci_dev = rte_zmalloc_socket(name, sizeof(*pci_dev), 0, numa_node);
> 	if (pci_dev == NULL)
> 		goto error;
>
> 	id_table = rte_zmalloc_socket(name, sizeof(*id_table), 0, numa_node);
> 	if (id_table == NULL)
> 		goto error;
>
> 	internals = rte_zmalloc_socket(name, sizeof(*internals), 0, numa_node);
> 	if (internals == NULL)
> 		goto error;
>
> 	eth_addr = rte_zmalloc_socket(name, sizeof(*eth_addr), 0, numa_node);
> 	if (internals == NULL)
> 		goto error;
>
> 	eth_dev = rte_eth_dev_allocate(name, RTE_ETH_DEV_VIRTUAL);
> 	if (eth_dev == NULL)
> 		goto error;
>
> 	eth_drv = rte_zmalloc_socket(name, sizeof(*eth_drv), 0, numa_node);
> 	if (eth_drv == NULL)
> 		goto error;
>
> 	internals->nb_rx_queues = nb_rx_queues;
> 	internals->nb_tx_queues = nb_tx_queues;
> 	internals->numa_node = numa_node;
> 	internals->dev = vhost_dev;
>
> 	internals->port_id = eth_dev->data->port_id;
>
> 	eth_drv->pci_drv.name = drivername;
> 	eth_drv->pci_drv.id_table = id_table;
> 	internals->eth_drv = eth_drv;
>
> 	pci_dev->numa_node = numa_node;
> 	pci_dev->driver = &eth_drv->pci_drv;
>
> 	data->dev_private = internals;
> 	data->port_id = eth_dev->data->port_id;
> 	data->nb_rx_queues = (uint16_t)nb_rx_queues;
> 	data->nb_tx_queues = (uint16_t)nb_tx_queues;
> 	data->dev_link = pmd_link;
> 	eth_random_addr(&eth_addr->addr_bytes[0]);
> 	data->mac_addrs = eth_addr;
> 	strncpy(data->name, eth_dev->data->name, strlen(eth_dev->data->name));
>
> 	eth_dev->data = data;
> 	eth_dev->dev_ops = &eth_ops;
> 	eth_dev->pci_dev = pci_dev;
> 	eth_dev->driver = &rte_vhost_pmd;
> 	eth_dev->rx_pkt_burst = eth_vhost_rx;
> 	eth_dev->tx_pkt_burst = eth_vhost_tx;
> 	TAILQ_INIT(&(eth_dev->link_intr_cbs));
>
> 	return 0;
>
> error:
> 	rte_free(data);
> 	rte_free(pci_dev);
> 	rte_free(id_table);
> 	rte_free(eth_drv);
> 	rte_free(eth_addr);
> 	rte_free(internals);
>
> 	return -1;
> }
>
> static int
> rte_pmd_vhost_devinit(const char *name,
> 		      const char *params __attribute__((unused)))
> {
> 	unsigned numa_node;
>
> 	if (name == NULL)
> 		return -EINVAL;
>
> 	RTE_LOG(DEBUG, PMD, "Initializing pmd_vhost for %s\n", name);
>
> 	numa_node = rte_socket_id();
>
> 	return eth_dev_vhost_create(name, numa_node);
> }
>
> static int
> rte_pmd_vhost_devuninit(const char *name)
> {
> 	struct rte_eth_dev *eth_dev = NULL;
> 	struct pmd_internals *internals = NULL;
>
> 	if (name == NULL)
> 		return -EINVAL;
>
> 	RTE_LOG(DEBUG, PMD, "Closing vhost ethdev on numa socket %u\n",
> 			rte_socket_id());
>
> 	/* reserve an ethdev entry */
> 	eth_dev = rte_eth_dev_allocated(name);
> 	if (eth_dev == NULL)
> 		return -1;
>
> 	internals = (struct pmd_internals *)eth_dev->data->dev_private;
> 	rte_free(internals->eth_drv->pci_drv.id_table);
> 	rte_free(internals->eth_drv);
> 	rte_free(eth_dev->data->dev_private);
> 	rte_free(eth_dev->data->mac_addrs);
> 	rte_free(eth_dev->data);
> 	rte_free(eth_dev->pci_dev);
>
> 	rte_eth_dev_release_port(eth_dev);
>
> 	return 0;
> }
>
> static struct rte_driver pmd_vhost_drv = {
> 	.name = "vhost",
> 	.type = PMD_VDEV,
> 	.init = rte_pmd_vhost_devinit,
> 	.uninit = rte_pmd_vhost_devuninit,
> };
>
> PMD_REGISTER_DRIVER(pmd_vhost_drv);