Re: [dpdk-dev] [PATCH 3/3] vhost: Add VHOST PMD

[Stephen Hemminger <stephen@networkplumber.org>]

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.


/*-
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 *
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 *       notice, this list of conditions and the following disclaimer.
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 *       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,
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 *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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 *   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);