blob: c10b6981fdabfd586cd2e1b3fae5886615677cc5 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0-only
/*
* VDPA simulator for networking device.
*
* Copyright (c) 2020, Red Hat Inc. All rights reserved.
* Author: Jason Wang <jasowang@redhat.com>
*
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/etherdevice.h>
#include <linux/vringh.h>
#include <linux/vdpa.h>
#include <uapi/linux/virtio_net.h>
#include "vdpa_sim.h"
#define DRV_VERSION "0.1"
#define DRV_AUTHOR "Jason Wang <jasowang@redhat.com>"
#define DRV_DESC "vDPA Device Simulator for networking device"
#define DRV_LICENSE "GPL v2"
#define VDPASIM_NET_FEATURES (VDPASIM_FEATURES | \
(1ULL << VIRTIO_NET_F_MAC))
#define VDPASIM_NET_VQ_NUM 2
static char *macaddr;
module_param(macaddr, charp, 0);
MODULE_PARM_DESC(macaddr, "Ethernet MAC address");
u8 macaddr_buf[ETH_ALEN];
static struct vdpasim *vdpasim_net_dev;
static void vdpasim_net_work(struct work_struct *work)
{
struct vdpasim *vdpasim = container_of(work, struct vdpasim, work);
struct vdpasim_virtqueue *txq = &vdpasim->vqs[1];
struct vdpasim_virtqueue *rxq = &vdpasim->vqs[0];
ssize_t read, write;
size_t total_write;
int pkts = 0;
int err;
spin_lock(&vdpasim->lock);
if (!(vdpasim->status & VIRTIO_CONFIG_S_DRIVER_OK))
goto out;
if (!txq->ready || !rxq->ready)
goto out;
while (true) {
total_write = 0;
err = vringh_getdesc_iotlb(&txq->vring, &txq->out_iov, NULL,
&txq->head, GFP_ATOMIC);
if (err <= 0)
break;
err = vringh_getdesc_iotlb(&rxq->vring, NULL, &rxq->in_iov,
&rxq->head, GFP_ATOMIC);
if (err <= 0) {
vringh_complete_iotlb(&txq->vring, txq->head, 0);
break;
}
while (true) {
read = vringh_iov_pull_iotlb(&txq->vring, &txq->out_iov,
vdpasim->buffer,
PAGE_SIZE);
if (read <= 0)
break;
write = vringh_iov_push_iotlb(&rxq->vring, &rxq->in_iov,
vdpasim->buffer, read);
if (write <= 0)
break;
total_write += write;
}
/* Make sure data is wrote before advancing index */
smp_wmb();
vringh_complete_iotlb(&txq->vring, txq->head, 0);
vringh_complete_iotlb(&rxq->vring, rxq->head, total_write);
/* Make sure used is visible before rasing the interrupt. */
smp_wmb();
local_bh_disable();
if (vringh_need_notify_iotlb(&txq->vring) > 0)
vringh_notify(&txq->vring);
if (vringh_need_notify_iotlb(&rxq->vring) > 0)
vringh_notify(&rxq->vring);
local_bh_enable();
if (++pkts > 4) {
schedule_work(&vdpasim->work);
goto out;
}
}
out:
spin_unlock(&vdpasim->lock);
}
static void vdpasim_net_get_config(struct vdpasim *vdpasim, void *config)
{
struct virtio_net_config *net_config =
(struct virtio_net_config *)config;
net_config->mtu = cpu_to_vdpasim16(vdpasim, 1500);
net_config->status = cpu_to_vdpasim16(vdpasim, VIRTIO_NET_S_LINK_UP);
memcpy(net_config->mac, macaddr_buf, ETH_ALEN);
}
static int __init vdpasim_net_init(void)
{
struct vdpasim_dev_attr dev_attr = {};
int ret;
if (macaddr) {
mac_pton(macaddr, macaddr_buf);
if (!is_valid_ether_addr(macaddr_buf)) {
ret = -EADDRNOTAVAIL;
goto out;
}
} else {
eth_random_addr(macaddr_buf);
}
dev_attr.id = VIRTIO_ID_NET;
dev_attr.supported_features = VDPASIM_NET_FEATURES;
dev_attr.nvqs = VDPASIM_NET_VQ_NUM;
dev_attr.config_size = sizeof(struct virtio_net_config);
dev_attr.get_config = vdpasim_net_get_config;
dev_attr.work_fn = vdpasim_net_work;
dev_attr.buffer_size = PAGE_SIZE;
vdpasim_net_dev = vdpasim_create(&dev_attr);
if (IS_ERR(vdpasim_net_dev)) {
ret = PTR_ERR(vdpasim_net_dev);
goto out;
}
ret = vdpa_register_device(&vdpasim_net_dev->vdpa);
if (ret)
goto put_dev;
return 0;
put_dev:
put_device(&vdpasim_net_dev->vdpa.dev);
out:
return ret;
}
static void __exit vdpasim_net_exit(void)
{
struct vdpa_device *vdpa = &vdpasim_net_dev->vdpa;
vdpa_unregister_device(vdpa);
}
module_init(vdpasim_net_init);
module_exit(vdpasim_net_exit);
MODULE_VERSION(DRV_VERSION);
MODULE_LICENSE(DRV_LICENSE);
MODULE_AUTHOR(DRV_AUTHOR);
MODULE_DESCRIPTION(DRV_DESC);