// SPDX-License-Identifier: GPL-2.0-only
/*
* VDPA simulator for networking device.
*
* Copyright (c) 2020, Red Hat Inc. All rights reserved.
* Author: Jason Wang <[email protected]>
*
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/etherdevice.h>
#include <linux/vringh.h>
#include <linux/vdpa.h>
#include <net/netlink.h>
#include <uapi/linux/virtio_net.h>
#include <uapi/linux/vdpa.h>
#include "vdpa_sim.h"
#define DRV_VERSION "0.1"
#define DRV_AUTHOR "Jason Wang <[email protected]>"
#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) | \
(1ULL << VIRTIO_NET_F_STATUS) | \
(1ULL << VIRTIO_NET_F_MTU) | \
(1ULL << VIRTIO_NET_F_CTRL_VQ) | \
(1ULL << VIRTIO_NET_F_CTRL_MAC_ADDR))
/* 3 virtqueues, 2 address spaces, 2 virtqueue groups */
#define VDPASIM_NET_VQ_NUM 3
#define VDPASIM_NET_AS_NUM 2
#define VDPASIM_NET_GROUP_NUM 2
struct vdpasim_dataq_stats {
struct u64_stats_sync syncp;
u64 pkts;
u64 bytes;
u64 drops;
u64 errors;
u64 overruns;
};
struct vdpasim_cq_stats {
struct u64_stats_sync syncp;
u64 requests;
u64 successes;
u64 errors;
};
struct vdpasim_net{
struct vdpasim vdpasim;
struct vdpasim_dataq_stats tx_stats;
struct vdpasim_dataq_stats rx_stats;
struct vdpasim_cq_stats cq_stats;
void *buffer;
};
static struct vdpasim_net *sim_to_net(struct vdpasim *vdpasim)
{
return container_of(vdpasim, struct vdpasim_net, vdpasim);
}
static void vdpasim_net_complete(struct vdpasim_virtqueue *vq, size_t len)
{
/* Make sure data is wrote before advancing index */
smp_wmb();
vringh_complete_iotlb(&vq->vring, vq->head, len);
/* Make sure used is visible before rasing the interrupt. */
smp_wmb();
local_bh_disable();
if (vringh_need_notify_iotlb(&vq->vring) > 0)
vringh_notify(&vq->vring);
local_bh_enable();
}
static bool receive_filter(struct vdpasim *vdpasim, size_t len)
{
bool modern = vdpasim->features & (1ULL << VIRTIO_F_VERSION_1);
size_t hdr_len = modern ? sizeof(struct virtio_net_hdr_v1) :
sizeof(struct virtio_net_hdr);
struct virtio_net_config *vio_config = vdpasim->config;
struct vdpasim_net *net = sim_to_net(vdpasim);
if (len < ETH_ALEN + hdr_len)
return false;
if (is_broadcast_ether_addr(net->buffer + hdr_len) ||
is_multicast_ether_addr(net->buffer + hdr_len))
return true;
if (!strncmp(net->buffer + hdr_len, vio_config->mac, ETH_ALEN))
return true;
return false;
}
static virtio_net_ctrl_ack vdpasim_handle_ctrl_mac(struct vdpasim *vdpasim,
u8 cmd)
{
struct virtio_net_config *vio_config = vdpasim->config;
struct vdpasim_virtqueue *cvq = &vdpasim->vqs[2];
virtio_net_ctrl_ack status = VIRTIO_NET_ERR;
size_t read;
switch (cmd) {
case VIRTIO_NET_CTRL_MAC_ADDR_SET:
read = vringh_iov_pull_iotlb(&cvq->vring, &cvq->in_iov,
vio_config->mac, ETH_ALEN);
if (read == ETH_ALEN)
status = VIRTIO_NET_OK;
break;
default:
break;
}
return status;
}
static void vdpasim_handle_cvq(struct vdpasim *vdpasim)
{
struct vdpasim_virtqueue *cvq = &vdpasim->vqs[2];
struct vdpasim_net *net = sim_to_net(vdpasim);
virtio_net_ctrl_ack status = VIRTIO_NET_ERR;
struct virtio_net_ctrl_hdr ctrl;
size_t read, write;
u64 requests = 0, errors = 0, successes = 0;
int err;
if (!(vdpasim->features & (1ULL << VIRTIO_NET_F_CTRL_VQ)))
return;
if (!cvq->ready)
return;
while (true) {
err = vringh_getdesc_iotlb(&cvq->vring, &cvq->in_iov,
&cvq->out_iov,
&cvq->head, GFP_ATOMIC);
if (err <= 0)
break;
++requests;
read = vringh_iov_pull_iotlb(&cvq->vring, &cvq->in_iov, &ctrl,
sizeof(ctrl));
if (read != sizeof(ctrl)) {
++errors;
break;
}
switch (ctrl.class) {
case VIRTIO_NET_CTRL_MAC:
status = vdpasim_handle_ctrl_mac(vdpasim, ctrl.cmd);
break;
default:
break;
}
if (status == VIRTIO_NET_OK)
++successes;
else
++errors;
/* Make sure data is wrote before advancing index */
smp_wmb();
write = vringh_iov_push_iotlb(&cvq->vring, &cvq->out_iov,
&status, sizeof(status));
vringh_complete_iotlb(&cvq->vring, cvq->head, write);
vringh_kiov_cleanup(&cvq->in_iov);
vringh_kiov_cleanup(&cvq->out_iov);
/* Make sure used is visible before rasing the interrupt. */
smp_wmb();
local_bh_disable();
if (cvq->cb)
cvq->cb(cvq->private);
local_bh_enable();
}
u64_stats_update_begin(&net->cq_stats.syncp);
net->cq_stats.requests += requests;
net->cq_stats.errors += errors;
net->cq_stats.successes += successes;
u64_stats_update_end(&net->cq_stats.syncp);
}
static void vdpasim_net_work(struct vdpasim *vdpasim)
{
struct vdpasim_virtqueue *txq = &vdpasim->vqs[1];
struct vdpasim_virtqueue *rxq = &vdpasim->vqs[0];
struct vdpasim_net *net = sim_to_net(vdpasim);
ssize_t read, write;
u64 tx_pkts = 0, rx_pkts = 0, tx_bytes = 0, rx_bytes = 0;
u64 rx_drops = 0, rx_overruns = 0, rx_errors = 0, tx_errors = 0;
int err;
mutex_lock(&vdpasim->mutex);
if (!vdpasim->running)
goto out;
if (!(vdpasim->status & VIRTIO_CONFIG_S_DRIVER_OK))
goto out;
vdpasim_handle_cvq(vdpasim);
if (!txq->ready || !rxq->ready)
goto out;
while (true) {
err = vringh_getdesc_iotlb(&txq->vring, &txq->out_iov, NULL,
&txq->head, GFP_ATOMIC);
if (err <= 0) {
if (err)
++tx_errors;
break;
}
++tx_pkts;
read = vringh_iov_pull_iotlb(&txq->vring, &txq->out_iov,
net->buffer, PAGE_SIZE);
tx_bytes += read;
if (!receive_filter(vdpasim, read)) {
++rx_drops;
vdpasim_net_complete(txq, 0);
continue;
}
err = vringh_getdesc_iotlb(&rxq->vring, NULL, &rxq->in_iov,
&rxq->head, GFP_ATOMIC);
if (err <= 0) {
++rx_overruns;
vdpasim_net_complete(txq, 0);
break;
}
write = vringh_iov_push_iotlb(&rxq->vring, &rxq->in_iov,
net->buffer, read);
if (write <= 0) {
++rx_errors;
break;
}
++rx_pkts;
rx_bytes += write;
vdpasim_net_complete(txq, 0);
vdpasim_net_complete(rxq, write);
if (tx_pkts > 4) {
vdpasim_schedule_work(vdpasim);
goto out;
}
}
out:
mutex_unlock(&vdpasim->mutex);
u64_stats_update_begin(&net->tx_stats.syncp);
net->tx_stats.pkts += tx_pkts;
net->tx_stats.bytes += tx_bytes;
net->tx_stats.errors += tx_errors;
u64_stats_update_end(&net->tx_stats.syncp);
u64_stats_update_begin(&net->rx_stats.syncp);
net->rx_stats.pkts += rx_pkts;
net->rx_stats.bytes += rx_bytes;
net->rx_stats.drops += rx_drops;
net->rx_stats.errors += rx_errors;
net->rx_stats.overruns += rx_overruns;
u64_stats_update_end(&net->rx_stats.syncp);
}
static int vdpasim_net_get_stats(struct vdpasim *vdpasim, u16 idx,
struct sk_buff *msg,
struct netlink_ext_ack *extack)
{
struct vdpasim_net *net = sim_to_net(vdpasim);
u64 rx_pkts, rx_bytes, rx_errors, rx_overruns, rx_drops;
u64 tx_pkts, tx_bytes, tx_errors, tx_drops;
u64 cq_requests, cq_successes, cq_errors;
unsigned int start;
int err = -EMSGSIZE;
switch(idx) {
case 0:
do {
start = u64_stats_fetch_begin(&net->rx_stats.syncp);
rx_pkts = net->rx_stats.pkts;
rx_bytes = net->rx_stats.bytes;
rx_errors = net->rx_stats.errors;
rx_overruns = net->rx_stats.overruns;
rx_drops = net->rx_stats.drops;
} while (u64_stats_fetch_retry(&net->rx_stats.syncp, start));
if (nla_put_string(msg, VDPA_ATTR_DEV_VENDOR_ATTR_NAME,
"rx packets"))
break;
if (nla_put_u64_64bit(msg, VDPA_ATTR_DEV_VENDOR_ATTR_VALUE,
rx_pkts, VDPA_ATTR_PAD))
break;
if (nla_put_string(msg, VDPA_ATTR_DEV_VENDOR_ATTR_NAME,
"rx bytes"))
break;
if (nla_put_u64_64bit(msg, VDPA_ATTR_DEV_VENDOR_ATTR_VALUE,
rx_bytes, VDPA_ATTR_PAD))
break;
if (nla_put_string(msg, VDPA_ATTR_DEV_VENDOR_ATTR_NAME,
"rx errors"))
break;
if (nla_put_u64_64bit(msg, VDPA_ATTR_DEV_VENDOR_ATTR_VALUE,
rx_errors, VDPA_ATTR_PAD))
break;
if (nla_put_string(msg, VDPA_ATTR_DEV_VENDOR_ATTR_NAME,
"rx overruns"))
break;
if (nla_put_u64_64bit(msg, VDPA_ATTR_DEV_VENDOR_ATTR_VALUE,
rx_overruns, VDPA_ATTR_PAD))
break;
if (nla_put_string(msg, VDPA_ATTR_DEV_VENDOR_ATTR_NAME,
"rx drops"))
break;
if (nla_put_u64_64bit(msg, VDPA_ATTR_DEV_VENDOR_ATTR_VALUE,
rx_drops, VDPA_ATTR_PAD))
break;
err = 0;
break;
case 1:
do {
start = u64_stats_fetch_begin(&net->tx_stats.syncp);
tx_pkts = net->tx_stats.pkts;
tx_bytes = net->tx_stats.bytes;
tx_errors = net->tx_stats.errors;
tx_drops = net->tx_stats.drops;
} while (u64_stats_fetch_retry(&net->tx_stats.syncp, start));
if (nla_put_string(msg, VDPA_ATTR_DEV_VENDOR_ATTR_NAME,
"tx packets"))
break;
if (nla_put_u64_64bit(msg, VDPA_ATTR_DEV_VENDOR_ATTR_VALUE,
tx_pkts, VDPA_ATTR_PAD))
break;
if (nla_put_string(msg, VDPA_ATTR_DEV_VENDOR_ATTR_NAME,
"tx bytes"))
break;
if (nla_put_u64_64bit(msg, VDPA_ATTR_DEV_VENDOR_ATTR_VALUE,
tx_bytes, VDPA_ATTR_PAD))
break;
if (nla_put_string(msg, VDPA_ATTR_DEV_VENDOR_ATTR_NAME,
"tx errors"))
break;
if (nla_put_u64_64bit(msg, VDPA_ATTR_DEV_VENDOR_ATTR_VALUE,
tx_errors, VDPA_ATTR_PAD))
break;
if (nla_put_string(msg, VDPA_ATTR_DEV_VENDOR_ATTR_NAME,
"tx drops"))
break;
if (nla_put_u64_64bit(msg, VDPA_ATTR_DEV_VENDOR_ATTR_VALUE,
tx_drops, VDPA_ATTR_PAD))
break;
err = 0;
break;
case 2:
do {
start = u64_stats_fetch_begin(&net->cq_stats.syncp);
cq_requests = net->cq_stats.requests;
cq_successes = net->cq_stats.successes;
cq_errors = net->cq_stats.errors;
} while (u64_stats_fetch_retry(&net->cq_stats.syncp, start));
if (nla_put_string(msg, VDPA_ATTR_DEV_VENDOR_ATTR_NAME,
"cvq requests"))
break;
if (nla_put_u64_64bit(msg, VDPA_ATTR_DEV_VENDOR_ATTR_VALUE,
cq_requests, VDPA_ATTR_PAD))
break;
if (nla_put_string(msg, VDPA_ATTR_DEV_VENDOR_ATTR_NAME,
"cvq successes"))
break;
if (nla_put_u64_64bit(msg, VDPA_ATTR_DEV_VENDOR_ATTR_VALUE,
cq_successes, VDPA_ATTR_PAD))
break;
if (nla_put_string(msg, VDPA_ATTR_DEV_VENDOR_ATTR_NAME,
"cvq errors"))
break;
if (nla_put_u64_64bit(msg, VDPA_ATTR_DEV_VENDOR_ATTR_VALUE,
cq_errors, VDPA_ATTR_PAD))
break;
err = 0;
break;
default:
err = -EINVAL;
break;
}
return err;
}
static void vdpasim_net_get_config(struct vdpasim *vdpasim, void *config)
{
struct virtio_net_config *net_config = config;
net_config->status = cpu_to_vdpasim16(vdpasim, VIRTIO_NET_S_LINK_UP);
}
static int vdpasim_net_set_attr(struct vdpa_mgmt_dev *mdev, struct vdpa_device *dev,
const struct vdpa_dev_set_config *config)
{
struct vdpasim *vdpasim = container_of(dev, struct vdpasim, vdpa);
struct virtio_net_config *vio_config = vdpasim->config;
mutex_lock(&vdpasim->mutex);
if (config->mask & (1 << VDPA_ATTR_DEV_NET_CFG_MACADDR)) {
ether_addr_copy(vio_config->mac, config->net.mac);
mutex_unlock(&vdpasim->mutex);
return 0;
}
mutex_unlock(&vdpasim->mutex);
return -EOPNOTSUPP;
}
static void vdpasim_net_setup_config(struct vdpasim *vdpasim,
const struct vdpa_dev_set_config *config)
{
struct virtio_net_config *vio_config = vdpasim->config;
if (config->mask & (1 << VDPA_ATTR_DEV_NET_CFG_MACADDR))
memcpy(vio_config->mac, config->net.mac, ETH_ALEN);
if (config->mask & (1 << VDPA_ATTR_DEV_NET_CFG_MTU))
vio_config->mtu = cpu_to_vdpasim16(vdpasim, config->net.mtu);
else
/* Setup default MTU to be 1500 */
vio_config->mtu = cpu_to_vdpasim16(vdpasim, 1500);
}
static void vdpasim_net_free(struct vdpasim *vdpasim)
{
struct vdpasim_net *net = sim_to_net(vdpasim);
kvfree(net->buffer);
}
static void vdpasim_net_mgmtdev_release(struct device *dev)
{
}
static struct device vdpasim_net_mgmtdev = {
.init_name = "vdpasim_net",
.release = vdpasim_net_mgmtdev_release,
};
static int vdpasim_net_dev_add(struct vdpa_mgmt_dev *mdev, const char *name,
const struct vdpa_dev_set_config *config)
{
struct vdpasim_dev_attr dev_attr = {};
struct vdpasim_net *net;
struct vdpasim *simdev;
int ret;
dev_attr.mgmt_dev = mdev;
dev_attr.name = name;
dev_attr.id = VIRTIO_ID_NET;
dev_attr.supported_features = VDPASIM_NET_FEATURES;
dev_attr.nvqs = VDPASIM_NET_VQ_NUM;
dev_attr.ngroups = VDPASIM_NET_GROUP_NUM;
dev_attr.nas = VDPASIM_NET_AS_NUM;
dev_attr.alloc_size = sizeof(struct vdpasim_net);
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.get_stats = vdpasim_net_get_stats;
dev_attr.free = vdpasim_net_free;
simdev = vdpasim_create(&dev_attr, config);
if (IS_ERR(simdev))
return PTR_ERR(simdev);
vdpasim_net_setup_config(simdev, config);
net = sim_to_net(simdev);
u64_stats_init(&net->tx_stats.syncp);
u64_stats_init(&net->rx_stats.syncp);
u64_stats_init(&net->cq_stats.syncp);
net->buffer = kvmalloc(PAGE_SIZE, GFP_KERNEL);
if (!net->buffer) {
ret = -ENOMEM;
goto reg_err;
}
/*
* Initialization must be completed before this call, since it can
* connect the device to the vDPA bus, so requests can arrive after
* this call.
*/
ret = _vdpa_register_device(&simdev->vdpa, VDPASIM_NET_VQ_NUM);
if (ret)
goto reg_err;
return 0;
reg_err:
put_device(&simdev->vdpa.dev);
return ret;
}
static void vdpasim_net_dev_del(struct vdpa_mgmt_dev *mdev,
struct vdpa_device *dev)
{
struct vdpasim *simdev = container_of(dev, struct vdpasim, vdpa);
_vdpa_unregister_device(&simdev->vdpa);
}
static const struct vdpa_mgmtdev_ops vdpasim_net_mgmtdev_ops = {
.dev_add = vdpasim_net_dev_add,
.dev_del = vdpasim_net_dev_del,
.dev_set_attr = vdpasim_net_set_attr
};
static struct virtio_device_id id_table[] = {
{ VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
{ 0 },
};
static struct vdpa_mgmt_dev mgmt_dev = {
.device = &vdpasim_net_mgmtdev,
.id_table = id_table,
.ops = &vdpasim_net_mgmtdev_ops,
.config_attr_mask = (1 << VDPA_ATTR_DEV_NET_CFG_MACADDR |
1 << VDPA_ATTR_DEV_NET_CFG_MTU |
1 << VDPA_ATTR_DEV_FEATURES),
.max_supported_vqs = VDPASIM_NET_VQ_NUM,
.supported_features = VDPASIM_NET_FEATURES,
};
static int __init vdpasim_net_init(void)
{
int ret;
ret = device_register(&vdpasim_net_mgmtdev);
if (ret) {
put_device(&vdpasim_net_mgmtdev);
return ret;
}
ret = vdpa_mgmtdev_register(&mgmt_dev);
if (ret)
goto parent_err;
return 0;
parent_err:
device_unregister(&vdpasim_net_mgmtdev);
return ret;
}
static void __exit vdpasim_net_exit(void)
{
vdpa_mgmtdev_unregister(&mgmt_dev);
device_unregister(&vdpasim_net_mgmtdev);
}
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);
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