blob: 6a90fdb9cbfc6f8070a43692b858f9349d577f0e [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0-only
/*
* VDPA networking device simulator.
*
* 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/fs.h>
#include <linux/poll.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/wait.h>
#include <linux/uuid.h>
#include <linux/iommu.h>
#include <linux/dma-map-ops.h>
#include <linux/sysfs.h>
#include <linux/file.h>
#include <linux/etherdevice.h>
#include <linux/vringh.h>
#include <linux/vdpa.h>
#include <linux/virtio_byteorder.h>
#include <linux/vhost_iotlb.h>
#include <uapi/linux/virtio_config.h>
#include <uapi/linux/virtio_net.h>
#define DRV_VERSION "0.1"
#define DRV_AUTHOR "Jason Wang <jasowang@redhat.com>"
#define DRV_DESC "vDPA Device Simulator"
#define DRV_LICENSE "GPL v2"
static int batch_mapping = 1;
module_param(batch_mapping, int, 0444);
MODULE_PARM_DESC(batch_mapping, "Batched mapping 1 -Enable; 0 - Disable");
static char *macaddr;
module_param(macaddr, charp, 0);
MODULE_PARM_DESC(macaddr, "Ethernet MAC address");
struct vdpasim_virtqueue {
struct vringh vring;
struct vringh_kiov iov;
unsigned short head;
bool ready;
u64 desc_addr;
u64 device_addr;
u64 driver_addr;
u32 num;
void *private;
irqreturn_t (*cb)(void *data);
};
#define VDPASIM_QUEUE_ALIGN PAGE_SIZE
#define VDPASIM_QUEUE_MAX 256
#define VDPASIM_DEVICE_ID 0x1
#define VDPASIM_VENDOR_ID 0
#define VDPASIM_VQ_NUM 0x2
#define VDPASIM_NAME "vdpasim-netdev"
static u64 vdpasim_features = (1ULL << VIRTIO_F_ANY_LAYOUT) |
(1ULL << VIRTIO_F_VERSION_1) |
(1ULL << VIRTIO_F_ACCESS_PLATFORM) |
(1ULL << VIRTIO_NET_F_MAC);
/* State of each vdpasim device */
struct vdpasim {
struct vdpa_device vdpa;
struct vdpasim_virtqueue vqs[VDPASIM_VQ_NUM];
struct work_struct work;
/* spinlock to synchronize virtqueue state */
spinlock_t lock;
struct virtio_net_config config;
struct vhost_iotlb *iommu;
void *buffer;
u32 status;
u32 generation;
u64 features;
/* spinlock to synchronize iommu table */
spinlock_t iommu_lock;
};
/* TODO: cross-endian support */
static inline bool vdpasim_is_little_endian(struct vdpasim *vdpasim)
{
return virtio_legacy_is_little_endian() ||
(vdpasim->features & (1ULL << VIRTIO_F_VERSION_1));
}
static inline u16 vdpasim16_to_cpu(struct vdpasim *vdpasim, __virtio16 val)
{
return __virtio16_to_cpu(vdpasim_is_little_endian(vdpasim), val);
}
static inline __virtio16 cpu_to_vdpasim16(struct vdpasim *vdpasim, u16 val)
{
return __cpu_to_virtio16(vdpasim_is_little_endian(vdpasim), val);
}
static struct vdpasim *vdpasim_dev;
static struct vdpasim *vdpa_to_sim(struct vdpa_device *vdpa)
{
return container_of(vdpa, struct vdpasim, vdpa);
}
static struct vdpasim *dev_to_sim(struct device *dev)
{
struct vdpa_device *vdpa = dev_to_vdpa(dev);
return vdpa_to_sim(vdpa);
}
static void vdpasim_queue_ready(struct vdpasim *vdpasim, unsigned int idx)
{
struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx];
vringh_init_iotlb(&vq->vring, vdpasim_features,
VDPASIM_QUEUE_MAX, false,
(struct vring_desc *)(uintptr_t)vq->desc_addr,
(struct vring_avail *)
(uintptr_t)vq->driver_addr,
(struct vring_used *)
(uintptr_t)vq->device_addr);
}
static void vdpasim_vq_reset(struct vdpasim_virtqueue *vq)
{
vq->ready = false;
vq->desc_addr = 0;
vq->driver_addr = 0;
vq->device_addr = 0;
vq->cb = NULL;
vq->private = NULL;
vringh_init_iotlb(&vq->vring, vdpasim_features, VDPASIM_QUEUE_MAX,
false, NULL, NULL, NULL);
}
static void vdpasim_reset(struct vdpasim *vdpasim)
{
int i;
for (i = 0; i < VDPASIM_VQ_NUM; i++)
vdpasim_vq_reset(&vdpasim->vqs[i]);
spin_lock(&vdpasim->iommu_lock);
vhost_iotlb_reset(vdpasim->iommu);
spin_unlock(&vdpasim->iommu_lock);
vdpasim->features = 0;
vdpasim->status = 0;
++vdpasim->generation;
}
static void vdpasim_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->iov, NULL,
&txq->head, GFP_ATOMIC);
if (err <= 0)
break;
err = vringh_getdesc_iotlb(&rxq->vring, NULL, &rxq->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->iov,
vdpasim->buffer,
PAGE_SIZE);
if (read <= 0)
break;
write = vringh_iov_push_iotlb(&rxq->vring, &rxq->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 (txq->cb)
txq->cb(txq->private);
if (rxq->cb)
rxq->cb(rxq->private);
local_bh_enable();
if (++pkts > 4) {
schedule_work(&vdpasim->work);
goto out;
}
}
out:
spin_unlock(&vdpasim->lock);
}
static int dir_to_perm(enum dma_data_direction dir)
{
int perm = -EFAULT;
switch (dir) {
case DMA_FROM_DEVICE:
perm = VHOST_MAP_WO;
break;
case DMA_TO_DEVICE:
perm = VHOST_MAP_RO;
break;
case DMA_BIDIRECTIONAL:
perm = VHOST_MAP_RW;
break;
default:
break;
}
return perm;
}
static dma_addr_t vdpasim_map_page(struct device *dev, struct page *page,
unsigned long offset, size_t size,
enum dma_data_direction dir,
unsigned long attrs)
{
struct vdpasim *vdpasim = dev_to_sim(dev);
struct vhost_iotlb *iommu = vdpasim->iommu;
u64 pa = (page_to_pfn(page) << PAGE_SHIFT) + offset;
int ret, perm = dir_to_perm(dir);
if (perm < 0)
return DMA_MAPPING_ERROR;
/* For simplicity, use identical mapping to avoid e.g iova
* allocator.
*/
spin_lock(&vdpasim->iommu_lock);
ret = vhost_iotlb_add_range(iommu, pa, pa + size - 1,
pa, dir_to_perm(dir));
spin_unlock(&vdpasim->iommu_lock);
if (ret)
return DMA_MAPPING_ERROR;
return (dma_addr_t)(pa);
}
static void vdpasim_unmap_page(struct device *dev, dma_addr_t dma_addr,
size_t size, enum dma_data_direction dir,
unsigned long attrs)
{
struct vdpasim *vdpasim = dev_to_sim(dev);
struct vhost_iotlb *iommu = vdpasim->iommu;
spin_lock(&vdpasim->iommu_lock);
vhost_iotlb_del_range(iommu, (u64)dma_addr,
(u64)dma_addr + size - 1);
spin_unlock(&vdpasim->iommu_lock);
}
static void *vdpasim_alloc_coherent(struct device *dev, size_t size,
dma_addr_t *dma_addr, gfp_t flag,
unsigned long attrs)
{
struct vdpasim *vdpasim = dev_to_sim(dev);
struct vhost_iotlb *iommu = vdpasim->iommu;
void *addr = kmalloc(size, flag);
int ret;
spin_lock(&vdpasim->iommu_lock);
if (!addr) {
*dma_addr = DMA_MAPPING_ERROR;
} else {
u64 pa = virt_to_phys(addr);
ret = vhost_iotlb_add_range(iommu, (u64)pa,
(u64)pa + size - 1,
pa, VHOST_MAP_RW);
if (ret) {
*dma_addr = DMA_MAPPING_ERROR;
kfree(addr);
addr = NULL;
} else
*dma_addr = (dma_addr_t)pa;
}
spin_unlock(&vdpasim->iommu_lock);
return addr;
}
static void vdpasim_free_coherent(struct device *dev, size_t size,
void *vaddr, dma_addr_t dma_addr,
unsigned long attrs)
{
struct vdpasim *vdpasim = dev_to_sim(dev);
struct vhost_iotlb *iommu = vdpasim->iommu;
spin_lock(&vdpasim->iommu_lock);
vhost_iotlb_del_range(iommu, (u64)dma_addr,
(u64)dma_addr + size - 1);
spin_unlock(&vdpasim->iommu_lock);
kfree(phys_to_virt((uintptr_t)dma_addr));
}
static const struct dma_map_ops vdpasim_dma_ops = {
.map_page = vdpasim_map_page,
.unmap_page = vdpasim_unmap_page,
.alloc = vdpasim_alloc_coherent,
.free = vdpasim_free_coherent,
};
static const struct vdpa_config_ops vdpasim_net_config_ops;
static const struct vdpa_config_ops vdpasim_net_batch_config_ops;
static struct vdpasim *vdpasim_create(void)
{
const struct vdpa_config_ops *ops;
struct vdpasim *vdpasim;
struct device *dev;
int ret = -ENOMEM;
if (batch_mapping)
ops = &vdpasim_net_batch_config_ops;
else
ops = &vdpasim_net_config_ops;
vdpasim = vdpa_alloc_device(struct vdpasim, vdpa, NULL, ops, VDPASIM_VQ_NUM);
if (!vdpasim)
goto err_alloc;
INIT_WORK(&vdpasim->work, vdpasim_work);
spin_lock_init(&vdpasim->lock);
spin_lock_init(&vdpasim->iommu_lock);
dev = &vdpasim->vdpa.dev;
dev->dma_mask = &dev->coherent_dma_mask;
if (dma_set_mask_and_coherent(dev, DMA_BIT_MASK(64)))
goto err_iommu;
set_dma_ops(dev, &vdpasim_dma_ops);
vdpasim->iommu = vhost_iotlb_alloc(2048, 0);
if (!vdpasim->iommu)
goto err_iommu;
vdpasim->buffer = kmalloc(PAGE_SIZE, GFP_KERNEL);
if (!vdpasim->buffer)
goto err_iommu;
if (macaddr) {
mac_pton(macaddr, vdpasim->config.mac);
if (!is_valid_ether_addr(vdpasim->config.mac)) {
ret = -EADDRNOTAVAIL;
goto err_iommu;
}
} else {
eth_random_addr(vdpasim->config.mac);
}
vringh_set_iotlb(&vdpasim->vqs[0].vring, vdpasim->iommu);
vringh_set_iotlb(&vdpasim->vqs[1].vring, vdpasim->iommu);
vdpasim->vdpa.dma_dev = dev;
ret = vdpa_register_device(&vdpasim->vdpa);
if (ret)
goto err_iommu;
return vdpasim;
err_iommu:
put_device(dev);
err_alloc:
return ERR_PTR(ret);
}
static int vdpasim_set_vq_address(struct vdpa_device *vdpa, u16 idx,
u64 desc_area, u64 driver_area,
u64 device_area)
{
struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx];
vq->desc_addr = desc_area;
vq->driver_addr = driver_area;
vq->device_addr = device_area;
return 0;
}
static void vdpasim_set_vq_num(struct vdpa_device *vdpa, u16 idx, u32 num)
{
struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx];
vq->num = num;
}
static void vdpasim_kick_vq(struct vdpa_device *vdpa, u16 idx)
{
struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx];
if (vq->ready)
schedule_work(&vdpasim->work);
}
static void vdpasim_set_vq_cb(struct vdpa_device *vdpa, u16 idx,
struct vdpa_callback *cb)
{
struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx];
vq->cb = cb->callback;
vq->private = cb->private;
}
static void vdpasim_set_vq_ready(struct vdpa_device *vdpa, u16 idx, bool ready)
{
struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx];
spin_lock(&vdpasim->lock);
vq->ready = ready;
if (vq->ready)
vdpasim_queue_ready(vdpasim, idx);
spin_unlock(&vdpasim->lock);
}
static bool vdpasim_get_vq_ready(struct vdpa_device *vdpa, u16 idx)
{
struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx];
return vq->ready;
}
static int vdpasim_set_vq_state(struct vdpa_device *vdpa, u16 idx,
const struct vdpa_vq_state *state)
{
struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx];
struct vringh *vrh = &vq->vring;
spin_lock(&vdpasim->lock);
vrh->last_avail_idx = state->avail_index;
spin_unlock(&vdpasim->lock);
return 0;
}
static int vdpasim_get_vq_state(struct vdpa_device *vdpa, u16 idx,
struct vdpa_vq_state *state)
{
struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx];
struct vringh *vrh = &vq->vring;
state->avail_index = vrh->last_avail_idx;
return 0;
}
static u32 vdpasim_get_vq_align(struct vdpa_device *vdpa)
{
return VDPASIM_QUEUE_ALIGN;
}
static u64 vdpasim_get_features(struct vdpa_device *vdpa)
{
return vdpasim_features;
}
static int vdpasim_set_features(struct vdpa_device *vdpa, u64 features)
{
struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
struct virtio_net_config *config = &vdpasim->config;
/* DMA mapping must be done by driver */
if (!(features & (1ULL << VIRTIO_F_ACCESS_PLATFORM)))
return -EINVAL;
vdpasim->features = features & vdpasim_features;
/* We generally only know whether guest is using the legacy interface
* here, so generally that's the earliest we can set config fields.
* Note: We actually require VIRTIO_F_ACCESS_PLATFORM above which
* implies VIRTIO_F_VERSION_1, but let's not try to be clever here.
*/
config->mtu = cpu_to_vdpasim16(vdpasim, 1500);
config->status = cpu_to_vdpasim16(vdpasim, VIRTIO_NET_S_LINK_UP);
return 0;
}
static void vdpasim_set_config_cb(struct vdpa_device *vdpa,
struct vdpa_callback *cb)
{
/* We don't support config interrupt */
}
static u16 vdpasim_get_vq_num_max(struct vdpa_device *vdpa)
{
return VDPASIM_QUEUE_MAX;
}
static u32 vdpasim_get_device_id(struct vdpa_device *vdpa)
{
return VDPASIM_DEVICE_ID;
}
static u32 vdpasim_get_vendor_id(struct vdpa_device *vdpa)
{
return VDPASIM_VENDOR_ID;
}
static u8 vdpasim_get_status(struct vdpa_device *vdpa)
{
struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
u8 status;
spin_lock(&vdpasim->lock);
status = vdpasim->status;
spin_unlock(&vdpasim->lock);
return status;
}
static void vdpasim_set_status(struct vdpa_device *vdpa, u8 status)
{
struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
spin_lock(&vdpasim->lock);
vdpasim->status = status;
if (status == 0)
vdpasim_reset(vdpasim);
spin_unlock(&vdpasim->lock);
}
static void vdpasim_get_config(struct vdpa_device *vdpa, unsigned int offset,
void *buf, unsigned int len)
{
struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
if (offset + len < sizeof(struct virtio_net_config))
memcpy(buf, (u8 *)&vdpasim->config + offset, len);
}
static void vdpasim_set_config(struct vdpa_device *vdpa, unsigned int offset,
const void *buf, unsigned int len)
{
/* No writable config supportted by vdpasim */
}
static u32 vdpasim_get_generation(struct vdpa_device *vdpa)
{
struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
return vdpasim->generation;
}
static struct vdpa_iova_range vdpasim_get_iova_range(struct vdpa_device *vdpa)
{
struct vdpa_iova_range range = {
.first = 0ULL,
.last = ULLONG_MAX,
};
return range;
}
static int vdpasim_set_map(struct vdpa_device *vdpa,
struct vhost_iotlb *iotlb)
{
struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
struct vhost_iotlb_map *map;
u64 start = 0ULL, last = 0ULL - 1;
int ret;
spin_lock(&vdpasim->iommu_lock);
vhost_iotlb_reset(vdpasim->iommu);
for (map = vhost_iotlb_itree_first(iotlb, start, last); map;
map = vhost_iotlb_itree_next(map, start, last)) {
ret = vhost_iotlb_add_range(vdpasim->iommu, map->start,
map->last, map->addr, map->perm);
if (ret)
goto err;
}
spin_unlock(&vdpasim->iommu_lock);
return 0;
err:
vhost_iotlb_reset(vdpasim->iommu);
spin_unlock(&vdpasim->iommu_lock);
return ret;
}
static int vdpasim_dma_map(struct vdpa_device *vdpa, u64 iova, u64 size,
u64 pa, u32 perm)
{
struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
int ret;
spin_lock(&vdpasim->iommu_lock);
ret = vhost_iotlb_add_range(vdpasim->iommu, iova, iova + size - 1, pa,
perm);
spin_unlock(&vdpasim->iommu_lock);
return ret;
}
static int vdpasim_dma_unmap(struct vdpa_device *vdpa, u64 iova, u64 size)
{
struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
spin_lock(&vdpasim->iommu_lock);
vhost_iotlb_del_range(vdpasim->iommu, iova, iova + size - 1);
spin_unlock(&vdpasim->iommu_lock);
return 0;
}
static void vdpasim_free(struct vdpa_device *vdpa)
{
struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
cancel_work_sync(&vdpasim->work);
kfree(vdpasim->buffer);
if (vdpasim->iommu)
vhost_iotlb_free(vdpasim->iommu);
}
static const struct vdpa_config_ops vdpasim_net_config_ops = {
.set_vq_address = vdpasim_set_vq_address,
.set_vq_num = vdpasim_set_vq_num,
.kick_vq = vdpasim_kick_vq,
.set_vq_cb = vdpasim_set_vq_cb,
.set_vq_ready = vdpasim_set_vq_ready,
.get_vq_ready = vdpasim_get_vq_ready,
.set_vq_state = vdpasim_set_vq_state,
.get_vq_state = vdpasim_get_vq_state,
.get_vq_align = vdpasim_get_vq_align,
.get_features = vdpasim_get_features,
.set_features = vdpasim_set_features,
.set_config_cb = vdpasim_set_config_cb,
.get_vq_num_max = vdpasim_get_vq_num_max,
.get_device_id = vdpasim_get_device_id,
.get_vendor_id = vdpasim_get_vendor_id,
.get_status = vdpasim_get_status,
.set_status = vdpasim_set_status,
.get_config = vdpasim_get_config,
.set_config = vdpasim_set_config,
.get_generation = vdpasim_get_generation,
.get_iova_range = vdpasim_get_iova_range,
.dma_map = vdpasim_dma_map,
.dma_unmap = vdpasim_dma_unmap,
.free = vdpasim_free,
};
static const struct vdpa_config_ops vdpasim_net_batch_config_ops = {
.set_vq_address = vdpasim_set_vq_address,
.set_vq_num = vdpasim_set_vq_num,
.kick_vq = vdpasim_kick_vq,
.set_vq_cb = vdpasim_set_vq_cb,
.set_vq_ready = vdpasim_set_vq_ready,
.get_vq_ready = vdpasim_get_vq_ready,
.set_vq_state = vdpasim_set_vq_state,
.get_vq_state = vdpasim_get_vq_state,
.get_vq_align = vdpasim_get_vq_align,
.get_features = vdpasim_get_features,
.set_features = vdpasim_set_features,
.set_config_cb = vdpasim_set_config_cb,
.get_vq_num_max = vdpasim_get_vq_num_max,
.get_device_id = vdpasim_get_device_id,
.get_vendor_id = vdpasim_get_vendor_id,
.get_status = vdpasim_get_status,
.set_status = vdpasim_set_status,
.get_config = vdpasim_get_config,
.set_config = vdpasim_set_config,
.get_generation = vdpasim_get_generation,
.get_iova_range = vdpasim_get_iova_range,
.set_map = vdpasim_set_map,
.free = vdpasim_free,
};
static int __init vdpasim_dev_init(void)
{
vdpasim_dev = vdpasim_create();
if (!IS_ERR(vdpasim_dev))
return 0;
return PTR_ERR(vdpasim_dev);
}
static void __exit vdpasim_dev_exit(void)
{
struct vdpa_device *vdpa = &vdpasim_dev->vdpa;
vdpa_unregister_device(vdpa);
}
module_init(vdpasim_dev_init)
module_exit(vdpasim_dev_exit)
MODULE_VERSION(DRV_VERSION);
MODULE_LICENSE(DRV_LICENSE);
MODULE_AUTHOR(DRV_AUTHOR);
MODULE_DESCRIPTION(DRV_DESC);