blob: a2dbc85e0b0d67b49ccc1f236f7f38c48035cd31 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2018-2020 Intel Corporation.
* Copyright (C) 2020 Red Hat, Inc.
*
* Author: Tiwei Bie <tiwei.bie@intel.com>
* Jason Wang <jasowang@redhat.com>
*
* Thanks Michael S. Tsirkin for the valuable comments and
* suggestions. And thanks to Cunming Liang and Zhihong Wang for all
* their supports.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/cdev.h>
#include <linux/device.h>
#include <linux/mm.h>
#include <linux/iommu.h>
#include <linux/uuid.h>
#include <linux/vdpa.h>
#include <linux/nospec.h>
#include <linux/vhost.h>
#include <linux/virtio_net.h>
#include "vhost.h"
enum {
VHOST_VDPA_BACKEND_FEATURES =
(1ULL << VHOST_BACKEND_F_IOTLB_MSG_V2) |
(1ULL << VHOST_BACKEND_F_IOTLB_BATCH),
};
#define VHOST_VDPA_DEV_MAX (1U << MINORBITS)
struct vhost_vdpa {
struct vhost_dev vdev;
struct iommu_domain *domain;
struct vhost_virtqueue *vqs;
struct completion completion;
struct vdpa_device *vdpa;
struct device dev;
struct cdev cdev;
atomic_t opened;
int nvqs;
int virtio_id;
int minor;
struct eventfd_ctx *config_ctx;
int in_batch;
};
static DEFINE_IDA(vhost_vdpa_ida);
static dev_t vhost_vdpa_major;
static void handle_vq_kick(struct vhost_work *work)
{
struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
poll.work);
struct vhost_vdpa *v = container_of(vq->dev, struct vhost_vdpa, vdev);
const struct vdpa_config_ops *ops = v->vdpa->config;
ops->kick_vq(v->vdpa, vq - v->vqs);
}
static irqreturn_t vhost_vdpa_virtqueue_cb(void *private)
{
struct vhost_virtqueue *vq = private;
struct eventfd_ctx *call_ctx = vq->call_ctx.ctx;
if (call_ctx)
eventfd_signal(call_ctx, 1);
return IRQ_HANDLED;
}
static irqreturn_t vhost_vdpa_config_cb(void *private)
{
struct vhost_vdpa *v = private;
struct eventfd_ctx *config_ctx = v->config_ctx;
if (config_ctx)
eventfd_signal(config_ctx, 1);
return IRQ_HANDLED;
}
static void vhost_vdpa_setup_vq_irq(struct vhost_vdpa *v, u16 qid)
{
struct vhost_virtqueue *vq = &v->vqs[qid];
const struct vdpa_config_ops *ops = v->vdpa->config;
struct vdpa_device *vdpa = v->vdpa;
int ret, irq;
if (!ops->get_vq_irq)
return;
irq = ops->get_vq_irq(vdpa, qid);
irq_bypass_unregister_producer(&vq->call_ctx.producer);
if (!vq->call_ctx.ctx || irq < 0)
return;
vq->call_ctx.producer.token = vq->call_ctx.ctx;
vq->call_ctx.producer.irq = irq;
ret = irq_bypass_register_producer(&vq->call_ctx.producer);
}
static void vhost_vdpa_unsetup_vq_irq(struct vhost_vdpa *v, u16 qid)
{
struct vhost_virtqueue *vq = &v->vqs[qid];
irq_bypass_unregister_producer(&vq->call_ctx.producer);
}
static void vhost_vdpa_reset(struct vhost_vdpa *v)
{
struct vdpa_device *vdpa = v->vdpa;
vdpa_reset(vdpa);
v->in_batch = 0;
}
static long vhost_vdpa_get_device_id(struct vhost_vdpa *v, u8 __user *argp)
{
struct vdpa_device *vdpa = v->vdpa;
const struct vdpa_config_ops *ops = vdpa->config;
u32 device_id;
device_id = ops->get_device_id(vdpa);
if (copy_to_user(argp, &device_id, sizeof(device_id)))
return -EFAULT;
return 0;
}
static long vhost_vdpa_get_status(struct vhost_vdpa *v, u8 __user *statusp)
{
struct vdpa_device *vdpa = v->vdpa;
const struct vdpa_config_ops *ops = vdpa->config;
u8 status;
status = ops->get_status(vdpa);
if (copy_to_user(statusp, &status, sizeof(status)))
return -EFAULT;
return 0;
}
static long vhost_vdpa_set_status(struct vhost_vdpa *v, u8 __user *statusp)
{
struct vdpa_device *vdpa = v->vdpa;
const struct vdpa_config_ops *ops = vdpa->config;
u8 status, status_old;
int nvqs = v->nvqs;
u16 i;
if (copy_from_user(&status, statusp, sizeof(status)))
return -EFAULT;
status_old = ops->get_status(vdpa);
/*
* Userspace shouldn't remove status bits unless reset the
* status to 0.
*/
if (status != 0 && (ops->get_status(vdpa) & ~status) != 0)
return -EINVAL;
ops->set_status(vdpa, status);
if ((status & VIRTIO_CONFIG_S_DRIVER_OK) && !(status_old & VIRTIO_CONFIG_S_DRIVER_OK))
for (i = 0; i < nvqs; i++)
vhost_vdpa_setup_vq_irq(v, i);
if ((status_old & VIRTIO_CONFIG_S_DRIVER_OK) && !(status & VIRTIO_CONFIG_S_DRIVER_OK))
for (i = 0; i < nvqs; i++)
vhost_vdpa_unsetup_vq_irq(v, i);
return 0;
}
static int vhost_vdpa_config_validate(struct vhost_vdpa *v,
struct vhost_vdpa_config *c)
{
long size = 0;
switch (v->virtio_id) {
case VIRTIO_ID_NET:
size = sizeof(struct virtio_net_config);
break;
}
if (c->len == 0)
return -EINVAL;
if (c->len > size - c->off)
return -E2BIG;
return 0;
}
static long vhost_vdpa_get_config(struct vhost_vdpa *v,
struct vhost_vdpa_config __user *c)
{
struct vdpa_device *vdpa = v->vdpa;
struct vhost_vdpa_config config;
unsigned long size = offsetof(struct vhost_vdpa_config, buf);
u8 *buf;
if (copy_from_user(&config, c, size))
return -EFAULT;
if (vhost_vdpa_config_validate(v, &config))
return -EINVAL;
buf = kvzalloc(config.len, GFP_KERNEL);
if (!buf)
return -ENOMEM;
vdpa_get_config(vdpa, config.off, buf, config.len);
if (copy_to_user(c->buf, buf, config.len)) {
kvfree(buf);
return -EFAULT;
}
kvfree(buf);
return 0;
}
static long vhost_vdpa_set_config(struct vhost_vdpa *v,
struct vhost_vdpa_config __user *c)
{
struct vdpa_device *vdpa = v->vdpa;
const struct vdpa_config_ops *ops = vdpa->config;
struct vhost_vdpa_config config;
unsigned long size = offsetof(struct vhost_vdpa_config, buf);
u8 *buf;
if (copy_from_user(&config, c, size))
return -EFAULT;
if (vhost_vdpa_config_validate(v, &config))
return -EINVAL;
buf = kvzalloc(config.len, GFP_KERNEL);
if (!buf)
return -ENOMEM;
if (copy_from_user(buf, c->buf, config.len)) {
kvfree(buf);
return -EFAULT;
}
ops->set_config(vdpa, config.off, buf, config.len);
kvfree(buf);
return 0;
}
static long vhost_vdpa_get_features(struct vhost_vdpa *v, u64 __user *featurep)
{
struct vdpa_device *vdpa = v->vdpa;
const struct vdpa_config_ops *ops = vdpa->config;
u64 features;
features = ops->get_features(vdpa);
if (copy_to_user(featurep, &features, sizeof(features)))
return -EFAULT;
return 0;
}
static long vhost_vdpa_set_features(struct vhost_vdpa *v, u64 __user *featurep)
{
struct vdpa_device *vdpa = v->vdpa;
const struct vdpa_config_ops *ops = vdpa->config;
u64 features;
/*
* It's not allowed to change the features after they have
* been negotiated.
*/
if (ops->get_status(vdpa) & VIRTIO_CONFIG_S_FEATURES_OK)
return -EBUSY;
if (copy_from_user(&features, featurep, sizeof(features)))
return -EFAULT;
if (vdpa_set_features(vdpa, features))
return -EINVAL;
return 0;
}
static long vhost_vdpa_get_vring_num(struct vhost_vdpa *v, u16 __user *argp)
{
struct vdpa_device *vdpa = v->vdpa;
const struct vdpa_config_ops *ops = vdpa->config;
u16 num;
num = ops->get_vq_num_max(vdpa);
if (copy_to_user(argp, &num, sizeof(num)))
return -EFAULT;
return 0;
}
static void vhost_vdpa_config_put(struct vhost_vdpa *v)
{
if (v->config_ctx)
eventfd_ctx_put(v->config_ctx);
}
static long vhost_vdpa_set_config_call(struct vhost_vdpa *v, u32 __user *argp)
{
struct vdpa_callback cb;
int fd;
struct eventfd_ctx *ctx;
cb.callback = vhost_vdpa_config_cb;
cb.private = v->vdpa;
if (copy_from_user(&fd, argp, sizeof(fd)))
return -EFAULT;
ctx = fd == VHOST_FILE_UNBIND ? NULL : eventfd_ctx_fdget(fd);
swap(ctx, v->config_ctx);
if (!IS_ERR_OR_NULL(ctx))
eventfd_ctx_put(ctx);
if (IS_ERR(v->config_ctx))
return PTR_ERR(v->config_ctx);
v->vdpa->config->set_config_cb(v->vdpa, &cb);
return 0;
}
static long vhost_vdpa_vring_ioctl(struct vhost_vdpa *v, unsigned int cmd,
void __user *argp)
{
struct vdpa_device *vdpa = v->vdpa;
const struct vdpa_config_ops *ops = vdpa->config;
struct vdpa_vq_state vq_state;
struct vdpa_callback cb;
struct vhost_virtqueue *vq;
struct vhost_vring_state s;
u32 idx;
long r;
r = get_user(idx, (u32 __user *)argp);
if (r < 0)
return r;
if (idx >= v->nvqs)
return -ENOBUFS;
idx = array_index_nospec(idx, v->nvqs);
vq = &v->vqs[idx];
switch (cmd) {
case VHOST_VDPA_SET_VRING_ENABLE:
if (copy_from_user(&s, argp, sizeof(s)))
return -EFAULT;
ops->set_vq_ready(vdpa, idx, s.num);
return 0;
case VHOST_GET_VRING_BASE:
r = ops->get_vq_state(v->vdpa, idx, &vq_state);
if (r)
return r;
vq->last_avail_idx = vq_state.avail_index;
break;
}
r = vhost_vring_ioctl(&v->vdev, cmd, argp);
if (r)
return r;
switch (cmd) {
case VHOST_SET_VRING_ADDR:
if (ops->set_vq_address(vdpa, idx,
(u64)(uintptr_t)vq->desc,
(u64)(uintptr_t)vq->avail,
(u64)(uintptr_t)vq->used))
r = -EINVAL;
break;
case VHOST_SET_VRING_BASE:
vq_state.avail_index = vq->last_avail_idx;
if (ops->set_vq_state(vdpa, idx, &vq_state))
r = -EINVAL;
break;
case VHOST_SET_VRING_CALL:
if (vq->call_ctx.ctx) {
cb.callback = vhost_vdpa_virtqueue_cb;
cb.private = vq;
} else {
cb.callback = NULL;
cb.private = NULL;
}
ops->set_vq_cb(vdpa, idx, &cb);
vhost_vdpa_setup_vq_irq(v, idx);
break;
case VHOST_SET_VRING_NUM:
ops->set_vq_num(vdpa, idx, vq->num);
break;
}
return r;
}
static long vhost_vdpa_unlocked_ioctl(struct file *filep,
unsigned int cmd, unsigned long arg)
{
struct vhost_vdpa *v = filep->private_data;
struct vhost_dev *d = &v->vdev;
void __user *argp = (void __user *)arg;
u64 __user *featurep = argp;
u64 features;
long r;
if (cmd == VHOST_SET_BACKEND_FEATURES) {
r = copy_from_user(&features, featurep, sizeof(features));
if (r)
return r;
if (features & ~VHOST_VDPA_BACKEND_FEATURES)
return -EOPNOTSUPP;
vhost_set_backend_features(&v->vdev, features);
return 0;
}
mutex_lock(&d->mutex);
switch (cmd) {
case VHOST_VDPA_GET_DEVICE_ID:
r = vhost_vdpa_get_device_id(v, argp);
break;
case VHOST_VDPA_GET_STATUS:
r = vhost_vdpa_get_status(v, argp);
break;
case VHOST_VDPA_SET_STATUS:
r = vhost_vdpa_set_status(v, argp);
break;
case VHOST_VDPA_GET_CONFIG:
r = vhost_vdpa_get_config(v, argp);
break;
case VHOST_VDPA_SET_CONFIG:
r = vhost_vdpa_set_config(v, argp);
break;
case VHOST_GET_FEATURES:
r = vhost_vdpa_get_features(v, argp);
break;
case VHOST_SET_FEATURES:
r = vhost_vdpa_set_features(v, argp);
break;
case VHOST_VDPA_GET_VRING_NUM:
r = vhost_vdpa_get_vring_num(v, argp);
break;
case VHOST_SET_LOG_BASE:
case VHOST_SET_LOG_FD:
r = -ENOIOCTLCMD;
break;
case VHOST_VDPA_SET_CONFIG_CALL:
r = vhost_vdpa_set_config_call(v, argp);
break;
case VHOST_GET_BACKEND_FEATURES:
features = VHOST_VDPA_BACKEND_FEATURES;
r = copy_to_user(featurep, &features, sizeof(features));
break;
default:
r = vhost_dev_ioctl(&v->vdev, cmd, argp);
if (r == -ENOIOCTLCMD)
r = vhost_vdpa_vring_ioctl(v, cmd, argp);
break;
}
mutex_unlock(&d->mutex);
return r;
}
static void vhost_vdpa_iotlb_unmap(struct vhost_vdpa *v, u64 start, u64 last)
{
struct vhost_dev *dev = &v->vdev;
struct vhost_iotlb *iotlb = dev->iotlb;
struct vhost_iotlb_map *map;
struct page *page;
unsigned long pfn, pinned;
while ((map = vhost_iotlb_itree_first(iotlb, start, last)) != NULL) {
pinned = map->size >> PAGE_SHIFT;
for (pfn = map->addr >> PAGE_SHIFT;
pinned > 0; pfn++, pinned--) {
page = pfn_to_page(pfn);
if (map->perm & VHOST_ACCESS_WO)
set_page_dirty_lock(page);
unpin_user_page(page);
}
atomic64_sub(map->size >> PAGE_SHIFT, &dev->mm->pinned_vm);
vhost_iotlb_map_free(iotlb, map);
}
}
static void vhost_vdpa_iotlb_free(struct vhost_vdpa *v)
{
struct vhost_dev *dev = &v->vdev;
vhost_vdpa_iotlb_unmap(v, 0ULL, 0ULL - 1);
kfree(dev->iotlb);
dev->iotlb = NULL;
}
static int perm_to_iommu_flags(u32 perm)
{
int flags = 0;
switch (perm) {
case VHOST_ACCESS_WO:
flags |= IOMMU_WRITE;
break;
case VHOST_ACCESS_RO:
flags |= IOMMU_READ;
break;
case VHOST_ACCESS_RW:
flags |= (IOMMU_WRITE | IOMMU_READ);
break;
default:
WARN(1, "invalidate vhost IOTLB permission\n");
break;
}
return flags | IOMMU_CACHE;
}
static int vhost_vdpa_map(struct vhost_vdpa *v,
u64 iova, u64 size, u64 pa, u32 perm)
{
struct vhost_dev *dev = &v->vdev;
struct vdpa_device *vdpa = v->vdpa;
const struct vdpa_config_ops *ops = vdpa->config;
int r = 0;
r = vhost_iotlb_add_range(dev->iotlb, iova, iova + size - 1,
pa, perm);
if (r)
return r;
if (ops->dma_map) {
r = ops->dma_map(vdpa, iova, size, pa, perm);
} else if (ops->set_map) {
if (!v->in_batch)
r = ops->set_map(vdpa, dev->iotlb);
} else {
r = iommu_map(v->domain, iova, pa, size,
perm_to_iommu_flags(perm));
}
if (r)
vhost_iotlb_del_range(dev->iotlb, iova, iova + size - 1);
return r;
}
static void vhost_vdpa_unmap(struct vhost_vdpa *v, u64 iova, u64 size)
{
struct vhost_dev *dev = &v->vdev;
struct vdpa_device *vdpa = v->vdpa;
const struct vdpa_config_ops *ops = vdpa->config;
vhost_vdpa_iotlb_unmap(v, iova, iova + size - 1);
if (ops->dma_map) {
ops->dma_unmap(vdpa, iova, size);
} else if (ops->set_map) {
if (!v->in_batch)
ops->set_map(vdpa, dev->iotlb);
} else {
iommu_unmap(v->domain, iova, size);
}
}
static int vhost_vdpa_process_iotlb_update(struct vhost_vdpa *v,
struct vhost_iotlb_msg *msg)
{
struct vhost_dev *dev = &v->vdev;
struct vhost_iotlb *iotlb = dev->iotlb;
struct page **page_list;
struct vm_area_struct **vmas;
unsigned int gup_flags = FOLL_LONGTERM;
unsigned long map_pfn, last_pfn = 0;
unsigned long npages, lock_limit;
unsigned long i, nmap = 0;
u64 iova = msg->iova;
long pinned;
int ret = 0;
if (vhost_iotlb_itree_first(iotlb, msg->iova,
msg->iova + msg->size - 1))
return -EEXIST;
if (msg->perm & VHOST_ACCESS_WO)
gup_flags |= FOLL_WRITE;
npages = PAGE_ALIGN(msg->size + (iova & ~PAGE_MASK)) >> PAGE_SHIFT;
if (!npages)
return -EINVAL;
page_list = kvmalloc_array(npages, sizeof(struct page *), GFP_KERNEL);
vmas = kvmalloc_array(npages, sizeof(struct vm_area_struct *),
GFP_KERNEL);
if (!page_list || !vmas) {
ret = -ENOMEM;
goto free;
}
mmap_read_lock(dev->mm);
lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
if (npages + atomic64_read(&dev->mm->pinned_vm) > lock_limit) {
ret = -ENOMEM;
goto unlock;
}
pinned = pin_user_pages(msg->uaddr & PAGE_MASK, npages, gup_flags,
page_list, vmas);
if (npages != pinned) {
if (pinned < 0) {
ret = pinned;
} else {
unpin_user_pages(page_list, pinned);
ret = -ENOMEM;
}
goto unlock;
}
iova &= PAGE_MASK;
map_pfn = page_to_pfn(page_list[0]);
/* One more iteration to avoid extra vdpa_map() call out of loop. */
for (i = 0; i <= npages; i++) {
unsigned long this_pfn;
u64 csize;
/* The last chunk may have no valid PFN next to it */
this_pfn = i < npages ? page_to_pfn(page_list[i]) : -1UL;
if (last_pfn && (this_pfn == -1UL ||
this_pfn != last_pfn + 1)) {
/* Pin a contiguous chunk of memory */
csize = last_pfn - map_pfn + 1;
ret = vhost_vdpa_map(v, iova, csize << PAGE_SHIFT,
map_pfn << PAGE_SHIFT,
msg->perm);
if (ret) {
/*
* Unpin the rest chunks of memory on the
* flight with no corresponding vdpa_map()
* calls having been made yet. On the other
* hand, vdpa_unmap() in the failure path
* is in charge of accounting the number of
* pinned pages for its own.
* This asymmetrical pattern of accounting
* is for efficiency to pin all pages at
* once, while there is no other callsite
* of vdpa_map() than here above.
*/
unpin_user_pages(&page_list[nmap],
npages - nmap);
goto out;
}
atomic64_add(csize, &dev->mm->pinned_vm);
nmap += csize;
iova += csize << PAGE_SHIFT;
map_pfn = this_pfn;
}
last_pfn = this_pfn;
}
WARN_ON(nmap != npages);
out:
if (ret)
vhost_vdpa_unmap(v, msg->iova, msg->size);
unlock:
mmap_read_unlock(dev->mm);
free:
kvfree(vmas);
kvfree(page_list);
return ret;
}
static int vhost_vdpa_process_iotlb_msg(struct vhost_dev *dev,
struct vhost_iotlb_msg *msg)
{
struct vhost_vdpa *v = container_of(dev, struct vhost_vdpa, vdev);
struct vdpa_device *vdpa = v->vdpa;
const struct vdpa_config_ops *ops = vdpa->config;
int r = 0;
r = vhost_dev_check_owner(dev);
if (r)
return r;
switch (msg->type) {
case VHOST_IOTLB_UPDATE:
r = vhost_vdpa_process_iotlb_update(v, msg);
break;
case VHOST_IOTLB_INVALIDATE:
vhost_vdpa_unmap(v, msg->iova, msg->size);
break;
case VHOST_IOTLB_BATCH_BEGIN:
v->in_batch = true;
break;
case VHOST_IOTLB_BATCH_END:
if (v->in_batch && ops->set_map)
ops->set_map(vdpa, dev->iotlb);
v->in_batch = false;
break;
default:
r = -EINVAL;
break;
}
return r;
}
static ssize_t vhost_vdpa_chr_write_iter(struct kiocb *iocb,
struct iov_iter *from)
{
struct file *file = iocb->ki_filp;
struct vhost_vdpa *v = file->private_data;
struct vhost_dev *dev = &v->vdev;
return vhost_chr_write_iter(dev, from);
}
static int vhost_vdpa_alloc_domain(struct vhost_vdpa *v)
{
struct vdpa_device *vdpa = v->vdpa;
const struct vdpa_config_ops *ops = vdpa->config;
struct device *dma_dev = vdpa_get_dma_dev(vdpa);
struct bus_type *bus;
int ret;
/* Device want to do DMA by itself */
if (ops->set_map || ops->dma_map)
return 0;
bus = dma_dev->bus;
if (!bus)
return -EFAULT;
if (!iommu_capable(bus, IOMMU_CAP_CACHE_COHERENCY))
return -ENOTSUPP;
v->domain = iommu_domain_alloc(bus);
if (!v->domain)
return -EIO;
ret = iommu_attach_device(v->domain, dma_dev);
if (ret)
goto err_attach;
return 0;
err_attach:
iommu_domain_free(v->domain);
return ret;
}
static void vhost_vdpa_free_domain(struct vhost_vdpa *v)
{
struct vdpa_device *vdpa = v->vdpa;
struct device *dma_dev = vdpa_get_dma_dev(vdpa);
if (v->domain) {
iommu_detach_device(v->domain, dma_dev);
iommu_domain_free(v->domain);
}
v->domain = NULL;
}
static int vhost_vdpa_open(struct inode *inode, struct file *filep)
{
struct vhost_vdpa *v;
struct vhost_dev *dev;
struct vhost_virtqueue **vqs;
int nvqs, i, r, opened;
v = container_of(inode->i_cdev, struct vhost_vdpa, cdev);
opened = atomic_cmpxchg(&v->opened, 0, 1);
if (opened)
return -EBUSY;
nvqs = v->nvqs;
vhost_vdpa_reset(v);
vqs = kmalloc_array(nvqs, sizeof(*vqs), GFP_KERNEL);
if (!vqs) {
r = -ENOMEM;
goto err;
}
dev = &v->vdev;
for (i = 0; i < nvqs; i++) {
vqs[i] = &v->vqs[i];
vqs[i]->handle_kick = handle_vq_kick;
}
vhost_dev_init(dev, vqs, nvqs, 0, 0, 0, false,
vhost_vdpa_process_iotlb_msg);
dev->iotlb = vhost_iotlb_alloc(0, 0);
if (!dev->iotlb) {
r = -ENOMEM;
goto err_init_iotlb;
}
r = vhost_vdpa_alloc_domain(v);
if (r)
goto err_init_iotlb;
filep->private_data = v;
return 0;
err_init_iotlb:
vhost_dev_cleanup(&v->vdev);
kfree(vqs);
err:
atomic_dec(&v->opened);
return r;
}
static void vhost_vdpa_clean_irq(struct vhost_vdpa *v)
{
struct vhost_virtqueue *vq;
int i;
for (i = 0; i < v->nvqs; i++) {
vq = &v->vqs[i];
if (vq->call_ctx.producer.irq)
irq_bypass_unregister_producer(&vq->call_ctx.producer);
}
}
static int vhost_vdpa_release(struct inode *inode, struct file *filep)
{
struct vhost_vdpa *v = filep->private_data;
struct vhost_dev *d = &v->vdev;
mutex_lock(&d->mutex);
filep->private_data = NULL;
vhost_vdpa_reset(v);
vhost_dev_stop(&v->vdev);
vhost_vdpa_iotlb_free(v);
vhost_vdpa_free_domain(v);
vhost_vdpa_config_put(v);
vhost_vdpa_clean_irq(v);
vhost_dev_cleanup(&v->vdev);
kfree(v->vdev.vqs);
mutex_unlock(&d->mutex);
atomic_dec(&v->opened);
complete(&v->completion);
return 0;
}
#ifdef CONFIG_MMU
static vm_fault_t vhost_vdpa_fault(struct vm_fault *vmf)
{
struct vhost_vdpa *v = vmf->vma->vm_file->private_data;
struct vdpa_device *vdpa = v->vdpa;
const struct vdpa_config_ops *ops = vdpa->config;
struct vdpa_notification_area notify;
struct vm_area_struct *vma = vmf->vma;
u16 index = vma->vm_pgoff;
notify = ops->get_vq_notification(vdpa, index);
vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
if (remap_pfn_range(vma, vmf->address & PAGE_MASK,
notify.addr >> PAGE_SHIFT, PAGE_SIZE,
vma->vm_page_prot))
return VM_FAULT_SIGBUS;
return VM_FAULT_NOPAGE;
}
static const struct vm_operations_struct vhost_vdpa_vm_ops = {
.fault = vhost_vdpa_fault,
};
static int vhost_vdpa_mmap(struct file *file, struct vm_area_struct *vma)
{
struct vhost_vdpa *v = vma->vm_file->private_data;
struct vdpa_device *vdpa = v->vdpa;
const struct vdpa_config_ops *ops = vdpa->config;
struct vdpa_notification_area notify;
unsigned long index = vma->vm_pgoff;
if (vma->vm_end - vma->vm_start != PAGE_SIZE)
return -EINVAL;
if ((vma->vm_flags & VM_SHARED) == 0)
return -EINVAL;
if (vma->vm_flags & VM_READ)
return -EINVAL;
if (index > 65535)
return -EINVAL;
if (!ops->get_vq_notification)
return -ENOTSUPP;
/* To be safe and easily modelled by userspace, We only
* support the doorbell which sits on the page boundary and
* does not share the page with other registers.
*/
notify = ops->get_vq_notification(vdpa, index);
if (notify.addr & (PAGE_SIZE - 1))
return -EINVAL;
if (vma->vm_end - vma->vm_start != notify.size)
return -ENOTSUPP;
vma->vm_ops = &vhost_vdpa_vm_ops;
return 0;
}
#endif /* CONFIG_MMU */
static const struct file_operations vhost_vdpa_fops = {
.owner = THIS_MODULE,
.open = vhost_vdpa_open,
.release = vhost_vdpa_release,
.write_iter = vhost_vdpa_chr_write_iter,
.unlocked_ioctl = vhost_vdpa_unlocked_ioctl,
#ifdef CONFIG_MMU
.mmap = vhost_vdpa_mmap,
#endif /* CONFIG_MMU */
.compat_ioctl = compat_ptr_ioctl,
};
static void vhost_vdpa_release_dev(struct device *device)
{
struct vhost_vdpa *v =
container_of(device, struct vhost_vdpa, dev);
ida_simple_remove(&vhost_vdpa_ida, v->minor);
kfree(v->vqs);
kfree(v);
}
static int vhost_vdpa_probe(struct vdpa_device *vdpa)
{
const struct vdpa_config_ops *ops = vdpa->config;
struct vhost_vdpa *v;
int minor;
int r;
/* Currently, we only accept the network devices. */
if (ops->get_device_id(vdpa) != VIRTIO_ID_NET)
return -ENOTSUPP;
v = kzalloc(sizeof(*v), GFP_KERNEL | __GFP_RETRY_MAYFAIL);
if (!v)
return -ENOMEM;
minor = ida_simple_get(&vhost_vdpa_ida, 0,
VHOST_VDPA_DEV_MAX, GFP_KERNEL);
if (minor < 0) {
kfree(v);
return minor;
}
atomic_set(&v->opened, 0);
v->minor = minor;
v->vdpa = vdpa;
v->nvqs = vdpa->nvqs;
v->virtio_id = ops->get_device_id(vdpa);
device_initialize(&v->dev);
v->dev.release = vhost_vdpa_release_dev;
v->dev.parent = &vdpa->dev;
v->dev.devt = MKDEV(MAJOR(vhost_vdpa_major), minor);
v->vqs = kmalloc_array(v->nvqs, sizeof(struct vhost_virtqueue),
GFP_KERNEL);
if (!v->vqs) {
r = -ENOMEM;
goto err;
}
r = dev_set_name(&v->dev, "vhost-vdpa-%u", minor);
if (r)
goto err;
cdev_init(&v->cdev, &vhost_vdpa_fops);
v->cdev.owner = THIS_MODULE;
r = cdev_device_add(&v->cdev, &v->dev);
if (r)
goto err;
init_completion(&v->completion);
vdpa_set_drvdata(vdpa, v);
return 0;
err:
put_device(&v->dev);
return r;
}
static void vhost_vdpa_remove(struct vdpa_device *vdpa)
{
struct vhost_vdpa *v = vdpa_get_drvdata(vdpa);
int opened;
cdev_device_del(&v->cdev, &v->dev);
do {
opened = atomic_cmpxchg(&v->opened, 0, 1);
if (!opened)
break;
wait_for_completion(&v->completion);
} while (1);
put_device(&v->dev);
}
static struct vdpa_driver vhost_vdpa_driver = {
.driver = {
.name = "vhost_vdpa",
},
.probe = vhost_vdpa_probe,
.remove = vhost_vdpa_remove,
};
static int __init vhost_vdpa_init(void)
{
int r;
r = alloc_chrdev_region(&vhost_vdpa_major, 0, VHOST_VDPA_DEV_MAX,
"vhost-vdpa");
if (r)
goto err_alloc_chrdev;
r = vdpa_register_driver(&vhost_vdpa_driver);
if (r)
goto err_vdpa_register_driver;
return 0;
err_vdpa_register_driver:
unregister_chrdev_region(vhost_vdpa_major, VHOST_VDPA_DEV_MAX);
err_alloc_chrdev:
return r;
}
module_init(vhost_vdpa_init);
static void __exit vhost_vdpa_exit(void)
{
vdpa_unregister_driver(&vhost_vdpa_driver);
unregister_chrdev_region(vhost_vdpa_major, VHOST_VDPA_DEV_MAX);
}
module_exit(vhost_vdpa_exit);
MODULE_VERSION("0.0.1");
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Intel Corporation");
MODULE_DESCRIPTION("vDPA-based vhost backend for virtio");