diff options
Diffstat (limited to 'drivers/vhost/vdpa.c')
| -rw-r--r-- | drivers/vhost/vdpa.c | 883 |
1 files changed, 883 insertions, 0 deletions
diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c new file mode 100644 index 000000000000..421f02a8530a --- /dev/null +++ b/drivers/vhost/vdpa.c @@ -0,0 +1,883 @@ +// 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/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_FEATURES = + (1ULL << VIRTIO_F_NOTIFY_ON_EMPTY) | + (1ULL << VIRTIO_F_ANY_LAYOUT) | + (1ULL << VIRTIO_F_VERSION_1) | + (1ULL << VIRTIO_F_IOMMU_PLATFORM) | + (1ULL << VIRTIO_F_RING_PACKED) | + (1ULL << VIRTIO_F_ORDER_PLATFORM) | + (1ULL << VIRTIO_RING_F_INDIRECT_DESC) | + (1ULL << VIRTIO_RING_F_EVENT_IDX), + + VHOST_VDPA_NET_FEATURES = VHOST_VDPA_FEATURES | + (1ULL << VIRTIO_NET_F_CSUM) | + (1ULL << VIRTIO_NET_F_GUEST_CSUM) | + (1ULL << VIRTIO_NET_F_MTU) | + (1ULL << VIRTIO_NET_F_MAC) | + (1ULL << VIRTIO_NET_F_GUEST_TSO4) | + (1ULL << VIRTIO_NET_F_GUEST_TSO6) | + (1ULL << VIRTIO_NET_F_GUEST_ECN) | + (1ULL << VIRTIO_NET_F_GUEST_UFO) | + (1ULL << VIRTIO_NET_F_HOST_TSO4) | + (1ULL << VIRTIO_NET_F_HOST_TSO6) | + (1ULL << VIRTIO_NET_F_HOST_ECN) | + (1ULL << VIRTIO_NET_F_HOST_UFO) | + (1ULL << VIRTIO_NET_F_MRG_RXBUF) | + (1ULL << VIRTIO_NET_F_STATUS) | + (1ULL << VIRTIO_NET_F_SPEED_DUPLEX), +}; + +/* Currently, only network backend w/o multiqueue is supported. */ +#define VHOST_VDPA_VQ_MAX 2 + +#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; +}; + +static DEFINE_IDA(vhost_vdpa_ida); + +static dev_t vhost_vdpa_major; + +static const u64 vhost_vdpa_features[] = { + [VIRTIO_ID_NET] = VHOST_VDPA_NET_FEATURES, +}; + +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; + + if (call_ctx) + eventfd_signal(call_ctx, 1); + + return IRQ_HANDLED; +} + +static void vhost_vdpa_reset(struct vhost_vdpa *v) +{ + struct vdpa_device *vdpa = v->vdpa; + const struct vdpa_config_ops *ops = vdpa->config; + + ops->set_status(vdpa, 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; + + if (copy_from_user(&status, statusp, sizeof(status))) + return -EFAULT; + + /* + * 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); + + 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; + 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; + + ops->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); + features &= vhost_vdpa_features[v->virtio_id]; + + 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 (features & ~vhost_vdpa_features[v->virtio_id]) + return -EINVAL; + + if (ops->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 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_callback cb; + struct vhost_virtqueue *vq; + struct vhost_vring_state s; + u8 status; + 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]; + + status = ops->get_status(vdpa); + + if (cmd == 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; + } + + if (cmd == VHOST_GET_VRING_BASE) + vq->last_avail_idx = ops->get_vq_state(v->vdpa, idx); + + 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: + if (ops->set_vq_state(vdpa, idx, vq->last_avail_idx)) + r = -EINVAL; + break; + + case VHOST_SET_VRING_CALL: + if (vq->call_ctx) { + cb.callback = vhost_vdpa_virtqueue_cb; + cb.private = vq; + } else { + cb.callback = NULL; + cb.private = NULL; + } + ops->set_vq_cb(vdpa, idx, &cb); + 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; + long r; + + 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; + 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) + r = ops->set_map(vdpa, dev->iotlb); + else + r = iommu_map(v->domain, iova, pa, size, + perm_to_iommu_flags(perm)); + + 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) + 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; + unsigned long list_size = PAGE_SIZE / sizeof(struct page *); + unsigned int gup_flags = FOLL_LONGTERM; + unsigned long npages, cur_base, map_pfn, last_pfn = 0; + unsigned long locked, lock_limit, pinned, i; + u64 iova = msg->iova; + int ret = 0; + + if (vhost_iotlb_itree_first(iotlb, msg->iova, + msg->iova + msg->size - 1)) + return -EEXIST; + + page_list = (struct page **) __get_free_page(GFP_KERNEL); + if (!page_list) + return -ENOMEM; + + if (msg->perm & VHOST_ACCESS_WO) + gup_flags |= FOLL_WRITE; + + npages = PAGE_ALIGN(msg->size + (iova & ~PAGE_MASK)) >> PAGE_SHIFT; + if (!npages) + return -EINVAL; + + down_read(&dev->mm->mmap_sem); + + locked = atomic64_add_return(npages, &dev->mm->pinned_vm); + lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; + + if (locked > lock_limit) { + ret = -ENOMEM; + goto out; + } + + cur_base = msg->uaddr & PAGE_MASK; + iova &= PAGE_MASK; + + while (npages) { + pinned = min_t(unsigned long, npages, list_size); + ret = pin_user_pages(cur_base, pinned, + gup_flags, page_list, NULL); + if (ret != pinned) + goto out; + + if (!last_pfn) + map_pfn = page_to_pfn(page_list[0]); + + for (i = 0; i < ret; i++) { + unsigned long this_pfn = page_to_pfn(page_list[i]); + u64 csize; + + if (last_pfn && (this_pfn != last_pfn + 1)) { + /* Pin a contiguous chunk of memory */ + csize = (last_pfn - map_pfn + 1) << PAGE_SHIFT; + if (vhost_vdpa_map(v, iova, csize, + map_pfn << PAGE_SHIFT, + msg->perm)) + goto out; + map_pfn = this_pfn; + iova += csize; + } + + last_pfn = this_pfn; + } + + cur_base += ret << PAGE_SHIFT; + npages -= ret; + } + + /* Pin the rest chunk */ + ret = vhost_vdpa_map(v, iova, (last_pfn - map_pfn + 1) << PAGE_SHIFT, + map_pfn << PAGE_SHIFT, msg->perm); +out: + if (ret) { + vhost_vdpa_unmap(v, msg->iova, msg->size); + atomic64_sub(npages, &dev->mm->pinned_vm); + } + up_read(&dev->mm->mmap_sem); + free_page((unsigned long)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); + 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; + 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); + if (!v) + return -ENODEV; + + 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, + 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); +err: + atomic_dec(&v->opened); + return r; +} + +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_dev_cleanup(&v->vdev); + kfree(v->vdev.vqs); + mutex_unlock(&d->mutex); + + atomic_dec(&v->opened); + complete(&v->completion); + + return 0; +} + +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, + .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, nvqs = VHOST_VDPA_VQ_MAX; + 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 = 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(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"); |