Re: [PATCH 1/2] Revert "vhost: access vq metadata through kernel virtual address"

Jason Wang
2019-09-09T07:16:36Z

On 2019/9/6 下午9:46, Michael S. Tsirkin wrote:
> On Thu, Sep 05, 2019 at 08:27:35PM +0800, Jason Wang wrote:
>> It was reported that metadata acceleration introduces several issues,
>> so this patch reverts commit ff466032dc9e5a61217f22ea34b2df932786bbfc,
>> 73f628ec9e6bcc45b77c53fe6d0c0ec55eaf82af and
>> 0b4a7092ffe568a55bf8f3cefdf79ff666586d91.
>>
>> We will rework it on the next version.
>>
>> Cc: Jason Gunthorpe <jgg@mellanox.com>
>> Signed-off-by: Jason Wang <jasowang@redhat.com>
>
> I am confused by the above.
> What I see upstream is 7f466032dc.
>
> commit 7f466032dc9e5a61217f22ea34b2df932786bbfc
> Author: Jason Wang <jasowang@redhat.com>
> Date: Fri May 24 04:12:18 2019 -0400
>
> vhost: access vq metadata through kernel virtual address
>
> so this is what I reverted.
>
> Pls take a look, and let me know if you see issues.
>
> Thanks!

Yes, my fault.

Thanks

>> ---
>> drivers/vhost/vhost.c | 515 +-----------------------------------------
>> drivers/vhost/vhost.h | 41 ----
>> 2 files changed, 3 insertions(+), 553 deletions(-)
>>
>> diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
>> index 0536f8526359..791562e03fe0 100644
>> --- a/drivers/vhost/vhost.c
>> +++ b/drivers/vhost/vhost.c
>> @@ -298,160 +298,6 @@ static void vhost_vq_meta_reset(struct vhost_dev *d)
>> __vhost_vq_meta_reset(d->vqs[i]);
>> }
>>
>> -#if VHOST_ARCH_CAN_ACCEL_UACCESS
>> -static void vhost_map_unprefetch(struct vhost_map *map)
>> -{
>> - kfree(map->pages);
>> - map->pages = NULL;
>> - map->npages = 0;
>> - map->addr = NULL;
>> -}
>> -
>> -static void vhost_uninit_vq_maps(struct vhost_virtqueue *vq)
>> -{
>> - struct vhost_map *map[VHOST_NUM_ADDRS];
>> - int i;
>> -
>> - spin_lock(&vq->mmu_lock);
>> - for (i = 0; i < VHOST_NUM_ADDRS; i++) {
>> - map[i] = rcu_dereference_protected(vq->maps[i],
>> - lockdep_is_held(&vq->mmu_lock));
>> - if (map[i])
>> - rcu_assign_pointer(vq->maps[i], NULL);
>> - }
>> - spin_unlock(&vq->mmu_lock);
>> -
>> - synchronize_rcu();
>> -
>> - for (i = 0; i < VHOST_NUM_ADDRS; i++)
>> - if (map[i])
>> - vhost_map_unprefetch(map[i]);
>> -
>> -}
>> -
>> -static void vhost_reset_vq_maps(struct vhost_virtqueue *vq)
>> -{
>> - int i;
>> -
>> - vhost_uninit_vq_maps(vq);
>> - for (i = 0; i < VHOST_NUM_ADDRS; i++)
>> - vq->uaddrs[i].size = 0;
>> -}
>> -
>> -static bool vhost_map_range_overlap(struct vhost_uaddr *uaddr,
>> - unsigned long start,
>> - unsigned long end)
>> -{
>> - if (unlikely(!uaddr->size))
>> - return false;
>> -
>> - return !(end < uaddr->uaddr || start > uaddr->uaddr - 1 + uaddr->size);
>> -}
>> -
>> -static void vhost_invalidate_vq_start(struct vhost_virtqueue *vq,
>> - int index,
>> - unsigned long start,
>> - unsigned long end)
>> -{
>> - struct vhost_uaddr *uaddr = &vq->uaddrs[index];
>> - struct vhost_map *map;
>> - int i;
>> -
>> - if (!vhost_map_range_overlap(uaddr, start, end))
>> - return;
>> -
>> - spin_lock(&vq->mmu_lock);
>> - ++vq->invalidate_count;
>> -
>> - map = rcu_dereference_protected(vq->maps[index],
>> - lockdep_is_held(&vq->mmu_lock));
>> - if (map) {
>> - if (uaddr->write) {
>> - for (i = 0; i < map->npages; i++)
>> - set_page_dirty(map->pages[i]);
>> - }
>> - rcu_assign_pointer(vq->maps[index], NULL);
>> - }
>> - spin_unlock(&vq->mmu_lock);
>> -
>> - if (map) {
>> - synchronize_rcu();
>> - vhost_map_unprefetch(map);
>> - }
>> -}
>> -
>> -static void vhost_invalidate_vq_end(struct vhost_virtqueue *vq,
>> - int index,
>> - unsigned long start,
>> - unsigned long end)
>> -{
>> - if (!vhost_map_range_overlap(&vq->uaddrs[index], start, end))
>> - return;
>> -
>> - spin_lock(&vq->mmu_lock);
>> - --vq->invalidate_count;
>> - spin_unlock(&vq->mmu_lock);
>> -}
>> -
>> -static int vhost_invalidate_range_start(struct mmu_notifier *mn,
>> - const struct mmu_notifier_range *range)
>> -{
>> - struct vhost_dev *dev = container_of(mn, struct vhost_dev,
>> - mmu_notifier);
>> - int i, j;
>> -
>> - if (!mmu_notifier_range_blockable(range))
>> - return -EAGAIN;
>> -
>> - for (i = 0; i < dev->nvqs; i++) {
>> - struct vhost_virtqueue *vq = dev->vqs[i];
>> -
>> - for (j = 0; j < VHOST_NUM_ADDRS; j++)
>> - vhost_invalidate_vq_start(vq, j,
>> - range->start,
>> - range->end);
>> - }
>> -
>> - return 0;
>> -}
>> -
>> -static void vhost_invalidate_range_end(struct mmu_notifier *mn,
>> - const struct mmu_notifier_range *range)
>> -{
>> - struct vhost_dev *dev = container_of(mn, struct vhost_dev,
>> - mmu_notifier);
>> - int i, j;
>> -
>> - for (i = 0; i < dev->nvqs; i++) {
>> - struct vhost_virtqueue *vq = dev->vqs[i];
>> -
>> - for (j = 0; j < VHOST_NUM_ADDRS; j++)
>> - vhost_invalidate_vq_end(vq, j,
>> - range->start,
>> - range->end);
>> - }
>> -}
>> -
>> -static const struct mmu_notifier_ops vhost_mmu_notifier_ops = {
>> - .invalidate_range_start = vhost_invalidate_range_start,
>> - .invalidate_range_end = vhost_invalidate_range_end,
>> -};
>> -
>> -static void vhost_init_maps(struct vhost_dev *dev)
>> -{
>> - struct vhost_virtqueue *vq;
>> - int i, j;
>> -
>> - dev->mmu_notifier.ops = &vhost_mmu_notifier_ops;
>> -
>> - for (i = 0; i < dev->nvqs; ++i) {
>> - vq = dev->vqs[i];
>> - for (j = 0; j < VHOST_NUM_ADDRS; j++)
>> - RCU_INIT_POINTER(vq->maps[j], NULL);
>> - }
>> -}
>> -#endif
>> -
>> static void vhost_vq_reset(struct vhost_dev *dev,
>> struct vhost_virtqueue *vq)
>> {
>> @@ -480,11 +326,7 @@ static void vhost_vq_reset(struct vhost_dev *dev,
>> vq->busyloop_timeout = 0;
>> vq->umem = NULL;
>> vq->iotlb = NULL;
>> - vq->invalidate_count = 0;
>> __vhost_vq_meta_reset(vq);
>> -#if VHOST_ARCH_CAN_ACCEL_UACCESS
>> - vhost_reset_vq_maps(vq);
>> -#endif
>> }
>>
>> static int vhost_worker(void *data)
>> @@ -634,9 +476,7 @@ void vhost_dev_init(struct vhost_dev *dev,
>> INIT_LIST_HEAD(&dev->read_list);
>> INIT_LIST_HEAD(&dev->pending_list);
>> spin_lock_init(&dev->iotlb_lock);
>> -#if VHOST_ARCH_CAN_ACCEL_UACCESS
>> - vhost_init_maps(dev);
>> -#endif
>> +
>>
>> for (i = 0; i < dev->nvqs; ++i) {
>> vq = dev->vqs[i];
>> @@ -645,7 +485,6 @@ void vhost_dev_init(struct vhost_dev *dev,
>> vq->heads = NULL;
>> vq->dev = dev;
>> mutex_init(&vq->mutex);
>> - spin_lock_init(&vq->mmu_lock);
>> vhost_vq_reset(dev, vq);
>> if (vq->handle_kick)
>> vhost_poll_init(&vq->poll, vq->handle_kick,
>> @@ -725,18 +564,7 @@ long vhost_dev_set_owner(struct vhost_dev *dev)
>> if (err)
>> goto err_cgroup;
>>
>> -#if VHOST_ARCH_CAN_ACCEL_UACCESS
>> - err = mmu_notifier_register(&dev->mmu_notifier, dev->mm);
>> - if (err)
>> - goto err_mmu_notifier;
>> -#endif
>> -
>> return 0;
>> -
>> -#if VHOST_ARCH_CAN_ACCEL_UACCESS
>> -err_mmu_notifier:
>> - vhost_dev_free_iovecs(dev);
>> -#endif
>> err_cgroup:
>> kthread_stop(worker);
>> dev->worker = NULL;
>> @@ -827,107 +655,6 @@ static void vhost_clear_msg(struct vhost_dev *dev)
>> spin_unlock(&dev->iotlb_lock);
>> }
>>
>> -#if VHOST_ARCH_CAN_ACCEL_UACCESS
>> -static void vhost_setup_uaddr(struct vhost_virtqueue *vq,
>> - int index, unsigned long uaddr,
>> - size_t size, bool write)
>> -{
>> - struct vhost_uaddr *addr = &vq->uaddrs[index];
>> -
>> - addr->uaddr = uaddr;
>> - addr->size = size;
>> - addr->write = write;
>> -}
>> -
>> -static void vhost_setup_vq_uaddr(struct vhost_virtqueue *vq)
>> -{
>> - vhost_setup_uaddr(vq, VHOST_ADDR_DESC,
>> - (unsigned long)vq->desc,
>> - vhost_get_desc_size(vq, vq->num),
>> - false);
>> - vhost_setup_uaddr(vq, VHOST_ADDR_AVAIL,
>> - (unsigned long)vq->avail,
>> - vhost_get_avail_size(vq, vq->num),
>> - false);
>> - vhost_setup_uaddr(vq, VHOST_ADDR_USED,
>> - (unsigned long)vq->used,
>> - vhost_get_used_size(vq, vq->num),
>> - true);
>> -}
>> -
>> -static int vhost_map_prefetch(struct vhost_virtqueue *vq,
>> - int index)
>> -{
>> - struct vhost_map *map;
>> - struct vhost_uaddr *uaddr = &vq->uaddrs[index];
>> - struct page **pages;
>> - int npages = DIV_ROUND_UP(uaddr->size, PAGE_SIZE);
>> - int npinned;
>> - void *vaddr, *v;
>> - int err;
>> - int i;
>> -
>> - spin_lock(&vq->mmu_lock);
>> -
>> - err = -EFAULT;
>> - if (vq->invalidate_count)
>> - goto err;
>> -
>> - err = -ENOMEM;
>> - map = kmalloc(sizeof(*map), GFP_ATOMIC);
>> - if (!map)
>> - goto err;
>> -
>> - pages = kmalloc_array(npages, sizeof(struct page *), GFP_ATOMIC);
>> - if (!pages)
>> - goto err_pages;
>> -
>> - err = EFAULT;
>> - npinned = __get_user_pages_fast(uaddr->uaddr, npages,
>> - uaddr->write, pages);
>> - if (npinned > 0)
>> - release_pages(pages, npinned);
>> - if (npinned != npages)
>> - goto err_gup;
>> -
>> - for (i = 0; i < npinned; i++)
>> - if (PageHighMem(pages[i]))
>> - goto err_gup;
>> -
>> - vaddr = v = page_address(pages[0]);
>> -
>> - /* For simplicity, fallback to userspace address if VA is not
>> - * contigious.
>> - */
>> - for (i = 1; i < npinned; i++) {
>> - v += PAGE_SIZE;
>> - if (v != page_address(pages[i]))
>> - goto err_gup;
>> - }
>> -
>> - map->addr = vaddr + (uaddr->uaddr & (PAGE_SIZE - 1));
>> - map->npages = npages;
>> - map->pages = pages;
>> -
>> - rcu_assign_pointer(vq->maps[index], map);
>> - /* No need for a synchronize_rcu(). This function should be
>> - * called by dev->worker so we are serialized with all
>> - * readers.
>> - */
>> - spin_unlock(&vq->mmu_lock);
>> -
>> - return 0;
>> -
>> -err_gup:
>> - kfree(pages);
>> -err_pages:
>> - kfree(map);
>> -err:
>> - spin_unlock(&vq->mmu_lock);
>> - return err;
>> -}
>> -#endif
>> -
>> void vhost_dev_cleanup(struct vhost_dev *dev)
>> {
>> int i;
>> @@ -957,16 +684,8 @@ void vhost_dev_cleanup(struct vhost_dev *dev)
>> kthread_stop(dev->worker);
>> dev->worker = NULL;
>> }
>> - if (dev->mm) {
>> -#if VHOST_ARCH_CAN_ACCEL_UACCESS
>> - mmu_notifier_unregister(&dev->mmu_notifier, dev->mm);
>> -#endif
>> + if (dev->mm)
>> mmput(dev->mm);
>> - }
>> -#if VHOST_ARCH_CAN_ACCEL_UACCESS
>> - for (i = 0; i < dev->nvqs; i++)
>> - vhost_uninit_vq_maps(dev->vqs[i]);
>> -#endif
>> dev->mm = NULL;
>> }
>> EXPORT_SYMBOL_GPL(vhost_dev_cleanup);
>> @@ -1195,26 +914,6 @@ static inline void __user *__vhost_get_user(struct vhost_virtqueue *vq,
>>
>> static inline int vhost_put_avail_event(struct vhost_virtqueue *vq)
>> {
>> -#if VHOST_ARCH_CAN_ACCEL_UACCESS
>> - struct vhost_map *map;
>> - struct vring_used *used;
>> -
>> - if (!vq->iotlb) {
>> - rcu_read_lock();
>> -
>> - map = rcu_dereference(vq->maps[VHOST_ADDR_USED]);
>> - if (likely(map)) {
>> - used = map->addr;
>> - *((__virtio16 *)&used->ring[vq->num]) =
>> - cpu_to_vhost16(vq, vq->avail_idx);
>> - rcu_read_unlock();
>> - return 0;
>> - }
>> -
>> - rcu_read_unlock();
>> - }
>> -#endif
>> -
>> return vhost_put_user(vq, cpu_to_vhost16(vq, vq->avail_idx),
>> vhost_avail_event(vq));
>> }
>> @@ -1223,27 +922,6 @@ static inline int vhost_put_used(struct vhost_virtqueue *vq,
>> struct vring_used_elem *head, int idx,
>> int count)
>> {
>> -#if VHOST_ARCH_CAN_ACCEL_UACCESS
>> - struct vhost_map *map;
>> - struct vring_used *used;
>> - size_t size;
>> -
>> - if (!vq->iotlb) {
>> - rcu_read_lock();
>> -
>> - map = rcu_dereference(vq->maps[VHOST_ADDR_USED]);
>> - if (likely(map)) {
>> - used = map->addr;
>> - size = count * sizeof(*head);
>> - memcpy(used->ring + idx, head, size);
>> - rcu_read_unlock();
>> - return 0;
>> - }
>> -
>> - rcu_read_unlock();
>> - }
>> -#endif
>> -
>> return vhost_copy_to_user(vq, vq->used->ring + idx, head,
>> count * sizeof(*head));
>> }
>> @@ -1251,25 +929,6 @@ static inline int vhost_put_used(struct vhost_virtqueue *vq,
>> static inline int vhost_put_used_flags(struct vhost_virtqueue *vq)
>>
>> {
>> -#if VHOST_ARCH_CAN_ACCEL_UACCESS
>> - struct vhost_map *map;
>> - struct vring_used *used;
>> -
>> - if (!vq->iotlb) {
>> - rcu_read_lock();
>> -
>> - map = rcu_dereference(vq->maps[VHOST_ADDR_USED]);
>> - if (likely(map)) {
>> - used = map->addr;
>> - used->flags = cpu_to_vhost16(vq, vq->used_flags);
>> - rcu_read_unlock();
>> - return 0;
>> - }
>> -
>> - rcu_read_unlock();
>> - }
>> -#endif
>> -
>> return vhost_put_user(vq, cpu_to_vhost16(vq, vq->used_flags),
>> &vq->used->flags);
>> }
>> @@ -1277,25 +936,6 @@ static inline int vhost_put_used_flags(struct vhost_virtqueue *vq)
>> static inline int vhost_put_used_idx(struct vhost_virtqueue *vq)
>>
>> {
>> -#if VHOST_ARCH_CAN_ACCEL_UACCESS
>> - struct vhost_map *map;
>> - struct vring_used *used;
>> -
>> - if (!vq->iotlb) {
>> - rcu_read_lock();
>> -
>> - map = rcu_dereference(vq->maps[VHOST_ADDR_USED]);
>> - if (likely(map)) {
>> - used = map->addr;
>> - used->idx = cpu_to_vhost16(vq, vq->last_used_idx);
>> - rcu_read_unlock();
>> - return 0;
>> - }
>> -
>> - rcu_read_unlock();
>> - }
>> -#endif
>> -
>> return vhost_put_user(vq, cpu_to_vhost16(vq, vq->last_used_idx),
>> &vq->used->idx);
>> }
>> @@ -1341,50 +981,12 @@ static void vhost_dev_unlock_vqs(struct vhost_dev *d)
>> static inline int vhost_get_avail_idx(struct vhost_virtqueue *vq,
>> __virtio16 *idx)
>> {
>> -#if VHOST_ARCH_CAN_ACCEL_UACCESS
>> - struct vhost_map *map;
>> - struct vring_avail *avail;
>> -
>> - if (!vq->iotlb) {
>> - rcu_read_lock();
>> -
>> - map = rcu_dereference(vq->maps[VHOST_ADDR_AVAIL]);
>> - if (likely(map)) {
>> - avail = map->addr;
>> - *idx = avail->idx;
>> - rcu_read_unlock();
>> - return 0;
>> - }
>> -
>> - rcu_read_unlock();
>> - }
>> -#endif
>> -
>> return vhost_get_avail(vq, *idx, &vq->avail->idx);
>> }
>>
>> static inline int vhost_get_avail_head(struct vhost_virtqueue *vq,
>> __virtio16 *head, int idx)
>> {
>> -#if VHOST_ARCH_CAN_ACCEL_UACCESS
>> - struct vhost_map *map;
>> - struct vring_avail *avail;
>> -
>> - if (!vq->iotlb) {
>> - rcu_read_lock();
>> -
>> - map = rcu_dereference(vq->maps[VHOST_ADDR_AVAIL]);
>> - if (likely(map)) {
>> - avail = map->addr;
>> - *head = avail->ring[idx & (vq->num - 1)];
>> - rcu_read_unlock();
>> - return 0;
>> - }
>> -
>> - rcu_read_unlock();
>> - }
>> -#endif
>> -
>> return vhost_get_avail(vq, *head,
>> &vq->avail->ring[idx & (vq->num - 1)]);
>> }
>> @@ -1392,98 +994,24 @@ static inline int vhost_get_avail_head(struct vhost_virtqueue *vq,
>> static inline int vhost_get_avail_flags(struct vhost_virtqueue *vq,
>> __virtio16 *flags)
>> {
>> -#if VHOST_ARCH_CAN_ACCEL_UACCESS
>> - struct vhost_map *map;
>> - struct vring_avail *avail;
>> -
>> - if (!vq->iotlb) {
>> - rcu_read_lock();
>> -
>> - map = rcu_dereference(vq->maps[VHOST_ADDR_AVAIL]);
>> - if (likely(map)) {
>> - avail = map->addr;
>> - *flags = avail->flags;
>> - rcu_read_unlock();
>> - return 0;
>> - }
>> -
>> - rcu_read_unlock();
>> - }
>> -#endif
>> -
>> return vhost_get_avail(vq, *flags, &vq->avail->flags);
>> }
>>
>> static inline int vhost_get_used_event(struct vhost_virtqueue *vq,
>> __virtio16 *event)
>> {
>> -#if VHOST_ARCH_CAN_ACCEL_UACCESS
>> - struct vhost_map *map;
>> - struct vring_avail *avail;
>> -
>> - if (!vq->iotlb) {
>> - rcu_read_lock();
>> - map = rcu_dereference(vq->maps[VHOST_ADDR_AVAIL]);
>> - if (likely(map)) {
>> - avail = map->addr;
>> - *event = (__virtio16)avail->ring[vq->num];
>> - rcu_read_unlock();
>> - return 0;
>> - }
>> - rcu_read_unlock();
>> - }
>> -#endif
>> -
>> return vhost_get_avail(vq, *event, vhost_used_event(vq));
>> }
>>
>> static inline int vhost_get_used_idx(struct vhost_virtqueue *vq,
>> __virtio16 *idx)
>> {
>> -#if VHOST_ARCH_CAN_ACCEL_UACCESS
>> - struct vhost_map *map;
>> - struct vring_used *used;
>> -
>> - if (!vq->iotlb) {
>> - rcu_read_lock();
>> -
>> - map = rcu_dereference(vq->maps[VHOST_ADDR_USED]);
>> - if (likely(map)) {
>> - used = map->addr;
>> - *idx = used->idx;
>> - rcu_read_unlock();
>> - return 0;
>> - }
>> -
>> - rcu_read_unlock();
>> - }
>> -#endif
>> -
>> return vhost_get_used(vq, *idx, &vq->used->idx);
>> }
>>
>> static inline int vhost_get_desc(struct vhost_virtqueue *vq,
>> struct vring_desc *desc, int idx)
>> {
>> -#if VHOST_ARCH_CAN_ACCEL_UACCESS
>> - struct vhost_map *map;
>> - struct vring_desc *d;
>> -
>> - if (!vq->iotlb) {
>> - rcu_read_lock();
>> -
>> - map = rcu_dereference(vq->maps[VHOST_ADDR_DESC]);
>> - if (likely(map)) {
>> - d = map->addr;
>> - *desc = *(d + idx);
>> - rcu_read_unlock();
>> - return 0;
>> - }
>> -
>> - rcu_read_unlock();
>> - }
>> -#endif
>> -
>> return vhost_copy_from_user(vq, desc, vq->desc + idx, sizeof(*desc));
>> }
>>
>> @@ -1824,32 +1352,12 @@ static bool iotlb_access_ok(struct vhost_virtqueue *vq,
>> return true;
>> }
>>
>> -#if VHOST_ARCH_CAN_ACCEL_UACCESS
>> -static void vhost_vq_map_prefetch(struct vhost_virtqueue *vq)
>> -{
>> - struct vhost_map __rcu *map;
>> - int i;
>> -
>> - for (i = 0; i < VHOST_NUM_ADDRS; i++) {
>> - rcu_read_lock();
>> - map = rcu_dereference(vq->maps[i]);
>> - rcu_read_unlock();
>> - if (unlikely(!map))
>> - vhost_map_prefetch(vq, i);
>> - }
>> -}
>> -#endif
>> -
>> int vq_meta_prefetch(struct vhost_virtqueue *vq)
>> {
>> unsigned int num = vq->num;
>>
>> - if (!vq->iotlb) {
>> -#if VHOST_ARCH_CAN_ACCEL_UACCESS
>> - vhost_vq_map_prefetch(vq);
>> -#endif
>> + if (!vq->iotlb)
>> return 1;
>> - }
>>
>> return iotlb_access_ok(vq, VHOST_ACCESS_RO, (u64)(uintptr_t)vq->desc,
>> vhost_get_desc_size(vq, num), VHOST_ADDR_DESC) &&
>> @@ -2060,16 +1568,6 @@ static long vhost_vring_set_num_addr(struct vhost_dev *d,
>>
>> mutex_lock(&vq->mutex);
>>
>> -#if VHOST_ARCH_CAN_ACCEL_UACCESS
>> - /* Unregister MMU notifer to allow invalidation callback
>> - * can access vq->uaddrs[] without holding a lock.
>> - */
>> - if (d->mm)
>> - mmu_notifier_unregister(&d->mmu_notifier, d->mm);
>> -
>> - vhost_uninit_vq_maps(vq);
>> -#endif
>> -
>> switch (ioctl) {
>> case VHOST_SET_VRING_NUM:
>> r = vhost_vring_set_num(d, vq, argp);
>> @@ -2081,13 +1579,6 @@ static long vhost_vring_set_num_addr(struct vhost_dev *d,
>> BUG();
>> }
>>
>> -#if VHOST_ARCH_CAN_ACCEL_UACCESS
>> - vhost_setup_vq_uaddr(vq);
>> -
>> - if (d->mm)
>> - mmu_notifier_register(&d->mmu_notifier, d->mm);
>> -#endif
>> -
>> mutex_unlock(&vq->mutex);
>>
>> return r;
>> diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
>> index 42a8c2a13ab1..e9ed2722b633 100644
>> --- a/drivers/vhost/vhost.h
>> +++ b/drivers/vhost/vhost.h
>> @@ -12,9 +12,6 @@
>> #include <linux/virtio_config.h>
>> #include <linux/virtio_ring.h>
>> #include <linux/atomic.h>
>> -#include <linux/pagemap.h>
>> -#include <linux/mmu_notifier.h>
>> -#include <asm/cacheflush.h>
>>
>> struct vhost_work;
>> typedef void (*vhost_work_fn_t)(struct vhost_work *work);
>> @@ -83,24 +80,6 @@ enum vhost_uaddr_type {
>> VHOST_NUM_ADDRS = 3,
>> };
>>
>> -struct vhost_map {
>> - int npages;
>> - void *addr;
>> - struct page **pages;
>> -};
>> -
>> -struct vhost_uaddr {
>> - unsigned long uaddr;
>> - size_t size;
>> - bool write;
>> -};
>> -
>> -#if defined(CONFIG_MMU_NOTIFIER) && ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 0
>> -#define VHOST_ARCH_CAN_ACCEL_UACCESS 0
>> -#else
>> -#define VHOST_ARCH_CAN_ACCEL_UACCESS 0
>> -#endif
>> -
>> /* The virtqueue structure describes a queue attached to a device. */
>> struct vhost_virtqueue {
>> struct vhost_dev *dev;
>> @@ -111,22 +90,7 @@ struct vhost_virtqueue {
>> struct vring_desc __user *desc;
>> struct vring_avail __user *avail;
>> struct vring_used __user *used;
>> -
>> -#if VHOST_ARCH_CAN_ACCEL_UACCESS
>> - /* Read by memory accessors, modified by meta data
>> - * prefetching, MMU notifier and vring ioctl().
>> - * Synchonrized through mmu_lock (writers) and RCU (writers
>> - * and readers).
>> - */
>> - struct vhost_map __rcu *maps[VHOST_NUM_ADDRS];
>> - /* Read by MMU notifier, modified by vring ioctl(),
>> - * synchronized through MMU notifier
>> - * registering/unregistering.
>> - */
>> - struct vhost_uaddr uaddrs[VHOST_NUM_ADDRS];
>> -#endif
>> const struct vhost_umem_node *meta_iotlb[VHOST_NUM_ADDRS];
>> -
>> struct file *kick;
>> struct eventfd_ctx *call_ctx;
>> struct eventfd_ctx *error_ctx;
>> @@ -181,8 +145,6 @@ struct vhost_virtqueue {
>> bool user_be;
>> #endif
>> u32 busyloop_timeout;
>> - spinlock_t mmu_lock;
>> - int invalidate_count;
>> };
>>
>> struct vhost_msg_node {
>> @@ -196,9 +158,6 @@ struct vhost_msg_node {
>>
>> struct vhost_dev {
>> struct mm_struct *mm;
>> -#ifdef CONFIG_MMU_NOTIFIER
>> - struct mmu_notifier mmu_notifier;
>> -#endif
>> struct mutex mutex;
>> struct vhost_virtqueue **vqs;
>> int nvqs;
>> --
>> 2.19.1