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

Michael S. Tsirkin
2019-09-06T13:46:53Z

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!

> ---
> 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