diff mbox series

[RFC,v3,06/11] vhost-vdpa: Add an opaque pointer for vhost IOTLB

Message ID 20210119045920.447-7-xieyongji@bytedance.com (mailing list archive)
State New
Headers show
Series Introduce VDUSE - vDPA Device in Userspace | expand

Commit Message

Yongji Xie Jan. 19, 2021, 4:59 a.m. UTC
Add an opaque pointer for vhost IOTLB to store the
corresponding vma->vm_file and offset on the DMA mapping.

It will be used in VDUSE case later.

Suggested-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Xie Yongji <xieyongji@bytedance.com>
---
 drivers/vdpa/vdpa_sim/vdpa_sim.c | 11 ++++---
 drivers/vhost/iotlb.c            |  5 ++-
 drivers/vhost/vdpa.c             | 66 +++++++++++++++++++++++++++++++++++-----
 drivers/vhost/vhost.c            |  4 +--
 include/linux/vdpa.h             |  3 +-
 include/linux/vhost_iotlb.h      |  8 ++++-
 6 files changed, 79 insertions(+), 18 deletions(-)

Comments

Jason Wang Jan. 20, 2021, 6:24 a.m. UTC | #1
On 2021/1/19 下午12:59, Xie Yongji wrote:
> Add an opaque pointer for vhost IOTLB to store the
> corresponding vma->vm_file and offset on the DMA mapping.


Let's split the patch into two.

1) opaque pointer
2) vma stuffs


>
> It will be used in VDUSE case later.
>
> Suggested-by: Jason Wang <jasowang@redhat.com>
> Signed-off-by: Xie Yongji <xieyongji@bytedance.com>
> ---
>   drivers/vdpa/vdpa_sim/vdpa_sim.c | 11 ++++---
>   drivers/vhost/iotlb.c            |  5 ++-
>   drivers/vhost/vdpa.c             | 66 +++++++++++++++++++++++++++++++++++-----
>   drivers/vhost/vhost.c            |  4 +--
>   include/linux/vdpa.h             |  3 +-
>   include/linux/vhost_iotlb.h      |  8 ++++-
>   6 files changed, 79 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c
> index 03c796873a6b..1ffcef67954f 100644
> --- a/drivers/vdpa/vdpa_sim/vdpa_sim.c
> +++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c
> @@ -279,7 +279,7 @@ static dma_addr_t vdpasim_map_page(struct device *dev, struct page *page,
>   	 */
>   	spin_lock(&vdpasim->iommu_lock);
>   	ret = vhost_iotlb_add_range(iommu, pa, pa + size - 1,
> -				    pa, dir_to_perm(dir));
> +				    pa, dir_to_perm(dir), NULL);


Maybe its better to introduce

vhost_iotlb_add_range_ctx() which can accepts the opaque (context). And 
let vhost_iotlb_add_range() just call that.


>   	spin_unlock(&vdpasim->iommu_lock);
>   	if (ret)
>   		return DMA_MAPPING_ERROR;
> @@ -317,7 +317,7 @@ static void *vdpasim_alloc_coherent(struct device *dev, size_t size,
>   
>   		ret = vhost_iotlb_add_range(iommu, (u64)pa,
>   					    (u64)pa + size - 1,
> -					    pa, VHOST_MAP_RW);
> +					    pa, VHOST_MAP_RW, NULL);
>   		if (ret) {
>   			*dma_addr = DMA_MAPPING_ERROR;
>   			kfree(addr);
> @@ -625,7 +625,8 @@ static int vdpasim_set_map(struct vdpa_device *vdpa,
>   	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);
> +					    map->last, map->addr,
> +					    map->perm, NULL);
>   		if (ret)
>   			goto err;
>   	}
> @@ -639,14 +640,14 @@ static int vdpasim_set_map(struct vdpa_device *vdpa,
>   }
>   
>   static int vdpasim_dma_map(struct vdpa_device *vdpa, u64 iova, u64 size,
> -			   u64 pa, u32 perm)
> +			   u64 pa, u32 perm, void *opaque)
>   {
>   	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);
> +				    perm, NULL);
>   	spin_unlock(&vdpasim->iommu_lock);
>   
>   	return ret;
> diff --git a/drivers/vhost/iotlb.c b/drivers/vhost/iotlb.c
> index 0fd3f87e913c..3bd5bd06cdbc 100644
> --- a/drivers/vhost/iotlb.c
> +++ b/drivers/vhost/iotlb.c
> @@ -42,13 +42,15 @@ EXPORT_SYMBOL_GPL(vhost_iotlb_map_free);
>    * @last: last of IOVA range
>    * @addr: the address that is mapped to @start
>    * @perm: access permission of this range
> + * @opaque: the opaque pointer for the IOTLB mapping
>    *
>    * Returns an error last is smaller than start or memory allocation
>    * fails
>    */
>   int vhost_iotlb_add_range(struct vhost_iotlb *iotlb,
>   			  u64 start, u64 last,
> -			  u64 addr, unsigned int perm)
> +			  u64 addr, unsigned int perm,
> +			  void *opaque)
>   {
>   	struct vhost_iotlb_map *map;
>   
> @@ -71,6 +73,7 @@ int vhost_iotlb_add_range(struct vhost_iotlb *iotlb,
>   	map->last = last;
>   	map->addr = addr;
>   	map->perm = perm;
> +	map->opaque = opaque;
>   
>   	iotlb->nmaps++;
>   	vhost_iotlb_itree_insert(map, &iotlb->root);
> diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
> index 36b6950ba37f..e83e5be7cec8 100644
> --- a/drivers/vhost/vdpa.c
> +++ b/drivers/vhost/vdpa.c
> @@ -488,6 +488,7 @@ static void vhost_vdpa_iotlb_unmap(struct vhost_vdpa *v, u64 start, u64 last)
>   	struct vhost_dev *dev = &v->vdev;
>   	struct vdpa_device *vdpa = v->vdpa;
>   	struct vhost_iotlb *iotlb = dev->iotlb;
> +	struct vhost_iotlb_file *iotlb_file;
>   	struct vhost_iotlb_map *map;
>   	struct page *page;
>   	unsigned long pfn, pinned;
> @@ -504,6 +505,10 @@ static void vhost_vdpa_iotlb_unmap(struct vhost_vdpa *v, u64 start, u64 last)
>   			}
>   			atomic64_sub(map->size >> PAGE_SHIFT,
>   					&dev->mm->pinned_vm);
> +		} else if (map->opaque) {
> +			iotlb_file = (struct vhost_iotlb_file *)map->opaque;
> +			fput(iotlb_file->file);
> +			kfree(iotlb_file);
>   		}
>   		vhost_iotlb_map_free(iotlb, map);
>   	}
> @@ -540,8 +545,8 @@ static int perm_to_iommu_flags(u32 perm)
>   	return flags | IOMMU_CACHE;
>   }
>   
> -static int vhost_vdpa_map(struct vhost_vdpa *v,
> -			  u64 iova, u64 size, u64 pa, u32 perm)
> +static int vhost_vdpa_map(struct vhost_vdpa *v, u64 iova,
> +			  u64 size, u64 pa, u32 perm, void *opaque)
>   {
>   	struct vhost_dev *dev = &v->vdev;
>   	struct vdpa_device *vdpa = v->vdpa;
> @@ -549,12 +554,12 @@ static int vhost_vdpa_map(struct vhost_vdpa *v,
>   	int r = 0;
>   
>   	r = vhost_iotlb_add_range(dev->iotlb, iova, iova + size - 1,
> -				  pa, perm);
> +				  pa, perm, opaque);
>   	if (r)
>   		return r;
>   
>   	if (ops->dma_map) {
> -		r = ops->dma_map(vdpa, iova, size, pa, perm);
> +		r = ops->dma_map(vdpa, iova, size, pa, perm, opaque);
>   	} else if (ops->set_map) {
>   		if (!v->in_batch)
>   			r = ops->set_map(vdpa, dev->iotlb);
> @@ -591,6 +596,51 @@ static void vhost_vdpa_unmap(struct vhost_vdpa *v, u64 iova, u64 size)
>   	}
>   }
>   
> +static int vhost_vdpa_sva_map(struct vhost_vdpa *v,
> +			      u64 iova, u64 size, u64 uaddr, u32 perm)
> +{
> +	u64 offset, map_size, map_iova = iova;
> +	struct vhost_iotlb_file *iotlb_file;
> +	struct vm_area_struct *vma;
> +	int ret;


Lacking mmap_read_lock().


> +
> +	while (size) {
> +		vma = find_vma(current->mm, uaddr);
> +		if (!vma) {
> +			ret = -EINVAL;
> +			goto err;
> +		}
> +		map_size = min(size, vma->vm_end - uaddr);
> +		offset = (vma->vm_pgoff << PAGE_SHIFT) + uaddr - vma->vm_start;
> +		iotlb_file = NULL;
> +		if (vma->vm_file && (vma->vm_flags & VM_SHARED)) {


I wonder if we need more strict check here. When developing vhost-vdpa, 
I try hard to make sure the map can only work for user pages.

So the question is: do we need to exclude MMIO area or only allow shmem 
to work here?



> +			iotlb_file = kmalloc(sizeof(*iotlb_file), GFP_KERNEL);
> +			if (!iotlb_file) {
> +				ret = -ENOMEM;
> +				goto err;
> +			}
> +			iotlb_file->file = get_file(vma->vm_file);
> +			iotlb_file->offset = offset;
> +		}


I wonder if it's better to allocate iotlb_file and make iotlb_file->file 
= NULL && iotlb_file->offset = 0. This can force a consistent code for 
the vDPA parents.

Or we can simply fail the map without a file as backend.


> +		ret = vhost_vdpa_map(v, map_iova, map_size, uaddr,
> +					perm, iotlb_file);
> +		if (ret) {
> +			if (iotlb_file) {
> +				fput(iotlb_file->file);
> +				kfree(iotlb_file);
> +			}
> +			goto err;
> +		}
> +		size -= map_size;
> +		uaddr += map_size;
> +		map_iova += map_size;
> +	}
> +	return 0;
> +err:
> +	vhost_vdpa_unmap(v, iova, map_iova - iova);
> +	return ret;
> +}
> +
>   static int vhost_vdpa_process_iotlb_update(struct vhost_vdpa *v,
>   					   struct vhost_iotlb_msg *msg)
>   {
> @@ -615,8 +665,8 @@ static int vhost_vdpa_process_iotlb_update(struct vhost_vdpa *v,
>   		return -EEXIST;
>   
>   	if (vdpa->sva)
> -		return vhost_vdpa_map(v, msg->iova, msg->size,
> -				      msg->uaddr, msg->perm);
> +		return vhost_vdpa_sva_map(v, msg->iova, msg->size,
> +					  msg->uaddr, msg->perm);


So I think it's better squash vhost_vdpa_sva_map() and related changes 
into previous patch.


>   
>   	/* Limit the use of memory for bookkeeping */
>   	page_list = (struct page **) __get_free_page(GFP_KERNEL);
> @@ -671,7 +721,7 @@ static int vhost_vdpa_process_iotlb_update(struct vhost_vdpa *v,
>   				csize = (last_pfn - map_pfn + 1) << PAGE_SHIFT;
>   				ret = vhost_vdpa_map(v, iova, csize,
>   						     map_pfn << PAGE_SHIFT,
> -						     msg->perm);
> +						     msg->perm, NULL);
>   				if (ret) {
>   					/*
>   					 * Unpin the pages that are left unmapped
> @@ -700,7 +750,7 @@ static int vhost_vdpa_process_iotlb_update(struct vhost_vdpa *v,
>   
>   	/* Pin the rest chunk */
>   	ret = vhost_vdpa_map(v, iova, (last_pfn - map_pfn + 1) << PAGE_SHIFT,
> -			     map_pfn << PAGE_SHIFT, msg->perm);
> +			     map_pfn << PAGE_SHIFT, msg->perm, NULL);
>   out:
>   	if (ret) {
>   		if (nchunks) {
> diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
> index a262e12c6dc2..120dd5b3c119 100644
> --- a/drivers/vhost/vhost.c
> +++ b/drivers/vhost/vhost.c
> @@ -1104,7 +1104,7 @@ static int vhost_process_iotlb_msg(struct vhost_dev *dev,
>   		vhost_vq_meta_reset(dev);
>   		if (vhost_iotlb_add_range(dev->iotlb, msg->iova,
>   					  msg->iova + msg->size - 1,
> -					  msg->uaddr, msg->perm)) {
> +					  msg->uaddr, msg->perm, NULL)) {
>   			ret = -ENOMEM;
>   			break;
>   		}
> @@ -1450,7 +1450,7 @@ static long vhost_set_memory(struct vhost_dev *d, struct vhost_memory __user *m)
>   					  region->guest_phys_addr +
>   					  region->memory_size - 1,
>   					  region->userspace_addr,
> -					  VHOST_MAP_RW))
> +					  VHOST_MAP_RW, NULL))
>   			goto err;
>   	}
>   
> diff --git a/include/linux/vdpa.h b/include/linux/vdpa.h
> index f86869651614..b264c627e94b 100644
> --- a/include/linux/vdpa.h
> +++ b/include/linux/vdpa.h
> @@ -189,6 +189,7 @@ struct vdpa_iova_range {
>    *				@size: size of the area
>    *				@pa: physical address for the map
>    *				@perm: device access permission (VHOST_MAP_XX)
> + *				@opaque: the opaque pointer for the mapping
>    *				Returns integer: success (0) or error (< 0)
>    * @dma_unmap:			Unmap an area of IOVA (optional but
>    *				must be implemented with dma_map)
> @@ -243,7 +244,7 @@ struct vdpa_config_ops {
>   	/* DMA ops */
>   	int (*set_map)(struct vdpa_device *vdev, struct vhost_iotlb *iotlb);
>   	int (*dma_map)(struct vdpa_device *vdev, u64 iova, u64 size,
> -		       u64 pa, u32 perm);
> +		       u64 pa, u32 perm, void *opaque);
>   	int (*dma_unmap)(struct vdpa_device *vdev, u64 iova, u64 size);
>   
>   	/* Free device resources */
> diff --git a/include/linux/vhost_iotlb.h b/include/linux/vhost_iotlb.h
> index 6b09b786a762..66a50c11c8ca 100644
> --- a/include/linux/vhost_iotlb.h
> +++ b/include/linux/vhost_iotlb.h
> @@ -4,6 +4,11 @@
>   
>   #include <linux/interval_tree_generic.h>
>   
> +struct vhost_iotlb_file {
> +	struct file *file;
> +	u64 offset;
> +};


I think we'd better either:

1) simply use struct vhost_iotlb_file * instead of void *opaque for 
vhost_iotlb_map

or

2)rename and move the vhost_iotlb_file to vdpa

2) looks better since we want to let vhost iotlb to carry any type of 
context (opaque pointer)

And if we do this, the modification of vdpa_config_ops deserves a 
separate patch.

Thanks


> +
>   struct vhost_iotlb_map {
>   	struct rb_node rb;
>   	struct list_head link;
> @@ -17,6 +22,7 @@ struct vhost_iotlb_map {
>   	u32 perm;
>   	u32 flags_padding;
>   	u64 __subtree_last;
> +	void *opaque;
>   };
>   
>   #define VHOST_IOTLB_FLAG_RETIRE 0x1
> @@ -30,7 +36,7 @@ struct vhost_iotlb {
>   };
>   
>   int vhost_iotlb_add_range(struct vhost_iotlb *iotlb, u64 start, u64 last,
> -			  u64 addr, unsigned int perm);
> +			  u64 addr, unsigned int perm, void *opaque);
>   void vhost_iotlb_del_range(struct vhost_iotlb *iotlb, u64 start, u64 last);
>   
>   struct vhost_iotlb *vhost_iotlb_alloc(unsigned int limit, unsigned int flags);
Yongji Xie Jan. 20, 2021, 7:52 a.m. UTC | #2
On Wed, Jan 20, 2021 at 2:24 PM Jason Wang <jasowang@redhat.com> wrote:
>
>
> On 2021/1/19 下午12:59, Xie Yongji wrote:
> > Add an opaque pointer for vhost IOTLB to store the
> > corresponding vma->vm_file and offset on the DMA mapping.
>
>
> Let's split the patch into two.
>
> 1) opaque pointer
> 2) vma stuffs
>

OK.

>
> >
> > It will be used in VDUSE case later.
> >
> > Suggested-by: Jason Wang <jasowang@redhat.com>
> > Signed-off-by: Xie Yongji <xieyongji@bytedance.com>
> > ---
> >   drivers/vdpa/vdpa_sim/vdpa_sim.c | 11 ++++---
> >   drivers/vhost/iotlb.c            |  5 ++-
> >   drivers/vhost/vdpa.c             | 66 +++++++++++++++++++++++++++++++++++-----
> >   drivers/vhost/vhost.c            |  4 +--
> >   include/linux/vdpa.h             |  3 +-
> >   include/linux/vhost_iotlb.h      |  8 ++++-
> >   6 files changed, 79 insertions(+), 18 deletions(-)
> >
> > diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c
> > index 03c796873a6b..1ffcef67954f 100644
> > --- a/drivers/vdpa/vdpa_sim/vdpa_sim.c
> > +++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c
> > @@ -279,7 +279,7 @@ static dma_addr_t vdpasim_map_page(struct device *dev, struct page *page,
> >        */
> >       spin_lock(&vdpasim->iommu_lock);
> >       ret = vhost_iotlb_add_range(iommu, pa, pa + size - 1,
> > -                                 pa, dir_to_perm(dir));
> > +                                 pa, dir_to_perm(dir), NULL);
>
>
> Maybe its better to introduce
>
> vhost_iotlb_add_range_ctx() which can accepts the opaque (context). And
> let vhost_iotlb_add_range() just call that.
>

If so, we need export both vhost_iotlb_add_range() and
vhost_iotlb_add_range_ctx() which will be used in VDUSE driver. Is it
a bit redundant?

>
> >       spin_unlock(&vdpasim->iommu_lock);
> >       if (ret)
> >               return DMA_MAPPING_ERROR;
> > @@ -317,7 +317,7 @@ static void *vdpasim_alloc_coherent(struct device *dev, size_t size,
> >
> >               ret = vhost_iotlb_add_range(iommu, (u64)pa,
> >                                           (u64)pa + size - 1,
> > -                                         pa, VHOST_MAP_RW);
> > +                                         pa, VHOST_MAP_RW, NULL);
> >               if (ret) {
> >                       *dma_addr = DMA_MAPPING_ERROR;
> >                       kfree(addr);
> > @@ -625,7 +625,8 @@ static int vdpasim_set_map(struct vdpa_device *vdpa,
> >       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);
> > +                                         map->last, map->addr,
> > +                                         map->perm, NULL);
> >               if (ret)
> >                       goto err;
> >       }
> > @@ -639,14 +640,14 @@ static int vdpasim_set_map(struct vdpa_device *vdpa,
> >   }
> >
> >   static int vdpasim_dma_map(struct vdpa_device *vdpa, u64 iova, u64 size,
> > -                        u64 pa, u32 perm)
> > +                        u64 pa, u32 perm, void *opaque)
> >   {
> >       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);
> > +                                 perm, NULL);
> >       spin_unlock(&vdpasim->iommu_lock);
> >
> >       return ret;
> > diff --git a/drivers/vhost/iotlb.c b/drivers/vhost/iotlb.c
> > index 0fd3f87e913c..3bd5bd06cdbc 100644
> > --- a/drivers/vhost/iotlb.c
> > +++ b/drivers/vhost/iotlb.c
> > @@ -42,13 +42,15 @@ EXPORT_SYMBOL_GPL(vhost_iotlb_map_free);
> >    * @last: last of IOVA range
> >    * @addr: the address that is mapped to @start
> >    * @perm: access permission of this range
> > + * @opaque: the opaque pointer for the IOTLB mapping
> >    *
> >    * Returns an error last is smaller than start or memory allocation
> >    * fails
> >    */
> >   int vhost_iotlb_add_range(struct vhost_iotlb *iotlb,
> >                         u64 start, u64 last,
> > -                       u64 addr, unsigned int perm)
> > +                       u64 addr, unsigned int perm,
> > +                       void *opaque)
> >   {
> >       struct vhost_iotlb_map *map;
> >
> > @@ -71,6 +73,7 @@ int vhost_iotlb_add_range(struct vhost_iotlb *iotlb,
> >       map->last = last;
> >       map->addr = addr;
> >       map->perm = perm;
> > +     map->opaque = opaque;
> >
> >       iotlb->nmaps++;
> >       vhost_iotlb_itree_insert(map, &iotlb->root);
> > diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
> > index 36b6950ba37f..e83e5be7cec8 100644
> > --- a/drivers/vhost/vdpa.c
> > +++ b/drivers/vhost/vdpa.c
> > @@ -488,6 +488,7 @@ static void vhost_vdpa_iotlb_unmap(struct vhost_vdpa *v, u64 start, u64 last)
> >       struct vhost_dev *dev = &v->vdev;
> >       struct vdpa_device *vdpa = v->vdpa;
> >       struct vhost_iotlb *iotlb = dev->iotlb;
> > +     struct vhost_iotlb_file *iotlb_file;
> >       struct vhost_iotlb_map *map;
> >       struct page *page;
> >       unsigned long pfn, pinned;
> > @@ -504,6 +505,10 @@ static void vhost_vdpa_iotlb_unmap(struct vhost_vdpa *v, u64 start, u64 last)
> >                       }
> >                       atomic64_sub(map->size >> PAGE_SHIFT,
> >                                       &dev->mm->pinned_vm);
> > +             } else if (map->opaque) {
> > +                     iotlb_file = (struct vhost_iotlb_file *)map->opaque;
> > +                     fput(iotlb_file->file);
> > +                     kfree(iotlb_file);
> >               }
> >               vhost_iotlb_map_free(iotlb, map);
> >       }
> > @@ -540,8 +545,8 @@ static int perm_to_iommu_flags(u32 perm)
> >       return flags | IOMMU_CACHE;
> >   }
> >
> > -static int vhost_vdpa_map(struct vhost_vdpa *v,
> > -                       u64 iova, u64 size, u64 pa, u32 perm)
> > +static int vhost_vdpa_map(struct vhost_vdpa *v, u64 iova,
> > +                       u64 size, u64 pa, u32 perm, void *opaque)
> >   {
> >       struct vhost_dev *dev = &v->vdev;
> >       struct vdpa_device *vdpa = v->vdpa;
> > @@ -549,12 +554,12 @@ static int vhost_vdpa_map(struct vhost_vdpa *v,
> >       int r = 0;
> >
> >       r = vhost_iotlb_add_range(dev->iotlb, iova, iova + size - 1,
> > -                               pa, perm);
> > +                               pa, perm, opaque);
> >       if (r)
> >               return r;
> >
> >       if (ops->dma_map) {
> > -             r = ops->dma_map(vdpa, iova, size, pa, perm);
> > +             r = ops->dma_map(vdpa, iova, size, pa, perm, opaque);
> >       } else if (ops->set_map) {
> >               if (!v->in_batch)
> >                       r = ops->set_map(vdpa, dev->iotlb);
> > @@ -591,6 +596,51 @@ static void vhost_vdpa_unmap(struct vhost_vdpa *v, u64 iova, u64 size)
> >       }
> >   }
> >
> > +static int vhost_vdpa_sva_map(struct vhost_vdpa *v,
> > +                           u64 iova, u64 size, u64 uaddr, u32 perm)
> > +{
> > +     u64 offset, map_size, map_iova = iova;
> > +     struct vhost_iotlb_file *iotlb_file;
> > +     struct vm_area_struct *vma;
> > +     int ret;
>
>
> Lacking mmap_read_lock().
>

Good catch! Will fix it.

>
> > +
> > +     while (size) {
> > +             vma = find_vma(current->mm, uaddr);
> > +             if (!vma) {
> > +                     ret = -EINVAL;
> > +                     goto err;
> > +             }
> > +             map_size = min(size, vma->vm_end - uaddr);
> > +             offset = (vma->vm_pgoff << PAGE_SHIFT) + uaddr - vma->vm_start;
> > +             iotlb_file = NULL;
> > +             if (vma->vm_file && (vma->vm_flags & VM_SHARED)) {
>
>
> I wonder if we need more strict check here. When developing vhost-vdpa,
> I try hard to make sure the map can only work for user pages.
>
> So the question is: do we need to exclude MMIO area or only allow shmem
> to work here?
>

Do you mean we need to check VM_MIXEDMAP | VM_PFNMAP here?

It makes sense to me.

>
>
> > +                     iotlb_file = kmalloc(sizeof(*iotlb_file), GFP_KERNEL);
> > +                     if (!iotlb_file) {
> > +                             ret = -ENOMEM;
> > +                             goto err;
> > +                     }
> > +                     iotlb_file->file = get_file(vma->vm_file);
> > +                     iotlb_file->offset = offset;
> > +             }
>
>
> I wonder if it's better to allocate iotlb_file and make iotlb_file->file
> = NULL && iotlb_file->offset = 0. This can force a consistent code for
> the vDPA parents.
>

Looks fine to me.

> Or we can simply fail the map without a file as backend.
>

Actually there will be some vma without vm_file during vm booting.

>
> > +             ret = vhost_vdpa_map(v, map_iova, map_size, uaddr,
> > +                                     perm, iotlb_file);
> > +             if (ret) {
> > +                     if (iotlb_file) {
> > +                             fput(iotlb_file->file);
> > +                             kfree(iotlb_file);
> > +                     }
> > +                     goto err;
> > +             }
> > +             size -= map_size;
> > +             uaddr += map_size;
> > +             map_iova += map_size;
> > +     }
> > +     return 0;
> > +err:
> > +     vhost_vdpa_unmap(v, iova, map_iova - iova);
> > +     return ret;
> > +}
> > +
> >   static int vhost_vdpa_process_iotlb_update(struct vhost_vdpa *v,
> >                                          struct vhost_iotlb_msg *msg)
> >   {
> > @@ -615,8 +665,8 @@ static int vhost_vdpa_process_iotlb_update(struct vhost_vdpa *v,
> >               return -EEXIST;
> >
> >       if (vdpa->sva)
> > -             return vhost_vdpa_map(v, msg->iova, msg->size,
> > -                                   msg->uaddr, msg->perm);
> > +             return vhost_vdpa_sva_map(v, msg->iova, msg->size,
> > +                                       msg->uaddr, msg->perm);
>
>
> So I think it's better squash vhost_vdpa_sva_map() and related changes
> into previous patch.
>

OK, so the order of the patches is:
1) opaque pointer
2) va support + vma stuffs?

Is it OK?

>
> >
> >       /* Limit the use of memory for bookkeeping */
> >       page_list = (struct page **) __get_free_page(GFP_KERNEL);
> > @@ -671,7 +721,7 @@ static int vhost_vdpa_process_iotlb_update(struct vhost_vdpa *v,
> >                               csize = (last_pfn - map_pfn + 1) << PAGE_SHIFT;
> >                               ret = vhost_vdpa_map(v, iova, csize,
> >                                                    map_pfn << PAGE_SHIFT,
> > -                                                  msg->perm);
> > +                                                  msg->perm, NULL);
> >                               if (ret) {
> >                                       /*
> >                                        * Unpin the pages that are left unmapped
> > @@ -700,7 +750,7 @@ static int vhost_vdpa_process_iotlb_update(struct vhost_vdpa *v,
> >
> >       /* Pin the rest chunk */
> >       ret = vhost_vdpa_map(v, iova, (last_pfn - map_pfn + 1) << PAGE_SHIFT,
> > -                          map_pfn << PAGE_SHIFT, msg->perm);
> > +                          map_pfn << PAGE_SHIFT, msg->perm, NULL);
> >   out:
> >       if (ret) {
> >               if (nchunks) {
> > diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
> > index a262e12c6dc2..120dd5b3c119 100644
> > --- a/drivers/vhost/vhost.c
> > +++ b/drivers/vhost/vhost.c
> > @@ -1104,7 +1104,7 @@ static int vhost_process_iotlb_msg(struct vhost_dev *dev,
> >               vhost_vq_meta_reset(dev);
> >               if (vhost_iotlb_add_range(dev->iotlb, msg->iova,
> >                                         msg->iova + msg->size - 1,
> > -                                       msg->uaddr, msg->perm)) {
> > +                                       msg->uaddr, msg->perm, NULL)) {
> >                       ret = -ENOMEM;
> >                       break;
> >               }
> > @@ -1450,7 +1450,7 @@ static long vhost_set_memory(struct vhost_dev *d, struct vhost_memory __user *m)
> >                                         region->guest_phys_addr +
> >                                         region->memory_size - 1,
> >                                         region->userspace_addr,
> > -                                       VHOST_MAP_RW))
> > +                                       VHOST_MAP_RW, NULL))
> >                       goto err;
> >       }
> >
> > diff --git a/include/linux/vdpa.h b/include/linux/vdpa.h
> > index f86869651614..b264c627e94b 100644
> > --- a/include/linux/vdpa.h
> > +++ b/include/linux/vdpa.h
> > @@ -189,6 +189,7 @@ struct vdpa_iova_range {
> >    *                          @size: size of the area
> >    *                          @pa: physical address for the map
> >    *                          @perm: device access permission (VHOST_MAP_XX)
> > + *                           @opaque: the opaque pointer for the mapping
> >    *                          Returns integer: success (0) or error (< 0)
> >    * @dma_unmap:                      Unmap an area of IOVA (optional but
> >    *                          must be implemented with dma_map)
> > @@ -243,7 +244,7 @@ struct vdpa_config_ops {
> >       /* DMA ops */
> >       int (*set_map)(struct vdpa_device *vdev, struct vhost_iotlb *iotlb);
> >       int (*dma_map)(struct vdpa_device *vdev, u64 iova, u64 size,
> > -                    u64 pa, u32 perm);
> > +                    u64 pa, u32 perm, void *opaque);
> >       int (*dma_unmap)(struct vdpa_device *vdev, u64 iova, u64 size);
> >
> >       /* Free device resources */
> > diff --git a/include/linux/vhost_iotlb.h b/include/linux/vhost_iotlb.h
> > index 6b09b786a762..66a50c11c8ca 100644
> > --- a/include/linux/vhost_iotlb.h
> > +++ b/include/linux/vhost_iotlb.h
> > @@ -4,6 +4,11 @@
> >
> >   #include <linux/interval_tree_generic.h>
> >
> > +struct vhost_iotlb_file {
> > +     struct file *file;
> > +     u64 offset;
> > +};
>
>
> I think we'd better either:
>
> 1) simply use struct vhost_iotlb_file * instead of void *opaque for
> vhost_iotlb_map
>
> or
>
> 2)rename and move the vhost_iotlb_file to vdpa
>
> 2) looks better since we want to let vhost iotlb to carry any type of
> context (opaque pointer)
>

I agree. So we need to introduce struct vdpa_iotlb_file in
include/linux/vdpa.h, right?

> And if we do this, the modification of vdpa_config_ops deserves a
> separate patch.
>

Sorry, I didn't get you here. What do you mean by the modification of
vdpa_config_ops? Do you mean adding an opaque pointer to ops.dma_map?

Thanks,
Yongji
Jason Wang Jan. 27, 2021, 3:51 a.m. UTC | #3
On 2021/1/20 下午3:52, Yongji Xie wrote:
> On Wed, Jan 20, 2021 at 2:24 PM Jason Wang <jasowang@redhat.com> wrote:
>>
>> On 2021/1/19 下午12:59, Xie Yongji wrote:
>>> Add an opaque pointer for vhost IOTLB to store the
>>> corresponding vma->vm_file and offset on the DMA mapping.
>>
>> Let's split the patch into two.
>>
>> 1) opaque pointer
>> 2) vma stuffs
>>
> OK.
>
>>> It will be used in VDUSE case later.
>>>
>>> Suggested-by: Jason Wang <jasowang@redhat.com>
>>> Signed-off-by: Xie Yongji <xieyongji@bytedance.com>
>>> ---
>>>    drivers/vdpa/vdpa_sim/vdpa_sim.c | 11 ++++---
>>>    drivers/vhost/iotlb.c            |  5 ++-
>>>    drivers/vhost/vdpa.c             | 66 +++++++++++++++++++++++++++++++++++-----
>>>    drivers/vhost/vhost.c            |  4 +--
>>>    include/linux/vdpa.h             |  3 +-
>>>    include/linux/vhost_iotlb.h      |  8 ++++-
>>>    6 files changed, 79 insertions(+), 18 deletions(-)
>>>
>>> diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c
>>> index 03c796873a6b..1ffcef67954f 100644
>>> --- a/drivers/vdpa/vdpa_sim/vdpa_sim.c
>>> +++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c
>>> @@ -279,7 +279,7 @@ static dma_addr_t vdpasim_map_page(struct device *dev, struct page *page,
>>>         */
>>>        spin_lock(&vdpasim->iommu_lock);
>>>        ret = vhost_iotlb_add_range(iommu, pa, pa + size - 1,
>>> -                                 pa, dir_to_perm(dir));
>>> +                                 pa, dir_to_perm(dir), NULL);
>>
>> Maybe its better to introduce
>>
>> vhost_iotlb_add_range_ctx() which can accepts the opaque (context). And
>> let vhost_iotlb_add_range() just call that.
>>
> If so, we need export both vhost_iotlb_add_range() and
> vhost_iotlb_add_range_ctx() which will be used in VDUSE driver. Is it
> a bit redundant?


Probably not, we do something similar in virtio core:

void *virtqueue_get_buf_ctx(struct virtqueue *_vq, unsigned int *len,
                 void **ctx)
{
     struct vring_virtqueue *vq = to_vvq(_vq);

     return vq->packed_ring ? virtqueue_get_buf_ctx_packed(_vq, len, ctx) :
                  virtqueue_get_buf_ctx_split(_vq, len, ctx);
}
EXPORT_SYMBOL_GPL(virtqueue_get_buf_ctx);

void *virtqueue_get_buf(struct virtqueue *_vq, unsigned int *len)
{
     return virtqueue_get_buf_ctx(_vq, len, NULL);
}
EXPORT_SYMBOL_GPL(virtqueue_get_buf);


>
>>>        spin_unlock(&vdpasim->iommu_lock);
>>>        if (ret)
>>>                return DMA_MAPPING_ERROR;
>>> @@ -317,7 +317,7 @@ static void *vdpasim_alloc_coherent(struct device *dev, size_t size,
>>>
>>>                ret = vhost_iotlb_add_range(iommu, (u64)pa,
>>>                                            (u64)pa + size - 1,
>>> -                                         pa, VHOST_MAP_RW);
>>> +                                         pa, VHOST_MAP_RW, NULL);
>>>                if (ret) {
>>>                        *dma_addr = DMA_MAPPING_ERROR;
>>>                        kfree(addr);
>>> @@ -625,7 +625,8 @@ static int vdpasim_set_map(struct vdpa_device *vdpa,
>>>        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);
>>> +                                         map->last, map->addr,
>>> +                                         map->perm, NULL);
>>>                if (ret)
>>>                        goto err;
>>>        }
>>> @@ -639,14 +640,14 @@ static int vdpasim_set_map(struct vdpa_device *vdpa,
>>>    }
>>>
>>>    static int vdpasim_dma_map(struct vdpa_device *vdpa, u64 iova, u64 size,
>>> -                        u64 pa, u32 perm)
>>> +                        u64 pa, u32 perm, void *opaque)
>>>    {
>>>        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);
>>> +                                 perm, NULL);
>>>        spin_unlock(&vdpasim->iommu_lock);
>>>
>>>        return ret;
>>> diff --git a/drivers/vhost/iotlb.c b/drivers/vhost/iotlb.c
>>> index 0fd3f87e913c..3bd5bd06cdbc 100644
>>> --- a/drivers/vhost/iotlb.c
>>> +++ b/drivers/vhost/iotlb.c
>>> @@ -42,13 +42,15 @@ EXPORT_SYMBOL_GPL(vhost_iotlb_map_free);
>>>     * @last: last of IOVA range
>>>     * @addr: the address that is mapped to @start
>>>     * @perm: access permission of this range
>>> + * @opaque: the opaque pointer for the IOTLB mapping
>>>     *
>>>     * Returns an error last is smaller than start or memory allocation
>>>     * fails
>>>     */
>>>    int vhost_iotlb_add_range(struct vhost_iotlb *iotlb,
>>>                          u64 start, u64 last,
>>> -                       u64 addr, unsigned int perm)
>>> +                       u64 addr, unsigned int perm,
>>> +                       void *opaque)
>>>    {
>>>        struct vhost_iotlb_map *map;
>>>
>>> @@ -71,6 +73,7 @@ int vhost_iotlb_add_range(struct vhost_iotlb *iotlb,
>>>        map->last = last;
>>>        map->addr = addr;
>>>        map->perm = perm;
>>> +     map->opaque = opaque;
>>>
>>>        iotlb->nmaps++;
>>>        vhost_iotlb_itree_insert(map, &iotlb->root);
>>> diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
>>> index 36b6950ba37f..e83e5be7cec8 100644
>>> --- a/drivers/vhost/vdpa.c
>>> +++ b/drivers/vhost/vdpa.c
>>> @@ -488,6 +488,7 @@ static void vhost_vdpa_iotlb_unmap(struct vhost_vdpa *v, u64 start, u64 last)
>>>        struct vhost_dev *dev = &v->vdev;
>>>        struct vdpa_device *vdpa = v->vdpa;
>>>        struct vhost_iotlb *iotlb = dev->iotlb;
>>> +     struct vhost_iotlb_file *iotlb_file;
>>>        struct vhost_iotlb_map *map;
>>>        struct page *page;
>>>        unsigned long pfn, pinned;
>>> @@ -504,6 +505,10 @@ static void vhost_vdpa_iotlb_unmap(struct vhost_vdpa *v, u64 start, u64 last)
>>>                        }
>>>                        atomic64_sub(map->size >> PAGE_SHIFT,
>>>                                        &dev->mm->pinned_vm);
>>> +             } else if (map->opaque) {
>>> +                     iotlb_file = (struct vhost_iotlb_file *)map->opaque;
>>> +                     fput(iotlb_file->file);
>>> +                     kfree(iotlb_file);
>>>                }
>>>                vhost_iotlb_map_free(iotlb, map);
>>>        }
>>> @@ -540,8 +545,8 @@ static int perm_to_iommu_flags(u32 perm)
>>>        return flags | IOMMU_CACHE;
>>>    }
>>>
>>> -static int vhost_vdpa_map(struct vhost_vdpa *v,
>>> -                       u64 iova, u64 size, u64 pa, u32 perm)
>>> +static int vhost_vdpa_map(struct vhost_vdpa *v, u64 iova,
>>> +                       u64 size, u64 pa, u32 perm, void *opaque)
>>>    {
>>>        struct vhost_dev *dev = &v->vdev;
>>>        struct vdpa_device *vdpa = v->vdpa;
>>> @@ -549,12 +554,12 @@ static int vhost_vdpa_map(struct vhost_vdpa *v,
>>>        int r = 0;
>>>
>>>        r = vhost_iotlb_add_range(dev->iotlb, iova, iova + size - 1,
>>> -                               pa, perm);
>>> +                               pa, perm, opaque);
>>>        if (r)
>>>                return r;
>>>
>>>        if (ops->dma_map) {
>>> -             r = ops->dma_map(vdpa, iova, size, pa, perm);
>>> +             r = ops->dma_map(vdpa, iova, size, pa, perm, opaque);
>>>        } else if (ops->set_map) {
>>>                if (!v->in_batch)
>>>                        r = ops->set_map(vdpa, dev->iotlb);
>>> @@ -591,6 +596,51 @@ static void vhost_vdpa_unmap(struct vhost_vdpa *v, u64 iova, u64 size)
>>>        }
>>>    }
>>>
>>> +static int vhost_vdpa_sva_map(struct vhost_vdpa *v,
>>> +                           u64 iova, u64 size, u64 uaddr, u32 perm)
>>> +{
>>> +     u64 offset, map_size, map_iova = iova;
>>> +     struct vhost_iotlb_file *iotlb_file;
>>> +     struct vm_area_struct *vma;
>>> +     int ret;
>>
>> Lacking mmap_read_lock().
>>
> Good catch! Will fix it.
>
>>> +
>>> +     while (size) {
>>> +             vma = find_vma(current->mm, uaddr);
>>> +             if (!vma) {
>>> +                     ret = -EINVAL;
>>> +                     goto err;
>>> +             }
>>> +             map_size = min(size, vma->vm_end - uaddr);
>>> +             offset = (vma->vm_pgoff << PAGE_SHIFT) + uaddr - vma->vm_start;
>>> +             iotlb_file = NULL;
>>> +             if (vma->vm_file && (vma->vm_flags & VM_SHARED)) {
>>
>> I wonder if we need more strict check here. When developing vhost-vdpa,
>> I try hard to make sure the map can only work for user pages.
>>
>> So the question is: do we need to exclude MMIO area or only allow shmem
>> to work here?
>>
> Do you mean we need to check VM_MIXEDMAP | VM_PFNMAP here?


I meant do we need to allow VM_IO here? (We don't allow such case in 
vhost-vdpa now).


>
> It makes sense to me.
>
>>
>>> +                     iotlb_file = kmalloc(sizeof(*iotlb_file), GFP_KERNEL);
>>> +                     if (!iotlb_file) {
>>> +                             ret = -ENOMEM;
>>> +                             goto err;
>>> +                     }
>>> +                     iotlb_file->file = get_file(vma->vm_file);
>>> +                     iotlb_file->offset = offset;
>>> +             }
>>
>> I wonder if it's better to allocate iotlb_file and make iotlb_file->file
>> = NULL && iotlb_file->offset = 0. This can force a consistent code for
>> the vDPA parents.
>>
> Looks fine to me.
>
>> Or we can simply fail the map without a file as backend.
>>
> Actually there will be some vma without vm_file during vm booting.


Yes, e.g bios or other rom. Vhost-user has the similar issue and they 
filter the out them in qemu.

For vhost-vDPA, consider it can supports various difference backends, we 
can't do that.


>
>>> +             ret = vhost_vdpa_map(v, map_iova, map_size, uaddr,
>>> +                                     perm, iotlb_file);
>>> +             if (ret) {
>>> +                     if (iotlb_file) {
>>> +                             fput(iotlb_file->file);
>>> +                             kfree(iotlb_file);
>>> +                     }
>>> +                     goto err;
>>> +             }
>>> +             size -= map_size;
>>> +             uaddr += map_size;
>>> +             map_iova += map_size;
>>> +     }
>>> +     return 0;
>>> +err:
>>> +     vhost_vdpa_unmap(v, iova, map_iova - iova);
>>> +     return ret;
>>> +}
>>> +
>>>    static int vhost_vdpa_process_iotlb_update(struct vhost_vdpa *v,
>>>                                           struct vhost_iotlb_msg *msg)
>>>    {
>>> @@ -615,8 +665,8 @@ static int vhost_vdpa_process_iotlb_update(struct vhost_vdpa *v,
>>>                return -EEXIST;
>>>
>>>        if (vdpa->sva)
>>> -             return vhost_vdpa_map(v, msg->iova, msg->size,
>>> -                                   msg->uaddr, msg->perm);
>>> +             return vhost_vdpa_sva_map(v, msg->iova, msg->size,
>>> +                                       msg->uaddr, msg->perm);
>>
>> So I think it's better squash vhost_vdpa_sva_map() and related changes
>> into previous patch.
>>
> OK, so the order of the patches is:
> 1) opaque pointer
> 2) va support + vma stuffs?
>
> Is it OK?


Fine with me.


>
>>>        /* Limit the use of memory for bookkeeping */
>>>        page_list = (struct page **) __get_free_page(GFP_KERNEL);
>>> @@ -671,7 +721,7 @@ static int vhost_vdpa_process_iotlb_update(struct vhost_vdpa *v,
>>>                                csize = (last_pfn - map_pfn + 1) << PAGE_SHIFT;
>>>                                ret = vhost_vdpa_map(v, iova, csize,
>>>                                                     map_pfn << PAGE_SHIFT,
>>> -                                                  msg->perm);
>>> +                                                  msg->perm, NULL);
>>>                                if (ret) {
>>>                                        /*
>>>                                         * Unpin the pages that are left unmapped
>>> @@ -700,7 +750,7 @@ static int vhost_vdpa_process_iotlb_update(struct vhost_vdpa *v,
>>>
>>>        /* Pin the rest chunk */
>>>        ret = vhost_vdpa_map(v, iova, (last_pfn - map_pfn + 1) << PAGE_SHIFT,
>>> -                          map_pfn << PAGE_SHIFT, msg->perm);
>>> +                          map_pfn << PAGE_SHIFT, msg->perm, NULL);
>>>    out:
>>>        if (ret) {
>>>                if (nchunks) {
>>> diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
>>> index a262e12c6dc2..120dd5b3c119 100644
>>> --- a/drivers/vhost/vhost.c
>>> +++ b/drivers/vhost/vhost.c
>>> @@ -1104,7 +1104,7 @@ static int vhost_process_iotlb_msg(struct vhost_dev *dev,
>>>                vhost_vq_meta_reset(dev);
>>>                if (vhost_iotlb_add_range(dev->iotlb, msg->iova,
>>>                                          msg->iova + msg->size - 1,
>>> -                                       msg->uaddr, msg->perm)) {
>>> +                                       msg->uaddr, msg->perm, NULL)) {
>>>                        ret = -ENOMEM;
>>>                        break;
>>>                }
>>> @@ -1450,7 +1450,7 @@ static long vhost_set_memory(struct vhost_dev *d, struct vhost_memory __user *m)
>>>                                          region->guest_phys_addr +
>>>                                          region->memory_size - 1,
>>>                                          region->userspace_addr,
>>> -                                       VHOST_MAP_RW))
>>> +                                       VHOST_MAP_RW, NULL))
>>>                        goto err;
>>>        }
>>>
>>> diff --git a/include/linux/vdpa.h b/include/linux/vdpa.h
>>> index f86869651614..b264c627e94b 100644
>>> --- a/include/linux/vdpa.h
>>> +++ b/include/linux/vdpa.h
>>> @@ -189,6 +189,7 @@ struct vdpa_iova_range {
>>>     *                          @size: size of the area
>>>     *                          @pa: physical address for the map
>>>     *                          @perm: device access permission (VHOST_MAP_XX)
>>> + *                           @opaque: the opaque pointer for the mapping
>>>     *                          Returns integer: success (0) or error (< 0)
>>>     * @dma_unmap:                      Unmap an area of IOVA (optional but
>>>     *                          must be implemented with dma_map)
>>> @@ -243,7 +244,7 @@ struct vdpa_config_ops {
>>>        /* DMA ops */
>>>        int (*set_map)(struct vdpa_device *vdev, struct vhost_iotlb *iotlb);
>>>        int (*dma_map)(struct vdpa_device *vdev, u64 iova, u64 size,
>>> -                    u64 pa, u32 perm);
>>> +                    u64 pa, u32 perm, void *opaque);
>>>        int (*dma_unmap)(struct vdpa_device *vdev, u64 iova, u64 size);
>>>
>>>        /* Free device resources */
>>> diff --git a/include/linux/vhost_iotlb.h b/include/linux/vhost_iotlb.h
>>> index 6b09b786a762..66a50c11c8ca 100644
>>> --- a/include/linux/vhost_iotlb.h
>>> +++ b/include/linux/vhost_iotlb.h
>>> @@ -4,6 +4,11 @@
>>>
>>>    #include <linux/interval_tree_generic.h>
>>>
>>> +struct vhost_iotlb_file {
>>> +     struct file *file;
>>> +     u64 offset;
>>> +};
>>
>> I think we'd better either:
>>
>> 1) simply use struct vhost_iotlb_file * instead of void *opaque for
>> vhost_iotlb_map
>>
>> or
>>
>> 2)rename and move the vhost_iotlb_file to vdpa
>>
>> 2) looks better since we want to let vhost iotlb to carry any type of
>> context (opaque pointer)
>>
> I agree. So we need to introduce struct vdpa_iotlb_file in
> include/linux/vdpa.h, right?


Yes.


>
>> And if we do this, the modification of vdpa_config_ops deserves a
>> separate patch.
>>
> Sorry, I didn't get you here. What do you mean by the modification of
> vdpa_config_ops? Do you mean adding an opaque pointer to ops.dma_map?


Yes.

Thanks


>
> Thanks,
> Yongji
>
Yongji Xie Jan. 27, 2021, 9:27 a.m. UTC | #4
On Wed, Jan 27, 2021 at 11:51 AM Jason Wang <jasowang@redhat.com> wrote:
>
>
> On 2021/1/20 下午3:52, Yongji Xie wrote:
> > On Wed, Jan 20, 2021 at 2:24 PM Jason Wang <jasowang@redhat.com> wrote:
> >>
> >> On 2021/1/19 下午12:59, Xie Yongji wrote:
> >>> Add an opaque pointer for vhost IOTLB to store the
> >>> corresponding vma->vm_file and offset on the DMA mapping.
> >>
> >> Let's split the patch into two.
> >>
> >> 1) opaque pointer
> >> 2) vma stuffs
> >>
> > OK.
> >
> >>> It will be used in VDUSE case later.
> >>>
> >>> Suggested-by: Jason Wang <jasowang@redhat.com>
> >>> Signed-off-by: Xie Yongji <xieyongji@bytedance.com>
> >>> ---
> >>>    drivers/vdpa/vdpa_sim/vdpa_sim.c | 11 ++++---
> >>>    drivers/vhost/iotlb.c            |  5 ++-
> >>>    drivers/vhost/vdpa.c             | 66 +++++++++++++++++++++++++++++++++++-----
> >>>    drivers/vhost/vhost.c            |  4 +--
> >>>    include/linux/vdpa.h             |  3 +-
> >>>    include/linux/vhost_iotlb.h      |  8 ++++-
> >>>    6 files changed, 79 insertions(+), 18 deletions(-)
> >>>
> >>> diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c
> >>> index 03c796873a6b..1ffcef67954f 100644
> >>> --- a/drivers/vdpa/vdpa_sim/vdpa_sim.c
> >>> +++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c
> >>> @@ -279,7 +279,7 @@ static dma_addr_t vdpasim_map_page(struct device *dev, struct page *page,
> >>>         */
> >>>        spin_lock(&vdpasim->iommu_lock);
> >>>        ret = vhost_iotlb_add_range(iommu, pa, pa + size - 1,
> >>> -                                 pa, dir_to_perm(dir));
> >>> +                                 pa, dir_to_perm(dir), NULL);
> >>
> >> Maybe its better to introduce
> >>
> >> vhost_iotlb_add_range_ctx() which can accepts the opaque (context). And
> >> let vhost_iotlb_add_range() just call that.
> >>
> > If so, we need export both vhost_iotlb_add_range() and
> > vhost_iotlb_add_range_ctx() which will be used in VDUSE driver. Is it
> > a bit redundant?
>
>
> Probably not, we do something similar in virtio core:
>
> void *virtqueue_get_buf_ctx(struct virtqueue *_vq, unsigned int *len,
>                  void **ctx)
> {
>      struct vring_virtqueue *vq = to_vvq(_vq);
>
>      return vq->packed_ring ? virtqueue_get_buf_ctx_packed(_vq, len, ctx) :
>                   virtqueue_get_buf_ctx_split(_vq, len, ctx);
> }
> EXPORT_SYMBOL_GPL(virtqueue_get_buf_ctx);
>
> void *virtqueue_get_buf(struct virtqueue *_vq, unsigned int *len)
> {
>      return virtqueue_get_buf_ctx(_vq, len, NULL);
> }
> EXPORT_SYMBOL_GPL(virtqueue_get_buf);
>

I see. Will do it in the next version.

>
> >
> >>>        spin_unlock(&vdpasim->iommu_lock);
> >>>        if (ret)
> >>>                return DMA_MAPPING_ERROR;
> >>> @@ -317,7 +317,7 @@ static void *vdpasim_alloc_coherent(struct device *dev, size_t size,
> >>>
> >>>                ret = vhost_iotlb_add_range(iommu, (u64)pa,
> >>>                                            (u64)pa + size - 1,
> >>> -                                         pa, VHOST_MAP_RW);
> >>> +                                         pa, VHOST_MAP_RW, NULL);
> >>>                if (ret) {
> >>>                        *dma_addr = DMA_MAPPING_ERROR;
> >>>                        kfree(addr);
> >>> @@ -625,7 +625,8 @@ static int vdpasim_set_map(struct vdpa_device *vdpa,
> >>>        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);
> >>> +                                         map->last, map->addr,
> >>> +                                         map->perm, NULL);
> >>>                if (ret)
> >>>                        goto err;
> >>>        }
> >>> @@ -639,14 +640,14 @@ static int vdpasim_set_map(struct vdpa_device *vdpa,
> >>>    }
> >>>
> >>>    static int vdpasim_dma_map(struct vdpa_device *vdpa, u64 iova, u64 size,
> >>> -                        u64 pa, u32 perm)
> >>> +                        u64 pa, u32 perm, void *opaque)
> >>>    {
> >>>        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);
> >>> +                                 perm, NULL);
> >>>        spin_unlock(&vdpasim->iommu_lock);
> >>>
> >>>        return ret;
> >>> diff --git a/drivers/vhost/iotlb.c b/drivers/vhost/iotlb.c
> >>> index 0fd3f87e913c..3bd5bd06cdbc 100644
> >>> --- a/drivers/vhost/iotlb.c
> >>> +++ b/drivers/vhost/iotlb.c
> >>> @@ -42,13 +42,15 @@ EXPORT_SYMBOL_GPL(vhost_iotlb_map_free);
> >>>     * @last: last of IOVA range
> >>>     * @addr: the address that is mapped to @start
> >>>     * @perm: access permission of this range
> >>> + * @opaque: the opaque pointer for the IOTLB mapping
> >>>     *
> >>>     * Returns an error last is smaller than start or memory allocation
> >>>     * fails
> >>>     */
> >>>    int vhost_iotlb_add_range(struct vhost_iotlb *iotlb,
> >>>                          u64 start, u64 last,
> >>> -                       u64 addr, unsigned int perm)
> >>> +                       u64 addr, unsigned int perm,
> >>> +                       void *opaque)
> >>>    {
> >>>        struct vhost_iotlb_map *map;
> >>>
> >>> @@ -71,6 +73,7 @@ int vhost_iotlb_add_range(struct vhost_iotlb *iotlb,
> >>>        map->last = last;
> >>>        map->addr = addr;
> >>>        map->perm = perm;
> >>> +     map->opaque = opaque;
> >>>
> >>>        iotlb->nmaps++;
> >>>        vhost_iotlb_itree_insert(map, &iotlb->root);
> >>> diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
> >>> index 36b6950ba37f..e83e5be7cec8 100644
> >>> --- a/drivers/vhost/vdpa.c
> >>> +++ b/drivers/vhost/vdpa.c
> >>> @@ -488,6 +488,7 @@ static void vhost_vdpa_iotlb_unmap(struct vhost_vdpa *v, u64 start, u64 last)
> >>>        struct vhost_dev *dev = &v->vdev;
> >>>        struct vdpa_device *vdpa = v->vdpa;
> >>>        struct vhost_iotlb *iotlb = dev->iotlb;
> >>> +     struct vhost_iotlb_file *iotlb_file;
> >>>        struct vhost_iotlb_map *map;
> >>>        struct page *page;
> >>>        unsigned long pfn, pinned;
> >>> @@ -504,6 +505,10 @@ static void vhost_vdpa_iotlb_unmap(struct vhost_vdpa *v, u64 start, u64 last)
> >>>                        }
> >>>                        atomic64_sub(map->size >> PAGE_SHIFT,
> >>>                                        &dev->mm->pinned_vm);
> >>> +             } else if (map->opaque) {
> >>> +                     iotlb_file = (struct vhost_iotlb_file *)map->opaque;
> >>> +                     fput(iotlb_file->file);
> >>> +                     kfree(iotlb_file);
> >>>                }
> >>>                vhost_iotlb_map_free(iotlb, map);
> >>>        }
> >>> @@ -540,8 +545,8 @@ static int perm_to_iommu_flags(u32 perm)
> >>>        return flags | IOMMU_CACHE;
> >>>    }
> >>>
> >>> -static int vhost_vdpa_map(struct vhost_vdpa *v,
> >>> -                       u64 iova, u64 size, u64 pa, u32 perm)
> >>> +static int vhost_vdpa_map(struct vhost_vdpa *v, u64 iova,
> >>> +                       u64 size, u64 pa, u32 perm, void *opaque)
> >>>    {
> >>>        struct vhost_dev *dev = &v->vdev;
> >>>        struct vdpa_device *vdpa = v->vdpa;
> >>> @@ -549,12 +554,12 @@ static int vhost_vdpa_map(struct vhost_vdpa *v,
> >>>        int r = 0;
> >>>
> >>>        r = vhost_iotlb_add_range(dev->iotlb, iova, iova + size - 1,
> >>> -                               pa, perm);
> >>> +                               pa, perm, opaque);
> >>>        if (r)
> >>>                return r;
> >>>
> >>>        if (ops->dma_map) {
> >>> -             r = ops->dma_map(vdpa, iova, size, pa, perm);
> >>> +             r = ops->dma_map(vdpa, iova, size, pa, perm, opaque);
> >>>        } else if (ops->set_map) {
> >>>                if (!v->in_batch)
> >>>                        r = ops->set_map(vdpa, dev->iotlb);
> >>> @@ -591,6 +596,51 @@ static void vhost_vdpa_unmap(struct vhost_vdpa *v, u64 iova, u64 size)
> >>>        }
> >>>    }
> >>>
> >>> +static int vhost_vdpa_sva_map(struct vhost_vdpa *v,
> >>> +                           u64 iova, u64 size, u64 uaddr, u32 perm)
> >>> +{
> >>> +     u64 offset, map_size, map_iova = iova;
> >>> +     struct vhost_iotlb_file *iotlb_file;
> >>> +     struct vm_area_struct *vma;
> >>> +     int ret;
> >>
> >> Lacking mmap_read_lock().
> >>
> > Good catch! Will fix it.
> >
> >>> +
> >>> +     while (size) {
> >>> +             vma = find_vma(current->mm, uaddr);
> >>> +             if (!vma) {
> >>> +                     ret = -EINVAL;
> >>> +                     goto err;
> >>> +             }
> >>> +             map_size = min(size, vma->vm_end - uaddr);
> >>> +             offset = (vma->vm_pgoff << PAGE_SHIFT) + uaddr - vma->vm_start;
> >>> +             iotlb_file = NULL;
> >>> +             if (vma->vm_file && (vma->vm_flags & VM_SHARED)) {
> >>
> >> I wonder if we need more strict check here. When developing vhost-vdpa,
> >> I try hard to make sure the map can only work for user pages.
> >>
> >> So the question is: do we need to exclude MMIO area or only allow shmem
> >> to work here?
> >>
> > Do you mean we need to check VM_MIXEDMAP | VM_PFNMAP here?
>
>
> I meant do we need to allow VM_IO here? (We don't allow such case in
> vhost-vdpa now).
>

OK, let's exclude the vma with VM_IO | VM_PFNMAP.

>
> >
> > It makes sense to me.
> >
> >>
> >>> +                     iotlb_file = kmalloc(sizeof(*iotlb_file), GFP_KERNEL);
> >>> +                     if (!iotlb_file) {
> >>> +                             ret = -ENOMEM;
> >>> +                             goto err;
> >>> +                     }
> >>> +                     iotlb_file->file = get_file(vma->vm_file);
> >>> +                     iotlb_file->offset = offset;
> >>> +             }
> >>
> >> I wonder if it's better to allocate iotlb_file and make iotlb_file->file
> >> = NULL && iotlb_file->offset = 0. This can force a consistent code for
> >> the vDPA parents.
> >>
> > Looks fine to me.
> >
> >> Or we can simply fail the map without a file as backend.
> >>
> > Actually there will be some vma without vm_file during vm booting.
>
>
> Yes, e.g bios or other rom. Vhost-user has the similar issue and they
> filter the out them in qemu.
>
> For vhost-vDPA, consider it can supports various difference backends, we
> can't do that.
>

OK, I will transfer iotlb_file with NULL file and let the backend do
the filtering.

Thanks,
Yongji
diff mbox series

Patch

diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c
index 03c796873a6b..1ffcef67954f 100644
--- a/drivers/vdpa/vdpa_sim/vdpa_sim.c
+++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c
@@ -279,7 +279,7 @@  static dma_addr_t vdpasim_map_page(struct device *dev, struct page *page,
 	 */
 	spin_lock(&vdpasim->iommu_lock);
 	ret = vhost_iotlb_add_range(iommu, pa, pa + size - 1,
-				    pa, dir_to_perm(dir));
+				    pa, dir_to_perm(dir), NULL);
 	spin_unlock(&vdpasim->iommu_lock);
 	if (ret)
 		return DMA_MAPPING_ERROR;
@@ -317,7 +317,7 @@  static void *vdpasim_alloc_coherent(struct device *dev, size_t size,
 
 		ret = vhost_iotlb_add_range(iommu, (u64)pa,
 					    (u64)pa + size - 1,
-					    pa, VHOST_MAP_RW);
+					    pa, VHOST_MAP_RW, NULL);
 		if (ret) {
 			*dma_addr = DMA_MAPPING_ERROR;
 			kfree(addr);
@@ -625,7 +625,8 @@  static int vdpasim_set_map(struct vdpa_device *vdpa,
 	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);
+					    map->last, map->addr,
+					    map->perm, NULL);
 		if (ret)
 			goto err;
 	}
@@ -639,14 +640,14 @@  static int vdpasim_set_map(struct vdpa_device *vdpa,
 }
 
 static int vdpasim_dma_map(struct vdpa_device *vdpa, u64 iova, u64 size,
-			   u64 pa, u32 perm)
+			   u64 pa, u32 perm, void *opaque)
 {
 	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);
+				    perm, NULL);
 	spin_unlock(&vdpasim->iommu_lock);
 
 	return ret;
diff --git a/drivers/vhost/iotlb.c b/drivers/vhost/iotlb.c
index 0fd3f87e913c..3bd5bd06cdbc 100644
--- a/drivers/vhost/iotlb.c
+++ b/drivers/vhost/iotlb.c
@@ -42,13 +42,15 @@  EXPORT_SYMBOL_GPL(vhost_iotlb_map_free);
  * @last: last of IOVA range
  * @addr: the address that is mapped to @start
  * @perm: access permission of this range
+ * @opaque: the opaque pointer for the IOTLB mapping
  *
  * Returns an error last is smaller than start or memory allocation
  * fails
  */
 int vhost_iotlb_add_range(struct vhost_iotlb *iotlb,
 			  u64 start, u64 last,
-			  u64 addr, unsigned int perm)
+			  u64 addr, unsigned int perm,
+			  void *opaque)
 {
 	struct vhost_iotlb_map *map;
 
@@ -71,6 +73,7 @@  int vhost_iotlb_add_range(struct vhost_iotlb *iotlb,
 	map->last = last;
 	map->addr = addr;
 	map->perm = perm;
+	map->opaque = opaque;
 
 	iotlb->nmaps++;
 	vhost_iotlb_itree_insert(map, &iotlb->root);
diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
index 36b6950ba37f..e83e5be7cec8 100644
--- a/drivers/vhost/vdpa.c
+++ b/drivers/vhost/vdpa.c
@@ -488,6 +488,7 @@  static void vhost_vdpa_iotlb_unmap(struct vhost_vdpa *v, u64 start, u64 last)
 	struct vhost_dev *dev = &v->vdev;
 	struct vdpa_device *vdpa = v->vdpa;
 	struct vhost_iotlb *iotlb = dev->iotlb;
+	struct vhost_iotlb_file *iotlb_file;
 	struct vhost_iotlb_map *map;
 	struct page *page;
 	unsigned long pfn, pinned;
@@ -504,6 +505,10 @@  static void vhost_vdpa_iotlb_unmap(struct vhost_vdpa *v, u64 start, u64 last)
 			}
 			atomic64_sub(map->size >> PAGE_SHIFT,
 					&dev->mm->pinned_vm);
+		} else if (map->opaque) {
+			iotlb_file = (struct vhost_iotlb_file *)map->opaque;
+			fput(iotlb_file->file);
+			kfree(iotlb_file);
 		}
 		vhost_iotlb_map_free(iotlb, map);
 	}
@@ -540,8 +545,8 @@  static int perm_to_iommu_flags(u32 perm)
 	return flags | IOMMU_CACHE;
 }
 
-static int vhost_vdpa_map(struct vhost_vdpa *v,
-			  u64 iova, u64 size, u64 pa, u32 perm)
+static int vhost_vdpa_map(struct vhost_vdpa *v, u64 iova,
+			  u64 size, u64 pa, u32 perm, void *opaque)
 {
 	struct vhost_dev *dev = &v->vdev;
 	struct vdpa_device *vdpa = v->vdpa;
@@ -549,12 +554,12 @@  static int vhost_vdpa_map(struct vhost_vdpa *v,
 	int r = 0;
 
 	r = vhost_iotlb_add_range(dev->iotlb, iova, iova + size - 1,
-				  pa, perm);
+				  pa, perm, opaque);
 	if (r)
 		return r;
 
 	if (ops->dma_map) {
-		r = ops->dma_map(vdpa, iova, size, pa, perm);
+		r = ops->dma_map(vdpa, iova, size, pa, perm, opaque);
 	} else if (ops->set_map) {
 		if (!v->in_batch)
 			r = ops->set_map(vdpa, dev->iotlb);
@@ -591,6 +596,51 @@  static void vhost_vdpa_unmap(struct vhost_vdpa *v, u64 iova, u64 size)
 	}
 }
 
+static int vhost_vdpa_sva_map(struct vhost_vdpa *v,
+			      u64 iova, u64 size, u64 uaddr, u32 perm)
+{
+	u64 offset, map_size, map_iova = iova;
+	struct vhost_iotlb_file *iotlb_file;
+	struct vm_area_struct *vma;
+	int ret;
+
+	while (size) {
+		vma = find_vma(current->mm, uaddr);
+		if (!vma) {
+			ret = -EINVAL;
+			goto err;
+		}
+		map_size = min(size, vma->vm_end - uaddr);
+		offset = (vma->vm_pgoff << PAGE_SHIFT) + uaddr - vma->vm_start;
+		iotlb_file = NULL;
+		if (vma->vm_file && (vma->vm_flags & VM_SHARED)) {
+			iotlb_file = kmalloc(sizeof(*iotlb_file), GFP_KERNEL);
+			if (!iotlb_file) {
+				ret = -ENOMEM;
+				goto err;
+			}
+			iotlb_file->file = get_file(vma->vm_file);
+			iotlb_file->offset = offset;
+		}
+		ret = vhost_vdpa_map(v, map_iova, map_size, uaddr,
+					perm, iotlb_file);
+		if (ret) {
+			if (iotlb_file) {
+				fput(iotlb_file->file);
+				kfree(iotlb_file);
+			}
+			goto err;
+		}
+		size -= map_size;
+		uaddr += map_size;
+		map_iova += map_size;
+	}
+	return 0;
+err:
+	vhost_vdpa_unmap(v, iova, map_iova - iova);
+	return ret;
+}
+
 static int vhost_vdpa_process_iotlb_update(struct vhost_vdpa *v,
 					   struct vhost_iotlb_msg *msg)
 {
@@ -615,8 +665,8 @@  static int vhost_vdpa_process_iotlb_update(struct vhost_vdpa *v,
 		return -EEXIST;
 
 	if (vdpa->sva)
-		return vhost_vdpa_map(v, msg->iova, msg->size,
-				      msg->uaddr, msg->perm);
+		return vhost_vdpa_sva_map(v, msg->iova, msg->size,
+					  msg->uaddr, msg->perm);
 
 	/* Limit the use of memory for bookkeeping */
 	page_list = (struct page **) __get_free_page(GFP_KERNEL);
@@ -671,7 +721,7 @@  static int vhost_vdpa_process_iotlb_update(struct vhost_vdpa *v,
 				csize = (last_pfn - map_pfn + 1) << PAGE_SHIFT;
 				ret = vhost_vdpa_map(v, iova, csize,
 						     map_pfn << PAGE_SHIFT,
-						     msg->perm);
+						     msg->perm, NULL);
 				if (ret) {
 					/*
 					 * Unpin the pages that are left unmapped
@@ -700,7 +750,7 @@  static int vhost_vdpa_process_iotlb_update(struct vhost_vdpa *v,
 
 	/* Pin the rest chunk */
 	ret = vhost_vdpa_map(v, iova, (last_pfn - map_pfn + 1) << PAGE_SHIFT,
-			     map_pfn << PAGE_SHIFT, msg->perm);
+			     map_pfn << PAGE_SHIFT, msg->perm, NULL);
 out:
 	if (ret) {
 		if (nchunks) {
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index a262e12c6dc2..120dd5b3c119 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -1104,7 +1104,7 @@  static int vhost_process_iotlb_msg(struct vhost_dev *dev,
 		vhost_vq_meta_reset(dev);
 		if (vhost_iotlb_add_range(dev->iotlb, msg->iova,
 					  msg->iova + msg->size - 1,
-					  msg->uaddr, msg->perm)) {
+					  msg->uaddr, msg->perm, NULL)) {
 			ret = -ENOMEM;
 			break;
 		}
@@ -1450,7 +1450,7 @@  static long vhost_set_memory(struct vhost_dev *d, struct vhost_memory __user *m)
 					  region->guest_phys_addr +
 					  region->memory_size - 1,
 					  region->userspace_addr,
-					  VHOST_MAP_RW))
+					  VHOST_MAP_RW, NULL))
 			goto err;
 	}
 
diff --git a/include/linux/vdpa.h b/include/linux/vdpa.h
index f86869651614..b264c627e94b 100644
--- a/include/linux/vdpa.h
+++ b/include/linux/vdpa.h
@@ -189,6 +189,7 @@  struct vdpa_iova_range {
  *				@size: size of the area
  *				@pa: physical address for the map
  *				@perm: device access permission (VHOST_MAP_XX)
+ *				@opaque: the opaque pointer for the mapping
  *				Returns integer: success (0) or error (< 0)
  * @dma_unmap:			Unmap an area of IOVA (optional but
  *				must be implemented with dma_map)
@@ -243,7 +244,7 @@  struct vdpa_config_ops {
 	/* DMA ops */
 	int (*set_map)(struct vdpa_device *vdev, struct vhost_iotlb *iotlb);
 	int (*dma_map)(struct vdpa_device *vdev, u64 iova, u64 size,
-		       u64 pa, u32 perm);
+		       u64 pa, u32 perm, void *opaque);
 	int (*dma_unmap)(struct vdpa_device *vdev, u64 iova, u64 size);
 
 	/* Free device resources */
diff --git a/include/linux/vhost_iotlb.h b/include/linux/vhost_iotlb.h
index 6b09b786a762..66a50c11c8ca 100644
--- a/include/linux/vhost_iotlb.h
+++ b/include/linux/vhost_iotlb.h
@@ -4,6 +4,11 @@ 
 
 #include <linux/interval_tree_generic.h>
 
+struct vhost_iotlb_file {
+	struct file *file;
+	u64 offset;
+};
+
 struct vhost_iotlb_map {
 	struct rb_node rb;
 	struct list_head link;
@@ -17,6 +22,7 @@  struct vhost_iotlb_map {
 	u32 perm;
 	u32 flags_padding;
 	u64 __subtree_last;
+	void *opaque;
 };
 
 #define VHOST_IOTLB_FLAG_RETIRE 0x1
@@ -30,7 +36,7 @@  struct vhost_iotlb {
 };
 
 int vhost_iotlb_add_range(struct vhost_iotlb *iotlb, u64 start, u64 last,
-			  u64 addr, unsigned int perm);
+			  u64 addr, unsigned int perm, void *opaque);
 void vhost_iotlb_del_range(struct vhost_iotlb *iotlb, u64 start, u64 last);
 
 struct vhost_iotlb *vhost_iotlb_alloc(unsigned int limit, unsigned int flags);