Re: [RFC PATCH 05/24] vhost-vdpa: passing iotlb to IOMMU mapping helpers

[Eli Cohen <elic@nvidia.com>]

On Thu, Sep 24, 2020 at 11:21:06AM +0800, Jason Wang wrote:
> To prepare for the ASID support for vhost-vdpa, try to pass IOTLB
> object to dma helpers.

Maybe it's worth mentioning here that this patch does not change any
functionality and is presented as a preparation for passing different
iotlb's instead of using dev->iotlb

> 
> Signed-off-by: Jason Wang <jasowang@redhat.com>
> ---
>  drivers/vhost/vdpa.c | 40 ++++++++++++++++++++++------------------
>  1 file changed, 22 insertions(+), 18 deletions(-)
> 
> diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
> index 9c641274b9f3..74bef1c15a70 100644
> --- a/drivers/vhost/vdpa.c
> +++ b/drivers/vhost/vdpa.c
> @@ -489,10 +489,11 @@ static long vhost_vdpa_unlocked_ioctl(struct file *filep,
>  	return r;
>  }
>  
> -static void vhost_vdpa_iotlb_unmap(struct vhost_vdpa *v, u64 start, u64 last)
> +static void vhost_vdpa_iotlb_unmap(struct vhost_vdpa *v,
> +				   struct vhost_iotlb *iotlb,
> +				   u64 start, u64 last)
>  {
>  	struct vhost_dev *dev = &v->vdev;
> -	struct vhost_iotlb *iotlb = dev->iotlb;
>  	struct vhost_iotlb_map *map;
>  	struct page *page;
>  	unsigned long pfn, pinned;
> @@ -514,8 +515,9 @@ static void vhost_vdpa_iotlb_unmap(struct vhost_vdpa *v, u64 start, u64 last)
>  static void vhost_vdpa_iotlb_free(struct vhost_vdpa *v)
>  {
>  	struct vhost_dev *dev = &v->vdev;
> +	struct vhost_iotlb *iotlb = dev->iotlb;
>  
> -	vhost_vdpa_iotlb_unmap(v, 0ULL, 0ULL - 1);
> +	vhost_vdpa_iotlb_unmap(v, iotlb, 0ULL, 0ULL - 1);
>  	kfree(dev->iotlb);
>  	dev->iotlb = NULL;
>  }
> @@ -542,15 +544,14 @@ static int perm_to_iommu_flags(u32 perm)
>  	return flags | IOMMU_CACHE;
>  }
>  
> -static int vhost_vdpa_map(struct vhost_vdpa *v,
> +static int vhost_vdpa_map(struct vhost_vdpa *v, struct vhost_iotlb *iotlb,
>  			  u64 iova, u64 size, u64 pa, u32 perm)
>  {
> -	struct vhost_dev *dev = &v->vdev;
>  	struct vdpa_device *vdpa = v->vdpa;
>  	const struct vdpa_config_ops *ops = vdpa->config;
>  	int r = 0;
>  
> -	r = vhost_iotlb_add_range(dev->iotlb, iova, iova + size - 1,
> +	r = vhost_iotlb_add_range(iotlb, iova, iova + size - 1,
>  				  pa, perm);
>  	if (r)
>  		return r;
> @@ -559,7 +560,7 @@ static int vhost_vdpa_map(struct vhost_vdpa *v,
>  		r = ops->dma_map(vdpa, iova, size, pa, perm);
>  	} else if (ops->set_map) {
>  		if (!v->in_batch)
> -			r = ops->set_map(vdpa, dev->iotlb);
> +			r = ops->set_map(vdpa, iotlb);
>  	} else {
>  		r = iommu_map(v->domain, iova, pa, size,
>  			      perm_to_iommu_flags(perm));
> @@ -568,29 +569,30 @@ static int vhost_vdpa_map(struct vhost_vdpa *v,
>  	return r;
>  }
>  
> -static void vhost_vdpa_unmap(struct vhost_vdpa *v, u64 iova, u64 size)
> +static void vhost_vdpa_unmap(struct vhost_vdpa *v,
> +			     struct vhost_iotlb *iotlb,
> +			     u64 iova, u64 size)
>  {
> -	struct vhost_dev *dev = &v->vdev;
>  	struct vdpa_device *vdpa = v->vdpa;
>  	const struct vdpa_config_ops *ops = vdpa->config;
>  
> -	vhost_vdpa_iotlb_unmap(v, iova, iova + size - 1);
> +	vhost_vdpa_iotlb_unmap(v, iotlb, iova, iova + size - 1);
>  
>  	if (ops->dma_map) {
>  		ops->dma_unmap(vdpa, iova, size);
>  	} else if (ops->set_map) {
>  		if (!v->in_batch)
> -			ops->set_map(vdpa, dev->iotlb);
> +			ops->set_map(vdpa, iotlb);
>  	} else {
>  		iommu_unmap(v->domain, iova, size);
>  	}
>  }
>  
>  static int vhost_vdpa_process_iotlb_update(struct vhost_vdpa *v,
> +					   struct vhost_iotlb *iotlb,
>  					   struct vhost_iotlb_msg *msg)
>  {
>  	struct vhost_dev *dev = &v->vdev;
> -	struct vhost_iotlb *iotlb = dev->iotlb;
>  	struct page **page_list;
>  	unsigned long list_size = PAGE_SIZE / sizeof(struct page *);
>  	unsigned int gup_flags = FOLL_LONGTERM;
> @@ -644,7 +646,7 @@ static int vhost_vdpa_process_iotlb_update(struct vhost_vdpa *v,
>  			if (last_pfn && (this_pfn != last_pfn + 1)) {
>  				/* Pin a contiguous chunk of memory */
>  				csize = (last_pfn - map_pfn + 1) << PAGE_SHIFT;
> -				if (vhost_vdpa_map(v, iova, csize,
> +				if (vhost_vdpa_map(v, iotlb, iova, csize,
>  						   map_pfn << PAGE_SHIFT,
>  						   msg->perm))
>  					goto out;
> @@ -660,11 +662,12 @@ 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,
> +	ret = vhost_vdpa_map(v, iotlb, iova,
> +			     (last_pfn - map_pfn + 1) << PAGE_SHIFT,
>  			     map_pfn << PAGE_SHIFT, msg->perm);
>  out:
>  	if (ret) {
> -		vhost_vdpa_unmap(v, msg->iova, msg->size);
> +		vhost_vdpa_unmap(v, iotlb, msg->iova, msg->size);
>  		atomic64_sub(npages, &dev->mm->pinned_vm);
>  	}
>  	mmap_read_unlock(dev->mm);
> @@ -678,6 +681,7 @@ static int vhost_vdpa_process_iotlb_msg(struct vhost_dev *dev,
>  	struct vhost_vdpa *v = container_of(dev, struct vhost_vdpa, vdev);
>  	struct vdpa_device *vdpa = v->vdpa;
>  	const struct vdpa_config_ops *ops = vdpa->config;
> +	struct vhost_iotlb *iotlb = dev->iotlb;
>  	int r = 0;
>  
>  	r = vhost_dev_check_owner(dev);
> @@ -686,17 +690,17 @@ static int vhost_vdpa_process_iotlb_msg(struct vhost_dev *dev,
>  
>  	switch (msg->type) {
>  	case VHOST_IOTLB_UPDATE:
> -		r = vhost_vdpa_process_iotlb_update(v, msg);
> +		r = vhost_vdpa_process_iotlb_update(v, iotlb, msg);
>  		break;
>  	case VHOST_IOTLB_INVALIDATE:
> -		vhost_vdpa_unmap(v, msg->iova, msg->size);
> +		vhost_vdpa_unmap(v, iotlb, msg->iova, msg->size);
>  		break;
>  	case VHOST_IOTLB_BATCH_BEGIN:
>  		v->in_batch = true;
>  		break;
>  	case VHOST_IOTLB_BATCH_END:
>  		if (v->in_batch && ops->set_map)
> -			ops->set_map(vdpa, dev->iotlb);
> +			ops->set_map(vdpa, iotlb);
>  		v->in_batch = false;
>  		break;
>  	default:
> -- 
> 2.20.1
>