Re: [PATCH v6 07/10] iommufd: Add a nested HW pagetable object

[Yi Liu]

On 2023/10/25 01:30, Jason Gunthorpe wrote:
> On Tue, Oct 24, 2023 at 02:18:10PM -0300, Jason Gunthorpe wrote:
> > On Tue, Oct 24, 2023 at 08:06:06AM -0700, Yi Liu wrote:
> > > @@ -195,6 +279,10 @@ int iommufd_hwpt_alloc(struct iommufd_ucmd *ucmd)
> > >   	if (pt_obj->type == IOMMUFD_OBJ_IOAS) {
> > >   		struct iommufd_hwpt_paging *hwpt_paging;
> > >   
> > > +		if (cmd->data_type != IOMMU_HWPT_DATA_NONE) {
> > > +			rc = -EINVAL;
> > > +			goto out_put_pt;
> > > +		}
> > >   		ioas = container_of(pt_obj, struct iommufd_ioas, obj);
> > >   		mutex_lock(&ioas->mutex);
> > >   		hwpt_paging = iommufd_hwpt_paging_alloc(ucmd->ictx, ioas, idev,
> >
> > ?? What is this?
> >
> > Ah something went wrong earlier in "iommu: Pass in parent domain with
> > user_data to domain_alloc_user op"
>
> Bah, I got confused because that had half the uapi, so in this pathc
>   
> > Once we added the user_data we should flow it through to the op
> > always.
>
> Like this:

ack.

> diff --git a/drivers/iommu/iommufd/device.c b/drivers/iommu/iommufd/device.c
> index 92859b907bb93c..a3382811af8a81 100644
> --- a/drivers/iommu/iommufd/device.c
> +++ b/drivers/iommu/iommufd/device.c
> @@ -586,8 +586,8 @@ iommufd_device_auto_get_domain(struct iommufd_device *idev,
>   		goto out_unlock;
>   	}
>   
> -	hwpt_paging = iommufd_hwpt_paging_alloc(idev->ictx, ioas, idev,
> -						 0, immediate_attach);
> +	hwpt_paging = iommufd_hwpt_paging_alloc(idev->ictx, ioas, idev, 0,
> +						immediate_attach, NULL);
>   	if (IS_ERR(hwpt_paging)) {
>   		destroy_hwpt = ERR_CAST(hwpt_paging);
>   		goto out_unlock;
> diff --git a/drivers/iommu/iommufd/hw_pagetable.c b/drivers/iommu/iommufd/hw_pagetable.c
> index cfd85df693d7b2..324a6d73f032ee 100644
> --- a/drivers/iommu/iommufd/hw_pagetable.c
> +++ b/drivers/iommu/iommufd/hw_pagetable.c
> @@ -96,7 +96,8 @@ iommufd_hwpt_paging_enforce_cc(struct iommufd_hwpt_paging *hwpt_paging)
>   struct iommufd_hwpt_paging *
>   iommufd_hwpt_paging_alloc(struct iommufd_ctx *ictx, struct iommufd_ioas *ioas,
>   			  struct iommufd_device *idev, u32 flags,
> -			  bool immediate_attach)
> +			  bool immediate_attach,
> +			  const struct iommu_user_data *user_data)
>   {
>   	const u32 valid_flags = IOMMU_HWPT_ALLOC_NEST_PARENT |
>   				IOMMU_HWPT_ALLOC_DIRTY_TRACKING;
> @@ -107,7 +108,7 @@ iommufd_hwpt_paging_alloc(struct iommufd_ctx *ictx, struct iommufd_ioas *ioas,
>   
>   	lockdep_assert_held(&ioas->mutex);
>   
> -	if (flags && !ops->domain_alloc_user)
> +	if ((flags || user_data) && !ops->domain_alloc_user)
>   		return ERR_PTR(-EOPNOTSUPP);
>   	if (flags & ~valid_flags)
>   		return ERR_PTR(-EOPNOTSUPP);
> @@ -127,7 +128,7 @@ iommufd_hwpt_paging_alloc(struct iommufd_ctx *ictx, struct iommufd_ioas *ioas,
>   
>   	if (ops->domain_alloc_user) {
>   		hwpt->domain = ops->domain_alloc_user(idev->dev, flags,
> -						      NULL, NULL);
> +						      NULL, user_data);
>   		if (IS_ERR(hwpt->domain)) {
>   			rc = PTR_ERR(hwpt->domain);
>   			hwpt->domain = NULL;
> @@ -210,8 +211,7 @@ iommufd_hwpt_nested_alloc(struct iommufd_ctx *ictx,
>   	struct iommufd_hw_pagetable *hwpt;
>   	int rc;
>   
> -	if (flags || user_data->type == IOMMU_HWPT_DATA_NONE ||
> -	    !ops->domain_alloc_user)
> +	if (flags || !user_data->len || !ops->domain_alloc_user)
>   		return ERR_PTR(-EOPNOTSUPP);
>   	if (parent->auto_domain || !parent->nest_parent)
>   		return ERR_PTR(-EINVAL);
> @@ -249,6 +249,11 @@ iommufd_hwpt_nested_alloc(struct iommufd_ctx *ictx,
>   int iommufd_hwpt_alloc(struct iommufd_ucmd *ucmd)
>   {
>   	struct iommu_hwpt_alloc *cmd = ucmd->cmd;
> +	const struct iommu_user_data user_data = {
> +		.type = cmd->data_type,
> +		.uptr = u64_to_user_ptr(cmd->data_uptr),
> +		.len = cmd->data_len,
> +	};
>   	struct iommufd_hw_pagetable *hwpt;
>   	struct iommufd_ioas *ioas = NULL;
>   	struct iommufd_object *pt_obj;
> @@ -273,25 +278,17 @@ int iommufd_hwpt_alloc(struct iommufd_ucmd *ucmd)
>   	if (pt_obj->type == IOMMUFD_OBJ_IOAS) {
>   		struct iommufd_hwpt_paging *hwpt_paging;
>   
> -		if (cmd->data_type != IOMMU_HWPT_DATA_NONE) {
> -			rc = -EINVAL;
> -			goto out_put_pt;
> -		}

it can be covered by iommu driver when checking user data pointer. hence
remove above if.

>   		ioas = container_of(pt_obj, struct iommufd_ioas, obj);
>   		mutex_lock(&ioas->mutex);
> -		hwpt_paging = iommufd_hwpt_paging_alloc(ucmd->ictx, ioas, idev,
> -							cmd->flags, false);
> +		hwpt_paging = iommufd_hwpt_paging_alloc(
> +			ucmd->ictx, ioas, idev, cmd->flags, false,
> +			user_data.len ? &user_data : NULL);
>   		if (IS_ERR(hwpt_paging)) {
>   			rc = PTR_ERR(hwpt_paging);
>   			goto out_unlock;
>   		}
>   		hwpt = &hwpt_paging->common;
>   	} else if (pt_obj->type == IOMMUFD_OBJ_HWPT_PAGING) {
> -		const struct iommu_user_data user_data = {
> -			.type = cmd->data_type,
> -			.uptr = u64_to_user_ptr(cmd->data_uptr),
> -			.len = cmd->data_len,
> -		};
>   		struct iommufd_hwpt_nested *hwpt_nested;
>   		struct iommufd_hwpt_paging *parent;
>   
> diff --git a/drivers/iommu/iommufd/iommufd_private.h b/drivers/iommu/iommufd/iommufd_private.h
> index 6fdad56893af4d..24e5a36fc875e0 100644
> --- a/drivers/iommu/iommufd/iommufd_private.h
> +++ b/drivers/iommu/iommufd/iommufd_private.h
> @@ -290,7 +290,8 @@ int iommufd_hwpt_get_dirty_bitmap(struct iommufd_ucmd *ucmd);
>   struct iommufd_hwpt_paging *
>   iommufd_hwpt_paging_alloc(struct iommufd_ctx *ictx, struct iommufd_ioas *ioas,
>   			  struct iommufd_device *idev, u32 flags,
> -			  bool immediate_attach);
> +			  bool immediate_attach,
> +			  const struct iommu_user_data *user_data);
>   int iommufd_hw_pagetable_attach(struct iommufd_hw_pagetable *hwpt,
>   				struct iommufd_device *idev);
>   struct iommufd_hw_pagetable *

--
Regards,
Yi Liu