Re: [PATCH v10 08/12] iommu/sva: Refactoring iommu_sva_bind/unbind_device()

[Jean-Philippe Brucker]

On Sun, Jul 24, 2022 at 09:48:15PM +0800, Baolu Lu wrote:
> /*
>  * iommu_detach_device_pasid() - Detach the domain from pasid of device
>  * @domain: the iommu domain.
>  * @dev: the attached device.
>  * @pasid: the pasid of the device.
>  *
>  * The @domain must have been attached to @pasid of the @dev with
>  * iommu_detach_device_pasid().
>  */
> void iommu_detach_device_pasid(struct iommu_domain *domain, struct device
> *dev,
> 			       ioasid_t pasid)
> {
> 	struct iommu_group *group = iommu_group_get(dev);
> 	struct group_pasid *param;
> 
> 	mutex_lock(&group->mutex);
> 	domain->ops->set_dev_pasid(group->blocking_domain, dev, pasid);

Please also pass the old domain to this detach() function, so that the
IOMMU driver doesn't have to keep track of them internally.

In addition to clearing contexts, detach() also needs to invalidate TLBs,
and for that the SMMU driver needs to know the old ASID (!= PASID) that
was used by the context descriptor.

Thanks,
Jean