Commit 17bad527 authored by Jason Gunthorpe's avatar Jason Gunthorpe
Browse files

iommufd: Add enforced_cache_coherency to iommufd_hw_pagetable_alloc() 

Logically the HWPT should have the coherency set properly for the device
that it is being created for when it is created.

This was happening implicitly if the immediate_attach was set because
iommufd_hw_pagetable_attach() does it as the first thing.

Do it unconditionally so !immediate_attach works properly.

Link: https://lore.kernel.org/r/9-v8-6659224517ea+532-iommufd_alloc_jgg@nvidia.com


Reviewed-by: default avatarKevin Tian <kevin.tian@intel.com>
Reviewed-by: default avatarLu Baolu <baolu.lu@linux.intel.com>
Tested-by: default avatarNicolin Chen <nicolinc@nvidia.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@nvidia.com>
parent d03f1336

drivers/iommu/iommufd/device.c

+4 −15
Original line number Diff line number Diff line
@@ -338,23 +338,12 @@ int iommufd_hw_pagetable_attach(struct iommufd_hw_pagetable *hwpt, 
		goto err_unlock;

	}



	/*

	 * Try to upgrade the domain we have, it is an iommu driver bug to

	 * report IOMMU_CAP_ENFORCE_CACHE_COHERENCY but fail

	 * enforce_cache_coherency when there are no devices attached to the

	 * domain.

	 */

	if (idev->enforce_cache_coherency && !hwpt->enforce_cache_coherency) {

		if (hwpt->domain->ops->enforce_cache_coherency)

			hwpt->enforce_cache_coherency =

				hwpt->domain->ops->enforce_cache_coherency(

					hwpt->domain);

		if (!hwpt->enforce_cache_coherency) {

			WARN_ON(list_empty(&idev->igroup->device_list));

			rc = -EINVAL;

	/* Try to upgrade the domain we have */

	if (idev->enforce_cache_coherency) {

		rc = iommufd_hw_pagetable_enforce_cc(hwpt);

		if (rc)

			goto err_unlock;

	}

	}



	rc = iopt_table_enforce_dev_resv_regions(&hwpt->ioas->iopt, idev->dev,

						 &idev->igroup->sw_msi_start);

drivers/iommu/iommufd/hw_pagetable.c

+27 −0
Original line number Diff line number Diff line
@@ -25,6 +25,20 @@ void iommufd_hw_pagetable_destroy(struct iommufd_object *obj) 
	refcount_dec(&hwpt->ioas->obj.users);

}



int iommufd_hw_pagetable_enforce_cc(struct iommufd_hw_pagetable *hwpt)

{

	if (hwpt->enforce_cache_coherency)

		return 0;



	if (hwpt->domain->ops->enforce_cache_coherency)

		hwpt->enforce_cache_coherency =

			hwpt->domain->ops->enforce_cache_coherency(

				hwpt->domain);

	if (!hwpt->enforce_cache_coherency)

		return -EINVAL;

	return 0;

}



/**

 * iommufd_hw_pagetable_alloc() - Get an iommu_domain for a device

 * @ictx: iommufd context
@@ -60,6 +74,19 @@ iommufd_hw_pagetable_alloc(struct iommufd_ctx *ictx, struct iommufd_ioas *ioas, 
		goto out_abort;

	}



	/*

	 * Set the coherency mode before we do iopt_table_add_domain() as some

	 * iommus have a per-PTE bit that controls it and need to decide before

	 * doing any maps. It is an iommu driver bug to report

	 * IOMMU_CAP_ENFORCE_CACHE_COHERENCY but fail enforce_cache_coherency on

	 * a new domain.

	 */

	if (idev->enforce_cache_coherency) {

		rc = iommufd_hw_pagetable_enforce_cc(hwpt);

		if (WARN_ON(rc))

			goto out_abort;

	}



	/*

	 * immediate_attach exists only to accommodate iommu drivers that cannot

	 * directly allocate a domain. These drivers do not finish creating the

drivers/iommu/iommufd/iommufd_private.h

+1 −0
Original line number Diff line number Diff line
@@ -254,6 +254,7 @@ struct iommufd_hw_pagetable { 
struct iommufd_hw_pagetable *

iommufd_hw_pagetable_alloc(struct iommufd_ctx *ictx, struct iommufd_ioas *ioas,

			   struct iommufd_device *idev, bool immediate_attach);

int iommufd_hw_pagetable_enforce_cc(struct iommufd_hw_pagetable *hwpt);

int iommufd_hw_pagetable_attach(struct iommufd_hw_pagetable *hwpt,

				struct iommufd_device *idev);

struct iommufd_hw_pagetable *