Commit 621838c7 authored by Lu Baolu's avatar Lu Baolu Committed by Joerg Roedel
Browse files

iommu/vt-d: Refine intel_iommu_domain_alloc_user() 



The domain_alloc_user ops should always allocate a guest-compatible page
table unless specific allocation flags are specified.

Currently, IOMMU_HWPT_ALLOC_NEST_PARENT and IOMMU_HWPT_ALLOC_DIRTY_TRACKING
require special handling, as both require hardware support for scalable
mode and second-stage translation. In such cases, the driver should select
a second-stage page table for the paging domain.

Suggested-by: default avatarJason Gunthorpe <jgg@nvidia.com>
Signed-off-by: default avatarLu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: default avatarJason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20241021085125.192333-8-baolu.lu@linux.intel.com


Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent ed56de8a

drivers/iommu/intel/iommu.c

+15 −2
Original line number Diff line number Diff line
@@ -3297,6 +3297,7 @@ intel_iommu_domain_alloc_user(struct device *dev, u32 flags, 
	struct intel_iommu *iommu = info->iommu;

	struct dmar_domain *dmar_domain;

	struct iommu_domain *domain;

	bool first_stage;



	/* Must be NESTING domain */

	if (parent) {
@@ -3313,8 +3314,20 @@ intel_iommu_domain_alloc_user(struct device *dev, u32 flags, 
	if (user_data || (dirty_tracking && !ssads_supported(iommu)))

		return ERR_PTR(-EOPNOTSUPP);



	/* Do not use first stage for user domain translation. */

	dmar_domain = paging_domain_alloc(dev, false);

	/*

	 * Always allocate the guest compatible page table unless

	 * IOMMU_HWPT_ALLOC_NEST_PARENT or IOMMU_HWPT_ALLOC_DIRTY_TRACKING

	 * is specified.

	 */

	if (nested_parent || dirty_tracking) {

		if (!sm_supported(iommu) || !ecap_slts(iommu->ecap))

			return ERR_PTR(-EOPNOTSUPP);

		first_stage = false;

	} else {

		first_stage = first_level_by_default(iommu);

	}



	dmar_domain = paging_domain_alloc(dev, first_stage);

	if (IS_ERR(dmar_domain))

		return ERR_CAST(dmar_domain);

	domain = &dmar_domain->domain;