[Deepin-Kernel-SIG] [linux 6.6.y] [Upstream] sync fixes for nested translation

[opsiff]

Fixes #1933

Summary by Sourcery

Improve Intel IOMMU nested translation handling, ensuring proper cache flushing and dirty tracking across parent and nested domains, and tighten validation in IOMMUFD user interfaces.

Bug Fixes:

• Fix nested translation TLB and device IOTLB synchronization by flushing parent and first-level domains when second-level mappings change.
• Correct dirty tracking setup to derive the domain ID from PASID entries and apply tracking consistently to nested child domains.
• Prevent invalid IOMMUFD hardware pagetable allocations by enforcing data type/length and owner consistency checks.
• Fix iommufd device replacement reserved IOVA cleanup to use the new paging HWPT instead of the old one.
• Avoid incorrect freeing and lifetime issues for nested domains and blocked domains by adjusting domain free logic and adding warnings for non-empty parent domain lists.
• Ensure iommu_user_data copying validates arguments in a safe order to avoid misuse.

Enhancements:

• Expose domain_update_iotlb for reuse by nested translation code.
• Add tracking structures and locking for first-level domains associated with a nested parent domain.
• Refactor dirty tracking enabling/disabling into reusable helpers for domain device lists and nested parents.

Documentation:

• Clarify iommu_copy_struct_from_user macro documentation wording for the min_last parameter.

[sourcery-ai]

Reviewer's Guide

Adds nested translation support fixes in the Intel IOMMU implementation, including PSI-based IOTLB flushing for parent domains, proper dirty tracking propagation across nested domains, correct lifetime/linkage for nested domains, and various small correctness checks and cleanups in iommufd and PASID handling.

Sequence diagram for dirty tracking propagation in nested translation

sequenceDiagram
  participant Caller as intel_iommu_set_dirty_tracking
  participant Parent as dmar_domain_parent
  participant Child as dmar_domain_s1
  participant DevInfo as device_domain_info
  participant IOMMU as intel_iommu

  Caller->>Parent: intel_iommu_set_dirty_tracking(domain, enable)
  activate Parent
  Parent->>Parent: device_set_dirty_tracking(&devices, enable)
  Parent-->>Caller: ret
  alt Parent.nested_parent && ret == 0
    Caller->>Parent: parent_domain_set_dirty_tracking(domain, enable)
    activate Parent
    loop for each s1_domain in s1_domains
      Parent->>Child: device_set_dirty_tracking(&devices, enable)
      loop for each info in devices
        Child->>IOMMU: intel_pasid_setup_dirty_tracking(iommu, dev, IOMMU_NO_PASID, enable)
      end
    end
    Parent-->>Caller: ret
  end

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File-Level Changes

Change	Details	Files
Refactor PSI IOTLB flushing and extend it to nested/parent domains and device caches.	Expose domain_update_iotlb as a non-static symbol in intel IOMMU and declare it in the header for nested code reuse. Introduce __iommu_flush_iotlb_psi helper to encapsulate PSI flush alignment/masking logic and reuse it for both first and second level domains. Add parent_domain_flush to walk s1_domains of a nested parent, flushing per-IOMMU IOTLBs via PSI and device-side address translation caches when S2 changes. Invoke parent_domain_flush from intel_flush_iotlb_all, switch_to_super_page, and intel_iommu_tlb_sync when the domain is marked as a nested_parent.	drivers/iommu/intel/iommu.c drivers/iommu/intel/iommu.h
Add tracking structures and lifecycle management for nested parent and child (S1/S2) domains.	Extend dmar_domain with s1_lock and s1_domains list to track first-level domains attached to a second-level parent, plus s2_link for child linkage. Initialize nested_parent-specific list and lock in intel_iommu_domain_alloc_user when allocating a nested parent domain. Ensure intel_iommu_domain_free warns if a nested parent still has attached s1_domains and no longer special-cases blocking_domain from domain_exit. Update intel_nested_domain_alloc to link the new S1 domain into the parent S2 domain's s1_domains list under s2_lock. Update intel_nested_domain_free to unlink the S1 domain from its S2 parent before freeing and to reuse domain_update_iotlb upon nested attach to refresh IOTLB state.	drivers/iommu/intel/iommu.c drivers/iommu/intel/iommu.h drivers/iommu/intel/nested.c
Propagate dirty tracking enable/disable to nested domains and fix PASID dirty tracking behavior.	Introduce device_set_dirty_tracking helper that iterates a domain's device list and calls intel_pasid_setup_dirty_tracking for each. Add parent_domain_set_dirty_tracking to enable/disable dirty tracking across all s1_domains under a nested parent, with an unwind path to restore previous state on error. Update intel_iommu_set_dirty_tracking to use device_set_dirty_tracking, and when nested_parent is set, also invoke parent_domain_set_dirty_tracking, with proper rollback to the previous dirty_tracking state. Simplify intel_pasid_setup_dirty_tracking interface by removing the domain parameter and deriving DID via pasid_get_domain_id from the PASID PTE, ensuring correct DID selection for nested translations. Ensure intel_pasid_setup_nested sets SSAD enable (ssade) in the PASID entry when the S2 domain has dirty_tracking enabled so device-side dirty logging operates correctly.	drivers/iommu/intel/iommu.c drivers/iommu/intel/pasid.c drivers/iommu/intel/pasid.h
Tighten correctness and validation in iommufd nested HWPT allocation and user data handling.	Adjust iommufd_hwpt_nested_alloc to reject parents whose common.domain->owner does not match the ops used, preventing mismatched driver ownership for nested hardware page tables. Strengthen iommufd_hwpt_alloc validation to ensure data_type/data_len combination is consistent: forbid non-zero data_len for IOMMU_HWPT_DATA_NONE and zero data_len when data_type requires data. Reorder null/WARN checks before type comparison in __iommu_copy_struct_from_user and fix documentation comment typos for min_last description.	drivers/iommu/iommufd/hw_pagetable.c include/linux/iommu.h
Fix small correctness issues and clean up special-case domain handling.	Set blocking_domain.type to IOMMU_DOMAIN_BLOCKED to fully initialize the static blocking domain object and rely on standard domain_exit semantics by removing its custom free op. Fix iommufd_device_do_replace to remove reserved IOVA from the new paging hwpt instead of the old one in error unwind path. Ensure intel_iommu_tlb_sync and related paths call parent_domain_flush when the domain is a nested_parent so S1 caches stay coherent with S2 mappings.	drivers/iommu/intel/iommu.c drivers/iommu/iommufd/device.c

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[Copilot]

Pull request overview

This PR updates Intel VT-d nested translation behavior and IOMMUFD validation to improve correctness around IOTLB/TLB synchronization, dirty tracking, and user-facing HW pagetable allocation constraints.

Changes:

• Extend Intel VT-d nested translation flushing so S2 mapping changes trigger appropriate flushes for nested/parent relationships.
• Refactor and correct dirty-tracking enablement (derive DID from PASID entry; propagate to nested child domains).
• Tighten IOMMUFD ioctl validation and fix reserved IOVA unwind during device replacement.

Reviewed changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
include/linux/iommu.h	Reorders NULL/type validation in user-data copy helper and clarifies kdoc wording.
drivers/iommu/iommufd/hw_pagetable.c	Adds validation for nested HWPT allocation (parent compatibility / user data constraints).
drivers/iommu/iommufd/device.c	Fixes reserved IOVA cleanup to unwind against the newly selected paging HWPT on error.
drivers/iommu/intel/pasid.h	Updates dirty-tracking helper prototype.
drivers/iommu/intel/pasid.c	Fixes dirty-tracking DID derivation and sets SSADE for nested setup when appropriate.
drivers/iommu/intel/nested.c	Updates nested attach/free/alloc to maintain parent tracking list and trigger IOTLB updates.
drivers/iommu/intel/iommu.h	Adds tracking/locking for S1 domains under a nested parent; exports domain_update_iotlb().
drivers/iommu/intel/iommu.c	Adds parent flush logic, refactors PSI flush helper, adjusts blocked/nested domain lifecycle and dirty-tracking propagation.

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