RE: [PATCH 4/4] iommupt: Return zero for invalid iova_to_phys() ranges

[Tian, Kevin]

> From: Shuai Xue <xueshuai@xxxxxxxxxxxxxxxxx>
> Sent: Sunday, July 26, 2026 3:44 PM
> 
> DOMAIN_NS(iova_to_phys) returns a phys_addr_t and follows the IOMMU
> iova_to_phys() convention of returning 0 when there is no valid
> translation.
> 
> make_range() returns a negative errno if the input IOVA cannot be
> represented by this page table format. Returning that errno directly
> casts it to phys_addr_t. Callers treat zero as no translation and use
> non-zero values as physical addresses, so this can make them consume a
> bogus physical address instead of seeing a failed translation.
> 
> Match the page-table walk failure path and return 0 for range validation
> failures too.
> 
> Fixes: 9d4c274cd7d5 ("iommupt: Add iova_to_phys op")
> Cc: stable@xxxxxxxxxxxxxxx
> Assisted-by: Qoder:Qwen-3.8-MAX-Preview
> Signed-off-by: Shuai Xue <xueshuai@xxxxxxxxxxxxxxxxx>

Reviewed-by: Kevin Tian <kevin.tian@xxxxxxxxx>