Re: [PATCH v9 3/4] iommu/arm-smmu-v3-iommufd: Report CFGI/TLBI-repeat erratum

On Sun, Jul 26, 2026 at 08:19:03AM +0000, Ashish Mhetre wrote:
> A guest with access to VCMDQ generates its own invalidation commands
> and must apply any invalidation errata before submitting them. If the
> host also repeats those commands, each affected invalidation is issued
> four times instead of twice.
> 
> Add IOMMU_HW_INFO_ARM_SMMUV3_ERRATA_REPEAT_TLBI_CFGI to report the
> CFGI/TLBI-repeat erratum to user space. This allows the VMM to expose
> the erratum to the guest or apply the workaround itself.
> 
> Use the raw __arm_smmu_cmdq_issue_cmdlist() helper for user-provided
> invalidations so the host does not apply the workaround a second time.
> Add arm_smmu_erratum_repeat_tlbi_cfgi() to query the static key when
> populating the SMMUv3 hardware information.
> 
> Signed-off-by: Ashish Mhetre <[email protected]>

Reviewed-by: Nicolin Chen <[email protected]>