Re: [PATCH v2 0/4] iommu/amd: IVMD handling cleanup and ivmd= boot override

["Suthikulpanit, Suravee" <suravee.suthikulpanit@amd.com>]

Hi All,

Are there any other concerns on this series?

Thanks
Suravee

On 4/24/2026 4:22 PM, Suravee Suthikulpanit wrote:
> This series refreshes how the AMD IOMMU driver models IVRS IVMD entries
> after the hardware exclusion range registers were repurposed.
> 
> The first patch renames the associated MMIO offsets to reflect completion-wait
> store base/limit.
> 
> The second patch drops the workaround that forced IVMD exclusion ranges to
> r/w unity mappings; the driver no longer programs exclusion range
> registers, so that the workaround is obsolete.
> 
> The third patch centralizes IVMD flag definitions, renames the unity-map
> structures to ivmd_entry, stores the raw IVMD flags byte from ACPI, and
> derives IOMMU reserved regions (including exclusion as IOMMU_RESV_RESERVED)
> from those flags.
> 
> The fourth patch adds an ivmd= kernel parameter so up to four per-device
> IVMD-style ranges can be supplied from the command line when the IVRS
> table is wrong or incomplete, documented in kernel-parameters.txt.
> 
> Change from v1:
> (https://lore.kernel.org/linux-iommu/20260420170033.6780-1-suravee.suthikulpanit@amd.com/)
> 
> * Rebase on top of patch "[PATCH] iommu/amd: Remove dead code for exclusion ranges in IVMD"
>    that was submitted by Yu Zhang <zhangyu1@linux.microsoft.com>.
>    (https://lore.kernel.org/all/20260331152550.479841-1-zhangyu1@linux.microsoft.com/)
> 
> * Patch 1: Modified to only rename the marco.
> 
> * Patch 3: Reintroduce logic to parse IVMD exclusion flag to allow
>    reserve region of type IOMMU_RESV_RESERVED.
> 
> * Patch 4:
>    - Update the sscan function to scan start, length, flags in hex format only.
>    - Fix apply_ivmd_cmdline_entries() to not free the cmd, which points to
>      the early_ivmd_cmdline_map[]  on failure path.
> 
> Thanks,
> Suravee
> 
> Suravee Suthikulpanit (4):
>    iommu/amd: Drop unused global exclusion range fields and init
>    iommu/amd: Do not convert IVMD exclusion range to unity range
>    iommu/amd: Clean up and simplify IVMD entry handling
>    iommu/amd: Introduce boot option ivmd=seg:bus:dev.fun,start,size,flags
> 
>   .../admin-guide/kernel-parameters.txt         |  16 ++
>   drivers/iommu/amd/amd_iommu_types.h           |  36 ++--
>   drivers/iommu/amd/init.c                      | 159 ++++++++++++++----
>   drivers/iommu/amd/iommu.c                     |  27 ++-
>   4 files changed, 187 insertions(+), 51 deletions(-)
>