Re: [PATCH v3 02/18] iommu: Implement IOMMU Live update FLB callbacks

[Samiullah Khawaja <skhawaja@google.com>]

On Fri, Jul 31, 2026 at 05:58:20AM +0000, Ankit Soni wrote:
>On Sun, Jun 14, 2026 at 11:37:12PM +0000, Samiullah Khawaja wrote:
>> Add liveupdate FLB for IOMMU state preservation. Use KHO preserve memory
>> alloc/free helper functions to allocate memory for the IOMMU Live update
>> FLB object and the serialization structs for device, domain and iommu.
>>
>> During retrieve, walk through the preserved obj array headers and
>> restore each folio. Also recreate the FLB obj.
>>
>> Signed-off-by: Samiullah Khawaja <skhawaja@google.com>
>> ---
>>  MAINTAINERS                      |   9 ++
>>  drivers/iommu/Kconfig            |  12 ++
>>  drivers/iommu/Makefile           |   1 +
>>  drivers/iommu/liveupdate.c       | 212 +++++++++++++++++++++++++++++++
>>  include/linux/iommu-liveupdate.h |  18 +++
>>  include/linux/kho/abi/iommu.h    | 207 ++++++++++++++++++++++++++++++
>>  6 files changed, 459 insertions(+)
>>  create mode 100644 drivers/iommu/liveupdate.c
>>  create mode 100644 include/linux/iommu-liveupdate.h
>>  create mode 100644 include/linux/kho/abi/iommu.h
>>
>
>../..
>

[snip]

>
>Hi,
>
>nit, The v3 changelog has "Replace bitfields with u32 flags", but sign_extend:1
>looks like it was missed. this is 37 bytes, the only arrayed record in this
>header that isn't a multiple of 8 (iommu_device_ser is 56, iommu_hw_ser 112).
>The arrays are strided with pointer arithmetic, so the skew accumulates: from
>objects[1] onwards none of the u64s are naturally aligned.
>
>Looks like a leftover from the bitfield cleanup.

Yes, missed this one in v3. Just sent out v4, it should be cleaned up now.

Thanks,
Sami
>
>-Ankit
>