Re: [PATCH v5 0/2] KVM: arm64: Support FF-A direct messaging interfaces

[Per Larsen <perl@immunant.com>]

Hi Yeoreum,

Sorry to keep you waiting; I'm addressing v5 feedback now.

Per

On 4/30/26 2:40 PM, Yeoreum Yun wrote:
> Hi Per,
> 
> May I ask how this patch is progressing?
> 
> Thanks!
> 
>> Support FFA_MSG_SEND_DIRECT_REQ unconditionally.
>> Support FFA_MSG_SEND_DIRECT_REQ2 if hypervisor negotiated version 1.2+.
>>
>> Framework messages (FF-A control plane) are filtered out. For
>> FFA_MSG_SEND_DIRECT_REQ, we look at flags in w2. Messages using the REQ2
>> interface are always partition messages.
>>
>> The second patch was part of a previous patch set [0] but was dropped
>> since the use case was unclear. A clear use case has now appeared: use
>> TPM device with CRB over FF-A when kernel boots with pkvm [1].
>>
>> Tested by booting Android under QEMU.
>>
>> Best Regards,
>> Per
>>
>> [0]: https://lore.kernel.org/all/20250730-virtio-msg-ffa-v9-0-7f1b55c8d149@google.com/
>> [1]: https://lore.kernel.org/all/20251027191729.1704744-1-yeoreum.yun@arm.com/
>>   
>>
>> Signed-off-by: Per Larsen <perlarsen@google.com>
>> ---
>> Changes in v5:
>> - 1/2: do_ffa_direct_msg: validate that sender is HOST_FFA_ID.
>> - Link to v4: https://lore.kernel.org/r/20260109-host-direct-messages-v4-0-95da4221d186@google.com
>>
>> Changes in v4:
>> - 1/2: do_ffa_direct_msg: check that flag in w2 is zero; drop unused vm_handle parameter.
>> - 2/2: ffa_call_supported: simplify logic by reordering cases.
>> -      do_ffa_direct_msg: switch polarity of check and update comment.
>> - Link to v3: https://lore.kernel.org/r/20251119-host-direct-messages-v3-0-c74d04944b26@google.com
>>
>> Changes in v3:
>> - Filter out framework messages as suggested by Will Deacon. Update cover letter accordingly.
>> - Update trailers: Reviewed-by: Yeoreum Yun <yeoreum.yun@arm.com>
>> - Link to v2: https://lore.kernel.org/r/20251030-host-direct-messages-v2-0-9f27cef36730@google.com
>>
>> Changes in v2:
>> - 1/2: Drop support for FFA_ID_GET interface in host handler.
>> - Link to v1: https://lore.kernel.org/r/20251030-host-direct-messages-v1-0-463e57871c8f@google.com
>>
>> ---
>> Per Larsen (1):
>>        KVM: arm64: Support FFA_MSG_SEND_DIRECT_REQ2 in host handler
>>
>> Sebastian Ene (1):
>>        KVM: arm64: Support FFA_MSG_SEND_DIRECT_REQ in host handler
>>
>>   arch/arm64/kvm/hyp/nvhe/ffa.c | 39 ++++++++++++++++++++++++++++++++++++++-
>>   1 file changed, 38 insertions(+), 1 deletion(-)
>> ---
>> base-commit: 6c790212c588fddeb0d852f2790840753bb604b1
>> change-id: 20251029-host-direct-messages-5201d7f55abd
>>
>> Best regards,
>> -- 
>> Per Larsen <perlarsen@google.com>
>>
>>
>