Re: [PATCH 0/3] KVM: arm64: Support FF-A 1.2 and SEND_DIRECT2 ABI

[Sebastian Ene <sebastianene@google.com>]

On Fri, May 02, 2025 at 02:21:05AM -0700, Per Larsen wrote:
> Hi,
> 
> The FF-A 1.2 specification introduces a new SEND_DIRECT2 ABI which
> allows registers x4-x17 to be used for the message payload. This patch
> set prevents the host from using a lower FF-A version than what has
> already been negotiated with the hypervisor. This is necessary because
> the hypervisor does not have the necessary compatibility paths to
> translate from the hypervisor FF-A version to a previous version.
> 
> Support for FF-A 1.2 in the hypervisor is added as a precursor to the
> addition of the FFA_MSG_SEND_DIRECT_REQ2 messaging interface. The bulk
> of this change has to do with the upgrade to SMCCC 1.2 required by
> FF-A 1.2. Additionally, unimplemented FF-A 1.2 interfaces are added to
> the list of unsupported functions.
> 
> Tested by booting Android under QEMU and loading Trusty as the guest
> VM and observing the SEND_DIRECT2 ABI being used successfully during
> guest boot.
> 
> (This is my second attempt at sending out these patches; sorry about
> my broken first try and the resulting duplicate messages.)

Please tag this series with v2 if this is the second one and include a
changelog.

> 
> Thanks,
> Per Larsen
> 
> Per Larsen (3):
>   KVM: arm64: Restrict FF-A host version renegotiation
>   KVM: arm64: Bump the supported version of FF-A to 1.2
>   KVM: arm64: Support FFA_MSG_SEND_DIRECT_REQ2 in host handler
> 
>  arch/arm64/kvm/hyp/nvhe/Makefile |   1 +
>  arch/arm64/kvm/hyp/nvhe/ffa.c    | 235 ++++++++++++++++++++++++++++---
>  include/linux/arm_ffa.h          |   2 +
>  3 files changed, 221 insertions(+), 17 deletions(-)
> 
> --
> 2.49.0
>

Thanks,
Seb