[PATCH v3 0/3] KVM: arm64: Support FF-A 1.2 and SEND_DIRECT2 ABI

[Per Larsen via B4 Relay]

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.

Changes since v2:
- 2/3: Removed files added by mistake.
       Add and use ffa_get_hypervisor_version to access hyp_ffa_version
- 3/3: Use ffa_get_hypervisor_version to access hyp_ffa_version safely
- Link to v2: https://lore.kernel.org/r/20250508-virtio-msg-ffa-v2-0-ed84f8053965@google.com

Changes since v1:
- 1/3: Simplify commit message; drop long comment in do_ffa_version
- 2/3: Correct use of Co-developed-by: footer
       s/arm_smccc_1_2_smc_fallback/arm_smccc_1_x_smc/
       Always access hyp_ffa_version w/lock held
       Remove superfluous comments in ffa_call_supported
       Add and use FFA_FEAT_RXTX_MIN_SZ_MASK instead of constant
       Add FFA_PARTITION_INFO_GET_REGS to calls that require SMCCC 1.2
- 3/3: Always access hyp_ffa_version w/lock held
       Correct formatting

Thanks,
Per Larsen

--
2.49.0

---
To: Marc Zyngier <maz at kernel.org>
To: Oliver Upton <oliver.upton at linux.dev>
To: Joey Gouly <joey.gouly at arm.com>
To: Suzuki K Poulose <suzuki.poulose at arm.com>
To: Zenghui Yu <yuzenghui at huawei.com>
To: Catalin Marinas <catalin.marinas at arm.com>
To: Will Deacon <will at kernel.org>
To: Sudeep Holla <sudeep.holla at arm.com>
Cc: linux-arm-kernel at lists.infradead.org
Cc: kvmarm at lists.linux.dev
Cc: linux-kernel at vger.kernel.org

---
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/include/nvhe/ffa.h |   1 +
 arch/arm64/kvm/hyp/nvhe/Makefile      |   1 +
 arch/arm64/kvm/hyp/nvhe/ffa.c         | 202 ++++++++++++++++++++++++++++++++--
 include/linux/arm_ffa.h               |   3 +
 4 files changed, 199 insertions(+), 8 deletions(-)
---
base-commit: e9565e23cd89d4d5cd4388f8742130be1d6f182d
change-id: 20250506-virtio-msg-ffa-22af72c92150

Best regards,
-- 
Per Larsen <perlarsen at google.com>