[PATCH] KVM: arm64: Fix error checking for FFA_VERSION

[Marc Zyngier]

On Fri, 14 Nov 2025 11:11:53 +0000, Kornel Dulęba wrote:
> According to section 13.2 of the DEN0077 FF-A specification, when
> firmware does not support the requested version, it should reply with
> FFA_RET_NOT_SUPPORTED(-1). Table 13.6 specifies the type of the error
> code as int32.
> Currently, the error checking logic compares the unsigned long return
> value it got from the SMC layer, against a "-1" literal. This fails due
> to a type mismatch: the literal is extended to 64 bits, whereas the
> register contains only 32 bits of ones(0x00000000ffffffff).
> Consequently, hyp_ffa_init misinterprets the "-1" return value as an
> invalid FF-A version. This prevents pKVM initialization on devices where
> FF-A is not supported in firmware.
> Fix this by explicitly casting res.a0 to s32.
> 
> [...]

Applied to next, thanks!

[1/1] KVM: arm64: Fix error checking for FFA_VERSION
      commit: 582234b0d8419e0b6cbfd87ae3f80568c8d0917e

Cheers,

	M.
-- 
Without deviation from the norm, progress is not possible.