Re: [PATCH] arm64: smccc: Remove broken support for SMCCCv1.3 SVE discard hint

On Wed, Nov 06, 2024 at 04:04:48PM +0000, Mark Rutland wrote:

SMCCCv1.3 added a hint bit which callers can set in an SMCCC function ID (AKA "FID") to indicate that it is acceptable for the SMCCC implementation to discard SVE and/or SME state over a specific SMCCC call. The kernel support for using this hint is broken and SMCCC calls may clobber the SVE and/or SME state of arbitrary tasks, though FPSIMD state is unaffected.

Reviewed-by: Mark Brown broonie@kernel.org