Re: [PATCH] KVM: arm64: Mark set_sysreg_masks() as inline to avoid build failure

[Joey Gouly <joey.gouly@arm.com>]

On Wed, Nov 20, 2024 at 11:15:16AM +0000, Marc Zyngier wrote:
> When compiling with CONFIG_CC_OPTIMIZE_FOR_SIZE=y, set_sysreg_masks()
> fails to compile thanks to:
> 
> 	BUILD_BUG_ON(!__builtin_constant_p(sr));
> 
> as the compiler doesn't identify sr as a constant, despite all the
> callers passing constants.
> 
> Fix the issue by always inlining this function, which allows GCC to
> do the right thing.
> 
> Reported-by: kernel test robot <lkp@intel.com>
> Closes: https://lore.kernel.org/oe-kbuild-all/202411201857.ZNudtGJl-lkp@intel.com/
> Fixes: a0162020095e2 ("KVM: arm64: Extend masking facility to arbitrary registers")
> Signed-off-by: Marc Zyngier <maz@kernel.org>
> ---
>  arch/arm64/kvm/nested.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/arm64/kvm/nested.c b/arch/arm64/kvm/nested.c
> index aeaa6017ffd89..9b36218b48def 100644
> --- a/arch/arm64/kvm/nested.c
> +++ b/arch/arm64/kvm/nested.c
> @@ -951,7 +951,7 @@ u64 kvm_vcpu_apply_reg_masks(const struct kvm_vcpu *vcpu,
>  	return v;
>  }
>  
> -static void set_sysreg_masks(struct kvm *kvm, int sr, u64 res0, u64 res1)
> +static __always_inline void set_sysreg_masks(struct kvm *kvm, int sr, u64 res0, u64 res1)
>  {
>  	int i = sr - __SANITISED_REG_START__;
>  


Reviewed-by: Joey Gouly <joey.gouly@arm.com>