Re: [PATCH v2 2/3] KVM: x86: introduce definitions to support static calls for kvm_x86_ops

[Peter Zijlstra]

On Thu, Jan 14, 2021 at 10:27:55PM -0500, Jason Baron wrote:
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index 3f7c1fc..c21927f 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -113,6 +113,15 @@ static int sync_regs(struct kvm_vcpu *vcpu);
>  struct kvm_x86_ops kvm_x86_ops __read_mostly;
>  EXPORT_SYMBOL_GPL(kvm_x86_ops);
>  
> +#define KVM_X86_OP(func)					     \
> +	DEFINE_STATIC_CALL_NULL(kvm_x86_##func,			     \
> +				*(((struct kvm_x86_ops *)0)->func));
> +#define KVM_X86_OP_NULL KVM_X86_OP
> +#include <asm/kvm-x86-ops.h>
> +EXPORT_STATIC_CALL_GPL(kvm_x86_get_cs_db_l_bits);
> +EXPORT_STATIC_CALL_GPL(kvm_x86_cache_reg);
> +EXPORT_STATIC_CALL_GPL(kvm_x86_tlb_flush_current);

Would something like:

  https://lkml.kernel.org/r/20201110103909.GD2594@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

Be useful? That way modules can call the static_call() but not change
it.