Re: [PATCH v2 03/25] KVM: x86/mmu: constify uses of struct kvm_mmu_role_regs

From: Sean Christopherson
Date: Tue Mar 08 2022 - 11:22:25 EST


On Mon, Feb 21, 2022, Paolo Bonzini wrote:
> struct kvm_mmu_role_regs is computed just once and then accessed. Use
> const to make this clearer, even though the const fields of struct
> kvm_mmu_role_regs already prevent modifications to the contents of the
> struct, or rather make them harder.
>
> Reviewed-by: David Matlack <dmatlack@xxxxxxxxxx>
> Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
> ---
> arch/x86/kvm/mmu/mmu.c | 25 ++++++++++++++-----------
> 1 file changed, 14 insertions(+), 11 deletions(-)
>
> diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
> index 4f9bbd02fb8b..97566ac539e3 100644
> --- a/arch/x86/kvm/mmu/mmu.c
> +++ b/arch/x86/kvm/mmu/mmu.c
> @@ -197,7 +197,7 @@ struct kvm_mmu_role_regs {
> * the single source of truth for the MMU's state.
> */
> #define BUILD_MMU_ROLE_REGS_ACCESSOR(reg, name, flag) \
> -static inline bool __maybe_unused ____is_##reg##_##name(struct kvm_mmu_role_regs *regs)\
> +static inline bool __maybe_unused ____is_##reg##_##name(const struct kvm_mmu_role_regs *regs)\

This is one of the very rare times I think it's worth splitting the prototype,
it's not like the function name is grep-friendly anyways. Either way,

Reviewed-by: Sean Christopherson <seanjc@xxxxxxxxxx>

static inline bool __maybe_unused \
____is_##reg##_##name(const struct kvm_mmu_role_regs *regs) \
{ \
return !!(regs->reg & flag); \
}