Re: [RFC PATCH 02/18] KVM: Add KVM_CAP_USERFAULT and KVM_MEMORY_ATTRIBUTE_USERFAULT

Anish Moorthy
2024-07-15T21:38:37Z

Not to nitpick an RFC, but since the stuff in this patch seems less
likely to change I think you should avoid using #ifdefs

For instance

On Wed, Jul 10, 2024 at 4:43 PM James Houghton <jthoughton@google.com> wrote:
> +static inline bool kvm_userfault_enabled(struct kvm *kvm)
> +{
> +#ifdef CONFIG_KVM_USERFAULT
> + return !!rcu_access_pointer(kvm->userfault_ctx);
> +#else
> + return false;
> +#endif
> +}

can be

> +static inline bool kvm_userfault_enabled(struct kvm *kvm)
> +{
> + if (IS_ENABLED(CONFIG_KVM_USERFAULT)) {
> + return !!rcu_access_pointer(kvm->userfault_ctx);
> + } else {
> + return false;
> + }
> +}

(however kernel style tells you to write that :), the cap-supported
check can be moved into kvm_vm_ioctl_enable_userfault(), etc