Subject: Re: [PATCH 01/26] vfio: Wrap KVM helpers with CONFIG_KVM instead of CONFIG_HAVE_KVM

From: Alex Williamson <[email-masked]>
Date: Thu, 28 Sep 2023 16:21:03 -0600

On Fri, 15 Sep 2023 17:30:53 -0700
Sean Christopherson <[email-masked]> wrote:

> Wrap the helpers for getting references to KVM instances with a check on
> CONFIG_KVM being enabled, not on CONFIG_HAVE_KVM being defined.  PPC does
> NOT select HAVE_KVM, despite obviously supporting KVM, and guarding code
> to get references to KVM based on whether or not the architecture supports
> KVM is nonsensical.
> 
> Drop the guard around linux/kvm_host.h entirely, conditionally including a
> generic headers is completely unnecessary.
> 
> Signed-off-by: Sean Christopherson <[email-masked]>
> ---
>  drivers/vfio/vfio.h      | 2 +-
>  drivers/vfio/vfio_main.c | 4 +---
>  2 files changed, 2 insertions(+), 4 deletions(-)

Reviewed-by: Alex Williamson <[email-masked]>

> diff --git a/drivers/vfio/vfio.h b/drivers/vfio/vfio.h
> index 307e3f29b527..c26d1ad68105 100644
> --- a/drivers/vfio/vfio.h
> +++ b/drivers/vfio/vfio.h
> @@ -434,7 +434,7 @@ static inline void vfio_virqfd_exit(void)
>  }
>  #endif
>  
> -#ifdef CONFIG_HAVE_KVM
> +#if IS_ENABLED(CONFIG_KVM)
>  void vfio_device_get_kvm_safe(struct vfio_device *device, struct kvm *kvm);
>  void vfio_device_put_kvm(struct vfio_device *device);
>  #else
> diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c
> index 40732e8ed4c6..80e39f7a6d8f 100644
> --- a/drivers/vfio/vfio_main.c
> +++ b/drivers/vfio/vfio_main.c
> @@ -16,9 +16,7 @@
>  #include <linux/fs.h>
>  #include <linux/idr.h>
>  #include <linux/iommu.h>
> -#ifdef CONFIG_HAVE_KVM
>  #include <linux/kvm_host.h>
> -#endif
>  #include <linux/list.h>
>  #include <linux/miscdevice.h>
>  #include <linux/module.h>
> @@ -383,7 +381,7 @@ void vfio_unregister_group_dev(struct vfio_device *device)
>  }
>  EXPORT_SYMBOL_GPL(vfio_unregister_group_dev);
>  
> -#ifdef CONFIG_HAVE_KVM
> +#if IS_ENABLED(CONFIG_KVM)
>  void vfio_device_get_kvm_safe(struct vfio_device *device, struct kvm *kvm)
>  {
>  	void (*pfn)(struct kvm *kvm);