Re: [PATCH v9 10/21] vfio/pci: introduce CONFIG_VFIO_PCI_ZDEV_KVM

[Alex Williamson <alex.williamson@redhat.com>]

On Mon,  6 Jun 2022 16:33:14 -0400
Matthew Rosato <mjrosato@linux.ibm.com> wrote:

> The current contents of vfio-pci-zdev are today only useful in a KVM
> environment; let's tie everything currently under vfio-pci-zdev to
> this Kconfig statement and require KVM in this case, reducing complexity
> (e.g. symbol lookups).
> 
> Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
> ---
>  drivers/vfio/pci/Kconfig      | 11 +++++++++++
>  drivers/vfio/pci/Makefile     |  2 +-
>  include/linux/vfio_pci_core.h |  2 +-
>  3 files changed, 13 insertions(+), 2 deletions(-)


Acked-by: Alex Williamson <alex.williamson@redhat.com>


> diff --git a/drivers/vfio/pci/Kconfig b/drivers/vfio/pci/Kconfig
> index 4da1914425e1..f9d0c908e738 100644
> --- a/drivers/vfio/pci/Kconfig
> +++ b/drivers/vfio/pci/Kconfig
> @@ -44,6 +44,17 @@ config VFIO_PCI_IGD
>  	  To enable Intel IGD assignment through vfio-pci, say Y.
>  endif
>  
> +config VFIO_PCI_ZDEV_KVM
> +	bool "VFIO PCI extensions for s390x KVM passthrough"
> +	depends on S390 && KVM
> +	default y
> +	help
> +	  Support s390x-specific extensions to enable support for enhancements
> +	  to KVM passthrough capabilities, such as interpretive execution of
> +	  zPCI instructions.
> +
> +	  To enable s390x KVM vfio-pci extensions, say Y.
> +
>  source "drivers/vfio/pci/mlx5/Kconfig"
>  
>  source "drivers/vfio/pci/hisilicon/Kconfig"
> diff --git a/drivers/vfio/pci/Makefile b/drivers/vfio/pci/Makefile
> index 7052ebd893e0..24c524224da5 100644
> --- a/drivers/vfio/pci/Makefile
> +++ b/drivers/vfio/pci/Makefile
> @@ -1,7 +1,7 @@
>  # SPDX-License-Identifier: GPL-2.0-only
>  
>  vfio-pci-core-y := vfio_pci_core.o vfio_pci_intrs.o vfio_pci_rdwr.o vfio_pci_config.o
> -vfio-pci-core-$(CONFIG_S390) += vfio_pci_zdev.o
> +vfio-pci-core-$(CONFIG_VFIO_PCI_ZDEV_KVM) += vfio_pci_zdev.o
>  obj-$(CONFIG_VFIO_PCI_CORE) += vfio-pci-core.o
>  
>  vfio-pci-y := vfio_pci.o
> diff --git a/include/linux/vfio_pci_core.h b/include/linux/vfio_pci_core.h
> index 23c176d4b073..63af2897939c 100644
> --- a/include/linux/vfio_pci_core.h
> +++ b/include/linux/vfio_pci_core.h
> @@ -206,7 +206,7 @@ static inline int vfio_pci_igd_init(struct vfio_pci_core_device *vdev)
>  }
>  #endif
>  
> -#ifdef CONFIG_S390
> +#ifdef CONFIG_VFIO_PCI_ZDEV_KVM
>  extern int vfio_pci_info_zdev_add_caps(struct vfio_pci_core_device *vdev,
>  				       struct vfio_info_cap *caps);
>  #else