Re: [PATCH 1/1] vfio/pci: remove CONFIG_VFIO_PCI_ZDEV from Kconfig

[Matthew Rosato <mjrosato@linux.ibm.com>]

On 2/18/21 5:44 AM, Max Gurtovoy wrote:
> In case we're running on s390 system always expose the capabilities for
> configuration of zPCI devices. In case we're running on different
> platform, continue as usual.
> 
> Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com>

Sanity-tested on s390 to verify that zdev caps are still available after 
CONFIG_VFIO_PCI_ZDEV is removed.

Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>

> ---
>   drivers/vfio/pci/Kconfig            | 12 ------------
>   drivers/vfio/pci/Makefile           |  2 +-
>   drivers/vfio/pci/vfio_pci.c         | 12 +++++-------
>   drivers/vfio/pci/vfio_pci_private.h |  2 +-
>   4 files changed, 7 insertions(+), 21 deletions(-)
> 
> diff --git a/drivers/vfio/pci/Kconfig b/drivers/vfio/pci/Kconfig
> index 40a223381ab6..ac3c1dd3edef 100644
> --- a/drivers/vfio/pci/Kconfig
> +++ b/drivers/vfio/pci/Kconfig
> @@ -45,15 +45,3 @@ config VFIO_PCI_NVLINK2
>   	depends on VFIO_PCI && PPC_POWERNV
>   	help
>   	  VFIO PCI support for P9 Witherspoon machine with NVIDIA V100 GPUs
> -
> -config VFIO_PCI_ZDEV
> -	bool "VFIO PCI ZPCI device CLP support"
> -	depends on VFIO_PCI && S390
> -	default y
> -	help
> -	  Enabling this option exposes VFIO capabilities containing hardware
> -	  configuration for zPCI devices. This enables userspace (e.g. QEMU)
> -	  to supply proper configuration values instead of hard-coded defaults
> -	  for zPCI devices passed through via VFIO on s390.
> -
> -	  Say Y here.
> diff --git a/drivers/vfio/pci/Makefile b/drivers/vfio/pci/Makefile
> index 781e0809d6ee..eff97a7cd9f1 100644
> --- a/drivers/vfio/pci/Makefile
> +++ b/drivers/vfio/pci/Makefile
> @@ -3,6 +3,6 @@
>   vfio-pci-y := vfio_pci.o vfio_pci_intrs.o vfio_pci_rdwr.o vfio_pci_config.o
>   vfio-pci-$(CONFIG_VFIO_PCI_IGD) += vfio_pci_igd.o
>   vfio-pci-$(CONFIG_VFIO_PCI_NVLINK2) += vfio_pci_nvlink2.o
> -vfio-pci-$(CONFIG_VFIO_PCI_ZDEV) += vfio_pci_zdev.o
> +vfio-pci-$(CONFIG_S390) += vfio_pci_zdev.o
>   
>   obj-$(CONFIG_VFIO_PCI) += vfio-pci.o
> diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
> index 706de3ef94bb..65e7e6b44578 100644
> --- a/drivers/vfio/pci/vfio_pci.c
> +++ b/drivers/vfio/pci/vfio_pci.c
> @@ -807,6 +807,7 @@ static long vfio_pci_ioctl(void *device_data,
>   		struct vfio_device_info info;
>   		struct vfio_info_cap caps = { .buf = NULL, .size = 0 };
>   		unsigned long capsz;
> +		int ret;
>   
>   		minsz = offsetofend(struct vfio_device_info, num_irqs);
>   
> @@ -832,13 +833,10 @@ static long vfio_pci_ioctl(void *device_data,
>   		info.num_regions = VFIO_PCI_NUM_REGIONS + vdev->num_regions;
>   		info.num_irqs = VFIO_PCI_NUM_IRQS;
>   
> -		if (IS_ENABLED(CONFIG_VFIO_PCI_ZDEV)) {
> -			int ret = vfio_pci_info_zdev_add_caps(vdev, &caps);
> -
> -			if (ret && ret != -ENODEV) {
> -				pci_warn(vdev->pdev, "Failed to setup zPCI info capabilities\n");
> -				return ret;
> -			}
> +		ret = vfio_pci_info_zdev_add_caps(vdev, &caps);
> +		if (ret && ret != -ENODEV) {
> +			pci_warn(vdev->pdev, "Failed to setup zPCI info capabilities\n");
> +			return ret;
>   		}
>   
>   		if (caps.size) {
> diff --git a/drivers/vfio/pci/vfio_pci_private.h b/drivers/vfio/pci/vfio_pci_private.h
> index 5c90e560c5c7..9cd1882a05af 100644
> --- a/drivers/vfio/pci/vfio_pci_private.h
> +++ b/drivers/vfio/pci/vfio_pci_private.h
> @@ -214,7 +214,7 @@ static inline int vfio_pci_ibm_npu2_init(struct vfio_pci_device *vdev)
>   }
>   #endif
>   
> -#ifdef CONFIG_VFIO_PCI_ZDEV
> +#ifdef CONFIG_S390
>   extern int vfio_pci_info_zdev_add_caps(struct vfio_pci_device *vdev,
>   				       struct vfio_info_cap *caps);
>   #else
>