Re: [PATCH v3 2/3] vfio: zpci: defining the VFIO headers

[Cornelia Huck <cohuck@redhat.com>]

On Thu, 23 May 2019 14:25:25 +0200
Pierre Morel <pmorel@linux.ibm.com> wrote:

> We define a new device region in vfio.h to be able to
> get the ZPCI CLP information by reading this region from
> userland.
> 
> We create a new file, vfio_zdev.h to define the structure
> of the new region we defined in vfio.h
> 
> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
> ---
>  include/uapi/linux/vfio.h      |  4 ++++
>  include/uapi/linux/vfio_zdev.h | 34 ++++++++++++++++++++++++++++++++++
>  2 files changed, 38 insertions(+)
>  create mode 100644 include/uapi/linux/vfio_zdev.h
> 
> diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
> index 8f10748..56595b8 100644
> --- a/include/uapi/linux/vfio.h
> +++ b/include/uapi/linux/vfio.h
> @@ -306,6 +306,10 @@ struct vfio_region_info_cap_type {
>  #define VFIO_REGION_TYPE_GFX                    (1)
>  #define VFIO_REGION_SUBTYPE_GFX_EDID            (1)
>  
> +/* IBM Subtypes */
> +#define VFIO_REGION_TYPE_IBM_ZDEV		(1)
> +#define VFIO_REGION_SUBTYPE_ZDEV_CLP		(1)

I'm afraid that confuses me a bit. You want to add the region to every
vfio-pci device when we're running under s390, right? So this does not
depend on the device type of the actual device (which may or may not be
from IBM), but only on the architecture?

(Generally speaking, I think using regions for this makes sense,
though.)

> +
>  /**
>   * struct vfio_region_gfx_edid - EDID region layout.
>   *
> diff --git a/include/uapi/linux/vfio_zdev.h b/include/uapi/linux/vfio_zdev.h
> new file mode 100644
> index 0000000..84b1a82
> --- /dev/null
> +++ b/include/uapi/linux/vfio_zdev.h
> @@ -0,0 +1,34 @@
> +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
> +/*
> + * Region definition for ZPCI devices
> + *
> + * Copyright IBM Corp. 2019
> + *
> + * Author(s): Pierre Morel <pmorel@linux.ibm.com>
> + */
> +
> +#ifndef _VFIO_ZDEV_H_
> +#define _VFIO_ZDEV_H_
> +
> +#include <linux/types.h>
> +
> +/**
> + * struct vfio_region_zpci_info - ZPCI information.
> + *
> + */
> +struct vfio_region_zpci_info {
> +	__u64 dasm;
> +	__u64 start_dma;
> +	__u64 end_dma;
> +	__u64 msi_addr;
> +	__u64 flags;
> +	__u16 pchid;
> +	__u16 mui;
> +	__u16 noi;
> +	__u8 gid;
> +	__u8 version;
> +#define VFIO_PCI_ZDEV_FLAGS_REFRESH 1
> +	__u8 util_str[CLP_UTIL_STR_LEN];
> +} __packed;
> +
> +#endif