Re: [PATCH v3 3/5] vfio: Introduce capability definitions for VFIO_DEVICE_GET_INFO

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

On Wed,  7 Oct 2020 14:56:22 -0400
Matthew Rosato <mjrosato@linux.ibm.com> wrote:

> Allow the VFIO_DEVICE_GET_INFO ioctl to include a capability chain.
> Add a flag indicating capability chain support, and introduce the
> definitions for the first set of capabilities which are specified to
> s390 zPCI devices.
> 
> Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
> ---
>  include/uapi/linux/vfio.h      | 11 ++++++
>  include/uapi/linux/vfio_zdev.h | 78 ++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 89 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 9204705..836a25b 100644
> --- a/include/uapi/linux/vfio.h
> +++ b/include/uapi/linux/vfio.h
> @@ -201,8 +201,10 @@ struct vfio_device_info {
>  #define VFIO_DEVICE_FLAGS_AMBA  (1 << 3)	/* vfio-amba device */
>  #define VFIO_DEVICE_FLAGS_CCW	(1 << 4)	/* vfio-ccw device */
>  #define VFIO_DEVICE_FLAGS_AP	(1 << 5)	/* vfio-ap device */
> +#define VFIO_DEVICE_FLAGS_CAPS	(1 << 6)	/* Info supports caps */


FYI, I'm going to change this to (1 << 7) because the new fsl-mc bus
driver patches are claiming a new device type with (1 << 6) and I don't
want the conflict to be magically resolved on merge.  Thanks,

Alex

>  	__u32	num_regions;	/* Max region index + 1 */
>  	__u32	num_irqs;	/* Max IRQ index + 1 */
> +	__u32   cap_offset;	/* Offset within info struct of first cap */
>  };
>  #define VFIO_DEVICE_GET_INFO		_IO(VFIO_TYPE, VFIO_BASE + 7)
>  
> @@ -218,6 +220,15 @@ struct vfio_device_info {
>  #define VFIO_DEVICE_API_CCW_STRING		"vfio-ccw"
>  #define VFIO_DEVICE_API_AP_STRING		"vfio-ap"
>  
> +/*
> + * The following capabilities are unique to s390 zPCI devices.  Their contents
> + * are further-defined in vfio_zdev.h
> + */
> +#define VFIO_DEVICE_INFO_CAP_ZPCI_BASE		1
> +#define VFIO_DEVICE_INFO_CAP_ZPCI_GROUP		2
> +#define VFIO_DEVICE_INFO_CAP_ZPCI_UTIL		3
> +#define VFIO_DEVICE_INFO_CAP_ZPCI_PFIP		4
> +
>  /**
>   * VFIO_DEVICE_GET_REGION_INFO - _IOWR(VFIO_TYPE, VFIO_BASE + 8,
>   *				       struct vfio_region_info)
> diff --git a/include/uapi/linux/vfio_zdev.h b/include/uapi/linux/vfio_zdev.h
> new file mode 100644
> index 0000000..b430939
> --- /dev/null
> +++ b/include/uapi/linux/vfio_zdev.h
> @@ -0,0 +1,78 @@
> +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
> +/*
> + * VFIO Region definitions for ZPCI devices
> + *
> + * Copyright IBM Corp. 2020
> + *
> + * Author(s): Pierre Morel <pmorel@linux.ibm.com>
> + *            Matthew Rosato <mjrosato@linux.ibm.com>
> + */
> +
> +#ifndef _VFIO_ZDEV_H_
> +#define _VFIO_ZDEV_H_
> +
> +#include <linux/types.h>
> +#include <linux/vfio.h>
> +
> +/**
> + * VFIO_DEVICE_INFO_CAP_ZPCI_BASE - Base PCI Function information
> + *
> + * This capability provides a set of descriptive information about the
> + * associated PCI function.
> + */
> +struct vfio_device_info_cap_zpci_base {
> +	struct vfio_info_cap_header header;
> +	__u64 start_dma;	/* Start of available DMA addresses */
> +	__u64 end_dma;		/* End of available DMA addresses */
> +	__u16 pchid;		/* Physical Channel ID */
> +	__u16 vfn;		/* Virtual function number */
> +	__u16 fmb_length;	/* Measurement Block Length (in bytes) */
> +	__u8 pft;		/* PCI Function Type */
> +	__u8 gid;		/* PCI function group ID */
> +};
> +
> +/**
> + * VFIO_DEVICE_INFO_CAP_ZPCI_GROUP - Base PCI Function Group information
> + *
> + * This capability provides a set of descriptive information about the group of
> + * PCI functions that the associated device belongs to.
> + */
> +struct vfio_device_info_cap_zpci_group {
> +	struct vfio_info_cap_header header;
> +	__u64 dasm;		/* DMA Address space mask */
> +	__u64 msi_addr;		/* MSI address */
> +	__u64 flags;
> +#define VFIO_DEVICE_INFO_ZPCI_FLAG_REFRESH 1 /* Program-specified TLB refresh */
> +	__u16 mui;		/* Measurement Block Update Interval */
> +	__u16 noi;		/* Maximum number of MSIs */
> +	__u16 maxstbl;		/* Maximum Store Block Length */
> +	__u8 version;		/* Supported PCI Version */
> +};
> +
> +/**
> + * VFIO_DEVICE_INFO_CAP_ZPCI_UTIL - Utility String
> + *
> + * This capability provides the utility string for the associated device, which
> + * is a device identifier string made up of EBCDID characters.  'size' specifies
> + * the length of 'util_str'.
> + */
> +struct vfio_device_info_cap_zpci_util {
> +	struct vfio_info_cap_header header;
> +	__u32 size;
> +	__u8 util_str[];
> +};
> +
> +/**
> + * VFIO_DEVICE_INFO_CAP_ZPCI_PFIP - PCI Function Path
> + *
> + * This capability provides the PCI function path string, which is an identifier
> + * that describes the internal hardware path of the device. 'size' specifies
> + * the length of 'pfip'.
> + */
> +struct vfio_device_info_cap_zpci_pfip {
> +	struct vfio_info_cap_header header;
> +	__u32 size;
> +	__u8 pfip[];
> +};
> +
> +#endif