vfio: Introduce capability definitions for VFIO_DEVICE_GET_INFO

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>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

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 << 7)	/* Info supports caps */
 	__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)

include/uapi/linux/vfio_zdev.h

+/* 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