[v2,2/5] vfio: VFIO core header

diff --git a/Documentation/ioctl/ioctl-number.txt b/Documentation/ioctl/ioctl-number.txt
index 2550754..79c5ef8 100644
--- a/Documentation/ioctl/ioctl-number.txt
+++ b/Documentation/ioctl/ioctl-number.txt
@@ -88,6 +88,7 @@  Code  Seq#(hex)	Include File		Comments
 		and kernel/power/user.c
 '8'	all				SNP8023 advanced NIC card
 					<mailto:mcr@solidum.com>
+';'	64-83	linux/vfio.h
 '@'	00-0F	linux/radeonfb.h	conflict!
 '@'	00-0F	drivers/video/aty/aty128fb.c	conflict!
 'A'	00-1F	linux/apm_bios.h	conflict!
diff --git a/include/linux/vfio.h b/include/linux/vfio.h
new file mode 100644
index 0000000..797dbe4
--- /dev/null
+++ b/include/linux/vfio.h
@@ -0,0 +1,395 @@ 
+/*
+ * VFIO API definition
+ *
+ * Copyright (C) 2012 Red Hat, Inc.  All rights reserved.
+ *     Author: Alex Williamson <alex.williamson@redhat.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#ifndef VFIO_H
+#define VFIO_H
+
+#include <linux/types.h>
+
+#ifdef __KERNEL__	/* Internal VFIO-core/bus driver API */
+
+/**
+ * struct vfio_device_ops - VFIO bus driver device callbacks
+ *
+ * @match: Return true if buf describes the device
+ * @claim: Force driver to attach to device
+ * @open: Called when userspace receives file descriptor for device
+ * @release: Called when userspace releases file descriptor for device
+ * @read: Perform read(2) on device file descriptor
+ * @write: Perform write(2) on device file descriptor
+ * @ioctl: Perform ioctl(2) on device file descriptor, supporting VFIO_DEVICE_*
+ *         operations documented below
+ * @mmap: Perform mmap(2) on a region of the device file descriptor
+ */
+struct vfio_device_ops {
+	bool	(*match)(struct device *dev, const char *buf);
+	int	(*claim)(struct device *dev);
+	int	(*open)(void *device_data);
+	void	(*release)(void *device_data);
+	ssize_t	(*read)(void *device_data, char __user *buf,
+			size_t count, loff_t *ppos);
+	ssize_t	(*write)(void *device_data, const char __user *buf,
+			 size_t count, loff_t *size);
+	long	(*ioctl)(void *device_data, unsigned int cmd,
+			 unsigned long arg);
+	int	(*mmap)(void *device_data, struct vm_area_struct *vma);
+};
+
+/**
+ * vfio_group_add_dev() - Add a device to the vfio-core
+ *
+ * @dev: Device to add
+ * @ops: VFIO bus driver callbacks for device
+ *
+ * This registration makes the VFIO core aware of the device, creates
+ * groups objects as required and exposes chardevs under /dev/vfio.
+ *
+ * Return 0 on success, errno on failure.
+ */
+extern int vfio_group_add_dev(struct device *dev,
+			      const struct vfio_device_ops *ops);
+
+/**
+ * vfio_group_del_dev() - Remove a device from the vfio-core
+ *
+ * @dev: Device to remove
+ *
+ * Remove a device previously added to the VFIO core, removing groups
+ * and chardevs as necessary.
+ */
+extern void vfio_group_del_dev(struct device *dev);
+
+/**
+ * vfio_bind_dev() - Indicate device is bound to the VFIO bus driver and
+ *                   register private data structure for ops callbacks.
+ *
+ * @dev: Device being bound
+ * @device_data: VFIO bus driver private data
+ *
+ * This registration indicate that a device previously registered with
+ * vfio_group_add_dev() is now available for use by the VFIO core.  When
+ * all devices within a group are available, the group is viable and my
+ * be used by userspace drivers.  Typically called from VFIO bus driver
+ * probe function.
+ *
+ * Return 0 on success, errno on failure
+ */
+extern int vfio_bind_dev(struct device *dev, void *device_data);
+
+/**
+ * vfio_unbind_dev() - Indicate device is unbinding from VFIO bus driver
+ *
+ * @dev: Device being unbound
+ *
+ * De-registration of the device previously registered with vfio_bind_dev()
+ * from VFIO.  Upon completion, the device is no longer available for use by
+ * the VFIO core.  Typically called from the VFIO bus driver remove function.
+ * The VFIO core will attempt to release the device from users and may take
+ * measures to free the device and/or block as necessary.
+ *
+ * Returns pointer to private device_data structure registered with
+ * vfio_bind_dev().
+ */
+extern void *vfio_unbind_dev(struct device *dev);
+
+
+/**
+ * offsetofend(TYPE, MEMBER)
+ *
+ * @TYPE: The type of the structure
+ * @MEMBER: The member within the structure to get the end offset of
+ *
+ * Simple helper macro for dealing with variable sized structures passed
+ * from user space.  This allows us to easily determine if the provided
+ * structure is sized to include various fields.
+ */
+#define offsetofend(TYPE, MEMBER) ({				\
+	TYPE tmp;						\
+	offsetof(TYPE, MEMBER) + sizeof(tmp.MEMBER); })		\
+
+#endif /* __KERNEL__ */
+
+/* Kernel & User level defines for VFIO IOCTLs. */
+
+/*
+ * The IOCTL interface is designed for extensibility by embedding the
+ * structure length (argsz) and flags into structures passed between
+ * kernel and userspace.  We therefore use the _IO() macro for these
+ * defines to avoid implicitly embedding a size into the ioctl request.
+ * As structure fields are added, argsz will increase to match and flag
+ * bits will be defined to indicate additional fields with valid data.
+ * It's *always* the caller's responsibility to indicate the size of
+ * the structure passed by setting argsz appropriately.
+ */
+
+#define VFIO_TYPE	(';')
+#define VFIO_BASE	100
+
+/* --------------- IOCTLs for GROUP file descriptors --------------- */
+
+/**
+ * VFIO_GROUP_GET_INFO - _IOR(VFIO_TYPE, VFIO_BASE + 0, struct vfio_group_info)
+ *
+ * Retrieve information about the group.  Fills in provided
+ * struct vfio_group_info.  Caller sets argsz.
+ */
+struct vfio_group_info {
+	__u32	argsz;
+	__u32	flags;
+#define VFIO_GROUP_FLAGS_VIABLE		(1 << 0)
+#define VFIO_GROUP_FLAGS_MM_LOCKED	(1 << 1)
+};
+
+#define VFIO_GROUP_GET_INFO		_IO(VFIO_TYPE, VFIO_BASE + 0)
+
+/**
+ * VFIO_GROUP_MERGE - _IOW(VFIO_TYPE, VFIO_BASE + 1, __s32)
+ *
+ * Merge group indicated by passed file descriptor into current group.
+ * Current group may be in use, group indicated by file descriptor
+ * cannot be in use (no open iommu or devices).
+ */
+#define VFIO_GROUP_MERGE		_IOW(VFIO_TYPE, VFIO_BASE + 1, __s32)
+
+/**
+ * VFIO_GROUP_UNMERGE - _IO(VFIO_TYPE, VFIO_BASE + 2)
+ *
+ * Remove the current group from a merged set.  The current group cannot
+ * have any open devices.
+ */
+#define VFIO_GROUP_UNMERGE		_IO(VFIO_TYPE, VFIO_BASE + 2)
+
+/**
+ * VFIO_GROUP_GET_IOMMU_FD - _IO(VFIO_TYPE, VFIO_BASE + 3)
+ *
+ * Return a new file descriptor for the IOMMU object.  The IOMMU object
+ * is shared among members of a merged group.
+ */
+#define VFIO_GROUP_GET_IOMMU_FD		_IO(VFIO_TYPE, VFIO_BASE + 3)
+
+/**
+ * VFIO_GROUP_GET_DEVICE_FD - _IOW(VFIO_TYPE, VFIO_BASE + 4, char)
+ *
+ * Return a new file descriptor for the device object described by
+ * the provided char array.
+ */
+#define VFIO_GROUP_GET_DEVICE_FD	_IOW(VFIO_TYPE, VFIO_BASE + 4, char)
+
+
+/* --------------- IOCTLs for IOMMU file descriptors --------------- */
+
+/**
+ * VFIO_IOMMU_GET_INFO - _IOR(VFIO_TYPE, VFIO_BASE + 5, struct vfio_iommu_info)
+ *
+ * Retrieve information about the IOMMU object.  Fills in provided
+ * struct vfio_iommu_info.  Caller sets argsz.
+ */
+struct vfio_iommu_info {
+	__u32	argsz;
+	__u32	flags;
+	__u64	iova_start;	/* IOVA base address */
+	__u64	iova_size;	/* IOVA window size */
+	__u64	iova_entries;	/* Number mapping entries available */
+	__u64	iova_pgsizes;	/* Bitmap of supported page sizes */
+};
+
+#define	VFIO_IOMMU_GET_INFO		_IO(VFIO_TYPE, VFIO_BASE + 5)
+
+/**
+ * VFIO_IOMMU_MAP_DMA - _IOW(VFIO_TYPE, VFIO_BASE + 6, struct vfio_dma_map)
+ *
+ * Map process virtual addresses to IO virtual addresses using the
+ * provided struct vfio_dma_map.  Caller sets argsz.  READ &/ WRITE required.
+ */
+struct vfio_dma_map {
+	__u32	argsz;
+	__u32	flags;
+#define VFIO_DMA_MAP_FLAG_READ	(1 << 0)	/* readable from device */
+#define VFIO_DMA_MAP_FLAG_WRITE	(1 << 1)	/* writable from device */
+	__u64	vaddr;		/* Process virtual address */
+	__u64	iova;		/* IO virtual address */
+	__u64	size;		/* Size of mapping (bytes) */
+};
+
+#define	VFIO_IOMMU_MAP_DMA		_IO(VFIO_TYPE, VFIO_BASE + 6)
+
+/**
+ * VFIO_IOMMU_UNMAP_DMA - _IOW(VFIO_TYPE, VFIO_BASE + 7, struct vfio_dma_unmap)
+ *
+ * Unmap IO virtual addresses using the provided struct vfio_dma_unmap.
+ * Caller sets argsz.
+ */
+struct vfio_dma_unmap {
+	__u32	argsz;
+	__u32	flags;
+	__u64	iova;		/* IO virtual address */
+	__u64	size;		/* Size of mapping (bytes) */
+};
+
+#define	VFIO_IOMMU_UNMAP_DMA		_IO(VFIO_TYPE, VFIO_BASE + 7)
+
+
+/* --------------- IOCTLs for DEVICE file descriptors --------------- */
+
+/**
+ * VFIO_DEVICE_GET_INFO - _IOR(VFIO_TYPE, VFIO_BASE + 8,
+ *			       struct vfio_device_info)
+ *
+ * Retrieve information about the device.  Fills in provided
+ * struct vfio_device_info.  Caller sets argsz.
+ */
+struct vfio_device_info {
+	__u32	argsz;
+	__u32	flags;
+#define VFIO_DEVICE_FLAGS_RESET	(1 << 0)	/* Device supports reset */
+	__u32	num_regions;	/* Max region index + 1 */
+	__u32	num_irqs;	/* Max IRQ index + 1 */
+};
+
+#define VFIO_DEVICE_GET_INFO		_IO(VFIO_TYPE, VFIO_BASE + 8)
+
+/**
+ * VFIO_DEVICE_GET_REGION_INFO - _IOWR(VFIO_TYPE, VFIO_BASE + 9,
+ *				       struct vfio_region_info)
+ *
+ * Retrieve information about a device region.  Caller provides
+ * struct vfio_region_info with index value set.  Caller sets argsz.
+ * Implementation of region mapping is bus driver specific.  This is
+ * intended to describe MMIO, I/O port, as well as bus specific
+ * regions (ex. PCI config space).  Zero sized regions may be used
+ * to describe unimplemented regions (ex. unimplemented PCI BARs).
+ */
+struct vfio_region_info {
+	__u32	argsz;
+	__u32	flags;
+#define VFIO_REGION_INFO_FLAG_MMAP	(1 << 0) /* Region supports mmap */
+#define VFIO_REGION_INFO_FLAG_RO	(1 << 1) /* Region is read-only */
+	__u32	index;		/* Region index */
+	__u32	resv;		/* Reserved for alignment */
+	__u64	size;		/* Region size (bytes) */
+	__u64	offset;		/* Region offset from start of device fd */
+};
+
+#define VFIO_DEVICE_GET_REGION_INFO	_IO(VFIO_TYPE, VFIO_BASE + 9)
+
+/**
+ * VFIO_DEVICE_GET_IRQ_INFO - _IOWR(VFIO_TYPE, VFIO_BASE + 10,
+ *				    struct vfio_irq_info)
+ *
+ * Retrieve information about a device IRQ.  Caller provides
+ * struct vfio_irq_info with index value set.  Caller sets argsz.
+ * Implementation of IRQ mapping is bus driver specific.  Indexes
+ * using multiple IRQs are primarily intended to support MSI-like
+ * interrupt blocks.  Zero count irq blocks may be used to describe
+ * unimplemented interrupt types.
+ *
+ * The EVENTFD flag indicates the interrupt index supports eventfd based
+ * signaling.
+ *
+ * The MASKABLE flags indicates the index supports MASK and UNMASK
+ * actions described below.
+ *
+ * AUTOMASKED indicates that after signaling, the interrupt line is
+ * automatically masked by VFIO and the user needs to unmask the line
+ * to receive new interrupts.  This is primarily intended to distinguish
+ * level triggered interrupts.
+ *
+ * The NORESIZE flag indicates that the interrupt lines within the index
+ * are setup as a set and new subindexes cannot be enabled without first
+ * disabling the entire index.  This is used for interrupts like PCI MSI
+ * and MSI-X where the driver may only use a subset of the available
+ * indexes, but VFIO needs to enable a specific number of vectors
+ * upfront.  In the case of MSI-X, where the user can enable MSI-X and
+ * then add and unmask vectors, it's up to userspace to make the decision
+ * whether to allocate the maximum supported number of vectors or tear
+ * down setup and incrementally increase the vectors as each is enabled.
+ */
+struct vfio_irq_info {
+	__u32	argsz;
+	__u32	flags;
+#define VFIO_IRQ_INFO_EVENTFD		(1 << 0)
+#define VFIO_IRQ_INFO_MASKABLE		(1 << 1)
+#define VFIO_IRQ_INFO_AUTOMASKED	(1 << 2)
+#define VFIO_IRQ_INFO_NORESIZE		(1 << 3)
+	__u32	index;		/* IRQ index */
+	__s32	count;		/* Number of IRQs within this index */
+};
+
+#define VFIO_DEVICE_GET_IRQ_INFO	_IO(VFIO_TYPE, VFIO_BASE + 10)
+
+/**
+ * VFIO_DEVICE_SET_IRQS - _IOW(VFIO_TYPE, VFIO_BASE + 11, struct vfio_irq_set)
+ *
+ * Set signaling, masking, and unmasking of interrupts.  Caller provides
+ * struct vfio_irq_set with all fields set.  'start' and 'count' indicate
+ * the range of subindexes being specified.
+ *
+ * The DATA flags specify the type of data provided.  If DATA_NONE, the
+ * operation performs the specified action immediately on the specified
+ * interrupt(s).  For example, to unmask AUTOMASKED interrupt [0,0]:
+ * flags = (DATA_NONE|ACTION_UNMASK), index = 0, start = 0, count = 1.
+ *
+ * DATA_BOOL allows sparse support for the same on arrays of interrupts.
+ * For example, to mask interrupts [0,1] and [0,3] (but not [0,2]):
+ * flags = (DATA_BOOL|ACTION_MASK), index = 0, start = 1, count = 3,
+ * data = {1,0,1}
+ *
+ * DATA_EVENTFD binds the specified ACTION to the provided __s32 eventfd.
+ * A value of -1 can be used to either de-assign interrupts if already
+ * assigned or skip un-assigned interrupts.  For example, to set an eventfd
+ * to be trigger for interrupts [0,0] and [0,2]:
+ * flags = (DATA_EVENTFD|ACTION_TRIGGER), index = 0, start = 0, count = 3,
+ * data = {fd1, -1, fd2}
+ * If index [0,1] is previously set, two count = 1 ioctls calls would be
+ * required to set [0,0] and [0,2] without changing [0,1].
+ *
+ * Once a signaling mechanism is set, DATA_BOOL or DATA_NONE can be used
+ * with ACTION_TRIGGER to perform kernel level interrupt loopback testing
+ * from userspace (ie. simulate hardware triggering).
+ *
+ * Setting of an event triggering mechanism to userspace for ACTION_TRIGGER
+ * enables the interrupt index for the device.  Individual subindex interrupts
+ * can be disabled using the -1 value for DATA_EVENTFD or the index can be
+ * disabled as a whole with: flags = (DATA_NONE|ACTION_TRIGGER), count = 0.
+ *
+ * Note that ACTION_[UN]MASK specify user->kernel signaling (irqfds) while
+ * ACTION_TRIGGER specifies kernel->user signaling.
+ */
+struct vfio_irq_set {
+	__u32	argsz;
+	__u32	flags;
+#define VFIO_IRQ_SET_DATA_NONE		(1 << 0) /* Data not present */
+#define VFIO_IRQ_SET_DATA_BOOL		(1 << 1) /* Data is bool (u8) */
+#define VFIO_IRQ_SET_DATA_EVENTFD	(1 << 2) /* Data is eventfd (s32) */
+#define VFIO_IRQ_SET_ACTION_MASK	(1 << 3) /* Mask interrupt */
+#define VFIO_IRQ_SET_ACTION_UNMASK	(1 << 4) /* Unmask interrupt */
+#define VFIO_IRQ_SET_ACTION_TRIGGER	(1 << 5) /* Trigger interrupt */
+	__u32	index;
+	__s32	start;
+	__s32	count;
+	__u8	data[];
+};
+
+#define VFIO_DEVICE_SET_IRQS		_IO(VFIO_TYPE, VFIO_BASE + 11)
+
+#define VFIO_IRQ_SET_DATA_TYPE_MASK	(VFIO_IRQ_SET_DATA_NONE | \
+					 VFIO_IRQ_SET_DATA_BOOL | \
+					 VFIO_IRQ_SET_DATA_EVENTFD)
+#define VFIO_IRQ_SET_ACTION_TYPE_MASK	(VFIO_IRQ_SET_ACTION_MASK | \
+					 VFIO_IRQ_SET_ACTION_UNMASK | \
+					 VFIO_IRQ_SET_ACTION_TRIGGER)
+/**
+ * VFIO_DEVICE_RESET - _IO(VFIO_TYPE, VFIO_BASE + 12)
+ *
+ * Reset a device.
+ */
+#define VFIO_DEVICE_RESET		_IO(VFIO_TYPE, VFIO_BASE + 12)
+
+#endif /* VFIO_H */