[Qemu-devel] [PATCH v2 2/5] vfio: VFIO core header

[Alex Williamson]

This defines both the user and bus driver APIs.

Signed-off-by: Alex Williamson <address@hidden>
---

 Documentation/ioctl/ioctl-number.txt |    1 
 include/linux/vfio.h                 |  395 ++++++++++++++++++++++++++++++++++
 2 files changed, 396 insertions(+), 0 deletions(-)
 create mode 100644 include/linux/vfio.h

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:address@hidden>
+';'    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 <address@hidden>
+ *
+ * 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 */