Merge tag 'vfio-for-v3.6' of git://github.com/awilliam/linux-vfio

Pull VFIO core from Alex Williamson:
 "This series includes the VFIO userspace driver interface for the 3.6
  kernel merge window.  This driver is intended to provide a secure
  interface for device access using IOMMU protection for applications
  like assignment of physical devices to virtual machines.

  Qemu will be the first user of this interface, enabling assignment of
  PCI devices to Qemu guests.  This interface is intended to eventually
  replace the x86-specific assignment mechanism currently available in
  KVM.

  This interface has the advantage of being more secure, by working with
  IOMMU groups to ensure device isolation and providing it's own
  filtered resource access mechanism, and also more flexible, in not
  being x86 or KVM specific (extensions to enable POWER are already
  working).

  This driver is originally the work of Tom Lyon, but has since been
  handed over to me and gone through a complete overhaul thanks to the
  input from David Gibson, Ben Herrenschmidt, Chris Wright, Joerg
  Roedel, and others.  This driver has been available in linux-next for
  the last month."

Paul Mackerras says:
 "I would be glad to see it go in since we want to use it with KVM on
  PowerPC.  If possible we'd like the PowerPC bits for it to go in as
  well."

* tag 'vfio-for-v3.6' of git://github.com/awilliam/linux-vfio:
  vfio: Add PCI device driver
  vfio: Type1 IOMMU implementation
  vfio: Add documentation
  vfio: VFIO core

1 files changed, 445 insertions, 0 deletions

diff --git a/include/linux/vfio.h b/include/linux/vfio.h
new file mode 100644
index 00000000000..0a4f180a11d
--- /dev/null
+++ b/include/linux/vfio.h
@@ -0,0 +1,445 @@
+/*
+ * 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>
+#include <linux/ioctl.h>
+
+#define VFIO_API_VERSION        0
+
+#ifdef __KERNEL__       /* Internal VFIO-core/bus driver API */
+
+#include <linux/iommu.h>
+#include <linux/mm.h>
+
+/**
+ * struct vfio_device_ops - VFIO bus driver device callbacks
+ *
+ * @open: Called when userspace creates new 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 {
+        char    *name;
+        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);
+};
+
+extern int vfio_add_group_dev(struct device *dev,
+                              const struct vfio_device_ops *ops,
+                              void *device_data);
+
+extern void *vfio_del_group_dev(struct device *dev);
+
+/**
+ * struct vfio_iommu_driver_ops - VFIO IOMMU driver callbacks
+ */
+struct vfio_iommu_driver_ops {
+        char            *name;
+        struct module   *owner;
+        void            *(*open)(unsigned long arg);
+        void            (*release)(void *iommu_data);
+        ssize_t         (*read)(void *iommu_data, char __user *buf,
+                                size_t count, loff_t *ppos);
+        ssize_t         (*write)(void *iommu_data, const char __user *buf,
+                                 size_t count, loff_t *size);
+        long            (*ioctl)(void *iommu_data, unsigned int cmd,
+                                 unsigned long arg);
+        int             (*mmap)(void *iommu_data, struct vm_area_struct *vma);
+        int             (*attach_group)(void *iommu_data,
+                                        struct iommu_group *group);
+        void            (*detach_group)(void *iommu_data,
+                                        struct iommu_group *group);
+
+};
+
+extern int vfio_register_iommu_driver(const struct vfio_iommu_driver_ops *ops);
+
+extern void vfio_unregister_iommu_driver(
+                                const struct vfio_iommu_driver_ops *ops);
+
+/**
+ * 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. */
+
+/* Extensions */
+
+#define VFIO_TYPE1_IOMMU                1
+
+/*
+ * 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 VFIO file descriptor (/dev/vfio/vfio) -------- */
+
+/**
+ * VFIO_GET_API_VERSION - _IO(VFIO_TYPE, VFIO_BASE + 0)
+ *
+ * Report the version of the VFIO API.  This allows us to bump the entire
+ * API version should we later need to add or change features in incompatible
+ * ways.
+ * Return: VFIO_API_VERSION
+ * Availability: Always
+ */
+#define VFIO_GET_API_VERSION            _IO(VFIO_TYPE, VFIO_BASE + 0)
+
+/**
+ * VFIO_CHECK_EXTENSION - _IOW(VFIO_TYPE, VFIO_BASE + 1, __u32)
+ *
+ * Check whether an extension is supported.
+ * Return: 0 if not supported, 1 (or some other positive integer) if supported.
+ * Availability: Always
+ */
+#define VFIO_CHECK_EXTENSION            _IO(VFIO_TYPE, VFIO_BASE + 1)
+
+/**
+ * VFIO_SET_IOMMU - _IOW(VFIO_TYPE, VFIO_BASE + 2, __s32)
+ *
+ * Set the iommu to the given type.  The type must be supported by an
+ * iommu driver as verified by calling CHECK_EXTENSION using the same
+ * type.  A group must be set to this file descriptor before this
+ * ioctl is available.  The IOMMU interfaces enabled by this call are
+ * specific to the value set.
+ * Return: 0 on success, -errno on failure
+ * Availability: When VFIO group attached
+ */
+#define VFIO_SET_IOMMU                  _IO(VFIO_TYPE, VFIO_BASE + 2)
+
+/* -------- IOCTLs for GROUP file descriptors (/dev/vfio/$GROUP) -------- */
+
+/**
+ * VFIO_GROUP_GET_STATUS - _IOR(VFIO_TYPE, VFIO_BASE + 3,
+ *                                              struct vfio_group_status)
+ *
+ * Retrieve information about the group.  Fills in provided
+ * struct vfio_group_info.  Caller sets argsz.
+ * Return: 0 on succes, -errno on failure.
+ * Availability: Always
+ */
+struct vfio_group_status {
+        __u32   argsz;
+        __u32   flags;
+#define VFIO_GROUP_FLAGS_VIABLE         (1 << 0)
+#define VFIO_GROUP_FLAGS_CONTAINER_SET  (1 << 1)
+};
+#define VFIO_GROUP_GET_STATUS           _IO(VFIO_TYPE, VFIO_BASE + 3)
+
+/**
+ * VFIO_GROUP_SET_CONTAINER - _IOW(VFIO_TYPE, VFIO_BASE + 4, __s32)
+ *
+ * Set the container for the VFIO group to the open VFIO file
+ * descriptor provided.  Groups may only belong to a single
+ * container.  Containers may, at their discretion, support multiple
+ * groups.  Only when a container is set are all of the interfaces
+ * of the VFIO file descriptor and the VFIO group file descriptor
+ * available to the user.
+ * Return: 0 on success, -errno on failure.
+ * Availability: Always
+ */
+#define VFIO_GROUP_SET_CONTAINER        _IO(VFIO_TYPE, VFIO_BASE + 4)
+
+/**
+ * VFIO_GROUP_UNSET_CONTAINER - _IO(VFIO_TYPE, VFIO_BASE + 5)
+ *
+ * Remove the group from the attached container.  This is the
+ * opposite of the SET_CONTAINER call and returns the group to
+ * an initial state.  All device file descriptors must be released
+ * prior to calling this interface.  When removing the last group
+ * from a container, the IOMMU will be disabled and all state lost,
+ * effectively also returning the VFIO file descriptor to an initial
+ * state.
+ * Return: 0 on success, -errno on failure.
+ * Availability: When attached to container
+ */
+#define VFIO_GROUP_UNSET_CONTAINER      _IO(VFIO_TYPE, VFIO_BASE + 5)
+
+/**
+ * VFIO_GROUP_GET_DEVICE_FD - _IOW(VFIO_TYPE, VFIO_BASE + 6, char)
+ *
+ * Return a new file descriptor for the device object described by
+ * the provided string.  The string should match a device listed in
+ * the devices subdirectory of the IOMMU group sysfs entry.  The
+ * group containing the device must already be added to this context.
+ * Return: new file descriptor on success, -errno on failure.
+ * Availability: When attached to container
+ */
+#define VFIO_GROUP_GET_DEVICE_FD        _IO(VFIO_TYPE, VFIO_BASE + 6)
+
+/* --------------- IOCTLs for DEVICE file descriptors --------------- */
+
+/**
+ * VFIO_DEVICE_GET_INFO - _IOR(VFIO_TYPE, VFIO_BASE + 7,
+ *                                              struct vfio_device_info)
+ *
+ * Retrieve information about the device.  Fills in provided
+ * struct vfio_device_info.  Caller sets argsz.
+ * Return: 0 on success, -errno on failure.
+ */
+struct vfio_device_info {
+        __u32   argsz;
+        __u32   flags;
+#define VFIO_DEVICE_FLAGS_RESET (1 << 0)        /* Device supports reset */
+#define VFIO_DEVICE_FLAGS_PCI   (1 << 1)        /* vfio-pci device */
+        __u32   num_regions;    /* Max region index + 1 */
+        __u32   num_irqs;       /* Max IRQ index + 1 */
+};
+#define VFIO_DEVICE_GET_INFO            _IO(VFIO_TYPE, VFIO_BASE + 7)
+
+/**
+ * VFIO_DEVICE_GET_REGION_INFO - _IOWR(VFIO_TYPE, VFIO_BASE + 8,
+ *                                     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).
+ * Return: 0 on success, -errno on failure.
+ */
+struct vfio_region_info {
+        __u32   argsz;
+        __u32   flags;
+#define VFIO_REGION_INFO_FLAG_READ      (1 << 0) /* Region supports read */
+#define VFIO_REGION_INFO_FLAG_WRITE     (1 << 1) /* Region supports write */
+#define VFIO_REGION_INFO_FLAG_MMAP      (1 << 2) /* Region supports mmap */
+        __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 + 8)
+
+/**
+ * VFIO_DEVICE_GET_IRQ_INFO - _IOWR(VFIO_TYPE, VFIO_BASE + 9,
+ *                                  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 */
+        __u32   count;          /* Number of IRQs within this index */
+};
+#define VFIO_DEVICE_GET_IRQ_INFO        _IO(VFIO_TYPE, VFIO_BASE + 9)
+
+/**
+ * VFIO_DEVICE_SET_IRQS - _IOW(VFIO_TYPE, VFIO_BASE + 10, 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;
+        __u32   start;
+        __u32   count;
+        __u8    data[];
+};
+#define VFIO_DEVICE_SET_IRQS            _IO(VFIO_TYPE, VFIO_BASE + 10)
+
+#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 + 11)
+ *
+ * Reset a device.
+ */
+#define VFIO_DEVICE_RESET               _IO(VFIO_TYPE, VFIO_BASE + 11)
+
+/*
+ * The VFIO-PCI bus driver makes use of the following fixed region and
+ * IRQ index mapping.  Unimplemented regions return a size of zero.
+ * Unimplemented IRQ types return a count of zero.
+ */
+
+enum {
+        VFIO_PCI_BAR0_REGION_INDEX,
+        VFIO_PCI_BAR1_REGION_INDEX,
+        VFIO_PCI_BAR2_REGION_INDEX,
+        VFIO_PCI_BAR3_REGION_INDEX,
+        VFIO_PCI_BAR4_REGION_INDEX,
+        VFIO_PCI_BAR5_REGION_INDEX,
+        VFIO_PCI_ROM_REGION_INDEX,
+        VFIO_PCI_CONFIG_REGION_INDEX,
+        VFIO_PCI_NUM_REGIONS
+};
+
+enum {
+        VFIO_PCI_INTX_IRQ_INDEX,
+        VFIO_PCI_MSI_IRQ_INDEX,
+        VFIO_PCI_MSIX_IRQ_INDEX,
+        VFIO_PCI_NUM_IRQS
+};
+
+/* -------- API for Type1 VFIO IOMMU -------- */
+
+/**
+ * VFIO_IOMMU_GET_INFO - _IOR(VFIO_TYPE, VFIO_BASE + 12, struct vfio_iommu_info)
+ *
+ * Retrieve information about the IOMMU object. Fills in provided
+ * struct vfio_iommu_info. Caller sets argsz.
+ *
+ * XXX Should we do these by CHECK_EXTENSION too?
+ */
+struct vfio_iommu_type1_info {
+        __u32   argsz;
+        __u32   flags;
+#define VFIO_IOMMU_INFO_PGSIZES (1 << 0)        /* supported page sizes info */
+        __u64   iova_pgsizes;           /* Bitmap of supported page sizes */
+};
+
+#define VFIO_IOMMU_GET_INFO _IO(VFIO_TYPE, VFIO_BASE + 12)
+
+/**
+ * VFIO_IOMMU_MAP_DMA - _IOW(VFIO_TYPE, VFIO_BASE + 13, 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_iommu_type1_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 + 13)
+
+/**
+ * VFIO_IOMMU_UNMAP_DMA - _IOW(VFIO_TYPE, VFIO_BASE + 14, struct vfio_dma_unmap)
+ *
+ * Unmap IO virtual addresses using the provided struct vfio_dma_unmap.
+ * Caller sets argsz.
+ */
+struct vfio_iommu_type1_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 + 14)
+
+#endif /* VFIO_H */