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vfio: Move vfio group specific code into group.c

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This prepares for compiling out vfio group after vfio device cdev is
added. No vfio_group decode code should be in vfio_main.c, and neither
device->group reference should be in vfio_main.c.

No functional change is intended.

Link: https://lore.kernel.org/r/20221201145535.589687-11-yi.l.liu@intel.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Tested-by: Yu He <yu.he@intel.com>
Tested-by: Lixiao Yang <lixiao.yang@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
This commit is contained in:
Yi Liu 2022-11-25 03:26:42 -08:00 committed by Jason Gunthorpe
parent 8da7a0e79f
commit 9eefba8002
4 changed files with 907 additions and 870 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
drivers/vfio/Makefile
View File

@ -4,6 +4,7 @@ vfio_virqfd-y := virqfd.o
obj-$(CONFIG_VFIO) += vfio.o
vfio-y += vfio_main.o \
group.o \
iova_bitmap.o
vfio-$(CONFIG_IOMMUFD) += iommufd.o
vfio-$(CONFIG_VFIO_CONTAINER) += container.o

877
drivers/vfio/group.c Normal file
View File

@ -0,0 +1,877 @@
// SPDX-License-Identifier: GPL-2.0-only
/*
* VFIO core
*
* Copyright (C) 2012 Red Hat, Inc. All rights reserved.
* Author: Alex Williamson <alex.williamson@redhat.com>
*
* Derived from original vfio:
* Copyright 2010 Cisco Systems, Inc. All rights reserved.
* Author: Tom Lyon, pugs@cisco.com
*/
#include <linux/vfio.h>
#include <linux/iommufd.h>
#include <linux/anon_inodes.h>
#include "vfio.h"
static struct vfio {
struct class *class;
struct list_head group_list;
struct mutex group_lock; /* locks group_list */
struct ida group_ida;
dev_t group_devt;
} vfio;
static struct vfio_device *vfio_device_get_from_name(struct vfio_group *group,
char *buf)
{
struct vfio_device *it, *device = ERR_PTR(-ENODEV);
mutex_lock(&group->device_lock);
list_for_each_entry(it, &group->device_list, group_next) {
int ret;
if (it->ops->match) {
ret = it->ops->match(it, buf);
if (ret < 0) {
device = ERR_PTR(ret);
break;
}
} else {
ret = !strcmp(dev_name(it->dev), buf);
}
if (ret && vfio_device_try_get_registration(it)) {
device = it;
break;
}
}
mutex_unlock(&group->device_lock);
return device;
}
/*
* VFIO Group fd, /dev/vfio/$GROUP
*/
static bool vfio_group_has_iommu(struct vfio_group *group)
{
lockdep_assert_held(&group->group_lock);
/*
* There can only be users if there is a container, and if there is a
* container there must be users.
*/
WARN_ON(!group->container != !group->container_users);
return group->container || group->iommufd;
}
/*
* VFIO_GROUP_UNSET_CONTAINER should fail if there are other users or
* if there was no container to unset. Since the ioctl is called on
* the group, we know that still exists, therefore the only valid
* transition here is 1->0.
*/
static int vfio_group_ioctl_unset_container(struct vfio_group *group)
{
int ret = 0;
mutex_lock(&group->group_lock);
if (!vfio_group_has_iommu(group)) {
ret = -EINVAL;
goto out_unlock;
}
if (group->container) {
if (group->container_users != 1) {
ret = -EBUSY;
goto out_unlock;
}
vfio_group_detach_container(group);
}
if (group->iommufd) {
iommufd_ctx_put(group->iommufd);
group->iommufd = NULL;
}
out_unlock:
mutex_unlock(&group->group_lock);
return ret;
}
static int vfio_group_ioctl_set_container(struct vfio_group *group,
int __user *arg)
{
struct vfio_container *container;
struct iommufd_ctx *iommufd;
struct fd f;
int ret;
int fd;
if (get_user(fd, arg))
return -EFAULT;
f = fdget(fd);
if (!f.file)
return -EBADF;
mutex_lock(&group->group_lock);
if (vfio_group_has_iommu(group)) {
ret = -EINVAL;
goto out_unlock;
}
if (!group->iommu_group) {
ret = -ENODEV;
goto out_unlock;
}
container = vfio_container_from_file(f.file);
if (container) {
ret = vfio_container_attach_group(container, group);
goto out_unlock;
}
iommufd = iommufd_ctx_from_file(f.file);
if (!IS_ERR(iommufd)) {
u32 ioas_id;
ret = iommufd_vfio_compat_ioas_id(iommufd, &ioas_id);
if (ret) {
iommufd_ctx_put(group->iommufd);
goto out_unlock;
}
group->iommufd = iommufd;
goto out_unlock;
}
/* The FD passed is not recognized. */
ret = -EBADFD;
out_unlock:
mutex_unlock(&group->group_lock);
fdput(f);
return ret;
}
static int vfio_device_group_open(struct vfio_device *device)
{
int ret;
mutex_lock(&device->group->group_lock);
if (!vfio_group_has_iommu(device->group)) {
ret = -EINVAL;
goto out_unlock;
}
/*
* Here we pass the KVM pointer with the group under the lock. If the
* device driver will use it, it must obtain a reference and release it
* during close_device.
*/
ret = vfio_device_open(device, device->group->iommufd,
device->group->kvm);
out_unlock:
mutex_unlock(&device->group->group_lock);
return ret;
}
void vfio_device_group_close(struct vfio_device *device)
{
mutex_lock(&device->group->group_lock);
vfio_device_close(device, device->group->iommufd);
mutex_unlock(&device->group->group_lock);
}
static struct file *vfio_device_open_file(struct vfio_device *device)
{
struct file *filep;
int ret;
ret = vfio_device_group_open(device);
if (ret)
goto err_out;
/*
* We can't use anon_inode_getfd() because we need to modify
* the f_mode flags directly to allow more than just ioctls
*/
filep = anon_inode_getfile("[vfio-device]", &vfio_device_fops,
device, O_RDWR);
if (IS_ERR(filep)) {
ret = PTR_ERR(filep);
goto err_close_device;
}
/*
* TODO: add an anon_inode interface to do this.
* Appears to be missing by lack of need rather than
* explicitly prevented. Now there's need.
*/
filep->f_mode |= (FMODE_PREAD | FMODE_PWRITE);
if (device->group->type == VFIO_NO_IOMMU)
dev_warn(device->dev, "vfio-noiommu device opened by user "
"(%s:%d)\n", current->comm, task_pid_nr(current));
/*
* On success the ref of device is moved to the file and
* put in vfio_device_fops_release()
*/
return filep;
err_close_device:
vfio_device_group_close(device);
err_out:
return ERR_PTR(ret);
}
static int vfio_group_ioctl_get_device_fd(struct vfio_group *group,
char __user *arg)
{
struct vfio_device *device;
struct file *filep;
char *buf;
int fdno;
int ret;
buf = strndup_user(arg, PAGE_SIZE);
if (IS_ERR(buf))
return PTR_ERR(buf);
device = vfio_device_get_from_name(group, buf);
kfree(buf);
if (IS_ERR(device))
return PTR_ERR(device);
fdno = get_unused_fd_flags(O_CLOEXEC);
if (fdno < 0) {
ret = fdno;
goto err_put_device;
}
filep = vfio_device_open_file(device);
if (IS_ERR(filep)) {
ret = PTR_ERR(filep);
goto err_put_fdno;
}
fd_install(fdno, filep);
return fdno;
err_put_fdno:
put_unused_fd(fdno);
err_put_device:
vfio_device_put_registration(device);
return ret;
}
static int vfio_group_ioctl_get_status(struct vfio_group *group,
struct vfio_group_status __user *arg)
{
unsigned long minsz = offsetofend(struct vfio_group_status, flags);
struct vfio_group_status status;
if (copy_from_user(&status, arg, minsz))
return -EFAULT;
if (status.argsz < minsz)
return -EINVAL;
status.flags = 0;
mutex_lock(&group->group_lock);
if (!group->iommu_group) {
mutex_unlock(&group->group_lock);
return -ENODEV;
}
/*
* With the container FD the iommu_group_claim_dma_owner() is done
* during SET_CONTAINER but for IOMMFD this is done during
* VFIO_GROUP_GET_DEVICE_FD. Meaning that with iommufd
* VFIO_GROUP_FLAGS_VIABLE could be set but GET_DEVICE_FD will fail due
* to viability.
*/
if (vfio_group_has_iommu(group))
status.flags |= VFIO_GROUP_FLAGS_CONTAINER_SET |
VFIO_GROUP_FLAGS_VIABLE;
else if (!iommu_group_dma_owner_claimed(group->iommu_group))
status.flags |= VFIO_GROUP_FLAGS_VIABLE;
mutex_unlock(&group->group_lock);
if (copy_to_user(arg, &status, minsz))
return -EFAULT;
return 0;
}
static long vfio_group_fops_unl_ioctl(struct file *filep,
unsigned int cmd, unsigned long arg)
{
struct vfio_group *group = filep->private_data;
void __user *uarg = (void __user *)arg;
switch (cmd) {
case VFIO_GROUP_GET_DEVICE_FD:
return vfio_group_ioctl_get_device_fd(group, uarg);
case VFIO_GROUP_GET_STATUS:
return vfio_group_ioctl_get_status(group, uarg);
case VFIO_GROUP_SET_CONTAINER:
return vfio_group_ioctl_set_container(group, uarg);
case VFIO_GROUP_UNSET_CONTAINER:
return vfio_group_ioctl_unset_container(group);
default:
return -ENOTTY;
}
}
static int vfio_group_fops_open(struct inode *inode, struct file *filep)
{
struct vfio_group *group =
container_of(inode->i_cdev, struct vfio_group, cdev);
int ret;
mutex_lock(&group->group_lock);
/*
* drivers can be zero if this races with vfio_device_remove_group(), it
* will be stable at 0 under the group rwsem
*/
if (refcount_read(&group->drivers) == 0) {
ret = -ENODEV;
goto out_unlock;
}
if (group->type == VFIO_NO_IOMMU && !capable(CAP_SYS_RAWIO)) {
ret = -EPERM;
goto out_unlock;
}
/*
* Do we need multiple instances of the group open? Seems not.
*/
if (group->opened_file) {
ret = -EBUSY;
goto out_unlock;
}
group->opened_file = filep;
filep->private_data = group;
ret = 0;
out_unlock:
mutex_unlock(&group->group_lock);
return ret;
}
static int vfio_group_fops_release(struct inode *inode, struct file *filep)
{
struct vfio_group *group = filep->private_data;
filep->private_data = NULL;
mutex_lock(&group->group_lock);
/*
* Device FDs hold a group file reference, therefore the group release
* is only called when there are no open devices.
*/
WARN_ON(group->notifier.head);
if (group->container)
vfio_group_detach_container(group);
if (group->iommufd) {
iommufd_ctx_put(group->iommufd);
group->iommufd = NULL;
}
group->opened_file = NULL;
mutex_unlock(&group->group_lock);
return 0;
}
static const struct file_operations vfio_group_fops = {
.owner = THIS_MODULE,
.unlocked_ioctl = vfio_group_fops_unl_ioctl,
.compat_ioctl = compat_ptr_ioctl,
.open = vfio_group_fops_open,
.release = vfio_group_fops_release,
};
/*
* Group objects - create, release, get, put, search
*/
static struct vfio_group *
vfio_group_find_from_iommu(struct iommu_group *iommu_group)
{
struct vfio_group *group;
lockdep_assert_held(&vfio.group_lock);
/*
* group->iommu_group from the vfio.group_list cannot be NULL
* under the vfio.group_lock.
*/
list_for_each_entry(group, &vfio.group_list, vfio_next) {
if (group->iommu_group == iommu_group)
return group;
}
return NULL;
}
static void vfio_group_release(struct device *dev)
{
struct vfio_group *group = container_of(dev, struct vfio_group, dev);
mutex_destroy(&group->device_lock);
mutex_destroy(&group->group_lock);
WARN_ON(group->iommu_group);
ida_free(&vfio.group_ida, MINOR(group->dev.devt));
kfree(group);
}
static struct vfio_group *vfio_group_alloc(struct iommu_group *iommu_group,
enum vfio_group_type type)
{
struct vfio_group *group;
int minor;
group = kzalloc(sizeof(*group), GFP_KERNEL);
if (!group)
return ERR_PTR(-ENOMEM);
minor = ida_alloc_max(&vfio.group_ida, MINORMASK, GFP_KERNEL);
if (minor < 0) {
kfree(group);
return ERR_PTR(minor);
}
device_initialize(&group->dev);
group->dev.devt = MKDEV(MAJOR(vfio.group_devt), minor);
group->dev.class = vfio.class;
group->dev.release = vfio_group_release;
cdev_init(&group->cdev, &vfio_group_fops);
group->cdev.owner = THIS_MODULE;
refcount_set(&group->drivers, 1);
mutex_init(&group->group_lock);
INIT_LIST_HEAD(&group->device_list);
mutex_init(&group->device_lock);
group->iommu_group = iommu_group;
/* put in vfio_group_release() */
iommu_group_ref_get(iommu_group);
group->type = type;
BLOCKING_INIT_NOTIFIER_HEAD(&group->notifier);
return group;
}
static struct vfio_group *vfio_create_group(struct iommu_group *iommu_group,
enum vfio_group_type type)
{
struct vfio_group *group;
struct vfio_group *ret;
int err;
lockdep_assert_held(&vfio.group_lock);
group = vfio_group_alloc(iommu_group, type);
if (IS_ERR(group))
return group;
err = dev_set_name(&group->dev, "%s%d",
group->type == VFIO_NO_IOMMU ? "noiommu-" : "",
iommu_group_id(iommu_group));
if (err) {
ret = ERR_PTR(err);
goto err_put;
}
err = cdev_device_add(&group->cdev, &group->dev);
if (err) {
ret = ERR_PTR(err);
goto err_put;
}
list_add(&group->vfio_next, &vfio.group_list);
return group;
err_put:
put_device(&group->dev);
return ret;
}
static struct vfio_group *vfio_noiommu_group_alloc(struct device *dev,
enum vfio_group_type type)
{
struct iommu_group *iommu_group;
struct vfio_group *group;
int ret;
iommu_group = iommu_group_alloc();
if (IS_ERR(iommu_group))
return ERR_CAST(iommu_group);
ret = iommu_group_set_name(iommu_group, "vfio-noiommu");
if (ret)
goto out_put_group;
ret = iommu_group_add_device(iommu_group, dev);
if (ret)
goto out_put_group;
mutex_lock(&vfio.group_lock);
group = vfio_create_group(iommu_group, type);
mutex_unlock(&vfio.group_lock);
if (IS_ERR(group)) {
ret = PTR_ERR(group);
goto out_remove_device;
}
iommu_group_put(iommu_group);
return group;
out_remove_device:
iommu_group_remove_device(dev);
out_put_group:
iommu_group_put(iommu_group);
return ERR_PTR(ret);
}
static bool vfio_group_has_device(struct vfio_group *group, struct device *dev)
{
struct vfio_device *device;
mutex_lock(&group->device_lock);
list_for_each_entry(device, &group->device_list, group_next) {
if (device->dev == dev) {
mutex_unlock(&group->device_lock);
return true;
}
}
mutex_unlock(&group->device_lock);
return false;
}
static struct vfio_group *vfio_group_find_or_alloc(struct device *dev)
{
struct iommu_group *iommu_group;
struct vfio_group *group;
iommu_group = iommu_group_get(dev);
if (!iommu_group && vfio_noiommu) {
/*
* With noiommu enabled, create an IOMMU group for devices that
* don't already have one, implying no IOMMU hardware/driver
* exists. Taint the kernel because we're about to give a DMA
* capable device to a user without IOMMU protection.
*/
group = vfio_noiommu_group_alloc(dev, VFIO_NO_IOMMU);
if (!IS_ERR(group)) {
add_taint(TAINT_USER, LOCKDEP_STILL_OK);
dev_warn(dev, "Adding kernel taint for vfio-noiommu group on device\n");
}
return group;
}
if (!iommu_group)
return ERR_PTR(-EINVAL);
/*
* VFIO always sets IOMMU_CACHE because we offer no way for userspace to
* restore cache coherency. It has to be checked here because it is only
* valid for cases where we are using iommu groups.
*/
if (!device_iommu_capable(dev, IOMMU_CAP_CACHE_COHERENCY)) {
iommu_group_put(iommu_group);
return ERR_PTR(-EINVAL);
}
mutex_lock(&vfio.group_lock);
group = vfio_group_find_from_iommu(iommu_group);
if (group) {
if (WARN_ON(vfio_group_has_device(group, dev)))
group = ERR_PTR(-EINVAL);
else
refcount_inc(&group->drivers);
} else {
group = vfio_create_group(iommu_group, VFIO_IOMMU);
}
mutex_unlock(&vfio.group_lock);
/* The vfio_group holds a reference to the iommu_group */
iommu_group_put(iommu_group);
return group;
}
int vfio_device_set_group(struct vfio_device *device,
enum vfio_group_type type)
{
struct vfio_group *group;
if (type == VFIO_IOMMU)
group = vfio_group_find_or_alloc(device->dev);
else
group = vfio_noiommu_group_alloc(device->dev, type);
if (IS_ERR(group))
return PTR_ERR(group);
/* Our reference on group is moved to the device */
device->group = group;
return 0;
}
void vfio_device_remove_group(struct vfio_device *device)
{
struct vfio_group *group = device->group;
struct iommu_group *iommu_group;
if (group->type == VFIO_NO_IOMMU || group->type == VFIO_EMULATED_IOMMU)
iommu_group_remove_device(device->dev);
/* Pairs with vfio_create_group() / vfio_group_get_from_iommu() */
if (!refcount_dec_and_mutex_lock(&group->drivers, &vfio.group_lock))
return;
list_del(&group->vfio_next);
/*
* We could concurrently probe another driver in the group that might
* race vfio_device_remove_group() with vfio_get_group(), so we have to
* ensure that the sysfs is all cleaned up under lock otherwise the
* cdev_device_add() will fail due to the name aready existing.
*/
cdev_device_del(&group->cdev, &group->dev);
mutex_lock(&group->group_lock);
/*
* These data structures all have paired operations that can only be
* undone when the caller holds a live reference on the device. Since
* all pairs must be undone these WARN_ON's indicate some caller did not
* properly hold the group reference.
*/
WARN_ON(!list_empty(&group->device_list));
WARN_ON(group->notifier.head);
/*
* Revoke all users of group->iommu_group. At this point we know there
* are no devices active because we are unplugging the last one. Setting
* iommu_group to NULL blocks all new users.
*/
if (group->container)
vfio_group_detach_container(group);
iommu_group = group->iommu_group;
group->iommu_group = NULL;
mutex_unlock(&group->group_lock);
mutex_unlock(&vfio.group_lock);
iommu_group_put(iommu_group);
put_device(&group->dev);
}
void vfio_device_group_register(struct vfio_device *device)
{
mutex_lock(&device->group->device_lock);
list_add(&device->group_next, &device->group->device_list);
mutex_unlock(&device->group->device_lock);
}
void vfio_device_group_unregister(struct vfio_device *device)
{
mutex_lock(&device->group->device_lock);
list_del(&device->group_next);
mutex_unlock(&device->group->device_lock);
}
int vfio_device_group_use_iommu(struct vfio_device *device)
{
struct vfio_group *group = device->group;
int ret = 0;
lockdep_assert_held(&group->group_lock);
if (WARN_ON(!group->container))
return -EINVAL;
ret = vfio_group_use_container(group);
if (ret)
return ret;
vfio_device_container_register(device);
return 0;
}
void vfio_device_group_unuse_iommu(struct vfio_device *device)
{
struct vfio_group *group = device->group;
lockdep_assert_held(&group->group_lock);
if (WARN_ON(!group->container))
return;
vfio_device_container_unregister(device);
vfio_group_unuse_container(group);
}
bool vfio_device_has_container(struct vfio_device *device)
{
return device->group->container;
}
/**
* vfio_file_iommu_group - Return the struct iommu_group for the vfio group file
* @file: VFIO group file
*
* The returned iommu_group is valid as long as a ref is held on the file. This
* returns a reference on the group. This function is deprecated, only the SPAPR
* path in kvm should call it.
*/
struct iommu_group *vfio_file_iommu_group(struct file *file)
{
struct vfio_group *group = file->private_data;
struct iommu_group *iommu_group = NULL;
if (!IS_ENABLED(CONFIG_SPAPR_TCE_IOMMU))
return NULL;
if (!vfio_file_is_group(file))
return NULL;
mutex_lock(&group->group_lock);
if (group->iommu_group) {
iommu_group = group->iommu_group;
iommu_group_ref_get(iommu_group);
}
mutex_unlock(&group->group_lock);
return iommu_group;
}
EXPORT_SYMBOL_GPL(vfio_file_iommu_group);
/**
* vfio_file_is_group - True if the file is usable with VFIO aPIS
* @file: VFIO group file
*/
bool vfio_file_is_group(struct file *file)
{
return file->f_op == &vfio_group_fops;
}
EXPORT_SYMBOL_GPL(vfio_file_is_group);
/**
* vfio_file_enforced_coherent - True if the DMA associated with the VFIO file
* is always CPU cache coherent
* @file: VFIO group file
*
* Enforced coherency means that the IOMMU ignores things like the PCIe no-snoop
* bit in DMA transactions. A return of false indicates that the user has
* rights to access additional instructions such as wbinvd on x86.
*/
bool vfio_file_enforced_coherent(struct file *file)
{
struct vfio_group *group = file->private_data;
struct vfio_device *device;
bool ret = true;
if (!vfio_file_is_group(file))
return true;
/*
* If the device does not have IOMMU_CAP_ENFORCE_CACHE_COHERENCY then
* any domain later attached to it will also not support it. If the cap
* is set then the iommu_domain eventually attached to the device/group
* must use a domain with enforce_cache_coherency().
*/
mutex_lock(&group->device_lock);
list_for_each_entry(device, &group->device_list, group_next) {
if (!device_iommu_capable(device->dev,
IOMMU_CAP_ENFORCE_CACHE_COHERENCY)) {
ret = false;
break;
}
}
mutex_unlock(&group->device_lock);
return ret;
}
EXPORT_SYMBOL_GPL(vfio_file_enforced_coherent);
/**
* vfio_file_set_kvm - Link a kvm with VFIO drivers
* @file: VFIO group file
* @kvm: KVM to link
*
* When a VFIO device is first opened the KVM will be available in
* device->kvm if one was associated with the group.
*/
void vfio_file_set_kvm(struct file *file, struct kvm *kvm)
{
struct vfio_group *group = file->private_data;
if (!vfio_file_is_group(file))
return;
mutex_lock(&group->group_lock);
group->kvm = kvm;
mutex_unlock(&group->group_lock);
}
EXPORT_SYMBOL_GPL(vfio_file_set_kvm);
/**
* vfio_file_has_dev - True if the VFIO file is a handle for device
* @file: VFIO file to check
* @device: Device that must be part of the file
*
* Returns true if given file has permission to manipulate the given device.
*/
bool vfio_file_has_dev(struct file *file, struct vfio_device *device)
{
struct vfio_group *group = file->private_data;
if (!vfio_file_is_group(file))
return false;
return group == device->group;
}
EXPORT_SYMBOL_GPL(vfio_file_has_dev);
static char *vfio_devnode(struct device *dev, umode_t *mode)
{
return kasprintf(GFP_KERNEL, "vfio/%s", dev_name(dev));
}
int __init vfio_group_init(void)
{
int ret;
ida_init(&vfio.group_ida);
mutex_init(&vfio.group_lock);
INIT_LIST_HEAD(&vfio.group_list);
ret = vfio_container_init();
if (ret)
return ret;
/* /dev/vfio/$GROUP */
vfio.class = class_create(THIS_MODULE, "vfio");
if (IS_ERR(vfio.class)) {
ret = PTR_ERR(vfio.class);
goto err_group_class;
}
vfio.class->devnode = vfio_devnode;
ret = alloc_chrdev_region(&vfio.group_devt, 0, MINORMASK + 1, "vfio");
if (ret)
goto err_alloc_chrdev;
return 0;
err_alloc_chrdev:
class_destroy(vfio.class);
vfio.class = NULL;
err_group_class:
vfio_container_cleanup();
return ret;
}
void vfio_group_cleanup(void)
{
WARN_ON(!list_empty(&vfio.group_list));
ida_destroy(&vfio.group_ida);
unregister_chrdev_region(vfio.group_devt, MINORMASK + 1);
class_destroy(vfio.class);
vfio.class = NULL;
vfio_container_cleanup();
}

22
drivers/vfio/vfio.h
View File

@ -6,6 +6,7 @@
#ifndef __VFIO_VFIO_H__
#define __VFIO_VFIO_H__
#include <linux/file.h>
#include <linux/device.h>
#include <linux/cdev.h>
#include <linux/module.h>
@ -15,6 +16,15 @@ struct iommu_group;
struct vfio_device;
struct vfio_container;
void vfio_device_put_registration(struct vfio_device *device);
bool vfio_device_try_get_registration(struct vfio_device *device);
int vfio_device_open(struct vfio_device *device,
struct iommufd_ctx *iommufd, struct kvm *kvm);
void vfio_device_close(struct vfio_device *device,
struct iommufd_ctx *iommufd);
extern const struct file_operations vfio_device_fops;
enum vfio_group_type {
/*
* Physical device with IOMMU backing.
@ -66,6 +76,18 @@ struct vfio_group {
struct iommufd_ctx *iommufd;
};
int vfio_device_set_group(struct vfio_device *device,
enum vfio_group_type type);
void vfio_device_remove_group(struct vfio_device *device);
void vfio_device_group_register(struct vfio_device *device);
void vfio_device_group_unregister(struct vfio_device *device);
int vfio_device_group_use_iommu(struct vfio_device *device);
void vfio_device_group_unuse_iommu(struct vfio_device *device);
void vfio_device_group_close(struct vfio_device *device);
bool vfio_device_has_container(struct vfio_device *device);
int __init vfio_group_init(void);
void vfio_group_cleanup(void);
#if IS_ENABLED(CONFIG_VFIO_CONTAINER)
/* events for the backend driver notify callback */
enum vfio_iommu_notify_type {

877
drivers/vfio/vfio_main.c
View File

@ -13,8 +13,6 @@
#include <linux/cdev.h>
#include <linux/compat.h>
#include <linux/device.h>
#include <linux/file.h>
#include <linux/anon_inodes.h>
#include <linux/fs.h>
#include <linux/idr.h>
#include <linux/iommu.h>
@ -43,17 +41,11 @@
#define DRIVER_DESC "VFIO - User Level meta-driver"
static struct vfio {
struct class *class;
struct list_head group_list;
struct mutex group_lock; /* locks group_list */
struct ida group_ida;
dev_t group_devt;
struct class *device_class;
struct ida device_ida;
} vfio;
static DEFINE_XARRAY(vfio_device_set_xa);
static const struct file_operations vfio_group_fops;
int vfio_assign_device_set(struct vfio_device *device, void *set_id)
{
@ -139,168 +131,17 @@ unsigned int vfio_device_set_open_count(struct vfio_device_set *dev_set)
}
EXPORT_SYMBOL_GPL(vfio_device_set_open_count);
/*
* Group objects - create, release, get, put, search
*/
static struct vfio_group *
vfio_group_find_from_iommu(struct iommu_group *iommu_group)
{
struct vfio_group *group;
lockdep_assert_held(&vfio.group_lock);
/*
* group->iommu_group from the vfio.group_list cannot be NULL
* under the vfio.group_lock.
*/
list_for_each_entry(group, &vfio.group_list, vfio_next) {
if (group->iommu_group == iommu_group)
return group;
}
return NULL;
}
static void vfio_group_release(struct device *dev)
{
struct vfio_group *group = container_of(dev, struct vfio_group, dev);
mutex_destroy(&group->device_lock);
mutex_destroy(&group->group_lock);
WARN_ON(group->iommu_group);
ida_free(&vfio.group_ida, MINOR(group->dev.devt));
kfree(group);
}
static struct vfio_group *vfio_group_alloc(struct iommu_group *iommu_group,
enum vfio_group_type type)
{
struct vfio_group *group;
int minor;
group = kzalloc(sizeof(*group), GFP_KERNEL);
if (!group)
return ERR_PTR(-ENOMEM);
minor = ida_alloc_max(&vfio.group_ida, MINORMASK, GFP_KERNEL);
if (minor < 0) {
kfree(group);
return ERR_PTR(minor);
}
device_initialize(&group->dev);
group->dev.devt = MKDEV(MAJOR(vfio.group_devt), minor);
group->dev.class = vfio.class;
group->dev.release = vfio_group_release;
cdev_init(&group->cdev, &vfio_group_fops);
group->cdev.owner = THIS_MODULE;
refcount_set(&group->drivers, 1);
mutex_init(&group->group_lock);
INIT_LIST_HEAD(&group->device_list);
mutex_init(&group->device_lock);
group->iommu_group = iommu_group;
/* put in vfio_group_release() */
iommu_group_ref_get(iommu_group);
group->type = type;
BLOCKING_INIT_NOTIFIER_HEAD(&group->notifier);
return group;
}
static struct vfio_group *vfio_create_group(struct iommu_group *iommu_group,
enum vfio_group_type type)
{
struct vfio_group *group;
struct vfio_group *ret;
int err;
lockdep_assert_held(&vfio.group_lock);
group = vfio_group_alloc(iommu_group, type);
if (IS_ERR(group))
return group;
err = dev_set_name(&group->dev, "%s%d",
group->type == VFIO_NO_IOMMU ? "noiommu-" : "",
iommu_group_id(iommu_group));
if (err) {
ret = ERR_PTR(err);
goto err_put;
}
err = cdev_device_add(&group->cdev, &group->dev);
if (err) {
ret = ERR_PTR(err);
goto err_put;
}
list_add(&group->vfio_next, &vfio.group_list);
return group;
err_put:
put_device(&group->dev);
return ret;
}
static void vfio_device_remove_group(struct vfio_device *device)
{
struct vfio_group *group = device->group;
struct iommu_group *iommu_group;
if (group->type == VFIO_NO_IOMMU || group->type == VFIO_EMULATED_IOMMU)
iommu_group_remove_device(device->dev);
/* Pairs with vfio_create_group() / vfio_group_get_from_iommu() */
if (!refcount_dec_and_mutex_lock(&group->drivers, &vfio.group_lock))
return;
list_del(&group->vfio_next);
/*
* We could concurrently probe another driver in the group that might
* race vfio_device_remove_group() with vfio_get_group(), so we have to
* ensure that the sysfs is all cleaned up under lock otherwise the
* cdev_device_add() will fail due to the name aready existing.
*/
cdev_device_del(&group->cdev, &group->dev);
mutex_lock(&group->group_lock);
/*
* These data structures all have paired operations that can only be
* undone when the caller holds a live reference on the device. Since
* all pairs must be undone these WARN_ON's indicate some caller did not
* properly hold the group reference.
*/
WARN_ON(!list_empty(&group->device_list));
WARN_ON(group->notifier.head);
/*
* Revoke all users of group->iommu_group. At this point we know there
* are no devices active because we are unplugging the last one. Setting
* iommu_group to NULL blocks all new users.
*/
if (group->container)
vfio_group_detach_container(group);
iommu_group = group->iommu_group;
group->iommu_group = NULL;
mutex_unlock(&group->group_lock);
mutex_unlock(&vfio.group_lock);
iommu_group_put(iommu_group);
put_device(&group->dev);
}
/*
* Device objects - create, release, get, put, search
*/
/* Device reference always implies a group reference */
static void vfio_device_put_registration(struct vfio_device *device)
void vfio_device_put_registration(struct vfio_device *device)
{
if (refcount_dec_and_test(&device->refcount))
complete(&device->comp);
}
static bool vfio_device_try_get_registration(struct vfio_device *device)
bool vfio_device_try_get_registration(struct vfio_device *device)
{
return refcount_inc_not_zero(&device->refcount);
}
@ -413,139 +254,6 @@ void vfio_free_device(struct vfio_device *device)
}
EXPORT_SYMBOL_GPL(vfio_free_device);
static struct vfio_group *vfio_noiommu_group_alloc(struct device *dev,
enum vfio_group_type type)
{
struct iommu_group *iommu_group;
struct vfio_group *group;
int ret;
iommu_group = iommu_group_alloc();
if (IS_ERR(iommu_group))
return ERR_CAST(iommu_group);
ret = iommu_group_set_name(iommu_group, "vfio-noiommu");
if (ret)
goto out_put_group;
ret = iommu_group_add_device(iommu_group, dev);
if (ret)
goto out_put_group;
mutex_lock(&vfio.group_lock);
group = vfio_create_group(iommu_group, type);
mutex_unlock(&vfio.group_lock);
if (IS_ERR(group)) {
ret = PTR_ERR(group);
goto out_remove_device;
}
iommu_group_put(iommu_group);
return group;
out_remove_device:
iommu_group_remove_device(dev);
out_put_group:
iommu_group_put(iommu_group);
return ERR_PTR(ret);
}
static bool vfio_group_has_device(struct vfio_group *group, struct device *dev)
{
struct vfio_device *device;
mutex_lock(&group->device_lock);
list_for_each_entry(device, &group->device_list, group_next) {
if (device->dev == dev) {
mutex_unlock(&group->device_lock);
return true;
}
}
mutex_unlock(&group->device_lock);
return false;
}
static struct vfio_group *vfio_group_find_or_alloc(struct device *dev)
{
struct iommu_group *iommu_group;
struct vfio_group *group;
iommu_group = iommu_group_get(dev);
if (!iommu_group && vfio_noiommu) {
/*
* With noiommu enabled, create an IOMMU group for devices that
* don't already have one, implying no IOMMU hardware/driver
* exists. Taint the kernel because we're about to give a DMA
* capable device to a user without IOMMU protection.
*/
group = vfio_noiommu_group_alloc(dev, VFIO_NO_IOMMU);
if (!IS_ERR(group)) {
add_taint(TAINT_USER, LOCKDEP_STILL_OK);
dev_warn(dev, "Adding kernel taint for vfio-noiommu group on device\n");
}
return group;
}
if (!iommu_group)
return ERR_PTR(-EINVAL);
/*
* VFIO always sets IOMMU_CACHE because we offer no way for userspace to
* restore cache coherency. It has to be checked here because it is only
* valid for cases where we are using iommu groups.
*/
if (!device_iommu_capable(dev, IOMMU_CAP_CACHE_COHERENCY)) {
iommu_group_put(iommu_group);
return ERR_PTR(-EINVAL);
}
mutex_lock(&vfio.group_lock);
group = vfio_group_find_from_iommu(iommu_group);
if (group) {
if (WARN_ON(vfio_group_has_device(group, dev)))
group = ERR_PTR(-EINVAL);
else
refcount_inc(&group->drivers);
} else {
group = vfio_create_group(iommu_group, VFIO_IOMMU);
}
mutex_unlock(&vfio.group_lock);
/* The vfio_group holds a reference to the iommu_group */
iommu_group_put(iommu_group);
return group;
}
static void vfio_device_group_register(struct vfio_device *device)
{
mutex_lock(&device->group->device_lock);
list_add(&device->group_next, &device->group->device_list);
mutex_unlock(&device->group->device_lock);
}
static void vfio_device_group_unregister(struct vfio_device *device)
{
mutex_lock(&device->group->device_lock);
list_del(&device->group_next);
mutex_unlock(&device->group->device_lock);
}
static int vfio_device_set_group(struct vfio_device *device,
enum vfio_group_type type)
{
struct vfio_group *group;
if (type == VFIO_IOMMU)
group = vfio_group_find_or_alloc(device->dev);
else
group = vfio_noiommu_group_alloc(device->dev, type);
if (IS_ERR(group))
return PTR_ERR(group);
/* Our reference on group is moved to the device */
device->group = group;
return 0;
}
static int __vfio_register_dev(struct vfio_device *device,
enum vfio_group_type type)
{
@ -602,35 +310,6 @@ int vfio_register_emulated_iommu_dev(struct vfio_device *device)
}
EXPORT_SYMBOL_GPL(vfio_register_emulated_iommu_dev);
static struct vfio_device *vfio_device_get_from_name(struct vfio_group *group,
char *buf)
{
struct vfio_device *it, *device = ERR_PTR(-ENODEV);
mutex_lock(&group->device_lock);
list_for_each_entry(it, &group->device_list, group_next) {
int ret;
if (it->ops->match) {
ret = it->ops->match(it, buf);
if (ret < 0) {
device = ERR_PTR(ret);
break;
}
} else {
ret = !strcmp(dev_name(it->dev), buf);
}
if (ret && vfio_device_try_get_registration(it)) {
device = it;
break;
}
}
mutex_unlock(&group->device_lock);
return device;
}
/*
* Decrement the device reference count and wait for the device to be
* removed. Open file descriptors for the device... */
@ -673,146 +352,12 @@ void vfio_unregister_group_dev(struct vfio_device *device)
}
EXPORT_SYMBOL_GPL(vfio_unregister_group_dev);
/*
* VFIO Group fd, /dev/vfio/$GROUP
*/
static bool vfio_group_has_iommu(struct vfio_group *group)
{
lockdep_assert_held(&group->group_lock);
/*
* There can only be users if there is a container, and if there is a
* container there must be users.
*/
WARN_ON(!group->container != !group->container_users);
return group->container || group->iommufd;
}
/*
* VFIO_GROUP_UNSET_CONTAINER should fail if there are other users or
* if there was no container to unset. Since the ioctl is called on
* the group, we know that still exists, therefore the only valid
* transition here is 1->0.
*/
static int vfio_group_ioctl_unset_container(struct vfio_group *group)
{
int ret = 0;
mutex_lock(&group->group_lock);
if (!vfio_group_has_iommu(group)) {
ret = -EINVAL;
goto out_unlock;
}
if (group->container) {
if (group->container_users != 1) {
ret = -EBUSY;
goto out_unlock;
}
vfio_group_detach_container(group);
}
if (group->iommufd) {
iommufd_ctx_put(group->iommufd);
group->iommufd = NULL;
}
out_unlock:
mutex_unlock(&group->group_lock);
return ret;
}
static int vfio_group_ioctl_set_container(struct vfio_group *group,
int __user *arg)
{
struct vfio_container *container;
struct iommufd_ctx *iommufd;
struct fd f;
int ret;
int fd;
if (get_user(fd, arg))
return -EFAULT;
f = fdget(fd);
if (!f.file)
return -EBADF;
mutex_lock(&group->group_lock);
if (vfio_group_has_iommu(group)) {
ret = -EINVAL;
goto out_unlock;
}
if (!group->iommu_group) {
ret = -ENODEV;
goto out_unlock;
}
container = vfio_container_from_file(f.file);
if (container) {
ret = vfio_container_attach_group(container, group);
goto out_unlock;
}
iommufd = iommufd_ctx_from_file(f.file);
if (!IS_ERR(iommufd)) {
u32 ioas_id;
ret = iommufd_vfio_compat_ioas_id(iommufd, &ioas_id);
if (ret) {
iommufd_ctx_put(group->iommufd);
goto out_unlock;
}
group->iommufd = iommufd;
goto out_unlock;
}
/* The FD passed is not recognized. */
ret = -EBADFD;
out_unlock:
mutex_unlock(&group->group_lock);
fdput(f);
return ret;
}
static const struct file_operations vfio_device_fops;
/* true if the vfio_device has open_device() called but not close_device() */
static bool vfio_assert_device_open(struct vfio_device *device)
{
return !WARN_ON_ONCE(!READ_ONCE(device->open_count));
}
static int vfio_device_group_use_iommu(struct vfio_device *device)
{
struct vfio_group *group = device->group;
int ret = 0;
lockdep_assert_held(&group->group_lock);
if (WARN_ON(!group->container))
return -EINVAL;
ret = vfio_group_use_container(group);
if (ret)
return ret;
vfio_device_container_register(device);
return 0;
}
static void vfio_device_group_unuse_iommu(struct vfio_device *device)
{
struct vfio_group *group = device->group;
lockdep_assert_held(&group->group_lock);
if (WARN_ON(!group->container))
return;
vfio_device_container_unregister(device);
vfio_group_unuse_container(group);
}
static int vfio_device_first_open(struct vfio_device *device,
struct iommufd_ctx *iommufd, struct kvm *kvm)
{
@ -864,8 +409,8 @@ static void vfio_device_last_close(struct vfio_device *device,
module_put(device->dev->driver->owner);
}
static int vfio_device_open(struct vfio_device *device,
struct iommufd_ctx *iommufd, struct kvm *kvm)
int vfio_device_open(struct vfio_device *device,
struct iommufd_ctx *iommufd, struct kvm *kvm)
{
int ret = 0;
@ -881,8 +426,8 @@ static int vfio_device_open(struct vfio_device *device,
return ret;
}
static void vfio_device_close(struct vfio_device *device,
struct iommufd_ctx *iommufd)
void vfio_device_close(struct vfio_device *device,
struct iommufd_ctx *iommufd)
{
mutex_lock(&device->dev_set->lock);
vfio_assert_device_open(device);
@ -892,245 +437,6 @@ static void vfio_device_close(struct vfio_device *device,
mutex_unlock(&device->dev_set->lock);
}
static int vfio_device_group_open(struct vfio_device *device)
{
int ret;
mutex_lock(&device->group->group_lock);
if (!vfio_group_has_iommu(device->group)) {
ret = -EINVAL;
goto out_unlock;
}
/*
* Here we pass the KVM pointer with the group under the lock. If the
* device driver will use it, it must obtain a reference and release it
* during close_device.
*/
ret = vfio_device_open(device, device->group->iommufd,
device->group->kvm);
out_unlock:
mutex_unlock(&device->group->group_lock);
return ret;
}
static void vfio_device_group_close(struct vfio_device *device)
{
mutex_lock(&device->group->group_lock);
vfio_device_close(device, device->group->iommufd);
mutex_unlock(&device->group->group_lock);
}
static struct file *vfio_device_open_file(struct vfio_device *device)
{
struct file *filep;
int ret;
ret = vfio_device_group_open(device);
if (ret)
goto err_out;
/*
* We can't use anon_inode_getfd() because we need to modify
* the f_mode flags directly to allow more than just ioctls
*/
filep = anon_inode_getfile("[vfio-device]", &vfio_device_fops,
device, O_RDWR);
if (IS_ERR(filep)) {
ret = PTR_ERR(filep);
goto err_close_device;
}
/*
* TODO: add an anon_inode interface to do this.
* Appears to be missing by lack of need rather than
* explicitly prevented. Now there's need.
*/
filep->f_mode |= (FMODE_PREAD | FMODE_PWRITE);
if (device->group->type == VFIO_NO_IOMMU)
dev_warn(device->dev, "vfio-noiommu device opened by user "
"(%s:%d)\n", current->comm, task_pid_nr(current));
/*
* On success the ref of device is moved to the file and
* put in vfio_device_fops_release()
*/
return filep;
err_close_device:
vfio_device_group_close(device);
err_out:
return ERR_PTR(ret);
}
static int vfio_group_ioctl_get_device_fd(struct vfio_group *group,
char __user *arg)
{
struct vfio_device *device;
struct file *filep;
char *buf;
int fdno;
int ret;
buf = strndup_user(arg, PAGE_SIZE);
if (IS_ERR(buf))
return PTR_ERR(buf);
device = vfio_device_get_from_name(group, buf);
kfree(buf);
if (IS_ERR(device))
return PTR_ERR(device);
fdno = get_unused_fd_flags(O_CLOEXEC);
if (fdno < 0) {
ret = fdno;
goto err_put_device;
}
filep = vfio_device_open_file(device);
if (IS_ERR(filep)) {
ret = PTR_ERR(filep);
goto err_put_fdno;
}
fd_install(fdno, filep);
return fdno;
err_put_fdno:
put_unused_fd(fdno);
err_put_device:
vfio_device_put_registration(device);
return ret;
}
static int vfio_group_ioctl_get_status(struct vfio_group *group,
struct vfio_group_status __user *arg)
{
unsigned long minsz = offsetofend(struct vfio_group_status, flags);
struct vfio_group_status status;
if (copy_from_user(&status, arg, minsz))
return -EFAULT;
if (status.argsz < minsz)
return -EINVAL;
status.flags = 0;
mutex_lock(&group->group_lock);
if (!group->iommu_group) {
mutex_unlock(&group->group_lock);
return -ENODEV;
}
/*
* With the container FD the iommu_group_claim_dma_owner() is done
* during SET_CONTAINER but for IOMMFD this is done during
* VFIO_GROUP_GET_DEVICE_FD. Meaning that with iommufd
* VFIO_GROUP_FLAGS_VIABLE could be set but GET_DEVICE_FD will fail due
* to viability.
*/
if (vfio_group_has_iommu(group))
status.flags |= VFIO_GROUP_FLAGS_CONTAINER_SET |
VFIO_GROUP_FLAGS_VIABLE;
else if (!iommu_group_dma_owner_claimed(group->iommu_group))
status.flags |= VFIO_GROUP_FLAGS_VIABLE;
mutex_unlock(&group->group_lock);
if (copy_to_user(arg, &status, minsz))
return -EFAULT;
return 0;
}
static long vfio_group_fops_unl_ioctl(struct file *filep,
unsigned int cmd, unsigned long arg)
{
struct vfio_group *group = filep->private_data;
void __user *uarg = (void __user *)arg;
switch (cmd) {
case VFIO_GROUP_GET_DEVICE_FD:
return vfio_group_ioctl_get_device_fd(group, uarg);
case VFIO_GROUP_GET_STATUS:
return vfio_group_ioctl_get_status(group, uarg);
case VFIO_GROUP_SET_CONTAINER:
return vfio_group_ioctl_set_container(group, uarg);
case VFIO_GROUP_UNSET_CONTAINER:
return vfio_group_ioctl_unset_container(group);
default:
return -ENOTTY;
}
}
static int vfio_group_fops_open(struct inode *inode, struct file *filep)
{
struct vfio_group *group =
container_of(inode->i_cdev, struct vfio_group, cdev);
int ret;
mutex_lock(&group->group_lock);
/*
* drivers can be zero if this races with vfio_device_remove_group(), it
* will be stable at 0 under the group rwsem
*/
if (refcount_read(&group->drivers) == 0) {
ret = -ENODEV;
goto out_unlock;
}
if (group->type == VFIO_NO_IOMMU && !capable(CAP_SYS_RAWIO)) {
ret = -EPERM;
goto out_unlock;
}
/*
* Do we need multiple instances of the group open? Seems not.
*/
if (group->opened_file) {
ret = -EBUSY;
goto out_unlock;
}
group->opened_file = filep;
filep->private_data = group;
ret = 0;
out_unlock:
mutex_unlock(&group->group_lock);
return ret;
}
static int vfio_group_fops_release(struct inode *inode, struct file *filep)
{
struct vfio_group *group = filep->private_data;
filep->private_data = NULL;
mutex_lock(&group->group_lock);
/*
* Device FDs hold a group file reference, therefore the group release
* is only called when there are no open devices.
*/
WARN_ON(group->notifier.head);
if (group->container)
vfio_group_detach_container(group);
if (group->iommufd) {
iommufd_ctx_put(group->iommufd);
group->iommufd = NULL;
}
group->opened_file = NULL;
mutex_unlock(&group->group_lock);
return 0;
}
static const struct file_operations vfio_group_fops = {
.owner = THIS_MODULE,
.unlocked_ioctl = vfio_group_fops_unl_ioctl,
.compat_ioctl = compat_ptr_ioctl,
.open = vfio_group_fops_open,
.release = vfio_group_fops_release,
};
/*
* Wrapper around pm_runtime_resume_and_get().
* Return error code on failure or 0 on success.
@ -1694,7 +1000,7 @@ static int vfio_device_fops_mmap(struct file *filep, struct vm_area_struct *vma)
return device->ops->mmap(device, vma);
}
static const struct file_operations vfio_device_fops = {
const struct file_operations vfio_device_fops = {
.owner = THIS_MODULE,
.release = vfio_device_fops_release,
.read = vfio_device_fops_read,
@ -1704,121 +1010,6 @@ static const struct file_operations vfio_device_fops = {
.mmap = vfio_device_fops_mmap,
};
/**
* vfio_file_iommu_group - Return the struct iommu_group for the vfio group file
* @file: VFIO group file
*
* The returned iommu_group is valid as long as a ref is held on the file. This
* returns a reference on the group. This function is deprecated, only the SPAPR
* path in kvm should call it.
*/
struct iommu_group *vfio_file_iommu_group(struct file *file)
{
struct vfio_group *group = file->private_data;
struct iommu_group *iommu_group = NULL;
if (!IS_ENABLED(CONFIG_SPAPR_TCE_IOMMU))
return NULL;
if (!vfio_file_is_group(file))
return NULL;
mutex_lock(&group->group_lock);
if (group->iommu_group) {
iommu_group = group->iommu_group;
iommu_group_ref_get(iommu_group);
}
mutex_unlock(&group->group_lock);
return iommu_group;
}
EXPORT_SYMBOL_GPL(vfio_file_iommu_group);
/**
* vfio_file_is_group - True if the file is usable with VFIO aPIS
* @file: VFIO group file
*/
bool vfio_file_is_group(struct file *file)
{
return file->f_op == &vfio_group_fops;
}
EXPORT_SYMBOL_GPL(vfio_file_is_group);
/**
* vfio_file_enforced_coherent - True if the DMA associated with the VFIO file
* is always CPU cache coherent
* @file: VFIO group file
*
* Enforced coherency means that the IOMMU ignores things like the PCIe no-snoop
* bit in DMA transactions. A return of false indicates that the user has
* rights to access additional instructions such as wbinvd on x86.
*/
bool vfio_file_enforced_coherent(struct file *file)
{
struct vfio_group *group = file->private_data;
struct vfio_device *device;
bool ret = true;
if (!vfio_file_is_group(file))
return true;
/*
* If the device does not have IOMMU_CAP_ENFORCE_CACHE_COHERENCY then
* any domain later attached to it will also not support it. If the cap
* is set then the iommu_domain eventually attached to the device/group
* must use a domain with enforce_cache_coherency().
*/
mutex_lock(&group->device_lock);
list_for_each_entry(device, &group->device_list, group_next) {
if (!device_iommu_capable(device->dev,
IOMMU_CAP_ENFORCE_CACHE_COHERENCY)) {
ret = false;
break;
}
}
mutex_unlock(&group->device_lock);
return ret;
}
EXPORT_SYMBOL_GPL(vfio_file_enforced_coherent);
/**
* vfio_file_set_kvm - Link a kvm with VFIO drivers
* @file: VFIO group file
* @kvm: KVM to link
*
* When a VFIO device is first opened the KVM will be available in
* device->kvm if one was associated with the group.
*/
void vfio_file_set_kvm(struct file *file, struct kvm *kvm)
{
struct vfio_group *group = file->private_data;
if (!vfio_file_is_group(file))
return;
mutex_lock(&group->group_lock);
group->kvm = kvm;
mutex_unlock(&group->group_lock);
}
EXPORT_SYMBOL_GPL(vfio_file_set_kvm);
/**
* vfio_file_has_dev - True if the VFIO file is a handle for device
* @file: VFIO file to check
* @device: Device that must be part of the file
*
* Returns true if given file has permission to manipulate the given device.
*/
bool vfio_file_has_dev(struct file *file, struct vfio_device *device)
{
struct vfio_group *group = file->private_data;
if (!vfio_file_is_group(file))
return false;
return group == device->group;
}
EXPORT_SYMBOL_GPL(vfio_file_has_dev);
/*
* Sub-module support
*/
@ -1938,11 +1129,6 @@ int vfio_set_irqs_validate_and_prepare(struct vfio_irq_set *hdr, int num_irqs,
}
EXPORT_SYMBOL(vfio_set_irqs_validate_and_prepare);
static bool vfio_device_has_container(struct vfio_device *device)
{
return device->group->container;
}
/*
* Pin contiguous user pages and return their associated host pages for local
* domain only.
@ -2064,55 +1250,6 @@ EXPORT_SYMBOL(vfio_dma_rw);
/*
* Module/class support
*/
static char *vfio_devnode(struct device *dev, umode_t *mode)
{
return kasprintf(GFP_KERNEL, "vfio/%s", dev_name(dev));
}
static int __init vfio_group_init(void)
{
int ret;
ida_init(&vfio.group_ida);
mutex_init(&vfio.group_lock);
INIT_LIST_HEAD(&vfio.group_list);
ret = vfio_container_init();
if (ret)
return ret;
/* /dev/vfio/$GROUP */
vfio.class = class_create(THIS_MODULE, "vfio");
if (IS_ERR(vfio.class)) {
ret = PTR_ERR(vfio.class);
goto err_group_class;
}
vfio.class->devnode = vfio_devnode;
ret = alloc_chrdev_region(&vfio.group_devt, 0, MINORMASK + 1, "vfio");
if (ret)
goto err_alloc_chrdev;
return 0;
err_alloc_chrdev:
class_destroy(vfio.class);
vfio.class = NULL;
err_group_class:
vfio_container_cleanup();
return ret;
}
static void vfio_group_cleanup(void)
{
WARN_ON(!list_empty(&vfio.group_list));
ida_destroy(&vfio.group_ida);
unregister_chrdev_region(vfio.group_devt, MINORMASK + 1);
class_destroy(vfio.class);
vfio.class = NULL;
vfio_container_cleanup();
}
static int __init vfio_init(void)
{
int ret;