linux/drivers/vfio/iommufd.c
Nicolin Chen c157fd8861 vfio: Support IO page table replacement
Now both the physical path and the emulated path can support an IO page
table replacement. Call iommufd_device_replace/iommufd_access_replace(),
when vdev->iommufd_attached is true.

Also update the VFIO_DEVICE_ATTACH_IOMMUFD_PT kdoc in the uAPI header.

Link: https://lore.kernel.org/r/b5f01956ff161f76aa52c95b0fa1ad6eaca95c4a.1690523699.git.nicolinc@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-07-28 13:31:24 -03:00

248 lines
6.0 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (c) 2021-2022, NVIDIA CORPORATION & AFFILIATES
*/
#include <linux/vfio.h>
#include <linux/iommufd.h>
#include "vfio.h"
MODULE_IMPORT_NS(IOMMUFD);
MODULE_IMPORT_NS(IOMMUFD_VFIO);
bool vfio_iommufd_device_has_compat_ioas(struct vfio_device *vdev,
struct iommufd_ctx *ictx)
{
u32 ioas_id;
return !iommufd_vfio_compat_ioas_get_id(ictx, &ioas_id);
}
int vfio_df_iommufd_bind(struct vfio_device_file *df)
{
struct vfio_device *vdev = df->device;
struct iommufd_ctx *ictx = df->iommufd;
lockdep_assert_held(&vdev->dev_set->lock);
return vdev->ops->bind_iommufd(vdev, ictx, &df->devid);
}
int vfio_iommufd_compat_attach_ioas(struct vfio_device *vdev,
struct iommufd_ctx *ictx)
{
u32 ioas_id;
int ret;
lockdep_assert_held(&vdev->dev_set->lock);
/* compat noiommu does not need to do ioas attach */
if (vfio_device_is_noiommu(vdev))
return 0;
ret = iommufd_vfio_compat_ioas_get_id(ictx, &ioas_id);
if (ret)
return ret;
/* The legacy path has no way to return the selected pt_id */
return vdev->ops->attach_ioas(vdev, &ioas_id);
}
void vfio_df_iommufd_unbind(struct vfio_device_file *df)
{
struct vfio_device *vdev = df->device;
lockdep_assert_held(&vdev->dev_set->lock);
if (vfio_device_is_noiommu(vdev))
return;
if (vdev->ops->unbind_iommufd)
vdev->ops->unbind_iommufd(vdev);
}
struct iommufd_ctx *vfio_iommufd_device_ictx(struct vfio_device *vdev)
{
if (vdev->iommufd_device)
return iommufd_device_to_ictx(vdev->iommufd_device);
return NULL;
}
EXPORT_SYMBOL_GPL(vfio_iommufd_device_ictx);
static int vfio_iommufd_device_id(struct vfio_device *vdev)
{
if (vdev->iommufd_device)
return iommufd_device_to_id(vdev->iommufd_device);
return -EINVAL;
}
/*
* Return devid for a device.
* valid ID for the device that is owned by the ictx
* -ENOENT = device is owned but there is no ID
* -ENODEV or other error = device is not owned
*/
int vfio_iommufd_get_dev_id(struct vfio_device *vdev, struct iommufd_ctx *ictx)
{
struct iommu_group *group;
int devid;
if (vfio_iommufd_device_ictx(vdev) == ictx)
return vfio_iommufd_device_id(vdev);
group = iommu_group_get(vdev->dev);
if (!group)
return -ENODEV;
if (iommufd_ctx_has_group(ictx, group))
devid = -ENOENT;
else
devid = -ENODEV;
iommu_group_put(group);
return devid;
}
EXPORT_SYMBOL_GPL(vfio_iommufd_get_dev_id);
/*
* The physical standard ops mean that the iommufd_device is bound to the
* physical device vdev->dev that was provided to vfio_init_group_dev(). Drivers
* using this ops set should call vfio_register_group_dev()
*/
int vfio_iommufd_physical_bind(struct vfio_device *vdev,
struct iommufd_ctx *ictx, u32 *out_device_id)
{
struct iommufd_device *idev;
idev = iommufd_device_bind(ictx, vdev->dev, out_device_id);
if (IS_ERR(idev))
return PTR_ERR(idev);
vdev->iommufd_device = idev;
return 0;
}
EXPORT_SYMBOL_GPL(vfio_iommufd_physical_bind);
void vfio_iommufd_physical_unbind(struct vfio_device *vdev)
{
lockdep_assert_held(&vdev->dev_set->lock);
if (vdev->iommufd_attached) {
iommufd_device_detach(vdev->iommufd_device);
vdev->iommufd_attached = false;
}
iommufd_device_unbind(vdev->iommufd_device);
vdev->iommufd_device = NULL;
}
EXPORT_SYMBOL_GPL(vfio_iommufd_physical_unbind);
int vfio_iommufd_physical_attach_ioas(struct vfio_device *vdev, u32 *pt_id)
{
int rc;
lockdep_assert_held(&vdev->dev_set->lock);
if (WARN_ON(!vdev->iommufd_device))
return -EINVAL;
if (vdev->iommufd_attached)
rc = iommufd_device_replace(vdev->iommufd_device, pt_id);
else
rc = iommufd_device_attach(vdev->iommufd_device, pt_id);
if (rc)
return rc;
vdev->iommufd_attached = true;
return 0;
}
EXPORT_SYMBOL_GPL(vfio_iommufd_physical_attach_ioas);
void vfio_iommufd_physical_detach_ioas(struct vfio_device *vdev)
{
lockdep_assert_held(&vdev->dev_set->lock);
if (WARN_ON(!vdev->iommufd_device) || !vdev->iommufd_attached)
return;
iommufd_device_detach(vdev->iommufd_device);
vdev->iommufd_attached = false;
}
EXPORT_SYMBOL_GPL(vfio_iommufd_physical_detach_ioas);
/*
* The emulated standard ops mean that vfio_device is going to use the
* "mdev path" and will call vfio_pin_pages()/vfio_dma_rw(). Drivers using this
* ops set should call vfio_register_emulated_iommu_dev(). Drivers that do
* not call vfio_pin_pages()/vfio_dma_rw() have no need to provide dma_unmap.
*/
static void vfio_emulated_unmap(void *data, unsigned long iova,
unsigned long length)
{
struct vfio_device *vdev = data;
if (vdev->ops->dma_unmap)
vdev->ops->dma_unmap(vdev, iova, length);
}
static const struct iommufd_access_ops vfio_user_ops = {
.needs_pin_pages = 1,
.unmap = vfio_emulated_unmap,
};
int vfio_iommufd_emulated_bind(struct vfio_device *vdev,
struct iommufd_ctx *ictx, u32 *out_device_id)
{
struct iommufd_access *user;
lockdep_assert_held(&vdev->dev_set->lock);
user = iommufd_access_create(ictx, &vfio_user_ops, vdev, out_device_id);
if (IS_ERR(user))
return PTR_ERR(user);
vdev->iommufd_access = user;
return 0;
}
EXPORT_SYMBOL_GPL(vfio_iommufd_emulated_bind);
void vfio_iommufd_emulated_unbind(struct vfio_device *vdev)
{
lockdep_assert_held(&vdev->dev_set->lock);
if (vdev->iommufd_access) {
iommufd_access_destroy(vdev->iommufd_access);
vdev->iommufd_attached = false;
vdev->iommufd_access = NULL;
}
}
EXPORT_SYMBOL_GPL(vfio_iommufd_emulated_unbind);
int vfio_iommufd_emulated_attach_ioas(struct vfio_device *vdev, u32 *pt_id)
{
int rc;
lockdep_assert_held(&vdev->dev_set->lock);
if (vdev->iommufd_attached)
rc = iommufd_access_replace(vdev->iommufd_access, *pt_id);
else
rc = iommufd_access_attach(vdev->iommufd_access, *pt_id);
if (rc)
return rc;
vdev->iommufd_attached = true;
return 0;
}
EXPORT_SYMBOL_GPL(vfio_iommufd_emulated_attach_ioas);
void vfio_iommufd_emulated_detach_ioas(struct vfio_device *vdev)
{
lockdep_assert_held(&vdev->dev_set->lock);
if (WARN_ON(!vdev->iommufd_access) ||
!vdev->iommufd_attached)
return;
iommufd_access_detach(vdev->iommufd_access);
vdev->iommufd_attached = false;
}
EXPORT_SYMBOL_GPL(vfio_iommufd_emulated_detach_ioas);