linux/drivers/vfio/platform/vfio_platform.c

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// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2013 - Virtual Open Systems
* Author: Antonios Motakis <a.motakis@virtualopensystems.com>
*/
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/vfio.h>
#include <linux/pm_runtime.h>
#include <linux/platform_device.h>
#include "vfio_platform_private.h"
#define DRIVER_VERSION "0.10"
#define DRIVER_AUTHOR "Antonios Motakis <a.motakis@virtualopensystems.com>"
#define DRIVER_DESC "VFIO for platform devices - User Level meta-driver"
static bool reset_required = true;
module_param(reset_required, bool, 0444);
MODULE_PARM_DESC(reset_required, "override reset requirement (default: 1)");
/* probing devices from the linux platform bus */
static struct resource *get_platform_resource(struct vfio_platform_device *vdev,
int num)
{
struct platform_device *dev = (struct platform_device *) vdev->opaque;
return platform_get_mem_or_io(dev, num);
}
static int get_platform_irq(struct vfio_platform_device *vdev, int i)
{
struct platform_device *pdev = (struct platform_device *) vdev->opaque;
return platform_get_irq_optional(pdev, i);
}
static int vfio_platform_init_dev(struct vfio_device *core_vdev)
{
struct vfio_platform_device *vdev =
container_of(core_vdev, struct vfio_platform_device, vdev);
struct platform_device *pdev = to_platform_device(core_vdev->dev);
vdev->opaque = (void *) pdev;
vdev->name = pdev->name;
vdev->flags = VFIO_DEVICE_FLAGS_PLATFORM;
vdev->get_resource = get_platform_resource;
vdev->get_irq = get_platform_irq;
vdev->reset_required = reset_required;
return vfio_platform_init_common(vdev);
}
static const struct vfio_device_ops vfio_platform_ops;
static int vfio_platform_probe(struct platform_device *pdev)
{
struct vfio_platform_device *vdev;
int ret;
vdev = vfio_alloc_device(vfio_platform_device, vdev, &pdev->dev,
&vfio_platform_ops);
if (IS_ERR(vdev))
return PTR_ERR(vdev);
ret = vfio_register_group_dev(&vdev->vdev);
if (ret)
goto out_put_vdev;
pm_runtime_enable(&pdev->dev);
dev_set_drvdata(&pdev->dev, vdev);
return 0;
out_put_vdev:
vfio_put_device(&vdev->vdev);
return ret;
}
static void vfio_platform_release_dev(struct vfio_device *core_vdev)
{
struct vfio_platform_device *vdev =
container_of(core_vdev, struct vfio_platform_device, vdev);
vfio_platform_release_common(vdev);
}
static void vfio_platform_remove(struct platform_device *pdev)
{
struct vfio_platform_device *vdev = dev_get_drvdata(&pdev->dev);
vfio_unregister_group_dev(&vdev->vdev);
pm_runtime_disable(vdev->device);
vfio_put_device(&vdev->vdev);
}
static const struct vfio_device_ops vfio_platform_ops = {
.name = "vfio-platform",
.init = vfio_platform_init_dev,
.release = vfio_platform_release_dev,
.open_device = vfio_platform_open_device,
.close_device = vfio_platform_close_device,
.ioctl = vfio_platform_ioctl,
.read = vfio_platform_read,
.write = vfio_platform_write,
.mmap = vfio_platform_mmap,
.bind_iommufd = vfio_iommufd_physical_bind,
.unbind_iommufd = vfio_iommufd_physical_unbind,
.attach_ioas = vfio_iommufd_physical_attach_ioas,
.detach_ioas = vfio_iommufd_physical_detach_ioas,
};
static struct platform_driver vfio_platform_driver = {
.probe = vfio_platform_probe,
.remove = vfio_platform_remove,
.driver = {
.name = "vfio-platform",
},
vfio: Set DMA ownership for VFIO devices Claim group dma ownership when an IOMMU group is set to a container, and release the dma ownership once the iommu group is unset from the container. This change disallows some unsafe bridge drivers to bind to non-ACS bridges while devices under them are assigned to user space. This is an intentional enhancement and possibly breaks some existing configurations. The recommendation to such an affected user would be that the previously allowed host bridge driver was unsafe for this use case and to continue to enable assignment of devices within that group, the driver should be unbound from the bridge device or replaced with the pci-stub driver. For any bridge driver, we consider it unsafe if it satisfies any of the following conditions: 1) The bridge driver uses DMA. Calling pci_set_master() or calling any kernel DMA API (dma_map_*() and etc.) is an indicate that the driver is doing DMA. 2) If the bridge driver uses MMIO, it should be tolerant to hostile userspace also touching the same MMIO registers via P2P DMA attacks. If the bridge driver turns out to be a safe one, it could be used as before by setting the driver's .driver_managed_dma field, just like what we have done in the pcieport driver. Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Acked-by: Alex Williamson <alex.williamson@redhat.com> Link: https://lore.kernel.org/r/20220418005000.897664-8-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel <jroedel@suse.de>
2022-04-18 00:49:56 +00:00
.driver_managed_dma = true,
};
module_platform_driver(vfio_platform_driver);
MODULE_VERSION(DRIVER_VERSION);
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);