Commit 29064134 authored by Yi Liu's avatar Yi Liu Committed by Jason Gunthorpe
Browse files

vfio-iommufd: Support pasid [at|de]tach for physical VFIO devices 

This adds pasid_at|de]tach_ioas ops for attaching hwpt to pasid of a
device and the helpers for it. For now, only vfio-pci supports pasid
attach/detach.

Link: https://patch.msgid.link/r/20250321180143.8468-3-yi.l.liu@intel.com


Signed-off-by: default avatarKevin Tian <kevin.tian@intel.com>
Reviewed-by: default avatarJason Gunthorpe <jgg@nvidia.com>
Reviewed-by: default avatarAlex Williamson <alex.williamson@redhat.com>
Tested-by: default avatarNicolin Chen <nicolinc@nvidia.com>
Signed-off-by: default avatarYi Liu <yi.l.liu@intel.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@nvidia.com>
parent 7fe6b987

drivers/vfio/iommufd.c

+50 −0
Original line number Diff line number Diff line
@@ -119,14 +119,22 @@ int vfio_iommufd_physical_bind(struct vfio_device *vdev, 
	if (IS_ERR(idev))

		return PTR_ERR(idev);

	vdev->iommufd_device = idev;

	ida_init(&vdev->pasids);

	return 0;

}

EXPORT_SYMBOL_GPL(vfio_iommufd_physical_bind);



void vfio_iommufd_physical_unbind(struct vfio_device *vdev)

{

	int pasid;



	lockdep_assert_held(&vdev->dev_set->lock);



	while ((pasid = ida_find_first(&vdev->pasids)) >= 0) {

		iommufd_device_detach(vdev->iommufd_device, pasid);

		ida_free(&vdev->pasids, pasid);

	}



	if (vdev->iommufd_attached) {

		iommufd_device_detach(vdev->iommufd_device, IOMMU_NO_PASID);

		vdev->iommufd_attached = false;
@@ -170,6 +178,48 @@ void vfio_iommufd_physical_detach_ioas(struct vfio_device *vdev) 
}

EXPORT_SYMBOL_GPL(vfio_iommufd_physical_detach_ioas);



int vfio_iommufd_physical_pasid_attach_ioas(struct vfio_device *vdev,

					    u32 pasid, u32 *pt_id)

{

	int rc;



	lockdep_assert_held(&vdev->dev_set->lock);



	if (WARN_ON(!vdev->iommufd_device))

		return -EINVAL;



	if (ida_exists(&vdev->pasids, pasid))

		return iommufd_device_replace(vdev->iommufd_device,

					      pasid, pt_id);



	rc = ida_alloc_range(&vdev->pasids, pasid, pasid, GFP_KERNEL);

	if (rc < 0)

		return rc;



	rc = iommufd_device_attach(vdev->iommufd_device, pasid, pt_id);

	if (rc)

		ida_free(&vdev->pasids, pasid);



	return rc;

}

EXPORT_SYMBOL_GPL(vfio_iommufd_physical_pasid_attach_ioas);



void vfio_iommufd_physical_pasid_detach_ioas(struct vfio_device *vdev,

					     u32 pasid)

{

	lockdep_assert_held(&vdev->dev_set->lock);



	if (WARN_ON(!vdev->iommufd_device))

		return;



	if (!ida_exists(&vdev->pasids, pasid))

		return;



	iommufd_device_detach(vdev->iommufd_device, pasid);

	ida_free(&vdev->pasids, pasid);

}

EXPORT_SYMBOL_GPL(vfio_iommufd_physical_pasid_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

drivers/vfio/pci/vfio_pci.c

+2 −0
Original line number Diff line number Diff line
@@ -144,6 +144,8 @@ static const struct vfio_device_ops vfio_pci_ops = { 
	.unbind_iommufd	= vfio_iommufd_physical_unbind,

	.attach_ioas	= vfio_iommufd_physical_attach_ioas,

	.detach_ioas	= vfio_iommufd_physical_detach_ioas,

	.pasid_attach_ioas	= vfio_iommufd_physical_pasid_attach_ioas,

	.pasid_detach_ioas	= vfio_iommufd_physical_pasid_detach_ioas,

};



static int vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)

include/linux/vfio.h

+14 −0
Original line number Diff line number Diff line
@@ -67,6 +67,7 @@ struct vfio_device { 
	struct inode *inode;

#if IS_ENABLED(CONFIG_IOMMUFD)

	struct iommufd_device *iommufd_device;

	struct ida pasids;

	u8 iommufd_attached:1;

#endif

	u8 cdev_opened:1;
@@ -91,6 +92,8 @@ struct vfio_device { 
 *		 bound iommufd. Undo in unbind_iommufd if @detach_ioas is not

 *		 called.

 * @detach_ioas: Opposite of attach_ioas

 * @pasid_attach_ioas: The pasid variation of attach_ioas

 * @pasid_detach_ioas: Opposite of pasid_attach_ioas

 * @open_device: Called when the first file descriptor is opened for this device

 * @close_device: Opposite of open_device

 * @read: Perform read(2) on device file descriptor
@@ -115,6 +118,9 @@ struct vfio_device_ops { 
	void	(*unbind_iommufd)(struct vfio_device *vdev);

	int	(*attach_ioas)(struct vfio_device *vdev, u32 *pt_id);

	void	(*detach_ioas)(struct vfio_device *vdev);

	int	(*pasid_attach_ioas)(struct vfio_device *vdev, u32 pasid,

				     u32 *pt_id);

	void	(*pasid_detach_ioas)(struct vfio_device *vdev, u32 pasid);

	int	(*open_device)(struct vfio_device *vdev);

	void	(*close_device)(struct vfio_device *vdev);

	ssize_t	(*read)(struct vfio_device *vdev, char __user *buf,
@@ -139,6 +145,10 @@ int vfio_iommufd_physical_bind(struct vfio_device *vdev, 
void vfio_iommufd_physical_unbind(struct vfio_device *vdev);

int vfio_iommufd_physical_attach_ioas(struct vfio_device *vdev, u32 *pt_id);

void vfio_iommufd_physical_detach_ioas(struct vfio_device *vdev);

int vfio_iommufd_physical_pasid_attach_ioas(struct vfio_device *vdev,

					    u32 pasid, u32 *pt_id);

void vfio_iommufd_physical_pasid_detach_ioas(struct vfio_device *vdev,

					     u32 pasid);

int vfio_iommufd_emulated_bind(struct vfio_device *vdev,

			       struct iommufd_ctx *ictx, u32 *out_device_id);

void vfio_iommufd_emulated_unbind(struct vfio_device *vdev);
@@ -166,6 +176,10 @@ vfio_iommufd_get_dev_id(struct vfio_device *vdev, struct iommufd_ctx *ictx) 
	((int (*)(struct vfio_device *vdev, u32 *pt_id)) NULL)

#define vfio_iommufd_physical_detach_ioas \

	((void (*)(struct vfio_device *vdev)) NULL)

#define vfio_iommufd_physical_pasid_attach_ioas \

	((int (*)(struct vfio_device *vdev, u32 pasid, u32 *pt_id)) NULL)

#define vfio_iommufd_physical_pasid_detach_ioas \

	((void (*)(struct vfio_device *vdev, u32 pasid)) NULL)

#define vfio_iommufd_emulated_bind                                      \

	((int (*)(struct vfio_device *vdev, struct iommufd_ctx *ictx,   \

		  u32 *out_device_id)) NULL)