Commit e2a4b294 authored by Joao Martins's avatar Joao Martins Committed by Jason Gunthorpe
Browse files

iommufd: Add IOMMU_HWPT_SET_DIRTY_TRACKING 

Every IOMMU driver should be able to implement the needed iommu domain ops
to control dirty tracking.

Connect a hw_pagetable to the IOMMU core dirty tracking ops, specifically
the ability to enable/disable dirty tracking on an IOMMU domain
(hw_pagetable id). To that end add an io_pagetable kernel API to toggle
dirty tracking:

* iopt_set_dirty_tracking(iopt, [domain], state)

The intended caller of this is via the hw_pagetable object that is created.

Internally it will ensure the leftover dirty state is cleared /right
before/ dirty tracking starts. This is also useful for iommu drivers which
may decide that dirty tracking is always-enabled at boot without wanting to
toggle dynamically via corresponding iommu domain op.

Link: https://lore.kernel.org/r/20231024135109.73787-7-joao.m.martins@oracle.com


Signed-off-by: default avatarJoao Martins <joao.m.martins@oracle.com>
Reviewed-by: default avatarJason Gunthorpe <jgg@nvidia.com>
Reviewed-by: default avatarKevin Tian <kevin.tian@intel.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@nvidia.com>
parent 5f9bdbf4

drivers/iommu/iommufd/hw_pagetable.c

+24 −0
Original line number Diff line number Diff line
@@ -196,3 +196,27 @@ int iommufd_hwpt_alloc(struct iommufd_ucmd *ucmd) 
	iommufd_put_object(&idev->obj);

	return rc;

}



int iommufd_hwpt_set_dirty_tracking(struct iommufd_ucmd *ucmd)

{

	struct iommu_hwpt_set_dirty_tracking *cmd = ucmd->cmd;

	struct iommufd_hw_pagetable *hwpt;

	struct iommufd_ioas *ioas;

	int rc = -EOPNOTSUPP;

	bool enable;



	if (cmd->flags & ~IOMMU_HWPT_DIRTY_TRACKING_ENABLE)

		return rc;



	hwpt = iommufd_get_hwpt(ucmd, cmd->hwpt_id);

	if (IS_ERR(hwpt))

		return PTR_ERR(hwpt);



	ioas = hwpt->ioas;

	enable = cmd->flags & IOMMU_HWPT_DIRTY_TRACKING_ENABLE;



	rc = iopt_set_dirty_tracking(&ioas->iopt, hwpt->domain, enable);



	iommufd_put_object(&hwpt->obj);

	return rc;

}

drivers/iommu/iommufd/io_pagetable.c

+54 −0
Original line number Diff line number Diff line
@@ -412,6 +412,60 @@ int iopt_map_user_pages(struct iommufd_ctx *ictx, struct io_pagetable *iopt, 
	return 0;

}



static int iopt_clear_dirty_data(struct io_pagetable *iopt,

				 struct iommu_domain *domain)

{

	const struct iommu_dirty_ops *ops = domain->dirty_ops;

	struct iommu_iotlb_gather gather;

	struct iommu_dirty_bitmap dirty;

	struct iopt_area *area;

	int ret = 0;



	lockdep_assert_held_read(&iopt->iova_rwsem);



	iommu_dirty_bitmap_init(&dirty, NULL, &gather);



	for (area = iopt_area_iter_first(iopt, 0, ULONG_MAX); area;

	     area = iopt_area_iter_next(area, 0, ULONG_MAX)) {

		if (!area->pages)

			continue;



		ret = ops->read_and_clear_dirty(domain, iopt_area_iova(area),

						iopt_area_length(area), 0,

						&dirty);

		if (ret)

			break;

	}



	iommu_iotlb_sync(domain, &gather);

	return ret;

}



int iopt_set_dirty_tracking(struct io_pagetable *iopt,

			    struct iommu_domain *domain, bool enable)

{

	const struct iommu_dirty_ops *ops = domain->dirty_ops;

	int ret = 0;



	if (!ops)

		return -EOPNOTSUPP;



	down_read(&iopt->iova_rwsem);



	/* Clear dirty bits from PTEs to ensure a clean snapshot */

	if (enable) {

		ret = iopt_clear_dirty_data(iopt, domain);

		if (ret)

			goto out_unlock;

	}



	ret = ops->set_dirty_tracking(domain, enable);



out_unlock:

	up_read(&iopt->iova_rwsem);

	return ret;

}



int iopt_get_pages(struct io_pagetable *iopt, unsigned long iova,

		   unsigned long length, struct list_head *pages_list)

{

drivers/iommu/iommufd/iommufd_private.h

+12 −0
Original line number Diff line number Diff line
@@ -8,6 +8,7 @@ 
#include <linux/xarray.h>

#include <linux/refcount.h>

#include <linux/uaccess.h>

#include <uapi/linux/iommufd.h>



struct iommu_domain;

struct iommu_group;
@@ -70,6 +71,9 @@ int iopt_unmap_iova(struct io_pagetable *iopt, unsigned long iova, 
		    unsigned long length, unsigned long *unmapped);

int iopt_unmap_all(struct io_pagetable *iopt, unsigned long *unmapped);



int iopt_set_dirty_tracking(struct io_pagetable *iopt,

			    struct iommu_domain *domain, bool enable);



void iommufd_access_notify_unmap(struct io_pagetable *iopt, unsigned long iova,

				 unsigned long length);

int iopt_table_add_domain(struct io_pagetable *iopt,
@@ -240,6 +244,14 @@ struct iommufd_hw_pagetable { 
	struct list_head hwpt_item;

};



static inline struct iommufd_hw_pagetable *

iommufd_get_hwpt(struct iommufd_ucmd *ucmd, u32 id)

{

	return container_of(iommufd_get_object(ucmd->ictx, id,

					       IOMMUFD_OBJ_HW_PAGETABLE),

			    struct iommufd_hw_pagetable, obj);

}

int iommufd_hwpt_set_dirty_tracking(struct iommufd_ucmd *ucmd);

struct iommufd_hw_pagetable *

iommufd_hw_pagetable_alloc(struct iommufd_ctx *ictx, struct iommufd_ioas *ioas,

			   struct iommufd_device *idev, u32 flags,

drivers/iommu/iommufd/main.c

+3 −0
Original line number Diff line number Diff line
@@ -307,6 +307,7 @@ union ucmd_buffer { 
	struct iommu_destroy destroy;

	struct iommu_hw_info info;

	struct iommu_hwpt_alloc hwpt;

	struct iommu_hwpt_set_dirty_tracking set_dirty_tracking;

	struct iommu_ioas_alloc alloc;

	struct iommu_ioas_allow_iovas allow_iovas;

	struct iommu_ioas_copy ioas_copy;
@@ -342,6 +343,8 @@ static const struct iommufd_ioctl_op iommufd_ioctl_ops[] = { 
		 __reserved),

	IOCTL_OP(IOMMU_HWPT_ALLOC, iommufd_hwpt_alloc, struct iommu_hwpt_alloc,

		 __reserved),

	IOCTL_OP(IOMMU_HWPT_SET_DIRTY_TRACKING, iommufd_hwpt_set_dirty_tracking,

		 struct iommu_hwpt_set_dirty_tracking, __reserved),

	IOCTL_OP(IOMMU_IOAS_ALLOC, iommufd_ioas_alloc_ioctl,

		 struct iommu_ioas_alloc, out_ioas_id),

	IOCTL_OP(IOMMU_IOAS_ALLOW_IOVAS, iommufd_ioas_allow_iovas,

include/uapi/linux/iommufd.h

+28 −0
Original line number Diff line number Diff line
@@ -47,6 +47,7 @@ enum { 
	IOMMUFD_CMD_VFIO_IOAS,

	IOMMUFD_CMD_HWPT_ALLOC,

	IOMMUFD_CMD_GET_HW_INFO,

	IOMMUFD_CMD_HWPT_SET_DIRTY_TRACKING,

};



/**
@@ -453,4 +454,31 @@ struct iommu_hw_info { 
	__u32 __reserved;

};

#define IOMMU_GET_HW_INFO _IO(IOMMUFD_TYPE, IOMMUFD_CMD_GET_HW_INFO)



/*

 * enum iommufd_hwpt_set_dirty_tracking_flags - Flags for steering dirty

 *                                              tracking

 * @IOMMU_HWPT_DIRTY_TRACKING_ENABLE: Enable dirty tracking

 */

enum iommufd_hwpt_set_dirty_tracking_flags {

	IOMMU_HWPT_DIRTY_TRACKING_ENABLE = 1,

};



/**

 * struct iommu_hwpt_set_dirty_tracking - ioctl(IOMMU_HWPT_SET_DIRTY_TRACKING)

 * @size: sizeof(struct iommu_hwpt_set_dirty_tracking)

 * @flags: Combination of enum iommufd_hwpt_set_dirty_tracking_flags

 * @hwpt_id: HW pagetable ID that represents the IOMMU domain

 * @__reserved: Must be 0

 *

 * Toggle dirty tracking on an HW pagetable.

 */

struct iommu_hwpt_set_dirty_tracking {

	__u32 size;

	__u32 flags;

	__u32 hwpt_id;

	__u32 __reserved;

};

#define IOMMU_HWPT_SET_DIRTY_TRACKING _IO(IOMMUFD_TYPE, \

					  IOMMUFD_CMD_HWPT_SET_DIRTY_TRACKING)

#endif