Commit f4986a72 authored by Steve Sistare's avatar Steve Sistare Committed by Jason Gunthorpe
Browse files

iommufd: Add IOMMU_IOAS_MAP_FILE 

Define the IOMMU_IOAS_MAP_FILE ioctl interface, which allows a user to
register memory by passing a memfd plus offset and length.  Implement it
using the memfd_pin_folios() kAPI.

Link: https://patch.msgid.link/r/1729861919-234514-8-git-send-email-steven.sistare@oracle.com


Suggested-by: default avatarJason Gunthorpe <jgg@nvidia.com>
Signed-off-by: default avatarSteve Sistare <steven.sistare@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 92687c79

drivers/iommu/iommufd/io_pagetable.c

+35 −1
Original line number Diff line number Diff line
@@ -268,7 +268,14 @@ static int iopt_alloc_area_pages(struct io_pagetable *iopt, 
		/* Use the first entry to guess the ideal IOVA alignment */

		elm = list_first_entry(pages_list, struct iopt_pages_list,

				       next);

		switch (elm->pages->type) {

		case IOPT_ADDRESS_USER:

			start = elm->start_byte + (uintptr_t)elm->pages->uptr;

			break;

		case IOPT_ADDRESS_FILE:

			start = elm->start_byte + elm->pages->start;

			break;

		}

		rc = iopt_alloc_iova(iopt, dst_iova, start, length);

		if (rc)

			goto out_unlock;
@@ -446,6 +453,33 @@ int iopt_map_user_pages(struct iommufd_ctx *ictx, struct io_pagetable *iopt, 
			       uptr - pages->uptr, iommu_prot, flags);

}



/**

 * iopt_map_file_pages() - Like iopt_map_user_pages, but map a file.

 * @ictx: iommufd_ctx the iopt is part of

 * @iopt: io_pagetable to act on

 * @iova: If IOPT_ALLOC_IOVA is set this is unused on input and contains

 *        the chosen iova on output. Otherwise is the iova to map to on input

 * @file: file to map

 * @start: map file starting at this byte offset

 * @length: Number of bytes to map

 * @iommu_prot: Combination of IOMMU_READ/WRITE/etc bits for the mapping

 * @flags: IOPT_ALLOC_IOVA or zero

 */

int iopt_map_file_pages(struct iommufd_ctx *ictx, struct io_pagetable *iopt,

			unsigned long *iova, struct file *file,

			unsigned long start, unsigned long length,

			int iommu_prot, unsigned int flags)

{

	struct iopt_pages *pages;



	pages = iopt_alloc_file_pages(file, start, length,

				      iommu_prot & IOMMU_WRITE);

	if (IS_ERR(pages))

		return PTR_ERR(pages);

	return iopt_map_common(ictx, iopt, pages, iova, length,

			       start - pages->start, iommu_prot, flags);

}



struct iova_bitmap_fn_arg {

	unsigned long flags;

	struct io_pagetable *iopt;

drivers/iommu/iommufd/io_pagetable.h

+2 −0
Original line number Diff line number Diff line
@@ -220,6 +220,8 @@ struct iopt_pages { 


struct iopt_pages *iopt_alloc_user_pages(void __user *uptr,

					 unsigned long length, bool writable);

struct iopt_pages *iopt_alloc_file_pages(struct file *file, unsigned long start,

					 unsigned long length, bool writable);

void iopt_release_pages(struct kref *kref);

static inline void iopt_put_pages(struct iopt_pages *pages)

{

drivers/iommu/iommufd/ioas.c

+47 −0
Original line number Diff line number Diff line
@@ -2,6 +2,7 @@ 
/*

 * Copyright (c) 2021-2022, NVIDIA CORPORATION & AFFILIATES

 */

#include <linux/file.h>

#include <linux/interval_tree.h>

#include <linux/iommu.h>

#include <linux/iommufd.h>
@@ -197,6 +198,52 @@ static int conv_iommu_prot(u32 map_flags) 
	return iommu_prot;

}



int iommufd_ioas_map_file(struct iommufd_ucmd *ucmd)

{

	struct iommu_ioas_map_file *cmd = ucmd->cmd;

	unsigned long iova = cmd->iova;

	struct iommufd_ioas *ioas;

	unsigned int flags = 0;

	struct file *file;

	int rc;



	if (cmd->flags &

	     ~(IOMMU_IOAS_MAP_FIXED_IOVA | IOMMU_IOAS_MAP_WRITEABLE |

	       IOMMU_IOAS_MAP_READABLE))

		return -EOPNOTSUPP;



	if (cmd->iova >= ULONG_MAX || cmd->length >= ULONG_MAX)

		return -EOVERFLOW;



	if (!(cmd->flags &

	      (IOMMU_IOAS_MAP_WRITEABLE | IOMMU_IOAS_MAP_READABLE)))

		return -EINVAL;



	ioas = iommufd_get_ioas(ucmd->ictx, cmd->ioas_id);

	if (IS_ERR(ioas))

		return PTR_ERR(ioas);



	if (!(cmd->flags & IOMMU_IOAS_MAP_FIXED_IOVA))

		flags = IOPT_ALLOC_IOVA;



	file = fget(cmd->fd);

	if (!file)

		return -EBADF;



	rc = iopt_map_file_pages(ucmd->ictx, &ioas->iopt, &iova, file,

				 cmd->start, cmd->length,

				 conv_iommu_prot(cmd->flags), flags);

	if (rc)

		goto out_put;



	cmd->iova = iova;

	rc = iommufd_ucmd_respond(ucmd, sizeof(*cmd));

out_put:

	iommufd_put_object(ucmd->ictx, &ioas->obj);

	fput(file);

	return rc;

}



int iommufd_ioas_map(struct iommufd_ucmd *ucmd)

{

	struct iommu_ioas_map *cmd = ucmd->cmd;

drivers/iommu/iommufd/iommufd_private.h

+5 −0
Original line number Diff line number Diff line
@@ -69,6 +69,10 @@ int iopt_map_user_pages(struct iommufd_ctx *ictx, struct io_pagetable *iopt, 
			unsigned long *iova, void __user *uptr,

			unsigned long length, int iommu_prot,

			unsigned int flags);

int iopt_map_file_pages(struct iommufd_ctx *ictx, struct io_pagetable *iopt,

			unsigned long *iova, struct file *file,

			unsigned long start, unsigned long length,

			int iommu_prot, unsigned int flags);

int iopt_map_pages(struct io_pagetable *iopt, struct list_head *pages_list,

		   unsigned long length, unsigned long *dst_iova,

		   int iommu_prot, unsigned int flags);
@@ -276,6 +280,7 @@ void iommufd_ioas_destroy(struct iommufd_object *obj); 
int iommufd_ioas_iova_ranges(struct iommufd_ucmd *ucmd);

int iommufd_ioas_allow_iovas(struct iommufd_ucmd *ucmd);

int iommufd_ioas_map(struct iommufd_ucmd *ucmd);

int iommufd_ioas_map_file(struct iommufd_ucmd *ucmd);

int iommufd_ioas_copy(struct iommufd_ucmd *ucmd);

int iommufd_ioas_unmap(struct iommufd_ucmd *ucmd);

int iommufd_ioas_option(struct iommufd_ucmd *ucmd);

drivers/iommu/iommufd/main.c

+2 −0
Original line number Diff line number Diff line
@@ -378,6 +378,8 @@ static const struct iommufd_ioctl_op iommufd_ioctl_ops[] = { 
		 struct iommu_ioas_iova_ranges, out_iova_alignment),

	IOCTL_OP(IOMMU_IOAS_MAP, iommufd_ioas_map, struct iommu_ioas_map,

		 iova),

	IOCTL_OP(IOMMU_IOAS_MAP_FILE, iommufd_ioas_map_file,

		 struct iommu_ioas_map_file, iova),

	IOCTL_OP(IOMMU_IOAS_UNMAP, iommufd_ioas_unmap, struct iommu_ioas_unmap,

		 length),

	IOCTL_OP(IOMMU_OPTION, iommufd_option, struct iommu_option,