From: Jason Gunthorpe <jgg@nvidia.com>
Date: Fri, 21 Nov 2025 15:51:04 +0000 (-0400)
Subject: iommufd: Have iopt_map_file_pages convert the fd to a file
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=217725f0b2c31d8328fe92b35ae4b38c102a846f;p=thirdparty%2Fkernel%2Fstable.git

iommufd: Have iopt_map_file_pages convert the fd to a file

Since dmabuf only has APIs that work on an int fd and not a struct file *,
pass the fd deeper into the call chain so we can use the dmabuf APIs as
is.

Link: https://patch.msgid.link/r/7-v2-b2c110338e3f+5c2-iommufd_dmabuf_jgg@nvidia.com
Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Shuai Xue <xueshuai@linux.alibaba.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
---

diff --git a/drivers/iommu/iommufd/io_pagetable.c b/drivers/iommu/iommufd/io_pagetable.c
index a120c2ae942a..0bf6ca77888c 100644
--- a/drivers/iommu/iommufd/io_pagetable.c
+++ b/drivers/iommu/iommufd/io_pagetable.c
@@ -10,6 +10,7 @@
  */
 #include <linux/err.h>
 #include <linux/errno.h>
+#include <linux/file.h>
 #include <linux/iommu.h>
 #include <linux/iommufd.h>
 #include <linux/lockdep.h>
@@ -471,21 +472,27 @@ int iopt_map_user_pages(struct iommufd_ctx *ictx, struct io_pagetable *iopt,
  * @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
+ * @fd: fdno of a 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)
+			unsigned long *iova, int fd, unsigned long start,
+			unsigned long length, int iommu_prot,
+			unsigned int flags)
 {
 	struct iopt_pages *pages;
+	struct file *file;
+
+	file = fget(fd);
+	if (!file)
+		return -EBADF;
 
 	pages = iopt_alloc_file_pages(file, start, length,
 				      iommu_prot & IOMMU_WRITE);
+	fput(file);
 	if (IS_ERR(pages))
 		return PTR_ERR(pages);
 	return iopt_map_common(ictx, iopt, pages, iova, length,
diff --git a/drivers/iommu/iommufd/ioas.c b/drivers/iommu/iommufd/ioas.c
index 1542c5fd10a8..0dee38d7252d 100644
--- a/drivers/iommu/iommufd/ioas.c
+++ b/drivers/iommu/iommufd/ioas.c
@@ -207,7 +207,6 @@ int iommufd_ioas_map_file(struct iommufd_ucmd *ucmd)
 	unsigned long iova = cmd->iova;
 	struct iommufd_ioas *ioas;
 	unsigned int flags = 0;
-	struct file *file;
 	int rc;
 
 	if (cmd->flags &
@@ -229,11 +228,7 @@ int iommufd_ioas_map_file(struct iommufd_ucmd *ucmd)
 	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,
+	rc = iopt_map_file_pages(ucmd->ictx, &ioas->iopt, &iova, cmd->fd,
 				 cmd->start, cmd->length,
 				 conv_iommu_prot(cmd->flags), flags);
 	if (rc)
@@ -243,7 +238,6 @@ int iommufd_ioas_map_file(struct iommufd_ucmd *ucmd)
 	rc = iommufd_ucmd_respond(ucmd, sizeof(*cmd));
 out_put:
 	iommufd_put_object(ucmd->ictx, &ioas->obj);
-	fput(file);
 	return rc;
 }
 
diff --git a/drivers/iommu/iommufd/iommufd_private.h b/drivers/iommu/iommufd/iommufd_private.h
index 10ee35103121..a2786fee7603 100644
--- a/drivers/iommu/iommufd/iommufd_private.h
+++ b/drivers/iommu/iommufd/iommufd_private.h
@@ -108,7 +108,7 @@ int iopt_map_user_pages(struct iommufd_ctx *ictx, struct io_pagetable *iopt,
 			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 *iova, int fd,
 			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,