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iommufd: Do not allow creating areas without READ or WRITE

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This results in passing 0 or just IOMMU_CACHE to iommu_map(). Most of
the page table formats don't like this:

  amdv1 - -EINVAL
  armv7s - returns 0, doesn't update mapped
  arm-lpae - returns 0 doesn't update mapped
  dart - returns 0, doesn't update mapped
  VT-D - returns -EINVAL

Unfortunately the three formats that return 0 cause serious problems:

 - Returning ret = but not uppdating mapped from domain->map_pages()
   causes an infinite loop in __iommu_map()

 - Not writing ioptes means that VFIO/iommufd have no way to recover them
   and we will have memory leaks and worse during unmap

Since almost nothing can support this, and it is a useless thing to do,
block it early in iommufd.

Cc: stable@kernel.org
Fixes: aad37e71d5 ("iommufd: IOCTLs for the io_pagetable")
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/1-v1-1211e1294c27+4b1-iommu_no_prot_jgg@nvidia.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
This commit is contained in:
Jason Gunthorpe 2024-08-22 11:45:54 -03:00 committed by Joerg Roedel
parent 7af6c72041
commit 996dc53ac2
2 changed files with 11 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
drivers/iommu/iommufd/ioas.c
View File

@ -213,6 +213,10 @@ int iommufd_ioas_map(struct iommufd_ucmd *ucmd)
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);
@ -253,6 +257,10 @@ int iommufd_ioas_copy(struct iommufd_ucmd *ucmd)
cmd->dst_iova >= ULONG_MAX)
return -EOVERFLOW;
if (!(cmd->flags &
(IOMMU_IOAS_MAP_WRITEABLE | IOMMU_IOAS_MAP_READABLE)))
return -EINVAL;
src_ioas = iommufd_get_ioas(ucmd->ictx, cmd->src_ioas_id);
if (IS_ERR(src_ioas))
return PTR_ERR(src_ioas);

6
tools/testing/selftests/iommu/iommufd.c
View File

@ -825,7 +825,7 @@ TEST_F(iommufd_ioas, copy_area)
{
struct iommu_ioas_copy copy_cmd = {
.size = sizeof(copy_cmd),
.flags = IOMMU_IOAS_MAP_FIXED_IOVA,
.flags = IOMMU_IOAS_MAP_FIXED_IOVA | IOMMU_IOAS_MAP_WRITEABLE,
.dst_ioas_id = self->ioas_id,
.src_ioas_id = self->ioas_id,
.length = PAGE_SIZE,
@ -1318,7 +1318,7 @@ TEST_F(iommufd_ioas, copy_sweep)
{
struct iommu_ioas_copy copy_cmd = {
.size = sizeof(copy_cmd),
.flags = IOMMU_IOAS_MAP_FIXED_IOVA,
.flags = IOMMU_IOAS_MAP_FIXED_IOVA | IOMMU_IOAS_MAP_WRITEABLE,
.src_ioas_id = self->ioas_id,
.dst_iova = MOCK_APERTURE_START,
.length = MOCK_PAGE_SIZE,
@ -1608,7 +1608,7 @@ TEST_F(iommufd_mock_domain, user_copy)
};
struct iommu_ioas_copy copy_cmd = {
.size = sizeof(copy_cmd),
.flags = IOMMU_IOAS_MAP_FIXED_IOVA,
.flags = IOMMU_IOAS_MAP_FIXED_IOVA | IOMMU_IOAS_MAP_WRITEABLE,
.dst_ioas_id = self->ioas_id,
.dst_iova = MOCK_APERTURE_START,
.length = BUFFER_SIZE,