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@xxxxxxxxxx
Fixes: aad37e71d5c4 ("iommufd: IOCTLs for the io_pagetable")
Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
---
drivers/iommu/iommufd/ioas.c | 8 ++++++++
tools/testing/selftests/iommu/iommufd.c | 6 +++---
2 files changed, 11 insertions(+), 3 deletions(-)
diff --git a/drivers/iommu/iommufd/ioas.c b/drivers/iommu/iommufd/ioas.c
index 82428e44a837ca..2c4b2bb11e78ce 100644
--- a/drivers/iommu/iommufd/ioas.c
+++ b/drivers/iommu/iommufd/ioas.c
@@ -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);
diff --git a/tools/testing/selftests/iommu/iommufd.c b/tools/testing/selftests/iommu/iommufd.c
index 6343f4053bd46e..4927b9add5add9 100644
--- a/tools/testing/selftests/iommu/iommufd.c
+++ b/tools/testing/selftests/iommu/iommufd.c
@@ -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,
--
2.46.0
