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authorJason Gunthorpe <jgg@nvidia.com>2025-11-04 14:11:49 -0400
committerJason Gunthorpe <jgg@nvidia.com>2025-11-05 15:11:26 -0400
commitafb47765f9235181fddc61c8633b5a8cfae29fd2 (patch)
treee8f71de2f20dad6559344fd1df5d69279d7b3acb
parentb09ed52db1e688eb8205b1939ca1345179ecd515 (diff)
iommufd: Make vfio_compat's unmap succeed if the range is already empty
iommufd returns ENOENT when attempting to unmap a range that is already empty, while vfio type1 returns success. Fix vfio_compat to match. Fixes: d624d6652a65 ("iommufd: vfio container FD ioctl compatibility") Link: https://patch.msgid.link/r/0-v1-76be45eff0be+5d-iommufd_unmap_compat_jgg@nvidia.com Reviewed-by: Nicolin Chen <nicolinc@nvidia.com> Reviewed-by: Alex Mastro <amastro@fb.com> Reported-by: Alex Mastro <amastro@fb.com> Closes: https://lore.kernel.org/r/aP0S5ZF9l3sWkJ1G@devgpu012.nha5.facebook.com Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
-rw-r--r--drivers/iommu/iommufd/io_pagetable.c12
-rw-r--r--drivers/iommu/iommufd/ioas.c4
-rw-r--r--tools/testing/selftests/iommu/iommufd.c2
3 files changed, 9 insertions, 9 deletions
diff --git a/drivers/iommu/iommufd/io_pagetable.c b/drivers/iommu/iommufd/io_pagetable.c
index c0360c450880..75d60f2ad900 100644
--- a/drivers/iommu/iommufd/io_pagetable.c
+++ b/drivers/iommu/iommufd/io_pagetable.c
@@ -707,7 +707,8 @@ static int iopt_unmap_iova_range(struct io_pagetable *iopt, unsigned long start,
struct iopt_area *area;
unsigned long unmapped_bytes = 0;
unsigned int tries = 0;
- int rc = -ENOENT;
+ /* If there are no mapped entries then success */
+ int rc = 0;
/*
* The domains_rwsem must be held in read mode any time any area->pages
@@ -777,8 +778,6 @@ again:
down_write(&iopt->iova_rwsem);
}
- if (unmapped_bytes)
- rc = 0;
out_unlock_iova:
up_write(&iopt->iova_rwsem);
@@ -815,13 +814,8 @@ int iopt_unmap_iova(struct io_pagetable *iopt, unsigned long iova,
int iopt_unmap_all(struct io_pagetable *iopt, unsigned long *unmapped)
{
- int rc;
-
- rc = iopt_unmap_iova_range(iopt, 0, ULONG_MAX, unmapped);
/* If the IOVAs are empty then unmap all succeeds */
- if (rc == -ENOENT)
- return 0;
- return rc;
+ return iopt_unmap_iova_range(iopt, 0, ULONG_MAX, unmapped);
}
/* The caller must always free all the nodes in the allowed_iova rb_root. */
diff --git a/drivers/iommu/iommufd/ioas.c b/drivers/iommu/iommufd/ioas.c
index 1542c5fd10a8..459a7c516915 100644
--- a/drivers/iommu/iommufd/ioas.c
+++ b/drivers/iommu/iommufd/ioas.c
@@ -367,6 +367,10 @@ int iommufd_ioas_unmap(struct iommufd_ucmd *ucmd)
&unmapped);
if (rc)
goto out_put;
+ if (!unmapped) {
+ rc = -ENOENT;
+ goto out_put;
+ }
}
cmd->length = unmapped;
diff --git a/tools/testing/selftests/iommu/iommufd.c b/tools/testing/selftests/iommu/iommufd.c
index 3eebf5e3b974..bb4d33dde3c8 100644
--- a/tools/testing/selftests/iommu/iommufd.c
+++ b/tools/testing/selftests/iommu/iommufd.c
@@ -2638,6 +2638,8 @@ TEST_F(vfio_compat_mock_domain, map)
ASSERT_EQ(0, ioctl(self->fd, VFIO_IOMMU_MAP_DMA, &map_cmd));
ASSERT_EQ(0, ioctl(self->fd, VFIO_IOMMU_UNMAP_DMA, &unmap_cmd));
ASSERT_EQ(BUFFER_SIZE, unmap_cmd.size);
+ /* Unmap of empty is success */
+ ASSERT_EQ(0, ioctl(self->fd, VFIO_IOMMU_UNMAP_DMA, &unmap_cmd));
/* UNMAP_FLAG_ALL requires 0 iova/size */
ASSERT_EQ(0, ioctl(self->fd, VFIO_IOMMU_MAP_DMA, &map_cmd));