6.15-stable review patch. If anyone has any objections, please let me know.
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From: Jacob Pan jacob.pan@linux.microsoft.com
[ Upstream commit b25e271b377999191b12f0afbe1861edcf57e3fe ]
For devices with no-iommu enabled in IOMMUFD VFIO compat mode, the group open path skips vfio_df_open(), leaving open_count at 0. This causes a warning in vfio_assert_device_open(device) when vfio_df_close() is called during group close.
The correct behavior is to skip only the IOMMUFD bind in the device open path for no-iommu devices. Commit 6086efe73498 omitted vfio_df_open(), which was too broad. This patch restores the previous behavior, ensuring the vfio_df_open is called in the group open path.
Fixes: 6086efe73498 ("vfio-iommufd: Move noiommu compat validation out of vfio_iommufd_bind()") Suggested-by: Alex Williamson alex.williamson@redhat.com Suggested-by: Jason Gunthorpe jgg@nvidia.com Signed-off-by: Jacob Pan jacob.pan@linux.microsoft.com Reviewed-by: Jason Gunthorpe jgg@nvidia.com Link: https://lore.kernel.org/r/20250618234618.1910456-1-jacob.pan@linux.microsoft... Signed-off-by: Alex Williamson alex.williamson@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/vfio/group.c | 7 +++---- drivers/vfio/iommufd.c | 4 ++++ 2 files changed, 7 insertions(+), 4 deletions(-)
diff --git a/drivers/vfio/group.c b/drivers/vfio/group.c index c321d442f0da..c376a6279de0 100644 --- a/drivers/vfio/group.c +++ b/drivers/vfio/group.c @@ -192,11 +192,10 @@ static int vfio_df_group_open(struct vfio_device_file *df) * implies they expected translation to exist */ if (!capable(CAP_SYS_RAWIO) || - vfio_iommufd_device_has_compat_ioas(device, df->iommufd)) + vfio_iommufd_device_has_compat_ioas(device, df->iommufd)) { ret = -EPERM; - else - ret = 0; - goto out_put_kvm; + goto out_put_kvm; + } }
ret = vfio_df_open(df); diff --git a/drivers/vfio/iommufd.c b/drivers/vfio/iommufd.c index c8c3a2d53f86..a38d262c6028 100644 --- a/drivers/vfio/iommufd.c +++ b/drivers/vfio/iommufd.c @@ -25,6 +25,10 @@ int vfio_df_iommufd_bind(struct vfio_device_file *df)
lockdep_assert_held(&vdev->dev_set->lock);
+ /* Returns 0 to permit device opening under noiommu mode */ + if (vfio_device_is_noiommu(vdev)) + return 0; + return vdev->ops->bind_iommufd(vdev, ictx, &df->devid); }