Re: [PATCH 1/2] vfio: Fix unbalanced vfio_df_close call in no-iommu mode

[Jacob Pan <jacob.pan@linux.microsoft.com>]

Hi Jason,

On Mon, 2 Jun 2025 20:49:03 -0300
Jason Gunthorpe <jgg@nvidia.com> wrote:

> On Mon, Jun 02, 2025 at 04:43:18PM -0700, Jacob Pan wrote:
> > For no-iommu enabled devices working under IOMMUFD VFIO compat
> > mode, the group open path does not call vfio_df_open() and the
> > open_count is 0. So calling vfio_df_close() in the group close path
> > will trigger warning in vfio_assert_device_open(device);
> > 
> > E.g. The following warning can be seen by running VFIO test.
> > https://github.com/awilliam/tests/blob/master/vfio-noiommu-pci-device-open.c
> > CONFIG_VFIO_CONTAINER = n
> > [   29.094781] vfio-pci 0000:02:01.0: vfio-noiommu device opened by
> > user (vfio-noiommu-pc:164) Failed to get device info
> > [   29.096540] ------------[ cut here ]------------
> > [   29.096616] WARNING: CPU: 1 PID: 164 at
> > drivers/vfio/vfio_main.c:487 vfio_df_close+0xac/0xb4
> > 
> > This patch adds checks for no-iommu mode and open_count to skip
> > calling vfio_df_close.
> > 
> > Signed-off-by: Jacob Pan <jacob.pan@linux.microsoft.com>
> > ---
> >  drivers/vfio/group.c | 7 ++++---
> >  1 file changed, 4 insertions(+), 3 deletions(-)  
> 
> Did you mean to resend the original version?
my mistake, just sent v2.

Thanks!

Jacob