Re: [PATCH] vfio/pci: Clean up DMABUFs before disabling function

[Leon Romanovsky]

On Wed, Apr 15, 2026 at 11:17:52AM -0700, Matt Evans wrote:
> On device shutdown, make vfio_pci_core_close_device() call
> vfio_pci_dma_buf_cleanup() before the function is disabled via
> vfio_pci_core_disable().  This ensures that all access via DMABUFs is
> revoked before the function's BARs become inaccessible.
> 
> This fixes an issue where, if the function is disabled first, a tiny
> window exists in which the function's MSE is cleared and yet BARs
> could still be accessed via the DMABUF.  The resources would also be
> freed and up for grabs by a different driver.
> 
> Fixes: 5d74781ebc86c ("vfio/pci: Add dma-buf export support for MMIO regions")
> Signed-off-by: Matt Evans <mattev@xxxxxxxx>
> Reviewed-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
> ---
> 
> Jason,
> 
> Added your R-B from https://lore.kernel.org/kvm/20260330132952.GS310919@xxxxxxxxxx/
> 
> Thanks, Matt
> 
> drivers/vfio/pci/vfio_pci_core.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 

Thanks,
Reviewed-by: Leon Romanovsky <leonro@xxxxxxxxxx>