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

[Tian, Kevin]

> From: Matt Evans <mattev@xxxxxxxx>
> Sent: Thursday, April 16, 2026 2:18 AM
> 
> 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>

Reviewed-by: Kevin Tian <kevin.tian@xxxxxxxxx>