Re: [PATCH v8 5/9] vfio/pci: Add a helper to create a DMABUF for a BAR-map VMA

[sashiko-bot@kernel.org]

> This helper, vfio_pci_core_mmap_prep_dmabuf(), creates a single-range
> DMABUF for the purpose of mapping a PCI BAR.  This is used in a future
> commit by VFIO's ordinary mmap() path.
> 
> This function transfers ownership of the VFIO device fd to the
> DMABUF, which fput()s when it's released.
> 
> Refactor the existing vfio_pci_core_feature_dma_buf() to split out
> export code common to the two paths, VFIO_DEVICE_FEATURE_DMA_BUF and
> this new VFIO_BAR mmap().
> 
> By exchanging the VMA file, we lose the original device path in
> /proc/<pid>/maps, lsof, etc.  Generate a debug-oriented synthetic
> 'filename' for BAR mappings based on the BDF, plus resource index.
> (This does not apply to explicitly-exported DMABUFs which are named by
> DMA_BUF_SET_NAME.)
> 
> Signed-off-by: Matt Evans <matt@ozlabs.org>

Sashiko has reviewed this patch and found no issues. It looks great!

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Sashiko AI review · https://sashiko.dev/#/patchset/20261006193643.76330-1-matt@ozlabs.org?part=5