Re: [PATCH v13 3/5] dma-buf: add optional get_pci_tph() callback

[email protected] Fri, 31 Jul 2026 21:37:53 +0000
Newsgroups org.kernel.vger.linux-pci,org.freedesktop.lists.dri-devel,org.kernel.vger.kvm
Message-ID <[email protected]>
> Add an optional dma_buf_ops.get_pci_tph callback and a
> DMA-buf importer wrapper, dma_buf_get_pci_tph().
> 
> TPH is PCIe TLP Processing Hint. 8-bit ST and 16-bit Extended ST are
> distinct PCIe TPH namespaces, so the importer requests the namespace it
> can emit and the exporter returns the matching ST/PH tuple or
> -EOPNOTSUPP.
> 
> dma_buf_get_pci_tph() is the importer entry point. It requires
> &dmabuf->resv to be held while the callback runs and returns
> -EOPNOTSUPP when the exporter does not provide PCI TPH metadata.
> 
> The first user is VFIO_DEVICE_FEATURE_DMA_BUF_TPH in vfio-pci, with
> mlx5 as the first importer.
> 
> Signed-off-by: Zhiping Zhang <[email protected]>

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

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