Re: [PATCH v20 03/16] vfio/pci: implement get_pci_tph and DMA_BUF_TPH feature

[sashiko-bot@kernel.org]

> From: Zhiping Zhang <zhipingz@meta.com>
> 
> Implement dma-buf get_pci_tph for vfio-pci exported dma-bufs and add
> VFIO_DEVICE_FEATURE_DMA_BUF_TPH so userspace can publish TPH metadata
> for a VFIO-owned device.
> 
> 8-bit ST and 16-bit Extended ST are distinct PCIe TPH namespaces; the
> uAPI carries both with explicit validity flags, and get_pci_tph()
> returns the value matching the importer's requested namespace or
> -EOPNOTSUPP.
> 
> Publish and read the TPH descriptor under dmabuf->resv, matching the
> locking used for other importer-visible dma-buf state. The SET ioctl
> takes dma_resv_lock_interruptible(), while the callback runs under
> DMA-buf's asserted resv lock.
> [ ... ]
> PCI_EXP_DEVCAP2_TPH_COMP_EXT_TPH. Make PROBE follow the same hardware
> gate so the feature only probes as supported when the device can really
> consume it.
> 
> Signed-off-by: Zhiping Zhang <zhipingz@meta.com>

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

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Sashiko AI review · https://sashiko.dev/#/patchset/20260714104325.54444-1-fengchengwen@huawei.com?part=3