Re: [PATCH v3 0/9] vfio/pci: Add mmap() for DMABUFs

[Pranjal Shrivastava <praan@google.com>]

On Fri, Jun 12, 2026 at 04:11:50PM +0100, Matt Evans wrote:
> Hi Kevin,
> 
> On 12/06/2026 09:27, Tian, Kevin wrote:
> >> From: Matt Evans <matt@ozlabs.org>
> >> Sent: Wednesday, June 10, 2026 11:43 PM
> >>
> > [...]
> >>
> >>  vfio/pci: Support mmap() of a VFIO DMABUF
> >>
> >>    Adds mmap() for a DMABUF fd exported from vfio-pci.
> >>
> >>    It was a goal to keep the VFIO device fd lifetime behaviour
> >>    unchanged with respect to the DMABUFs.  An application can close
> >>    all device fds, and this will revoke/clean up all DMABUFs; no
> >>    mappings or other access can be performed now.  When enabling
> >>    mmap() of the DMABUFs, this means access through the VMA is also
> >>    revoked.  This complicates the fault handler because whilst the
> >>    DMABUF exists, it has no guarantee that the corresponding VFIO
> >>    device is still alive.  Adds synchronisation ensuring the vdev is
> >>    available before vdev->memory_lock is touched; this holds the
> >>    device registration so that even if the buffer has been cleaned up,
> >>    vdev hasn't been freed and so the lock can be safely taken.
> >>
> >>    This commit makes VFIO_PCI_CORE depend on PCI_P2PDMA_CORE
> >> (commit
> >>    1) to bring in (only) the P2PDMA provider code.
> > 
> > the last sentence is stale as the dependency is now added in patch4.
> 
> Right, will fix.
> 
> >>
> >> End
> >> ===
> >>
> >> This is based on VFIO next (e.g. at b9285405c5f6).
> >>
> > 
> > Sashiko failed to apply this series. Is there dependent work in vfio-next?
> > 
> > otherwise getting a Sashiko review is helpful here.
> 
> It _did_ depend on (at least the context of) some fixes in vfio-next.
> Looks like it'll rebase on master now those are merged.  I should've
> re-checked this for v3, oops. :|
> 
> (FWIW, I had Robot Claude Opus 4.8 to review several times up to v3.
> But I agree, Sashiko would be interesting too.  Can it be manually
> triggered with branch guidance?)

I guess relevant steps to run locally are here:
https://github.com/sashiko-dev/sashiko/blob/main/README.md

Additionally, we can try providing a base-commit (which points to a
public commit). 

Thanks,
Praan