From: Alex Mastro <amastro@fb.com>
To: Jason Gunthorpe <jgg@nvidia.com>
Cc: "Matt Evans" <mattev@meta.com>,
"Christian König" <christian.koenig@amd.com>,
"Alex Williamson" <alex@shazbot.org>,
"Leon Romanovsky" <leon@kernel.org>,
"Mahmoud Adam" <mngyadam@amazon.de>,
"David Matlack" <dmatlack@google.com>,
"Björn Töpel" <bjorn@kernel.org>,
"Sumit Semwal" <sumit.semwal@linaro.org>,
"Kevin Tian" <kevin.tian@intel.com>,
"Ankit Agrawal" <ankita@nvidia.com>,
"Pranjal Shrivastava" <praan@google.com>,
"Alistair Popple" <apopple@nvidia.com>,
"Vivek Kasireddy" <vivek.kasireddy@intel.com>,
linux-kernel@vger.kernel.org, linux-media@vger.kernel.org,
dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org,
kvm@vger.kernel.org
Subject: Re: [RFC PATCH 3/7] vfio/pci: Support mmap() of a DMABUF
Date: Fri, 27 Feb 2026 13:52:15 -0800 [thread overview]
Message-ID: <aaISD4mw1XzQl1S8@devgpu015.cco6.facebook.com> (raw)
In-Reply-To: <20260227194807.GL5933@nvidia.com>
On Fri, Feb 27, 2026 at 03:48:07PM -0400, Jason Gunthorpe wrote:
> > > I actually would like to go the other way and have VFIO always have a
> > > DMABUF under the VMA's it mmaps because that will make it easy to
> > > finish the type1 emulation which requires finding dmabufs for the
> > > VMAs.
>
> This is a still better idea since it avoid duplicating the VMA flow
> into two parts..
I suppose this would also compose with your idea to use dma-buf for
iommufd_compat support of VFIO_IOMMU_MAP_DMA of vfio device fd-backed mmap()s
[1]? Instead of needing to materialize a new dma-buf, you could use the existing
backing one?
[1] https://lore.kernel.org/all/20260108141044.GC545276@ziepe.ca/
next prev parent reply other threads:[~2026-02-27 21:52 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-02-26 20:21 [RFC PATCH 0/7] vfio/pci: Add mmap() for DMABUFs Matt Evans
2026-02-26 20:21 ` [RFC PATCH 1/7] vfio/pci: Ensure VFIO barmap is set up before creating a DMABUF Matt Evans
2026-02-26 20:21 ` [RFC PATCH 2/7] vfio/pci: Clean up DMABUFs before disabling function Matt Evans
2026-02-26 20:21 ` [RFC PATCH 3/7] vfio/pci: Support mmap() of a DMABUF Matt Evans
2026-02-27 10:09 ` Christian König
2026-02-27 12:51 ` Jason Gunthorpe
2026-02-27 19:42 ` Matt Evans
2026-02-27 19:48 ` Jason Gunthorpe
2026-02-27 21:52 ` Alex Mastro [this message]
2026-02-27 22:00 ` Alex Mastro
2026-02-27 22:04 ` Jason Gunthorpe
2026-03-02 10:07 ` Christian König
2026-03-02 12:54 ` Jason Gunthorpe
2026-03-02 13:20 ` Christian König
2026-02-26 20:22 ` [RFC PATCH 4/7] dma-buf: uapi: Mechanism to revoke DMABUFs via ioctl() Matt Evans
2026-02-27 10:05 ` Christian König
2026-02-27 12:56 ` Jason Gunthorpe
2026-02-27 13:02 ` Matt Evans
2026-02-27 15:20 ` Christian König
2026-02-27 16:19 ` Matt Evans
2026-02-26 20:22 ` [RFC PATCH 5/7] vfio/pci: Permanently revoke a DMABUF on request Matt Evans
2026-02-26 20:22 ` [RFC PATCH 6/7] vfio/pci: Add mmap() attributes to DMABUF feature Matt Evans
2026-02-26 20:22 ` [RFC PATCH 7/7] [RFC ONLY] selftests: vfio: Add standalone vfio_dmabuf_mmap_test Matt Evans
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