From: Jason Gunthorpe <jgg@ziepe.ca>
To: "Christian König" <christian.koenig@amd.com>
Cc: "Leon Romanovsky" <leon@kernel.org>,
"Sumit Semwal" <sumit.semwal@linaro.org>,
"Alex Deucher" <alexander.deucher@amd.com>,
"David Airlie" <airlied@gmail.com>,
"Simona Vetter" <simona@ffwll.ch>,
"Gerd Hoffmann" <kraxel@redhat.com>,
"Dmitry Osipenko" <dmitry.osipenko@collabora.com>,
"Gurchetan Singh" <gurchetansingh@chromium.org>,
"Chia-I Wu" <olvaffe@gmail.com>,
"Maarten Lankhorst" <maarten.lankhorst@linux.intel.com>,
"Maxime Ripard" <mripard@kernel.org>,
"Thomas Zimmermann" <tzimmermann@suse.de>,
"Lucas De Marchi" <lucas.demarchi@intel.com>,
"Thomas Hellström" <thomas.hellstrom@linux.intel.com>,
"Rodrigo Vivi" <rodrigo.vivi@intel.com>,
"Kevin Tian" <kevin.tian@intel.com>,
"Joerg Roedel" <joro@8bytes.org>, "Will Deacon" <will@kernel.org>,
"Robin Murphy" <robin.murphy@arm.com>,
"Felix Kuehling" <Felix.Kuehling@amd.com>,
"Alex Williamson" <alex@shazbot.org>,
"Ankit Agrawal" <ankita@nvidia.com>,
"Vivek Kasireddy" <vivek.kasireddy@intel.com>,
linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org,
linaro-mm-sig@lists.linaro.org, linux-kernel@vger.kernel.org,
amd-gfx@lists.freedesktop.org, virtualization@lists.linux.dev,
intel-xe@lists.freedesktop.org, linux-rdma@vger.kernel.org,
iommu@lists.linux.dev, kvm@vger.kernel.org
Subject: Re: [PATCH v5 4/8] vfio: Wait for dma-buf invalidation to complete
Date: Fri, 30 Jan 2026 09:56:18 -0400 [thread overview]
Message-ID: <20260130135618.GC2328995@ziepe.ca> (raw)
In-Reply-To: <d25bead8-8372-4791-a741-3371342f4698@amd.com>
On Fri, Jan 30, 2026 at 02:21:08PM +0100, Christian König wrote:
> That would work for me.
>
> Question is if you really want to do it this way? See usually
> exporters try to avoid blocking such functions.
Yes, it has to be this way, revoke is a synchronous user space
triggered operation around things like FLR or device close. We can't
defer it into some background operation like pm.
> >>> }
> >>> fput(priv->dmabuf->file);
> >>
> >> This is also extremely questionable. Why doesn't the dmabuf have
> >> a reference while on the linked list?
If we hold a refcount while on the list then the FD can never be
closed.
There is locking protecting the list so that it is safe and close
continues to work right.
Jason
next prev parent reply other threads:[~2026-01-30 13:56 UTC|newest]
Thread overview: 51+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-01-24 19:14 [PATCH v5 0/8] dma-buf: Use revoke mechanism to invalidate shared buffers Leon Romanovsky
2026-01-24 19:14 ` [PATCH v5 1/8] dma-buf: Rename .move_notify() callback to a clearer identifier Leon Romanovsky
2026-01-24 19:14 ` [PATCH v5 2/8] dma-buf: Rename dma_buf_move_notify() to dma_buf_invalidate_mappings() Leon Romanovsky
2026-01-27 9:21 ` Christian König
2026-01-24 19:14 ` [PATCH v5 3/8] dma-buf: Always build with DMABUF_MOVE_NOTIFY Leon Romanovsky
2026-01-27 9:26 ` Christian König
2026-01-27 9:58 ` Leon Romanovsky
2026-01-27 10:02 ` Christian König
2026-01-27 11:42 ` Leon Romanovsky
2026-01-27 20:45 ` Leon Romanovsky
2026-01-30 7:00 ` Leon Romanovsky
2026-01-24 19:14 ` [PATCH v5 4/8] vfio: Wait for dma-buf invalidation to complete Leon Romanovsky
2026-01-26 20:53 ` Pranjal Shrivastava
2026-01-27 8:58 ` Leon Romanovsky
2026-01-27 16:27 ` Jason Gunthorpe
2026-01-29 7:06 ` Tian, Kevin
2026-01-29 7:33 ` Leon Romanovsky
2026-01-29 8:13 ` Tian, Kevin
2026-01-29 8:41 ` Leon Romanovsky
2026-01-29 21:04 ` Alex Williamson
2026-01-30 3:10 ` Tian, Kevin
2026-01-29 14:58 ` Jason Gunthorpe
2026-01-30 3:12 ` Tian, Kevin
2026-01-30 5:43 ` Mauro Carvalho Chehab
2026-01-30 5:48 ` Tian, Kevin
2026-01-30 8:46 ` Christian König
2026-01-30 8:30 ` Christian König
2026-01-30 13:01 ` Leon Romanovsky
2026-01-30 13:21 ` Christian König
2026-01-30 13:31 ` Leon Romanovsky
2026-01-30 13:56 ` Jason Gunthorpe [this message]
2026-01-30 14:11 ` Christian König
2026-01-30 14:44 ` Jason Gunthorpe
2026-02-02 8:42 ` Christian König
2026-02-02 15:12 ` Jason Gunthorpe
2026-02-02 15:21 ` Christian König
2026-02-02 15:55 ` Jason Gunthorpe
2026-01-24 19:14 ` [PATCH v5 5/8] dma-buf: Make .invalidate_mapping() truly optional Leon Romanovsky
2026-01-30 8:30 ` Christian König
2026-01-30 12:55 ` Leon Romanovsky
2026-01-24 19:14 ` [PATCH v5 6/8] dma-buf: Add dma_buf_attach_revocable() Leon Romanovsky
2026-01-26 20:38 ` Pranjal Shrivastava
2026-01-26 21:01 ` Jason Gunthorpe
2026-01-30 8:43 ` Christian König
2026-01-30 14:00 ` Jason Gunthorpe
2026-01-24 19:14 ` [PATCH v5 7/8] vfio: Permit VFIO to work with pinned importers Leon Romanovsky
2026-01-29 21:04 ` Alex Williamson
2026-01-30 3:14 ` Tian, Kevin
2026-01-24 19:14 ` [PATCH v5 8/8] iommufd: Add dma_buf_pin() Leon Romanovsky
2026-01-29 7:08 ` Tian, Kevin
2026-01-30 0:17 ` Jason Gunthorpe
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