From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 717A3D46950 for ; Wed, 21 Jan 2026 15:46:28 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 1D8B510E822; Wed, 21 Jan 2026 15:46:28 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.b="t97wEG8R"; dkim-atps=neutral Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by gabe.freedesktop.org (Postfix) with ESMTPS id A8B5510E21F; Wed, 21 Jan 2026 15:46:26 +0000 (UTC) Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id C74B2600AA; Wed, 21 Jan 2026 15:46:25 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C79C7C4CEF1; Wed, 21 Jan 2026 15:46:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1769010385; bh=wsp0Ee/Wyi7vSUVwVM1dt7Rh8gLnheehWV+BoZfOvsU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=t97wEG8R3Vclg+HjbADh6Re31LoTY+IEQ//+/mnlWg1SY0DWWznX+wkzufS/8RTPw cFRK4kAf7NSHmPyBgCi82jqY7mcIsr1SPIUA+DfGH+0sVbcGIIjaD3E9NvDWdaGQVx LdTOIbm0sfpJbWGFzlKIoFrPX2a1YPoLdupT/uZEE8P5zTY/Y9osGFW/VyLT82WWgJ TZMQRbM9NUBS2Upq18HxU+6bzyq7clPDWPDeMzkHTDGuxQmBCpWoxQ0JRBZ6ihl7MC pISuKsiX5PxQGXQHWql6x3YzR56jEtvSfhu2oH2477i9lN+U+568UYrW9OFuumSVq0 ES+FsrOJCjoVw== Date: Wed, 21 Jan 2026 17:46:21 +0200 From: Leon Romanovsky To: Jason Gunthorpe , Alex Williamson Cc: Sumit Semwal , Christian =?iso-8859-1?Q?K=F6nig?= , Alex Deucher , David Airlie , Simona Vetter , Gerd Hoffmann , Dmitry Osipenko , Gurchetan Singh , Chia-I Wu , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , Lucas De Marchi , Thomas =?iso-8859-1?Q?Hellstr=F6m?= , Rodrigo Vivi , Kevin Tian , Joerg Roedel , Will Deacon , Robin Murphy , Felix Kuehling , Ankit Agrawal , Vivek Kasireddy , 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 v4 8/8] vfio: Validate dma-buf revocation semantics Message-ID: <20260121154621.GH13201@unreal> References: <20260121-dmabuf-revoke-v4-0-d311cbc8633d@nvidia.com> <20260121-dmabuf-revoke-v4-8-d311cbc8633d@nvidia.com> <20260121134712.GZ961572@ziepe.ca> <20260121144701.GF13201@unreal> <20260121154137.GD961572@ziepe.ca> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260121154137.GD961572@ziepe.ca> X-BeenThere: intel-xe@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel Xe graphics driver List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-xe-bounces@lists.freedesktop.org Sender: "Intel-xe" On Wed, Jan 21, 2026 at 11:41:37AM -0400, Jason Gunthorpe wrote: > On Wed, Jan 21, 2026 at 04:47:01PM +0200, Leon Romanovsky wrote: > > > We need to push an urgent -rc fix to implement a pin function here > > > that always fails. That was missed and it means things like rdma can > > > import vfio when the intention was to block that. It would be bad for > > > that uAPI mistake to reach a released kernel. > > > > I don't see any urgency here. In the current kernel, the RDMA importer > > prints a warning to indicate it was attached to the wrong exporter. > > VFIO also invokes dma_buf_move_notify(). > > The design of vfio was always that it must not work with RDMA because > we cannot tolerate the errors that happen due to ignoring the > move_notify. > > The entire purpose of this series could be stated as continuing to > block RDMA while opening up other pining users. > > So it must be addressed urgently before someone builds an application > relying on this connection. Done, https://lore.kernel.org/all/20260121-vfio-add-pin-v1-1-4e04916b17f1@nvidia.com/T/#u Thanks > > Jason