From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-qv1-f47.google.com (mail-qv1-f47.google.com [209.85.219.47]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B902041C300 for ; Wed, 21 Jan 2026 15:41:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.219.47 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769010101; cv=none; b=aCN2Yer6Ps23jMZqxdPDlT7pv07u27JkbCcq27lMGlsCCzrPHZMHdx4S9k36C10TFcpdVQO1o5FYm1ixg8kXQs5JT8o/eV1M5xlsXIeN8VrET3BgI1fWyJF4uP8hr4NDKWEoVyrjnXN8JuzkKFsV0zLxxpGebwgJeutJJXrMO2Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769010101; c=relaxed/simple; bh=MtzfM60Cs9mbb/vDYLGt1i8sN5P/nhUKDazT3BzO028=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=tcVJKQTUj2uoPyRKMGnC/71gvwybpvYRelHxCSQ3UXKHFY8tqW6CWLMVZGwp4fXHbAavP5BKs1UisYodZpD7CqyS9mTD64rovg3dKio9G8tZhYsI3Zp8W+LvDitoDridUmfynBY8jxxx26U7AnjQ+H8dzJViRRsD4A7ZXgiqROY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=ziepe.ca; spf=pass smtp.mailfrom=ziepe.ca; dkim=pass (2048-bit key) header.d=ziepe.ca header.i=@ziepe.ca header.b=d8ipf+KU; arc=none smtp.client-ip=209.85.219.47 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=ziepe.ca Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=ziepe.ca Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=ziepe.ca header.i=@ziepe.ca header.b="d8ipf+KU" Received: by mail-qv1-f47.google.com with SMTP id 6a1803df08f44-88a37cb5afdso14960646d6.0 for ; Wed, 21 Jan 2026 07:41:39 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ziepe.ca; s=google; t=1769010099; x=1769614899; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=Ou8wYJVgke38aZatOGIOXXNbnvyF2AuO4MiXOCQfuAM=; b=d8ipf+KU++d9oWZgIR6lkxHBb8zf4MCRmoRwF7J76jVX9G5OiIyG0n6WJtb9AzNyCW jOjZq8LRWOOMO+Er2zSfMqVdcWQ5lDt4hZIILiz99LspfnYKq6Vm96pR1HOSOWuJs1ZG 32i4aWr/fTBs/O3a8mldRbft0k6Baj9NWL2EeQdEiMYBskC4B9Yc5557kORXLi+3GJG7 Pb8f/UNhY3khb4fQObQ8ddLiXbUAdCup/sKMLFCrWUMLzi9q2BqKM2Vaqyonmzp/1hPw 25xyxonm5frcsDVntEjX1kH31oHyKXlWqJew8afiw3qggmbb8YPqg0OOTeGFqoKjzyCd pF9g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1769010099; x=1769614899; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-gg:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=Ou8wYJVgke38aZatOGIOXXNbnvyF2AuO4MiXOCQfuAM=; b=pSp3HUGjranQq53NMocEPfGS2wSWbJZExz2ujyOuP5W0ru9epzBlCiUmasq5jH4Jc3 82pZIu4z65jS1bOQISzUiwSDIQAkaT/bHgAEyDd98KSTa/uNfaxDdI96vUusZGNXZa29 mCEh1S2z48uKnebSoY24HlLY5saj0HxOnDx5k++nwsN1ibwaPmO7PJhXbfPFPn3DkhRy RLhJ6HZZJlRS4qWPKjACTSnSVe2XW6n0wkVXEDuj8nafVCQYuJZlfHGmDH+4X0gTruL6 W7rJIwymQxpn5eyBa8jRDSHEbUuPLBkPDVxeu92Gai4h9BU5DHYotdVMYXOYb4+Dd6Vj SYdg== X-Forwarded-Encrypted: i=1; AJvYcCU8pATgtygSXV2RIDRLD2q6q0rZQnIjwcsV9AyvdPkA+ojCMnwFIznAbLOKK55J3U32vQ8sBe9ka5iH@vger.kernel.org X-Gm-Message-State: AOJu0YwQLj44RxhXTnLlrcTu4FowNCkTKoG4kx88XLcpW4bfF2vcKSZz uaeQaG9A2hMgW9NrBfh7JEa2ly0eDPjixcIvPERp0PpHCuZ/zuXaB5FKV9e+vk0I63E= X-Gm-Gg: AZuq6aJjtIFKqMj0Ea1Pi5+BxOVVlIpSvOERqjdkRcWc/c7ITECBKDgjr60JF6TZD1g 6hLetmDmOD9esAQviENqj4/fa0XsN3cuG3v4EVQeFpf0Lf+du1D7QThvxuyu1qwNjKwP75xo/MJ 1lD4GGDBlObflwWXXGu91TzMSRCE0rJaiLpq3sl1sgs7rXZaO6xCiqXWT6Vf40iHco0en94iCx/ t4CBeVw9faOMMW+UqWcno1ySxHvqIOyMDpWGd6YJnGHYUvk4fz919UxvYY/MfVZvhquVKCcQga+ LirRlSs64akNBEM/rKWgijD4yYZ9aoDU6t/n4cS652KnKtOy3BURJxQJbRVnDZChefneoNeEg4D lbrwymjZ17PKn2dm64JdCwjT3qO1AKynwAZlLQYLwDuFaabcCjMrM3oIBmny40InbPijpbsCMtc 8Mpt3N9AuhhLYS6UxebVdr54dvIPKFLNoQz7ulTvOxCgaqhaJbbZjb3WhSu/g4EC+V9uGzTMint Xfy/A== X-Received: by 2002:a05:6214:212b:b0:888:6fde:7b72 with SMTP id 6a1803df08f44-8942d7e0460mr262093776d6.32.1769010098574; Wed, 21 Jan 2026 07:41:38 -0800 (PST) Received: from ziepe.ca (hlfxns017vw-142-162-112-119.dhcp-dynamic.fibreop.ns.bellaliant.net. [142.162.112.119]) by smtp.gmail.com with ESMTPSA id 6a1803df08f44-8946a1e3d28sm30951806d6.7.2026.01.21.07.41.37 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 21 Jan 2026 07:41:37 -0800 (PST) Received: from jgg by wakko with local (Exim 4.97) (envelope-from ) id 1viaKv-00000006EjK-1pDz; Wed, 21 Jan 2026 11:41:37 -0400 Date: Wed, 21 Jan 2026 11:41:37 -0400 From: Jason Gunthorpe To: Leon Romanovsky Cc: Sumit Semwal , Christian =?utf-8?B?S8O2bmln?= , 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 =?utf-8?Q?Hellstr=C3=B6m?= , Rodrigo Vivi , Kevin Tian , Joerg Roedel , Will Deacon , Robin Murphy , Felix Kuehling , Alex Williamson , 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: <20260121154137.GD961572@ziepe.ca> References: <20260121-dmabuf-revoke-v4-0-d311cbc8633d@nvidia.com> <20260121-dmabuf-revoke-v4-8-d311cbc8633d@nvidia.com> <20260121134712.GZ961572@ziepe.ca> <20260121144701.GF13201@unreal> Precedence: bulk X-Mailing-List: linux-rdma@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260121144701.GF13201@unreal> 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. Jason