From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.ozlabs.org (gandalf.ozlabs.org [150.107.74.76]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1074A4ACC60; Wed, 23 Sep 2026 17:06:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=150.107.74.76 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790183207; cv=none; b=aDwANGwOI3B/PrmSwtjSm9fvlMxIxX8BwAJEBB8tcJqXfYwQ6kZtI7IvTuEmrn6aPIZUdSqPqUWWQL8peMqDekZ5reysBRf911OPsHlopr/UWgk9JafC9bL+oeZdQP8fHtZ+lY9ByyUfICyop5tFyof6DN6xFdOVrM3NBqqGHSM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790183207; c=relaxed/simple; bh=lOKvbj2MaK9aA/44kvy0ob+64Z+dgv72IDjwAwjQxqA=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=muDuwOaAi8dPo2bsh3+xAK0daXTltGy2Nkvo10Ui0pjUskCwtiwmu96PEkaC/o6eDoyhbMB07usDUnNNJd+qtFBxByEhmooAQdTHY7q+7wVHEmVilMy0eXfv09umOUbvmVHLlqqLkrmnlyHec4hlPfENJesrtn3GYUPusYFPYM0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=ozlabs.org; spf=pass smtp.mailfrom=ozlabs.org; dkim=pass (2048-bit key) header.d=ozlabs.org header.i=@ozlabs.org header.b=j5E2EGCt; arc=none smtp.client-ip=150.107.74.76 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=ozlabs.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=ozlabs.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=ozlabs.org header.i=@ozlabs.org header.b="j5E2EGCt" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ozlabs.org; s=201707; t=1790183171; bh=9sC2s9c4kVeESBcaRi7B3uwGv/f+ZIkXcJcmd7k9ey8=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=j5E2EGCtmyxhWxVJokXSHuw5C+yOnbLNZ4baCc6TxSShKtCuvjiVhGivVSg4y9UBb wnR9pqB/7HRav14UHp41aEMlivzBf+DFHzPwkIodntCWIG+OKKwGVY12JZrjXXkzd7 wDsg5AR5j92BLqYgQgAzqFba9bej7kNF/YGJmH5/r8KTgFf+hQwllvGWnlyhEfuWDJ WZpFpA1B6pu5Dt6m9RxXdFvGM4SgoChPa+o0Nb2Ts97Caz7JL2UOpUbXYO178MNDFv 2MWuWwmCRW69gSB4p2RSn1ZxW7RVEqY4o2lmhGPTckm202dPtO9K6hE5CRQMm8HckY QciTOSpaF0/Bg== Received: from authenticated.ozlabs.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange x25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by mail.ozlabs.org (Postfix) with ESMTPSA id 4hqjzG4ycBz4wCx; Thu, 24 Sep 2026 03:06:02 +1000 (AEST) Message-ID: <39fdd41d-fd6e-4f88-be35-28ce93482605@ozlabs.org> Date: Wed, 23 Sep 2026 18:06:22 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v6 9/9] vfio/pci: Permanently revoke a DMABUF on request Content-Language: en-GB To: Leon Romanovsky Cc: Jason Gunthorpe , Alex Mastro , =?UTF-8?Q?Christian_K=C3=B6nig?= , Alex Williamson , Bjorn Helgaas , Logan Gunthorpe , Kevin Tian , Pranjal Shrivastava , Longfang Liu , Mahmoud Adam , David Matlack , =?UTF-8?B?QmrDtnJuIFTDtnBlbA==?= , Sumit Semwal , Ankit Agrawal , Alistair Popple , Vivek Kasireddy , 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, linux-pci@vger.kernel.org References: <20260921132208.GA1507824@nvidia.com> <20260921134924.GB1507824@nvidia.com> <2d15cca5-0bbe-461a-baf3-56758e82cfb7@amd.com> <20260922124137.GD1507824@nvidia.com> <20260922124637.GG563127@unreal> <20260922125421.GE1507824@nvidia.com> <20260922225747.GB2545495@nvidia.com> <20260923165240.GS563127@unreal> From: Matt Evans In-Reply-To: <20260923165240.GS563127@unreal> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Hi Leon, On 23/09/2026 17:52, Leon Romanovsky wrote: > On Wed, Sep 23, 2026 at 04:40:03PM +0100, Matt Evans wrote: >> >> So the worry was that the VFIO DMABUF's temp/perm state could be >> misconstrued as an implication/guarantee about the future availability >> of that DMABUF to importers, OK. And we want the existing move(false) >> behaviour still, for dynamic importers that treat it as a move. > > This is not a bug; the behavior is intentional. I wasn't meaning to imply that! :) > During review of the initial> versions of the revoke mechanism, it was pointed out that > `move_notify == invalidate_mappings == revoke`. The initial versions > introduced a separate function call for revocation, which we abandon in > favour of move semantics. That makes sense, and it's good to know that background. Thank you, Matt