From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-qv1-f45.google.com (mail-qv1-f45.google.com [209.85.219.45]) (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 1CA12421895 for ; Wed, 21 Jan 2026 15:41:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.219.45 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769010102; cv=none; b=gu2NJhoOrkVqVDZNTolGMoCLA8y/vff0duoShJZk28PeZlfBk2qSPI72JXm/JKFmKphussREpCJmTEVgA+bhGpvWqQ9m+vwwUMWySmi5+aRdzokSqSmLIaYnOPePLBrDcE51qsPLKLOpOztfV2zrm1Gs6CDUk03j/nPKTRyP1Yc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769010102; 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=F5i4i2wHKnP6SmbhyFk6CLaDTjbWJMdh+OUylwIe6ly8CblatNvV3fM1MB0FEfoYnpoCV6TL/xH4leqzSFw3sivnDmGkv5GzKxiG1dANoUuGIh9owwihKQcj3wA59twb0ISYcEPSp4bR0KVq8BDyR58sQ2ZV/V+dMf8xzE4H/1U= 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=Pkdw/Wdx; arc=none smtp.client-ip=209.85.219.45 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="Pkdw/Wdx" Received: by mail-qv1-f45.google.com with SMTP id 6a1803df08f44-88a37cb5afdso14960586d6.0 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=lists.linux.dev; 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=Pkdw/Wdx7h3NSghDc1cg/82xhZWnvj2ZYNn45nAQFE7AWVSRoSTmKI901S1zsEIC2V l1yu63YMa/eM8dHf5nzXO0ls87Pdth5WFh7LA3RX9hVQw4ptxoDxn5tC0PQK++mqEXh5 PIA0u1NXCff5BDr5GvJWMTnnlIBv66j3oDj9ZjueQraOjV3IfDfim0Z0V9AnB22emdN5 KTkZ3GgCO+pGskteahcW+Tt8M7jU+VVwuHutXCel8cyOThOBtPvPtq65gY9W+SEjVKBS QqV0umdQtOVW/RxK+N9a+w2SC3vHGNo5+LNyPkGzJnLgw4ByRTlzCF+WD66xBaaDWmLQ fMBg== 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=hS2tnXUeZPi8KngFXpAZb1vfqJQbuGcfQT1OudFJkIxTixnQ8OuZreZurpVO3kEGHL WrY+RXKQKY1T9YX60nsH1bCHk4pNwKVSMbaZdbemqi6fCPXb37h9TeqoqJX27cOvHlTX CmvN7M6tuuomS6tcar/jEpHEAdWd5OugP0LDTD5a5afu0xmo/2MwTNpeyfxvtYtH23sO 3mJIf12PnBFv8nIwA6LHWEwmBZa3h2d926pcrMibv8hDWkh4McrbOR2CayC0OkKSug6f ycrnPWToDEJzXjx3Fa0xP3gD6cXwU1hwUVXvOD0u+L3fgMZuvDo+w4Yj5giuKtK2PrGS eQQQ== X-Forwarded-Encrypted: i=1; AJvYcCWCS+GA4yXn63c03GpTJPGMTyV3TxtF969yIMrq48tlQlRlLZvwSBJYUefKaFbns+q7OzSoFw==@lists.linux.dev X-Gm-Message-State: AOJu0YyMEO3kkXoa3GmD5HuMOkL2yCkYCSjtzBFbHxI24WZpYOaenPJc iKWFxPb1LRier1+5Sgz4WeQSM5OreNlRPg+2ecU9visS+D7XiEkg8PKaMZq1mYZcQHs= X-Gm-Gg: AZuq6aID4SRsl2Ls5zmqHHRA0+Hrpnf2IHuxHX2IolnuKczxYl+BiJbA1mdQVBVk3IE mi/vvYfI/bDd2F7cXvcEEw5GYqnzdYZdrqShUNKanveoMxQXnvPalSr/99Zq0mnArrtB8uhxcIW ZSt8iD7qTfWkSZ3JdQELwhu/dd74Q0P3Zl+WzVJioDV88YqkM1jbXsyGVmcgxBhSIEslqNPtC55 YN9N2o4mPzAJsHE5m/OvDMpcT/7LBmF+tMCk2jT1XvpYvQctfesgi1qcu0jEpYi6/XktOdxU1RU jrpWwgkibefHBn9KVZ4JP0+J2ibshooe5++qBfrhZP3XwpLc+UKz4O4OUnEoeWGQVmy73eWVxB4 B5M7jjAX+C63H81hjfj26waXQ4SGJg5aQPQQyc2/hOHCJnN8gb3WsZjC5RSiQv4TxCun+BKM2bZ YF70LkCFzUQIpq6worMCW97R/GpBxBsEmNbc0IpP+ioxCXbloZep6+0TGzLmBObnnqQBjY69Rm/ IBHxg== 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: iommu@lists.linux.dev 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