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 75680CD5BD1 for ; Mon, 1 Jun 2026 17:50:08 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id CC14810E297; Mon, 1 Jun 2026 17:50:07 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; secure) header.d=ziepe.ca header.i=@ziepe.ca header.b="hnefms2J"; dkim-atps=neutral Received: from mail-qt1-f173.google.com (mail-qt1-f173.google.com [209.85.160.173]) by gabe.freedesktop.org (Postfix) with ESMTPS id 6E80A10E297 for ; Mon, 1 Jun 2026 17:50:06 +0000 (UTC) Received: by mail-qt1-f173.google.com with SMTP id d75a77b69052e-5174a3a025aso17924351cf.3 for ; Mon, 01 Jun 2026 10:50:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ziepe.ca; s=google; t=1780336205; x=1780941005; darn=lists.freedesktop.org; h=in-reply-to:content-transfer-encoding:content-disposition :mime-version:references:message-id:subject:cc:to:from:date:from:to :cc:subject:date:message-id:reply-to; bh=GKY9bYORGkGGjohi6puGGa+RVGmQ7HsclerYSswNqXE=; b=hnefms2JKKYT1nI2PYDy1tCiUSUOpybsbiHwR5sbRJ9ocdZf2SGqnYUWe8Mxmd1qze nV4hRQoxHprLdeW4lhSdcM7lTDEQQw+foMagx5fXTRaA+kplMcVMiShycu2XfLAMlFYN yZ4gWPLxEMApsO1m3d93lMU47CWVdx3LSEQPzQULEr7SOAi5N43ww7qnd7hc1dmQDHqQ gD1W5nc5ArbS199sEAjmopUPqijfigWkuSBXVICfVYqu1bxSSrZ8i+ttaLVfGT5Cghdo OF0iYvyoB4/0m/BujC7WXE+1XRdNihen2kTiE4twutjSlHR2vO6riOC9Ih+KsB692Tip BP4Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1780336205; x=1780941005; h=in-reply-to:content-transfer-encoding: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=GKY9bYORGkGGjohi6puGGa+RVGmQ7HsclerYSswNqXE=; b=eArbDsaMNNC+aHWndtudU4lkOTK5HAFr4AtSo+k0IvHmHGFdTg/s5tx6ZA/yvrD6Yj oh+PMCz1dqVFp/cdCfQT/HnkpiEZBjDJiMgIN4WtrxUBWe5o1/TW9VbyjBfk6Ybnq+ZH 5kUdTOuWWZ9CTV1p05+qr82xrkqS56D6VVcb1TCKO+gucvmEnOGKWHKihZyb/RhUgOWT /7r7JFsSfvV0SIjOa6UPCTvQOOzui0UEQ5HDXKRrRH3PjsJLtE+nJoeTA/6Cq9KFIAvw kKZhinUTICGR/osZZ7If8ZaON2uzf+MAckX9GFmk1NhOkwzov1zGBrizCV3OhbJvvxRi ufbQ== X-Forwarded-Encrypted: i=1; AFNElJ8KadK//7Ur2Rg60ebkcG8vmSxCiRnIa93An1k7b7zF7SSOaWjKmwEP6vWmrqpB7OkVUZPPVnwRwIM=@lists.freedesktop.org X-Gm-Message-State: AOJu0YyuYVkPYr4cpR1DFjQJZpJAGiOnW4WuXlKsnA61ppEq7Pay7nev saJNxuu1HjGdXkdjXNyry6GXxjgAeH/p+mMHKOVwsySTbrHA2u9gumCUgrHEqiayezY= X-Gm-Gg: Acq92OG2UPqNfOzr+r0ugth5Lt68WoXoMz+KlJj9GW35e8xd8LFbQyjnxd/BH/lRKA/ dTtn9BenoFQuBsZYCBh/DmApwOIC8cyHHE54OATGu44H9kDL4GWExqCh6Z2m8qfvwx1KgpbfRiX NYPexucaTXctp2WUVpJccaY+y9VQQz75zdplWNoCvY8bWMrRaqoSmWN3TaxEm49DTn7AqE1e9GL Ji3MD42bNX4PhLLWNU06tK48QP1CJImMUtptv4vL5WL8eZZniyqSSVKVGQ+g5VsQOa5o3haZno6 wBkEV3lITuiK46pFUptLsZAMBgGLHoJ9oMyiUhmswod+b557eaENyiuJu+57f8UpPVgsZjQ0rqK hpODJlnh9E8wbDyK6hz7hC0S6RCcRkY7mLGv/4oLcFRHGlnBIYyQrIOoQWW6zk5q2SFOaA5U2j+ JzO8RPoKU3tMGFG1totkPQON1mjZltN9XCrOHHCEAKxM4GauAUftYT4NbF6nXHCycCsTwpyGNqu MJb4yPwqW4mRani X-Received: by 2002:a05:622a:1148:b0:50d:d1ea:65dd with SMTP id d75a77b69052e-5173a722af3mr169052191cf.14.1780336205151; Mon, 01 Jun 2026 10:50:05 -0700 (PDT) Received: from ziepe.ca (crbknf0213w-47-54-130-67.pppoe-dynamic.high-speed.nl.bellaliant.net. [47.54.130.67]) by smtp.gmail.com with ESMTPSA id d75a77b69052e-51741d6a240sm60989871cf.18.2026.06.01.10.50.04 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 01 Jun 2026 10:50:04 -0700 (PDT) Received: from jgg by wakko with local (Exim 4.97) (envelope-from ) id 1wU6m4-000000027Uh-034u; Mon, 01 Jun 2026 14:50:04 -0300 Date: Mon, 1 Jun 2026 14:50:03 -0300 From: Jason Gunthorpe To: Keith Busch Cc: Christian =?utf-8?B?S8O2bmln?= , Zhiping Zhang , Alex Williamson , Leon Romanovsky , Sumit Semwal , Bjorn Helgaas , kvm@vger.kernel.org, linux-rdma@vger.kernel.org, linux-pci@vger.kernel.org, netdev@vger.kernel.org, dri-devel@lists.freedesktop.org, Yochai Cohen , Yishai Hadas , Linus Torvalds Subject: Re: [PATCH v5 0/4] vfio/dma-buf: add TPH support for peer-to-peer access Message-ID: <20260601175003.GC2487554@ziepe.ca> References: <20260527121438.GJ2487554@ziepe.ca> <20260527123634.GK2487554@ziepe.ca> <71302a7a-6b9f-40da-af81-b1862dbd637a@amd.com> <8d9bb0b7-182d-4930-b683-d5d24da6b2ab@amd.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On Fri, May 29, 2026 at 02:31:30PM -0600, Keith Busch wrote: > On Fri, May 29, 2026 at 09:36:00AM +0200, Christian König wrote: > > On 5/29/26 08:34, Zhiping Zhang wrote: > > ... > > > There's no in-tree vendor PF driver > > > > Well I have to admit it's a bit on the edge but this sentence is a show stopper. > > > > DMA-buf is an in kernel interface for buffer sharing between drivers and any change to it needs an in kernel driver as justification for the added complexity. > > > > > - the device is a Meta MTIA > > > accelerator managed entirely from userspace via VFIO passthrough. > > > > When you have a complete open source driver stack which utilizes VFIO passthrough as the interface to communicate with the kernel drivers then we can eventually talk about that. > > > > But as far as I can see without upstreaming or at least open sourcing the full stack to utilize this functionality it's a clear NAK to upstreaming this. > > But the existing dmabuf for vfio-pci was accepted upstream without these > requirements. I see you had concerns about even that, but still Acked > under the same model that's propsed in this series: > > https://lore.kernel.org/linux-pci/57b8876f-1399-4e4d-a44b-1177787aa17d@amd.com/ To be fair that is quite different there isn't a proprietary userspace issue for that series, and there should be more users of the API when the GPU drivers migrate.. Jason