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 2A431C61DB9 for ; Thu, 27 Aug 2026 17:09:18 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 7E4A410EFE6; Thu, 27 Aug 2026 17:09:17 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.b="VIqrCKX+"; dkim-atps=neutral Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by gabe.freedesktop.org (Postfix) with ESMTPS id 33ED310EFE6 for ; Thu, 27 Aug 2026 17:09:16 +0000 (UTC) Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id C075641A9E; Thu, 27 Aug 2026 17:09:15 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id F33F01F000E9; Thu, 27 Aug 2026 17:09:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1787850555; bh=pxe2I/QgTe79nkIJa+GTgxKyMaq8Csj03/OYd3xEmvk=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=VIqrCKX+wTnEtyc/9X0BbcUg6tAVAJ9EMfYxSM8vmU3EhE/Yt5rr5/fOgjMkfh58Y ets88aLe5ekWPr0NVaExRb/K6efqyMVnP1WMEsDryNmV+aQlHDOzuY7PBBQKFRjjvp N0HhCHm6ADoqx9YwUov91e6cZ27S8QV7NoSsKmObVbhPbiAtpiAKF4ieKi65jsYzHy cam03ruaoNkQ67HEdw04GLiXfPvbXcd+9ydohe7v/ysuhRNsDRsuMhOA4TTZO3RDUw Xu0X0fv/0c+57n3yGziCLiAbmpkxC9ds8YKp/X2jE2yrEvpvlEjyu2d6zqmOcCWciS Xvl24iyzVJIeA== Date: Thu, 27 Aug 2026 20:09:11 +0300 From: Leon Romanovsky To: Konstantin Sinyuk Cc: dri-devel@lists.freedesktop.org, Maarten Lankhorst , Francois Dugast , David Airlie , Simona Vetter , Maxime Ripard , Thomas Zimmermann , Jonathan Corbet , Shuah Khan , Donald Hunter , Jakub Kicinski , "David S. Miller" , Eric Dumazet , Paolo Abeni , Simon Horman , Ilia Levi , Rodrigo Vivi , linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [RFC PATCH 0/12] drm/fabric: vendor-neutral topology infrastructure for scale-up accelerator interconnects Message-ID: <20260827170911.GG42790@unreal> References: <20260826093222.GC42790@unreal> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline 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 Wed, Aug 26, 2026 at 06:38:58PM +0300, Konstantin Sinyuk wrote: > On Wed, Aug 26, 2026 at 12:32:22PM +0300, Leon Romanovsky wrote: > > Tell your AI that this is not how things work in the real world. The chances > > of multiple hardware implementations fitting a software model designed > > without considering the actual hardware are effectively zero. This is why > > successful subsystems have emerged from consolidating support for multiple > > existing hardware implementations. > > Fair point. The simulator validates the implementation, not whether the > abstraction fits real hardware. > > The model was shaped by the public amdgpu xGMI implementation, and the > cover letter asks AMD whether it covers their requirements. It still > needs validation against production implementations, and the read-only > milestone will not be proposed for merge without a production provider. > I will fix the wording in the next revision. The wording alone is not sufficient. Your proposal should be backed by real devices representing different architectures from different vendors. The current proposal is based on a single implementation, which is unlikely to be ported to this new framework in the foreseeable future. The amdgpu xGMI implementation already exposes the required UAPI through sysfs and would need very strong incentives to abandon its "legacy" users in favor of this new netlink interface. The last new subsystem I am aware of was introduced with implementations from three different vendors to demonstrate its robustness. You should probably aim for a similar level of coverage here. Thanks > > Thanks, > Konstantin.