From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 4C84513B2B0; Wed, 24 Jul 2024 21:10:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721855404; cv=none; b=G6GnGSoAiSJcZ0UBOHNGH5zTtIoB4zqmQyjC/rbn20WhZIfWxXArS3/L0cclvrQXLvvTrYFV143XMpHMlBcJuze+3bm4yDIqesNXL8wDIL3aYy384ZfhNbzkDluYICpzhei065txvTktmilrM+n71k33oYyJw5n6i+i7SLpPwKc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721855404; c=relaxed/simple; bh=iecHcjgY45N2onErv+rBPVHXu+Da7UgJDK2xSAz9nR4=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=Fnz39EvTtLZf+dCtCX9zrfcb6aABnouePxeMgGoXURqxT+Oj1l/r8ySwZovf69sNXg9IPZ/7s1JNyDftNHOdvAajiwIPr0iiURwRborcTMGP+lG64yhoDJtr8zu+/8IZtKw2GQhDcnIASynjK4zzb55RLpJzN2xguT1Lcwuks2c= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 Received: by smtp.kernel.org (Postfix) with ESMTPSA id CAFB9C32781; Wed, 24 Jul 2024 21:10:02 +0000 (UTC) Date: Wed, 24 Jul 2024 17:10:21 -0400 From: Steven Rostedt To: James Bottomley Cc: Laurent Pinchart , Jiri Kosina , Dan Williams , ksummit@lists.linux.dev, linux-cxl@vger.kernel.org, linux-rdma@vger.kernel.org, netdev@vger.kernel.org, jgg@nvidia.com Subject: Re: [MAINTAINERS SUMMIT] Device Passthrough Considered Harmful? Message-ID: <20240724171021.05fbbadd@gandalf.local.home> In-Reply-To: References: <668c67a324609_ed99294c0@dwillia2-xfh.jf.intel.com.notmuch> <1e82a5c97e915144e01dd65575929c15bc0db397.camel@HansenPartnership.com> <20240724200012.GA23293@pendragon.ideasonboard.com> X-Mailer: Claws Mail 3.20.0git84 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: ksummit@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Wed, 24 Jul 2024 16:37:21 -0400 James Bottomley wrote: > > The first point is that hardware gets more complicated over time, and > > in some markets there's also an increase in the number of vendors and > > devices. There's a perceived (whether true or not) danger that we > > won't be able to keep up with just reverse engineering and a > > development model relying on hobyists. Getting vendors involved is > > important if we want to scale. > > Yes, but there are lots of not very useful complex devices being > produced every day that fail to capture market share. Not having > reverse engineered drivers for them is no real loss. If a device does > gain market share, it gains a huge pool of users some of whom become > interested in reverse engineering, so I think market forces actually > work in our favour: we get reverse engineering mostly where the devices > are actually interesting and capture market share. It's self scaling. I agree with this. If a small vendor with low market share has a proprietary device where they could easily port to Linux via a pass through, they may do that. But if they don't have that, and require engineering resources to port to Linux, they will not bother. As they would only care about the Windows market. So the device becomes useless for the Linux system. There's not enough Linux users to make a small vendor care about losing us. That just shrinks the number of devices that are available to Linux. My guess is that vendors want to write one piece of code. If it they only need to modify a small portion to get it to another OS, they would do that. But if it takes more effort than that, there's not enough cost incentive to bother. For devices with a larger market share, it would make it more worth their while to open source their work, otherwise there's more incentive for us to reverse engineer it anyway. -- Steve