From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=209.85.221.171 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793890796; b=0QkK7YwkWXQxLUVmb7FgLdYOBksyccwW8L9rEK0YZM1o6tT5O8pKuna9iEdisNAuwx+q nc8cshnSwseKu2p/6qMmI+0SkQH8sFEbWTDrJmPnFKrDKauE4zbwH/fGqUGM4CTzTC4EH O9wAw3jLC3tTidLhWc806s1kqbvvnS1t/cNUptqCcqPsQPZd2FnkTZW6hycIvB5KSrkHb 1mbSff3C6mxXtYSD6y/gHz8K42XLDV/rjPrXH0od7ToInf+dncdWYsWlwprkIY9VpeNSi a5fFxjZqkD3wKVvrXG8SAvv3SfbKolEyPnMecAYcb3qpQzNvrEZodHuWDioJ0sdlQ+Q== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793890796; h=DMARC-Filter:Received:DKIM-Signature:X-Google-DKIM-Signature: X-Forwarded-Encrypted:X-Gm-Message-State:X-Gm-Gg:X-Received:Received: Received:Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; bh=sv1GqJtGOVxD2bg62FKkDXwLV7ybcH0/LrV/szN48RM=; b=UMGOXxoOFBuh57b6+dr+7VSSF9dl8/33Co95+Jj67YdyBvhw0XSJtGkH6bUygca9tzS9 756atQD0i3pO2UDATw37EoTFdiCsIpEcVIUsUrrS5NpeekKIX+h+6znPomwx3yp4vb6g9 8olpEy+dqzRFwEFzMUrpZ6ZP6Zv5X5RK1uw38i8WKvUbXvub6nj6droLcXhiZOBqLY6Od Pz6Vi4yohnawNWkDYE17wzoqSACYbPdMd79vgaePvPKLhw2f0FIQt/nysnPjdRGi6vUi7 ncaatJvCoKgSaHtTKUJ3KQpUzh3FRKG9J1IQ+GbIQRHoYbpMbhT9ywpUhfXLx5pLRuA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none header.from=ziepe.ca; spf=pass smtp.mailfrom=ziepe.ca; dkim=pass header.d=ziepe.ca header.i=@ziepe.ca header.a=rsa-sha256 header.s=google header.b=bpBlGkKK; arc=none smtp.remote-ip=209.85.221.171 Received: from mail-vk1-f171.google.com (mail-vk1-f171.google.com [209.85.221.171]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id EB3B7606A33E for ; Thu, 5 Nov 2026 14:59:55 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org EB3B7606A33E 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, unprotected) header.d=ziepe.ca header.i=@ziepe.ca header.a=rsa-sha256 header.s=google header.b=bpBlGkKK Received: by mail-vk1-f171.google.com with SMTP id 71dfb90a1353d-5ead9f60e26so745678e0c.1 for ; Thu, 05 Nov 2026 06:59:55 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ziepe.ca; s=google; t=1793890795; x=1794495595; darn=vger.kernel.org; h=in-reply-to:content-disposition:content-type:mime-version :references:message-id:subject:cc:to:from:date:from:to:cc:subject :date:message-id:reply-to:content-type; bh=sv1GqJtGOVxD2bg62FKkDXwLV7ybcH0/LrV/szN48RM=; b=bpBlGkKKYmX68RAsE9EkcMc+aPwep+Jt4D7c/OZg3kVQeHpZyfmkntRrTHho6EP8wd Ydil1svNY3g9CpIhj2GHYQ7d434gL/SpPpSr+DXV/upiAZMCvC9nreTgfts3zuhMwCcm Qskdy4s4owr7KaU/9VifToG4uoaZc2rkAAcVF19z0f6dAbM64dHUzvDPxywg/TCQt9WF 2ooxRy05KElc/DdqHagH2RzabKyRAsKGjv0e7Kqhd2EeSxnmqf8lncs0n6nLDm8+XKat ++mZs0G+SfgC2WTprHf/u2SbYhDe7xP1yG7Q6zYRZWtdxX3hRx/GELgc/Kk/Jaz7fcIZ 8CIA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1793890795; x=1794495595; h=in-reply-to:content-disposition:content-type: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 :content-type; bh=sv1GqJtGOVxD2bg62FKkDXwLV7ybcH0/LrV/szN48RM=; b=VNGxysO+HFdyxKiq295TdshRqjA1WtavknmmBzr96M/rc5ZZQO3YFI6w3q/kRbyB3P bT9EU1ruKcurl0Q1DjCiXkeeflr3wJlfJmJgVisXuOsSLnjKhUktxZ9aN4uXyBogOC9V Clm95ur8BNgxnwEKOdDRRi30XH4rqagrseGk0xOaJwwl6gQk7Fv6rxr1PV8cYwtv4Dig NRV2rFtFaeIy4meqfBV0HZ/EUnPt67iCIPDHXzelLkwM4KJbBgwFEXdl//tLdzMnkcX2 PvQ+s7C58nwfcv1GJ/583dEPF2YSPmk0Rwr/zRL8/oxOMV3+H4oJWfh71fNR/OyRqzh5 IXNA== X-Forwarded-Encrypted: i=1; AKwUvBzxbBEIIOM6cauhwI4rLgf3bFWP/nWM3Kd2egUAxxwdIjuJI/FBK4m5+FZnaM/Habd5FTUHZ59un2Y=@vger.kernel.org X-Gm-Message-State: APuU4Z+jqpNpUwqCvqJGL/daiRbvt9Tk4F2fXzPfCiQgiJB2b2wdi9oM fv6GUUmDC6qkIYo0GLqXHP0PYdB1FGrRAygr7PLyMQs9BNz8+CZL2+9Ysnqm/ANMK/E= X-Gm-Gg: AYBFou35GH2NgG34Ffjf2WGKeSWtlswJYltispwmcPKC4u4tJfDP/3upja1mdIoL53M aedapMrxSU7Fae+3vknZT/hCi7d7/tjNnwPb5IXBomlLVcBILfRRHTZPJIOZ4e9+93rRr2k9s3e Jm0FmO/OitXEaCgBjgUKoTaMQEHujXEiw1R+Vgn4XEgER3LtUeLO9HkwOoikWLqnsCx1fs3aeCB z5jglTg9YlAVS2PD5z+UIBz2Zyn+7/GfXNAXbR6nQng4w9YJwnt2ZtbTk2rqkCfxoaA3HqxFBTe xiFTwrjFt7MR/IfMPtbF16UIhmfa+6GjjiokFUoK25ZqlDbl4Rp4N9GNf+jVzrR1mkVqBaPur2c Hl3GLgy1n+P+VeH+eQXAYMsUY0h0DIbOsYMaVhk9sS3KdT4IdiyCFUCMiVvi790ft7Df/uq/Yo5 sP83fN9m1cnuWschfnkUcQsQYXxDOhm3viES9A+Ab167j8TK8sgBJwkTCJX0/YfhX2HNkkbps/C zdToXG/CUKziX+7OhQgDo/RRRfch9iPl8Lm9Cu21ZiCHNBtBgVTRvz5yLSzefeVlqPgomAh7H5C 2/or7tb7M1U4RSeSSAtqu1p2+KFfZLJwpOAiO6jbCZdOD1fEp1iOtIeY3HWv+JQ396djlDNEZuG bNCYkQHzyfQo= X-Received: by 2002:a05:6122:6c0a:b0:5d9:302a:8243 with SMTP id 71dfb90a1353d-5ecb429571cmr1423011e0c.12.1793890794801; Thu, 05 Nov 2026 06:59:54 -0800 (PST) Received: from ziepe.ca (hlfxns010zw-159-2-239-150.pppoe-dynamic.high-speed.ns.bellaliant.net. [159.2.239.150]) by smtp.gmail.com with ESMTPSA id 71dfb90a1353d-5eca8df2a38sm4234612e0c.16.2026.11.05.06.59.53 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 05 Nov 2026 06:59:53 -0800 (PST) Received: from jgg by wakko with local (Exim 4.97) (envelope-from ) id 1xOywS-00000002o7b-2oaN; Thu, 05 Nov 2026 10:59:52 -0400 Date: Thu, 5 Nov 2026 10:59:52 -0400 From: Jason Gunthorpe To: Andrew Lunn Cc: Robin Murphy , Greg Kroah-Hartman , Leon Romanovsky , "Rafael J. Wysocki" , Danilo Krummrich , Dmitry Torokhov , Heiner Kallweit , Russell King , "David S. Miller" , Jakub Kicinski , Paolo Abeni , Johannes Berg , Jonathan Corbet , Shuah Khan , Randy Dunlap , Bjorn Helgaas , "Joerg Roedel (AMD)" , Suravee Suthikulpanit , Vasant Hegde , Will Deacon , David Woodhouse , Lu Baolu , Johan Hovold , Eric Dumazet , Marcel Holtmann , Luiz Augusto von Dentz , Nipun Gupta , Nikhil Agarwal , Pieter Jansen van Vuuren , linux-kernel@vger.kernel.org, driver-core@lists.linux.dev, linux-input@vger.kernel.org, netdev@vger.kernel.org, linux-wireless@vger.kernel.org, linux-usb@vger.kernel.org, linux-bluetooth@vger.kernel.org, linux-acpi@vger.kernel.org, linux-doc@vger.kernel.org, linux-pci@vger.kernel.org, iommu@lists.linux.dev Subject: Re: [PATCH 10/17] driver core: Expose device trust authorization through sysfs Message-ID: <20261105145952.GA663069@ziepe.ca> References: <20261105-device-trust-core-v1-0-1e536825b4eb@nvidia.com> <20261105-device-trust-core-v1-10-1e536825b4eb@nvidia.com> <2026110514-bunkhouse-handset-6a3a@gregkh> <20261105132729.GB8298@unreal> <2026110535-engulf-precut-cf10@gregkh> <9d896ebb-6892-4cac-a7c5-41def47f0be0@arm.com> <54c9476c-9f76-4ea1-a73a-c9937d6b463c@lunn.ch> X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <54c9476c-9f76-4ea1-a73a-c9937d6b463c@lunn.ch> On Thu, Nov 05, 2026 at 03:43:53PM +0100, Andrew Lunn wrote: > > Yup, and that's true even in the PCI TDISP case - there's a major amount of > > "communication" and "configuration" involved in that. The principle which > > should (hopefully) generalise is that a bus/host controller driver can > > always interrogate its child device to perform whatever attestation and > > general configuration is appropriate, but we won't hand off any _control_ of > > that device to a specific device driver (nor enable potentially-impactful > > bus-level features like DMA, interrupts, etc. if relevant) without the > > requisite agreement between the bus code and the user. > > Maybe it would be good to list subsystems which the bus driver can > use, and cannot use. > > You list interrupts as potentially being dangerous. What about reset > controllers, GPIOs, regulators? At least in the embedded world, the > bus driver might need to enable power, set a clock ticking, and take > the device out of reset via a GPIO, before the device pops into > existence and will enumerate on the bus. > > I don't see why interrupts are dangerous, which makes it hard for me > to determine if GPIOs and clocks, and regulators are also dangerous? IMHO we shouldn't try to over think this. The overall point is to give the userspace a place to inject policy. Bus drivers should try as hard as they can to contain their child devices. Like PCIE should activate the iommu, disable ATS. USB should limit the messages it exchanges, and so on. When userspace accepts the bus driver it also accepts its containment capability. So if it accepts one that uses gpio, etc then that's fine. We are not the point of trying to describe what threat models various kernel drivers can support. Userspace has to figure that out on their own. Jason