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 185424C7C; Wed, 4 Jun 2025 16:35:37 +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=1749054938; cv=none; b=qf4D2LQ6BXBhZHdsZRdbw3pBjIh//HuAwDg08PGKxxrJLpUAvaan72H8BAR20R6723q8FgY+UxP7p4OW4Ummlba4izvn3FSt7Gw4beMSzKrNebGaKKNdNCWc7VnR1/5Zf8xkW4M3zp6eTgcHvs7IWA4m3vt/zhKY7YZDTUWaSWc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749054938; c=relaxed/simple; bh=bvurVI1LpPnY3JIRxy7/BJjVKXElOxjO6xxlddeu1CU=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=gGYM9uXh0aZAdlgw/6+Mu7KM0rXYTS5x1EdB7mAH15sUs/EqLC8ux284glD8qXrWHpsXAN3HUlDDd0shMvTuswNlTHXWGSAsZrzCruFZkRD65A3akYsPzTvHiAT1Wsph/HUEMt0fMhMLlsIi2dvsl5T9oHw7yx79e+sXNORhLaA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=scI70OW0; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="scI70OW0" Received: by smtp.kernel.org (Postfix) with ESMTPSA id AD4B8C4CEE4; Wed, 4 Jun 2025 16:35:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1749054937; bh=bvurVI1LpPnY3JIRxy7/BJjVKXElOxjO6xxlddeu1CU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=scI70OW08HFi5o6W890W7Xetgm51jFGoRvAoyEflLYSXv+VQ1O9lNMBkXQg7lxYXX wh+7cLfW5d0l6zyyM4qgVCV8tg2Kxv0t+yFa5rj2PwHlXUApQvsnR094N1fzvveMDG GH2kwyvLqrF3jFffdFDiVh7zRdHIb9YV8CyW0wcgZUIkOFR6FpStap15X4vDLufD+v /AWrul29FnQbuy41U467dT4+53KeuNzGqw90T+h1pA8Lm+w3Q9A8KZ54BDMaYqJ6su fAZSBbVmOckDm4vnEZOzZRlrm6D+FJPBeTj1jeIiwUShd4zzC5bQyIW7wNuugFXzHI l24x4Ijc1RLGA== Date: Wed, 4 Jun 2025 18:35:28 +0200 From: Lorenzo Pieralisi To: Marc Zyngier Cc: Rob Herring , Peter Maydell , Krzysztof Kozlowski , Thomas Gleixner , Conor Dooley , Catalin Marinas , Will Deacon , andre.przywara@arm.com, Arnd Bergmann , Sascha Bischoff , Timothy Hayes , "Liam R. Howlett" , Mark Rutland , Jiri Slaby , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, suzuki.poulose@arm.com Subject: Re: [PATCH v4 01/26] dt-bindings: interrupt-controller: Add Arm GICv5 Message-ID: References: <20250513-gicv5-host-v4-0-b36e9b15a6c3@kernel.org> <20250513-gicv5-host-v4-1-b36e9b15a6c3@kernel.org> <878qm7ec19.wl-maz@kernel.org> Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <878qm7ec19.wl-maz@kernel.org> On Wed, Jun 04, 2025 at 04:56:02PM +0100, Marc Zyngier wrote: > On Wed, 04 Jun 2025 08:24:38 +0100, > Lorenzo Pieralisi wrote: > > > > On Tue, Jun 03, 2025 at 02:11:34PM -0500, Rob Herring wrote: > > > On Tue, Jun 3, 2025 at 10:37 AM Peter Maydell wrote: > > > > > > > > On Tue, 3 Jun 2025 at 16:15, Rob Herring wrote: > > > > > > > > > > On Tue, Jun 3, 2025 at 2:48 AM Lorenzo Pieralisi wrote: > > > > > > > > > > > > On Thu, May 29, 2025 at 02:17:26PM +0100, Peter Maydell wrote: > > > > > > > secure.txt says: > > > > > > > # The general principle of the naming scheme for Secure world bindings > > > > > > > # is that any property that needs a different value in the Secure world > > > > > > > # can be supported by prefixing the property name with "secure-". So for > > > > > > > # instance "secure-foo" would override "foo". > > > > > > > > > > Today I would say a 'secure-' prefix is a mistake. To my knowledge, > > > > > it's never been used anyways. But I don't have much visibility into > > > > > what secure world firmware is doing. > > > > > > > > QEMU uses it for communicating with the secure firmware if > > > > you run secure firmware on the virt board. It's done that > > > > since we introduced that binding. Indeed that use case is *why* > > > > the binding is there. It works fine for the intended purpose, > > > > which is "most devices are visible in both S and NS, but a few > > > > things are S only (UART, a bit of RAM, secure-only flash"). > > > > > > I meant "secure-" as a prefix allowed on *any* property, not > > > "secure-status" specifically, which is the only thing QEMU uses > > > AFAICT. IOW, I don't think we should be creating secure-reg, > > > secure-interrupts, secure-clocks, etc. > > > > Reading secure.txt, what does it mean "device present and usable in > > the secure world" ? > > > > So: > > > > status = "disabled" > > secure-status = "okay" > > > > basically means that the device in question allows secure-only MMIO > > access, is that what it says ? > > > > If that's the case and we really want to have all config frames > > in a single DT, would it be reasonable to have an IRS/ITS DT node > > per-frame ? > > > > Then yes, the secure- tag is not enough any longer (because we have to > > cope with 4 interrupt domains) but that's a separate problem - again, > > this would leave the current reviewed bindings unchanged. > > No, this is the same problem, and we need a way to address it. > "secure-*" doesn't cut it in a system with FEAT_RME, where resources > are only available to a single Physical Address Space (PAS). So we > need a way to qualify these resources with a PAS. Can I ask again what: status = "disabled" secure-status = "okay" for a device means in practice in the current bindings ? When I said "a separate problem", I meant that, extending secure- tag (that applies to the "status" property only) to cover other PASes is independent from the GICv5 binding *if* we define, for a single DT an eg IRS device per-PAS (with realm-status, root-status, describing what the reg property represents. Is that what secure-status does today ? Does it say "this device MMIO space is secure-only" ?). It does not look like there is much appetite for tagging the reg property either and making it GICv5 specific is a shortcut IMO. > Either that, or we have to restrict DT to describe the view of a > single PAS. Which Peter will understandably be unhappy about. Well, I listed a couple of options in this thread, let's try to converge. Thanks, Lorenzo