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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 4478CCD37B5 for ; Mon, 11 May 2026 10:40:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=IHWHch/qko4wao+fS50y7d50pedNNAlWeE+oNJVyWiY=; b=Hy1KBm6gMU9LWZ/cIn68UlwBaN ObR3erq2w3mZzR1wQhQ79SIbgCUw5Zwkm/R6bletdK6ATBDQ9bVqWwby2q/EiUDy2kCHotqUcrqgi JIT5o18M2AzaDfKFLP3HMEgH9U9svn5ef5oqgiGebVcRoxyQXgey/LoiBdprJ87j5oewUoaEo5pCn 1vkRD80s0IoAly1GsgVFtbbA8VgMIRH/Mn0bxd9bmS+ajljMwMuayWaYkzhHiwwRfHHJpBS528xwM 4oYVBg4dgtPPdHqt0mfB/wmpR7SAorFY9xwKvN8dZ0FZ1l0gr7KQog8jofI5F9yJ/2/kQNq19ny3X xA6m1ZJQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wMO3Z-0000000D86z-12oW; Mon, 11 May 2026 10:40:13 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wMO3W-0000000D86E-1HBK for linux-arm-kernel@lists.infradead.org; Mon, 11 May 2026 10:40:12 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 75A2E16F2; Mon, 11 May 2026 03:40:03 -0700 (PDT) Received: from J2N7QTR9R3.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id F384E3F836; Mon, 11 May 2026 03:40:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1778496008; bh=qIBIaoZMw/edt0QBmUc5C+O+459IgUULanpiPn179Hg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=AZqdSIPcNDUt2vsK0aBBMNGq9ftbYQkLtJzZEzpQyfsNIjrAIFSQvILVMNzfskFEI 3FSQiqKU+OjtNIqZZdvzkW0W9FwO3XyBsK96xa0zZ+jH7MmqlpmVwr9Vzdo88s+c3e Y04PU7WiXTlkgUqc0fJH/a8rXBHvUWHvl79a6z4o= Date: Mon, 11 May 2026 11:40:02 +0100 From: Mark Rutland To: Mark Brown Cc: Marc Zyngier , Joey Gouly , Catalin Marinas , Suzuki K Poulose , Will Deacon , Paolo Bonzini , Jonathan Corbet , Shuah Khan , Oliver Upton , Dave Martin , Fuad Tabba , Ben Horgan , linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org, Peter Maydell , Eric Auger Subject: Re: [PATCH v10 01/30] arm64/sysreg: Update SMIDR_EL1 to DDI0601 2025-06 Message-ID: References: <20260306-kvm-arm64-sme-v10-0-43f7683a0fb7@kernel.org> <20260306-kvm-arm64-sme-v10-1-43f7683a0fb7@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260511_034010_434332_E227AAB2 X-CRM114-Status: GOOD ( 21.07 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Sat, May 09, 2026 at 09:43:11AM +0900, Mark Brown wrote: > On Fri, May 08, 2026 at 06:12:01PM +0100, Mark Rutland wrote: > > On Fri, Mar 06, 2026 at 05:00:53PM +0000, Mark Brown wrote: > > > > Update the definition of SMIDR_EL1 in the sysreg definition to reflect the > > > information in DD0601 2025-06. This includes somewhat more generic ways of > > > describing the sharing of SMCUs, more information on supported priorities > > > and provides additional resolution for describing affinity groups. > > > FWIW, these are all in ARM DDI 0487 M.b: > > > https://developer.arm.com/documentation/ddi0487/mb/ > > > Is anything later in the series going to depend on these fields, or > > would everything behave correctly with the existing RES0 field > > definitions? > > We're exposing the affinity fields so there's a build time issue. What I'm asking is what is the rationale for updating these definitions? e.g. * Are we planning to use any of the fields in a specific way in the *host*? * Are we planning to use any of the fields in a specific way in the *guest*? * Is this updated just out of habit? Knowing the rationale would help with review, even if that rationale is just "it seemed nice to use the latest". > > > +Field 55:52 HIP > > > Reading the ARM ARM, HIP is arguably a backwards-incompatible change. > > Yes, I belive people are aware. Ok. Is that considered a problem, or accepted? Which people are aware? > > Do we expect to expose that to VMs, or just hide priorities entirely? I > > suspect we probably want to require that the guest sees > > SMIDR_EL1.SMPS==0, and not care about any of that. > > Currently we're not exposing priority support to guests so we don't need > to worry about it yet. Do we plan to in future? Mark.