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 lists.gnu.org (lists.gnu.org [209.51.188.17]) (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 34F71C61DA4 for ; Mon, 6 Mar 2023 14:33:20 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pZBtU-0004iE-9F; Mon, 06 Mar 2023 09:32:52 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pZBtS-0004gE-Ad; Mon, 06 Mar 2023 09:32:50 -0500 Received: from ams.source.kernel.org ([145.40.68.75]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pZBtP-00054U-Ta; Mon, 06 Mar 2023 09:32:49 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id B8C2AB80E55; Mon, 6 Mar 2023 14:32:39 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7BC30C433EF; Mon, 6 Mar 2023 14:32:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1678113158; bh=6metGQJLLrMIQV46HL1rHuWCjpPItz5EEpI2mdssYmI=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=mxA8CViUGcBd5JTsSkVRDV1Ju3DwDKl0DYjS1Cod2g9WsXItj3yq68ptU7Q5DHj6S wwTRqUpyv3NnHz3OqVq3+q25+Hd6Inaswfx8SBY7VjRGSyz8VcghiNofu+iZENy9pt NP4QR5lfX2BJfYevphtARkGkJS8IFwD55SE7e0JzJcAwUdN8Cg6zf77RTrycwKRUQ9 6rhQ/xIskhYtwGkWLdK/M1q98XN7qIqO7l2EfnzeB6gdwD1yGORjCbQzHOr9cNPEhQ u1xXB/tkN0p9BdwnGeui44vFmkn9F83DyOG/uuXesXCGL7B4k+3qYVR1cwZhMjGBnm z4wpUsKjZdmig== Received: from sofa.misterjones.org ([185.219.108.64] helo=goblin-girl.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1pZBtE-00FEK3-Ax; Mon, 06 Mar 2023 14:32:36 +0000 Date: Mon, 06 Mar 2023 14:32:36 +0000 Message-ID: <864jqyympn.wl-maz@kernel.org> From: Marc Zyngier To: Peter Maydell , Miguel Luis Cc: "Michael S . Tsirkin" , Cornelia Huck , Paolo Bonzini , qemu-arm@nongnu.org, qemu-devel@nongnu.org, Haibo Xu , Andrew Jones Subject: Re: [RFC PATCH 2/5] hw/intc/gicv3: add support for setting KVM vGIC maintenance IRQ In-Reply-To: References: <20230227163718.62003-1-miguel.luis@oracle.com> <20230227163718.62003-3-miguel.luis@oracle.com> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/28.2 (aarch64-unknown-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; charset=US-ASCII X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: peter.maydell@linaro.org, miguel.luis@oracle.com, mst@redhat.com, cohuck@redhat.com, pbonzini@redhat.com, qemu-arm@nongnu.org, qemu-devel@nongnu.org, haibo.xu@linaro.org, drjones@redhat.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Received-SPF: pass client-ip=145.40.68.75; envelope-from=maz@kernel.org; helo=ams.source.kernel.org X-Spam_score_int: -70 X-Spam_score: -7.1 X-Spam_bar: ------- X-Spam_report: (-7.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_HI=-5, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Mon, 06 Mar 2023 14:02:33 +0000, Peter Maydell wrote: > > On Mon, 27 Feb 2023 at 16:37, Miguel Luis wrote: > > > > From: Haibo Xu > > > > Use the VGIC maintenance IRQ if VHE is requested. As per the ARM GIC > > Architecture Specification for GICv3 and GICv4 Arm strongly recommends that > > maintenance interrupts are configured to use INTID 25 matching the > > Server Base System Architecture (SBSA) recomendation. > > What does this mean for QEMU, though? If the issue is > "KVM doesn't support the maintenance interrupt being anything > other than INTID 25" then we should say so (and have our code > error out if the board tries to use some other value). No, KVM doesn't give two hoots about the INTID, as long as this is a PPI that is otherwise unused. > If the > issue is "the *host* has to be using the right INTID" then I > would hope that KVM simply doesn't expose the capability if > the host h/w won't let it work correctly. No host maintenance interrupt, no NV. This is specially mandatory as the L1 guest is in (almost) complete control of the ICH_*_EL2 registers and expects MIs to be delivered. > If KVM can happily > use any maintenance interrupt ID that the board model wants, > then we should make that work, rather than hardcoding 25 into > our gicv3 code. +1. I'd eliminate any reference to SBSA, as it has no bearing on either KVM nor the QEMU GIC code. I also question the "if VHE is requested". Not having VHE doesn't preclude virtualisation. Was that supposed to be "virtualisation extension" instead? Thanks, M. -- Without deviation from the norm, progress is not possible.