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 X-Spam-Level: X-Spam-Status: No, score=-9.0 required=3.0 tests=BAYES_00,INCLUDES_CR_TRAILER, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 76BE6C433DB for ; Wed, 17 Mar 2021 14:05:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2540664F67 for ; Wed, 17 Mar 2021 14:05:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231630AbhCQOFE (ORCPT ); Wed, 17 Mar 2021 10:05:04 -0400 Received: from mail.kernel.org ([198.145.29.99]:49534 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231735AbhCQOEj (ORCPT ); Wed, 17 Mar 2021 10:04:39 -0400 Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 12BC364F69; Wed, 17 Mar 2021 14:04:39 +0000 (UTC) Received: from 78.163-31-62.static.virginmediabusiness.co.uk ([62.31.163.78] helo=why.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94) (envelope-from ) id 1lMWmq-002DkG-OQ; Wed, 17 Mar 2021 14:04:36 +0000 Date: Wed, 17 Mar 2021 14:04:36 +0000 Message-ID: <87blbhj2q3.wl-maz@kernel.org> From: Marc Zyngier To: Lorenzo Pieralisi Cc: linux-kernel@vger.kernel.org, LAKML , KVM Subject: Re: [PATCH v3 1/1] irqchip/gic-v4.1: Disable vSGI upon (GIC CPUIF < v4.1) detection In-Reply-To: <20210317100719.3331-2-lorenzo.pieralisi@arm.com> References: <20210302102744.12692-1-lorenzo.pieralisi@arm.com> <20210317100719.3331-1-lorenzo.pieralisi@arm.com> <20210317100719.3331-2-lorenzo.pieralisi@arm.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/27.1 (x86_64-pc-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: 62.31.163.78 X-SA-Exim-Rcpt-To: lorenzo.pieralisi@arm.com, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Hi Lorenzo, Wed, 17 Mar 2021 10:07:19 +0000, Lorenzo Pieralisi wrote: > > GIC CPU interfaces versions predating GIC v4.1 were not built to > accommodate vINTID within the vSGI range; as reported in the GIC > specifications (8.2 "Changes to the CPU interface"), it is > CONSTRAINED UNPREDICTABLE to deliver a vSGI to a PE with > ID_AA64PFR0_EL1.GIC < b0011. > > Check the GIC CPUIF version by reading the SYS_ID_AA64_PFR0_EL1. > > Disable vSGIs if a CPUIF version < 4.1 is detected to prevent using > vSGIs on systems where they may misbehave. > > Signed-off-by: Lorenzo Pieralisi > Cc: Marc Zyngier Does it need to go in as a fix? or can it just be pushed into 5.13? Given that there is no such HW in the wild just yet, I'm inclined to do the latter... Thanks, M. -- Without deviation from the norm, progress is not possible.