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 B9F3DC433E1 for ; Thu, 25 Mar 2021 09:34:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6BDCE61A2B for ; Thu, 25 Mar 2021 09:34:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229581AbhCYJdu (ORCPT ); Thu, 25 Mar 2021 05:33:50 -0400 Received: from mail.kernel.org ([198.145.29.99]:38324 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229629AbhCYJdV (ORCPT ); Thu, 25 Mar 2021 05:33:21 -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 2CA7F619E3; Thu, 25 Mar 2021 09:33:20 +0000 (UTC) Received: from disco-boy.misterjones.org ([51.254.78.96] helo=www.loen.fr) by disco-boy.misterjones.org with esmtpsa (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.94) (envelope-from ) id 1lPMMf-003hPI-SL; Thu, 25 Mar 2021 09:33:18 +0000 MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Thu, 25 Mar 2021 09:33:17 +0000 From: Marc Zyngier To: Shameer Kolothum Cc: kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, stable@vger.kernel.org, pbonzini@redhat.com, linuxarm@huawei.com Subject: Re: [PATCH for-stable-5.10 2/2] KVM: arm64: Workaround firmware wrongly advertising GICv2-on-v3 compatibility In-Reply-To: <20210325091424.26348-3-shameerali.kolothum.thodi@huawei.com> References: <20210325091424.26348-1-shameerali.kolothum.thodi@huawei.com> <20210325091424.26348-3-shameerali.kolothum.thodi@huawei.com> User-Agent: Roundcube Webmail/1.4.11 Message-ID: <9850fc39c1c80840ea77eba60ee5e663@kernel.org> X-Sender: maz@kernel.org X-SA-Exim-Connect-IP: 51.254.78.96 X-SA-Exim-Rcpt-To: shameerali.kolothum.thodi@huawei.com, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, stable@vger.kernel.org, pbonzini@redhat.com, linuxarm@huawei.com 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 On 2021-03-25 09:14, Shameer Kolothum wrote: > From: Marc Zyngier > > commit 9739f6ef053f104a997165701c6e15582c4307ee upstream. > > It looks like we have broken firmware out there that wrongly advertises > a GICv2 compatibility interface, despite the CPUs not being able to > deal > with it. > > To work around this, check that the CPU initialising KVM is actually > able > to switch to MMIO instead of system registers, and use that as a > precondition to enable GICv2 compatibility in KVM. > > Note that the detection happens on a single CPU. If the firmware is > lying *and* that the CPUs are asymetric, all hope is lost anyway. > > Cc: stable@vger.kernel.org #5.10 > Reported-by: Shameerali Kolothum Thodi > > Tested-by: Shameer Kolothum > Signed-off-by: Marc Zyngier > Message-Id: <20210305185254.3730990-8-maz@kernel.org> > Signed-off-by: Paolo Bonzini > Signed-off-by: Shameer Kolothum Please hold on on that. This patch causes a regression, and needs a fix that is currently queued for 5.12 [1]. Once this hits upstream, please add the fix to the series and post it as a whole. Thanks, M. [1] https://lore.kernel.org/r/20210323162301.2049595-1-maz@kernel.org -- Jazz is not dead. It just smells funny...