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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED 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 37A8DC43381 for ; Sat, 23 Feb 2019 18:38:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 13EC6206B6 for ; Sat, 23 Feb 2019 18:38:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727147AbfBWSiG (ORCPT ); Sat, 23 Feb 2019 13:38:06 -0500 Received: from foss.arm.com ([217.140.101.70]:48022 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725893AbfBWSiF (ORCPT ); Sat, 23 Feb 2019 13:38:05 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 10184A78; Sat, 23 Feb 2019 10:38:05 -0800 (PST) Received: from big-swifty.misterjones.org (usa-sjc-mx-foss1.foss.arm.com [217.140.101.70]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id B943F3F575; Sat, 23 Feb 2019 10:38:02 -0800 (PST) Date: Sat, 23 Feb 2019 18:37:46 +0000 Message-ID: <86zhqm8i6d.wl-marc.zyngier@arm.com> From: Marc Zyngier To: Bjorn Andersson Cc: AngeloGioacchino Del Regno , Will Deacon , Jens Axboe , Catalin Marinas , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-arm-msm@vger.kernel.org, Robin Murphy Subject: Re: [PATCH] arm64/io: Don't use WZR in writel In-Reply-To: <20190223181254.GC572@tuxbook-pro> References: <68b71c15f32341468a868f6418e4fcb375bc49ba.camel@gmail.com> <20190211105755.GB30880@fuggles.cambridge.arm.com> <38d8965a-cd41-17cf-1b95-8dd58c079be4@arm.com> <874c702b8af760aa8fae38d478c79e3ecba00515.camel@gmail.com> <235d20ef-3054-69d9-975d-25aebf32aad3@arm.com> <20190223181254.GC572@tuxbook-pro> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL/10.8 EasyPG/1.0.0 Emacs/25.1 (aarch64-unknown-linux-gnu) MULE/6.0 (HANACHIRUSATO) Organization: ARM Ltd MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, 23 Feb 2019 18:12:54 +0000, Bjorn Andersson wrote: > > On Mon 11 Feb 06:59 PST 2019, Marc Zyngier wrote: > > > On 11/02/2019 14:29, AngeloGioacchino Del Regno wrote: > > > > [...] > > > > > Also, just one more thing: yes this thing is going ARM64-wide and > > > - from my findings - it's targeting certain Qualcomm SoCs, but... > > > I'm not sure that only QC is affected by that, others may as well > > > have the same stupid bug. > > > > > > > At the moment, only QC SoCs seem to be affected, probably because > > everyone else has debugged their hypervisor (or most likely doesn't > > bother with shipping one). > > > > In all honesty, we need some information from QC here: which SoCs are > > affected, what is the exact nature of the bug, can it be triggered from > > EL0. Randomly papering over symptoms is not something I really like > > doing, and is likely to generate problems on unaffected systems. > > > > The bug at hand is that the XZR is not deemed a valid source in the > virtualization of the SMMU registers. It was identified and fixed for > all platforms that are shipping kernels based on v4.9 or later. When you say "fixed": Do you mean fixed in the firmware? Or by adding a workaround in the shipped kernel? If the former, is this part of an official QC statement, with an associated erratum number? Is this really limited to the SMMU accesses? > As such Angelo's list of affected platforms covers the high-profile > ones. In particular MSM8996 and MSM8998 is getting pretty good support > upstream, if we can figure out a way around this issue. We'd need an exhaustive list of the affected SoCs, and work out if we can limit the hack to the SMMU driver (cc'ing Robin, who's the one who'd know about it). Thanks, M. -- Jazz is not dead, it just smell funny.