Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758569AbbGHKot (ORCPT ); Wed, 8 Jul 2015 06:44:49 -0400 Received: from foss.arm.com ([217.140.101.70]:40105 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758118AbbGHKon (ORCPT ); Wed, 8 Jul 2015 06:44:43 -0400 Message-ID: <559CFF18.8090803@arm.com> Date: Wed, 08 Jul 2015 11:44:40 +0100 From: Marc Zyngier Organization: ARM Ltd User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Icedove/31.7.0 MIME-Version: 1.0 To: Robert Richter CC: Robert Richter , Thomas Gleixner , Jason Cooper , Tirumalesh Chalamarla , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" Subject: Re: [PATCH 3/4] irqchip, gicv3: Implement Cavium ThunderX erratum 23154 References: <1435673643-31676-1-git-send-email-rric@kernel.org> <1435673643-31676-4-git-send-email-rric@kernel.org> <559A5BB6.2040509@arm.com> <20150708102846.GT10428@rric.localhost> In-Reply-To: <20150708102846.GT10428@rric.localhost> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1408 Lines: 41 On 08/07/15 11:28, Robert Richter wrote: > Marc, > > On 06.07.15 11:43:02, Marc Zyngier wrote: >> On 30/06/15 15:14, Robert Richter wrote: >>> static const struct gic_capabilities gicv3_errata[] = { >>> { >>> + .desc = "GIC: Cavium erratum 23154", >>> + .id = 0xa100034c, /* ThunderX pass 1.x */ >>> + .mask = 0xffff0fff, >>> + .init = gicv3_enable_cavium_thunderx, >>> + }, >>> + { >>> } >>> }; >>> >>> >> >> How does this work when running a guest? Does the virtualized access >> suffer from the same erratum? If that's the case, we need a better >> workaround... > > We need to apply the workaround also for guests. So you are right, > evaluating GICD_IIDR does not enable the workaround then as the > register is emulated with ARM as implementer. > > We considering MIDR_EL1 as a version check for this errata now. This > should be the host's cpuid when running as a guest, right? Yes, that should work, as we don't repaint MIDR_EL1 *yet*. But it also means that we're going to have a hard time emulating another CPU (such as A57) on top of ThunderX. Probably not a big deal at the moment... M. -- Jazz is not dead. It just smells funny... -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/