From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joel Schopp Subject: Re: [PATCH v2] kvm: arm64: vgic: fix hyp panic with 64k pages on juno platform Date: Fri, 25 Jul 2014 11:24:18 -0500 Message-ID: <53D284B2.60204@amd.com> References: <1406302152-32335-1-git-send-email-will.deacon@arm.com> <53D27E22.2050602@amd.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: Will Deacon , Paolo Bonzini , "gleb@kernel.org" , "kvmarm@lists.cs.columbia.edu" , kvm-devel , Christoffer Dall , Marc Zyngier , Don Dutile To: Peter Maydell Return-path: Received: from mail-bl2lp0209.outbound.protection.outlook.com ([207.46.163.209]:47788 "EHLO na01-bl2-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752683AbaGYQ02 (ORCPT ); Fri, 25 Jul 2014 12:26:28 -0400 In-Reply-To: Sender: kvm-owner@vger.kernel.org List-ID: On 07/25/2014 11:02 AM, Peter Maydell wrote: > On 25 July 2014 16:56, Joel Schopp wrote: >> The problem with this patch is the gicv is really 8K. The reason you >> would map at a 60K offset (0xf000), and why we do on our SOC, is so that >> the 8K gicv would pick up the last 4K from the first page and the first >> 4K from the next page. With your patch it is impossible to map all 8K >> of the gicv with 64K pages. >> >> My SOC which works fine with kvm now will go to not working with kvm >> after this patch. > Your SOC currently works by fluke because the guest doesn't > look at the last 4K of the GICC. If you're happy with it continuing > to work by fluke you could make your device tree say it had a > 64K GICV region with a 64K-aligned base. > > To make it work not by fluke but actually correctly requires > Marc's patchset, at a minimum. Since we aren't actually using the last 4K of the gicv at the moment I supppose I could drop my objections to this patch and change my device tree until Marc's patchset provides a proper solution for the gicv's second 4K that works for everybody. Acked-by: Joel Schopp