From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752704AbcBOKXb (ORCPT ); Mon, 15 Feb 2016 05:23:31 -0500 Received: from foss.arm.com ([217.140.101.70]:43991 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750960AbcBOKXa (ORCPT ); Mon, 15 Feb 2016 05:23:30 -0500 Date: Mon, 15 Feb 2016 10:23:25 +0000 From: Catalin Marinas To: Marc Zyngier Cc: Christoffer Dall , Mark Rutland , kvm@vger.kernel.org, Will Deacon , linux-kernel@vger.kernel.org, Alex =?iso-8859-1?Q?Benn=E9e?= , kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v4 00/23] arm64: Virtualization Host Extension support Message-ID: <20160215102324.GD13683@e104818-lin.cambridge.arm.com> References: <1455216004-19499-1-git-send-email-marc.zyngier@arm.com> <20160211190701.GA4842@cbox> <56BCDCBA.5080202@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <56BCDCBA.5080202@arm.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Feb 11, 2016 at 07:10:50PM +0000, Marc Zyngier wrote: > On 11/02/16 19:07, Christoffer Dall wrote: > > On Thu, Feb 11, 2016 at 06:39:41PM +0000, Marc Zyngier wrote: > >> ARMv8.1 comes with the "Virtualization Host Extension" (VHE for > >> short), which enables simpler support of Type-2 hypervisors. > >> > >> This extension allows the kernel to directly run at EL2, and > >> significantly reduces the number of system registers shared between > >> host and guest, reducing the overhead of virtualization. > >> > >> In order to have the same kernel binary running on all versions of the > >> architecture, this series makes heavy use of runtime code patching. > >> > >> The first 22 patches massage the KVM code to deal with VHE and enable > >> Linux to run at EL2. The last patch catches an ugly case when VHE > >> capable CPUs are paired with some of their less capable siblings. This > >> should never happen, but hey... > >> > >> I have deliberately left out some of the more "advanced" > >> optimizations, as they are likely to distract the reviewer from the > >> core infrastructure, which is what I care about at the moment. > >> > >> Note: GDB is currently busted on VHE systems, as it checks for version > >> 6 on the debug architecture, while VHE is version 7. The > >> binutils people are on the case. > >> > >> This has been tested on the FVP_Base_SLV-V8-A model, and based on > >> v4.5-rc3 + kvmarm/master. I've put a branch out on: > >> > >> git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms.git kvm-arm64/vhe > > > > I'm happy with this series as it stands, we just need someone to take a > > look at that debug patch and be happy with it. > > I think Will is planning to have a go at it shortly. Once he and Catalin > are happy with the thing, I'll throw it into -next for a good shake. Fine by me but it would be good for Will to have a look, especially on the debug and perf stuff. -- Catalin