From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marc Zyngier Subject: Re: [PATCH v4 00/23] arm64: Virtualization Host Extension support Date: Mon, 15 Feb 2016 10:34:18 +0000 Message-ID: <56C1A9AA.9040504@arm.com> References: <1455216004-19499-1-git-send-email-marc.zyngier@arm.com> <20160211190701.GA4842@cbox> <56BCDCBA.5080202@arm.com> <20160215102324.GD13683@e104818-lin.cambridge.arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 56280496E4 for ; Mon, 15 Feb 2016 05:28:14 -0500 (EST) Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id OSKWUPUJjwNq for ; Mon, 15 Feb 2016 05:28:12 -0500 (EST) Received: from foss.arm.com (foss.arm.com [217.140.101.70]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 20803496C2 for ; Mon, 15 Feb 2016 05:28:11 -0500 (EST) In-Reply-To: <20160215102324.GD13683@e104818-lin.cambridge.arm.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu To: Catalin Marinas Cc: kvm@vger.kernel.org, Will Deacon , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu List-Id: kvmarm@lists.cs.columbia.edu On 15/02/16 10:23, Catalin Marinas wrote: > 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. Definitely. To make it clear, I do not intend to put anything in -next until all the relevant people has reviewed it, and at least given their Ack. Thanks, M. -- Jazz is not dead. It just smells funny...