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: Thu, 11 Feb 2016 19:10:50 +0000 Message-ID: <56BCDCBA.5080202@arm.com> References: <1455216004-19499-1-git-send-email-marc.zyngier@arm.com> <20160211190701.GA4842@cbox> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org, Catalin Marinas , Will Deacon , linux-kernel@vger.kernel.org, kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org To: Christoffer Dall Return-path: In-Reply-To: <20160211190701.GA4842@cbox> 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 List-Id: kvm.vger.kernel.org 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. Thanks, M. -- Jazz is not dead. It just smells funny...