From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoffer Dall Subject: Re: [PATCH v3 00/23] arm64: Virtualization Host Extension support Date: Thu, 4 Feb 2016 20:26:41 +0100 Message-ID: <20160204192641.GJ13974@cbox> References: <1454522416-6874-1-git-send-email-marc.zyngier@arm.com> 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: Marc Zyngier Return-path: Content-Disposition: inline In-Reply-To: <1454522416-6874-1-git-send-email-marc.zyngier@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 List-Id: kvm.vger.kernel.org On Wed, Feb 03, 2016 at 05:59:53PM +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-rc2. I've put a branch out on: > > git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms.git kvm-arm64/vhe > You can have my reviewed-by on all patches that I didn't already review or ack explicitly. Only exception is the debug stuff where I didn't manage to page in the context, so hopefully familiar with that code can have a look. Then this is ready to be queued. Thanks, -Christoffer