Re: [PATCH v3 00/23] arm64: Virtualization Host Extension support

Christoffer Dall
2016-02-04T19:26:41Z

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