Re: [RFC PATCH 45/45] KVM: arm/arm64: vgic-new: enable build

Christoffer Dall
2016-04-12T13:21:31Z

On Mon, Apr 11, 2016 at 03:45:02PM +0100, Andre Przywara wrote:
> Hi,
>
> On 31/03/16 19:18, Christoffer Dall wrote:
> > On Fri, Mar 25, 2016 at 02:05:08AM +0000, Andre Przywara wrote:
> >> Now that the new VGIC implementation has reached feature parity with
> >> the old one, add the new files to the build system and add a Kconfig
> >> option to switch between the two versions.
> >> We set the default to the new version to get maximum test coverage,
> >> in case people experience problems they can switch back to the old
> >> behaviour if needed.
> >>
> >> Signed-off-by: Andre Przywara <andre.przywara@arm.com>
> >> ---
> >> arch/arm/kvm/Kconfig | 7 +++++++
> >> arch/arm/kvm/Makefile | 10 ++++++++++
> >> arch/arm64/kvm/Kconfig | 7 +++++++
> >> arch/arm64/kvm/Makefile | 10 ++++++++++
> >> 4 files changed, 34 insertions(+)
> >>
> >> diff --git a/arch/arm/kvm/Kconfig b/arch/arm/kvm/Kconfig
> >> index 95a0005..02abfff 100644
> >> --- a/arch/arm/kvm/Kconfig
> >> +++ b/arch/arm/kvm/Kconfig
> >> @@ -46,6 +46,13 @@ config KVM_ARM_HOST
> >> ---help---
> >> Provides host support for ARM processors.
> >>
> >> +config KVM_NEW_VGIC
> >> + bool "New VGIC implementation"
> >> + depends on KVM
> >> + default y
> >> + ---help---
> >> + uses the new VGIC implementation
> >> +
> >
> > I had imagined we'd name it in the reverse, so the option would have
> > been CONFIG_KVM_VGIC_LEGACY, but I guess the net effect should be the
> > same, assuming most people just go with the default anyway.
>
> I think originally the assumption was to make the old VGIC the default
> in the beginning, but that changed later. By that time I considered it
> too tedious to change all patches in this regard, so I just kept the old
> symbol and semantic in.
> Shouldn't matter, really, I guess there are arguments for both ways.
>

Agreed, shouldn't matter.

-Christoffer