Re: [PATCH 2/2] KVM: arm64: Depend on HAVE_KVM => OF instead of directly on OF

From: Sean Christopherson
Date: Wed Sep 29 2021 - 11:56:24 EST


On Wed, Sep 29, 2021, Will Deacon wrote:
> On Tue, Sep 21, 2021 at 03:22:31PM -0700, Sean Christopherson wrote:
> > Select HAVE_KVM if the KVM dependency is met (OF / Open Firmware), and
> > make KVM depend on HAVE_KVM instead of directly on OF. This fixes the
> > oddity where arm64 configs can end up with KVM=y and HAVE_KVM=n, and will
> > hopefully prevent breakage if there are future users of HAVE_KVM.
> >
> > Note, arm64 unconditionally selects OF, and has always done so (see
> > commit 8c2c3df31e3b ("arm64: Build infrastructure"). Keep the somewhat
> > pointless HAVE_KVM dependency on OF to document that KVM requires Open
> > Firmware support.
> >
> > No functional change intended.
> >
> > Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
> > ---
> > arch/arm64/Kconfig | 1 +
> > arch/arm64/kvm/Kconfig | 2 +-
> > 2 files changed, 2 insertions(+), 1 deletion(-)
> >
> > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
> > index b5b13a932561..38c0f36a5ed4 100644
> > --- a/arch/arm64/Kconfig
> > +++ b/arch/arm64/Kconfig
> > @@ -187,6 +187,7 @@ config ARM64
> > select HAVE_GCC_PLUGINS
> > select HAVE_HW_BREAKPOINT if PERF_EVENTS
> > select HAVE_IRQ_TIME_ACCOUNTING
> > + select HAVE_KVM if OF
>
> Honestly, I'd just drop the 'if OF' here. We select it unconditionally a
> few lines below and so I think it's more confusing to have the check.

Work for me. I all but flipped a coin when deciding whether or not to keep the
OF dependency.

Thanks!