RE: [PATCH v12 5/5] Drivers: hv: Enable Hyper-V code to be built on ARM64

[Michael Kelley <mikelley@microsoft.com>]

From: Wei Liu <wei.liu@kernel.org> Sent: Wednesday, August 4, 2021 9:40 AM
> 
> On Wed, Aug 04, 2021 at 05:10:41PM +0100, Catalin Marinas wrote:
> > On Wed, Aug 04, 2021 at 08:52:39AM -0700, Michael Kelley wrote:
> > > Update drivers/hv/Kconfig so CONFIG_HYPERV can be selected on
> > > ARM64, causing the Hyper-V specific code to be built. Exclude the
> > > Hyper-V enlightened clocks/timers code from being built for ARM64.
> > >
> > > Signed-off-by: Michael Kelley <mikelley@microsoft.com>
> > > Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
> > > Acked-by: Marc Zyngier <maz@kernel.org>
> > > Acked-by: Mark Rutland <mark.rutland@arm.com>
> > >
> > > ---
> > >  drivers/hv/Kconfig | 5 +++--
> > >  1 file changed, 3 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/drivers/hv/Kconfig b/drivers/hv/Kconfig
> > > index 66c794d..e509d5d 100644
> > > --- a/drivers/hv/Kconfig
> > > +++ b/drivers/hv/Kconfig
> > > @@ -4,7 +4,8 @@ menu "Microsoft Hyper-V guest support"
> > >
> > >  config HYPERV
> > >  	tristate "Microsoft Hyper-V client drivers"
> > > -	depends on X86 && ACPI && X86_LOCAL_APIC && HYPERVISOR_GUEST
> > > +	depends on ACPI && ((X86 && X86_LOCAL_APIC && HYPERVISOR_GUEST) \
> > > +		|| (ARM64 && !CPU_BIG_ENDIAN))
> > >  	select PARAVIRT
> > >  	select X86_HV_CALLBACK_VECTOR
> >
> > Does this need to be:
> >
> > 	select X86_HV_CALLBACK_VECTOR if X86
> >
> > I haven't checked whether it gives a warning on arm64 but that symbol
> > doesn't exist.

The symbol is only referenced in code under arch/x86, so there's
no warning when building for arm64.  But yes, it would be good
hygiene to add the "if X86".

Michael

> >
> > Anyway, I can fix it up locally.
> 
> I can fix it up while I queue these patches.
> 
> Wei.