RE: [PATCH v14 07/10] arm64/kvm: Add hypercall service for kvm ptp.

[Jianyong Wu]

Hi Marc,

> -----Original Message-----
> From: Marc Zyngier <maz@xxxxxxxxxx>
> Sent: Saturday, September 5, 2020 7:04 PM
> To: Jianyong Wu <Jianyong.Wu@xxxxxxx>
> Cc: netdev@xxxxxxxxxxxxxxx; yangbo.lu@xxxxxxx; john.stultz@xxxxxxxxxx;
> tglx@xxxxxxxxxxxxx; pbonzini@xxxxxxxxxx; sean.j.christopherson@xxxxxxxxx;
> richardcochran@xxxxxxxxx; Mark Rutland <Mark.Rutland@xxxxxxx>;
> will@xxxxxxxxxx; Suzuki Poulose <Suzuki.Poulose@xxxxxxx>; Steven Price
> <Steven.Price@xxxxxxx>; linux-kernel@xxxxxxxxxxxxxxx; linux-arm-
> kernel@xxxxxxxxxxxxxxxxxxx; kvmarm@xxxxxxxxxxxxxxxxxxxxx;
> kvm@xxxxxxxxxxxxxxx; Steve Capper <Steve.Capper@xxxxxxx>; Justin He
> <Justin.He@xxxxxxx>; nd <nd@xxxxxxx>
> Subject: Re: [PATCH v14 07/10] arm64/kvm: Add hypercall service for kvm
> ptp.
> 
> On Fri, 04 Sep 2020 10:27:41 +0100,
> Jianyong Wu <jianyong.wu@xxxxxxx> wrote:
> >
> > ptp_kvm will get this service through smccc call.
> > The service offers wall time and counter cycle of host for guest.
> > caller must explicitly determines which cycle of virtual counter or
> > physical counter to return if it needs counter cycle.
> >
> > Signed-off-by: Jianyong Wu <jianyong.wu@xxxxxxx>
> > ---
> >  arch/arm64/kvm/Kconfig       |  6 +++++
> >  arch/arm64/kvm/arch_timer.c  |  2 +-
> >  arch/arm64/kvm/hypercalls.c  | 49
> > ++++++++++++++++++++++++++++++++++++
> >  include/kvm/arm_arch_timer.h |  1 +
> >  include/linux/arm-smccc.h    | 16 ++++++++++++
> >  5 files changed, 73 insertions(+), 1 deletion(-)
> >
> 
> [...]
> 
> On top of what I said yesterday:
> 
> > index 32ba6fbc3814..eb85f6701845 100644
> > --- a/arch/arm64/kvm/arch_timer.c
> > +++ b/arch/arm64/kvm/arch_timer.c
> > @@ -81,7 +81,7 @@ u64 timer_get_cval(struct arch_timer_context *ctxt)
> >  	}
> >  }
> >
> > -static u64 timer_get_offset(struct arch_timer_context *ctxt)
> > +u64 timer_get_offset(struct arch_timer_context *ctxt)
> >  {
> >  	struct kvm_vcpu *vcpu = ctxt->vcpu;
> >
> 
> Why has this become global? I can't see a reason why we would want to
> expose this purely KVM internal helper.
> 
Sorry to have forgotten remove this change.

Thanks
Jianyong 
> 	M.
> 
> --
> Without deviation from the norm, progress is not possible.