RE: [RFC PATCH v6 5/7] psci: Add hvc call service for ptp_kvm.

From: Jianyong Wu (Arm Technology China)
Date: Thu Nov 07 2019 - 21:52:09 EST


Hi tglx,

> -----Original Message-----
> From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Sent: Thursday, November 7, 2019 4:01 PM
> To: Jianyong Wu (Arm Technology China) <Jianyong.Wu@xxxxxxx>
> Cc: netdev@xxxxxxxxxxxxxxx; yangbo.lu@xxxxxxx; john.stultz@xxxxxxxxxx;
> pbonzini@xxxxxxxxxx; sean.j.christopherson@xxxxxxxxx; maz@xxxxxxxxxx;
> richardcochran@xxxxxxxxx; Mark Rutland <Mark.Rutland@xxxxxxx>;
> will@xxxxxxxxxx; Suzuki Poulose <Suzuki.Poulose@xxxxxxx>; linux-
> kernel@xxxxxxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx;
> kvmarm@xxxxxxxxxxxxxxxxxxxxx; kvm@xxxxxxxxxxxxxxx; Steve Capper
> <Steve.Capper@xxxxxxx>; Kaly Xin (Arm Technology China)
> <Kaly.Xin@xxxxxxx>; Justin He (Arm Technology China)
> <Justin.He@xxxxxxx>; nd <nd@xxxxxxx>
> Subject: Re: [RFC PATCH v6 5/7] psci: Add hvc call service for ptp_kvm.
>
> On Thu, 24 Oct 2019, Jianyong Wu wrote:
>
> > This patch is the base of ptp_kvm for arm64.
>
> This patch ...
>

Yeah, avoid subjective expression.

> > ptp_kvm modules will call hvc to get this service.
> > The service offers real time and counter cycle of host for guest.
> >
> > Signed-off-by: Jianyong Wu <jianyong.wu@xxxxxxx>
> > ---
> > drivers/clocksource/arm_arch_timer.c | 2 ++
> > include/clocksource/arm_arch_timer.h | 4 ++++
> > include/linux/arm-smccc.h | 12 ++++++++++++
> > virt/kvm/arm/psci.c | 22 ++++++++++++++++++++++
> > 4 files changed, 40 insertions(+)
> >
> > diff --git a/drivers/clocksource/arm_arch_timer.c
> > b/drivers/clocksource/arm_arch_timer.c
> > index 07e57a49d1e8..e4ad38042ef6 100644
> > --- a/drivers/clocksource/arm_arch_timer.c
> > +++ b/drivers/clocksource/arm_arch_timer.c
> > @@ -29,6 +29,7 @@
> > #include <asm/virt.h>
> >
> > #include <clocksource/arm_arch_timer.h>
> > +#include <linux/clocksource_ids.h>
>
> Same ordering issue and lack of file.
>
OK,

> > diff --git a/include/clocksource/arm_arch_timer.h
> > b/include/clocksource/arm_arch_timer.h
> > index 1d68d5613dae..426d749e8cf8 100644
> > --- a/include/clocksource/arm_arch_timer.h
> > +++ b/include/clocksource/arm_arch_timer.h
> > @@ -104,6 +104,10 @@ static inline bool
> arch_timer_evtstrm_available(void)
> > return false;
> > }
> >
> > +bool is_arm_arch_counter(void *unuse)
>
> A global function in a header file? You might want to make this static inline.
> And while at it please s/unuse/unused/
>

Should remove this residue line from v5 in v6.

> > +{
> > + return false;
> > +}
> > #endif
> > #include <linux/linkage.h>
> > diff --git a/virt/kvm/arm/psci.c b/virt/kvm/arm/psci.c index
> > 0debf49bf259..339bcbafac7b 100644
> > --- a/virt/kvm/arm/psci.c
> > +++ b/virt/kvm/arm/psci.c
> > @@ -15,6 +15,7 @@
> > #include <asm/kvm_host.h>
> >
> > #include <kvm/arm_psci.h>
> > +#include <linux/clocksource_ids.h>
>
> Sigh.
>
Yeah,

> > /*
> > * This is an implementation of the Power State Coordination
> > Interface @@ -392,6 +393,8 @@ int kvm_hvc_call_handler(struct
> kvm_vcpu *vcpu)
> > u32 func_id = smccc_get_function(vcpu);
> > u32 val[4] = {};
> > u32 option;
> > + u64 cycles;
> > + struct system_time_snapshot systime_snapshot;
>
> Also here you might notice that the variables are not randomly ordered.
>
Do you mean considering the alignment then put "struct system_time_snapshot systime_snapshot" as the top one and u64 cycles as the second?

Thanks
Jianyong

> Thanks,
>
> tglx