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

From: "Jianyong Wu (Arm Technology China)" <Jianyong.Wu@arm.com>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: "netdev@vger.kernel.org" <netdev@vger.kernel.org>,
	"yangbo.lu@nxp.com" <yangbo.lu@nxp.com>,
	"john.stultz@linaro.org" <john.stultz@linaro.org>,
	"pbonzini@redhat.com" <pbonzini@redhat.com>,
	"sean.j.christopherson@intel.com"
	<sean.j.christopherson@intel.com>,
	"maz@kernel.org" <maz@kernel.org>,
	"richardcochran@gmail.com" <richardcochran@gmail.com>,
	Mark Rutland <Mark.Rutland@arm.com>,
	"will@kernel.org" <will@kernel.org>,
	Suzuki Poulose <Suzuki.Poulose@arm.com>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"linux-arm-kernel@lists.infradead.org" 
	<linux-arm-kernel@lists.infradead.org>,
	"kvmarm@lists.cs.columbia.edu" <kvmarm@lists.cs.columbia.edu>,
	"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
	Steve Capper <Steve.Capper@arm.com>,
	"Kaly Xin (Arm Technology China)" <Kaly.Xin@arm.com>,
	"Justin He (Arm Technology China)" <Justin.He@arm.com>,
	nd <nd@arm.com>
Subject: RE: [RFC PATCH v6 5/7] psci: Add hvc call service for ptp_kvm.
Date: Fri, 8 Nov 2019 02:51:44 +0000	[thread overview]
Message-ID: <HE1PR0801MB16766C7E11CF88D32BC0A4BAF47B0@HE1PR0801MB1676.eurprd08.prod.outlook.com> (raw)
In-Reply-To: <alpine.DEB.2.21.1911070856100.1869@nanos.tec.linutronix.de>

Hi tglx,

> -----Original Message-----
> From: Thomas Gleixner <tglx@linutronix.de>
> Sent: Thursday, November 7, 2019 4:01 PM
> To: Jianyong Wu (Arm Technology China) <Jianyong.Wu@arm.com>
> Cc: netdev@vger.kernel.org; yangbo.lu@nxp.com; john.stultz@linaro.org;
> pbonzini@redhat.com; sean.j.christopherson@intel.com; maz@kernel.org;
> richardcochran@gmail.com; Mark Rutland <Mark.Rutland@arm.com>;
> will@kernel.org; Suzuki Poulose <Suzuki.Poulose@arm.com>; linux-
> kernel@vger.kernel.org; linux-arm-kernel@lists.infradead.org;
> kvmarm@lists.cs.columbia.edu; kvm@vger.kernel.org; Steve Capper
> <Steve.Capper@arm.com>; Kaly Xin (Arm Technology China)
> <Kaly.Xin@arm.com>; Justin He (Arm Technology China)
> <Justin.He@arm.com>; nd <nd@arm.com>
> 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@arm.com>
> > ---
> >  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