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Date:   Tue, 15 Sep 2020 19:57:02 +0900
From:   Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
To:     Leo Yan <leo.yan@linaro.org>
Cc:     Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Will Deacon <will@kernel.org>,
        John Garry <john.garry@huawei.com>,
        Mathieu Poirier <mathieu.poirier@linaro.org>,
        Namhyung Kim <namhyung@kernel.org>,
        Suleiman Souhlal <suleiman@google.com>,
        linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCHv2] perf kvm: add kvm-stat for arm64
Message-ID: <20200915105702.GA604@jagdpanzerIV.localdomain>
References: <20200915091140.152775-1-sergey.senozhatsky@gmail.com>
 <20200915103644.GA32758@leoy-ThinkPad-X240s>
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Hello,

On (20/09/15 18:36), Leo Yan wrote:
> > +#define HVC_STUB_ERR		  0xbadca11
> > +
> > +/* Per asm/kvm_asm.h */
> > +#define ARM_EXCEPTION_IRQ		0
> > +#define ARM_EXCEPTION_EL1_SERROR	1
> > +#define ARM_EXCEPTION_TRAP		2
> > +#define ARM_EXCEPTION_IL		3
>
> Nitpick: from completeness, we also can give out KVM exiting reason
> for 'ARM_EXCEPTION_IL'.

OK, let me take a look.

> > +define_exit_reasons_table(arm64_exit_reasons, kvm_arm_exception_type);
> > +define_exit_reasons_table(arm64_trap_exit_reasons, kvm_arm_exception_class);
> > +
> > +const char *kvm_trap_exit_reason = "esr_ec";
> > +const char *vcpu_id_str = "id";
> > +const int decode_str_len = 20;
> > +const char *kvm_exit_reason = "ret";
> > +const char *kvm_entry_trace = "kvm:kvm_entry";
> > +const char *kvm_exit_trace = "kvm:kvm_exit";
> > +
> > +const char *kvm_events_tp[] = {
> > +	"kvm:kvm_entry",
> > +	"kvm:kvm_exit",
>
> I think Arm64 needs to support event 'kvm_mmio'.  It's good to use a
> new patch for support this event?

Yes, I guess a follow up kvm_mmio patch would be a better option.

> > +int cpu_isa_init(struct perf_kvm_stat *kvm, const char *cpuid __maybe_unused)
> > +{
> > +	kvm->exit_reasons = arm64_exit_reasons;
>
> Since the "kvm->exit_reasons" will be always set in the function
> event_get_key(), seems to me here can remove this assignment.

Yes, this assignment is a leftover.

	-ss