Re: [PATCH 3/5] perf: arm_spe: Add nested virt event decoding

From: Leo Yan <leo.yan@linaro.org>
To: Andre Przywara <andre.przywara@arm.com>
Cc: Will Deacon <will@kernel.org>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@redhat.com>,
	Arnaldo Carvalho de Melo <acme@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	Alexander Shishkin <alexander.shishkin@linux.intel.com>,
	Jiri Olsa <jolsa@redhat.com>, Namhyung Kim <namhyung@kernel.org>,
	Suzuki K Poulose <suzuki.poulose@arm.com>,
	Tan Xiaojun <tanxiaojun@huawei.com>,
	James Clark <james.clark@arm.com>,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH 3/5] perf: arm_spe: Add nested virt event decoding
Date: Sun, 27 Sep 2020 11:11:27 +0800	[thread overview]
Message-ID: <20200927031127.GC9677@leoy-ThinkPad-X240s> (raw)
In-Reply-To: <20200922101225.183554-4-andre.przywara@arm.com>

On Tue, Sep 22, 2020 at 11:12:23AM +0100, Andre Przywara wrote:
> The ARMv8.4 nested virtualisation extension can redirect system register
> accesses to a memory page controlled by the hypervisor. The SPE
> profiling feature in newer implementations can tag those memory accesses
> accordingly.
> 
> Add the bit pattern describing this load/store type, so that the perf
> tool can decode it properly.
> 
> Signed-off-by: Andre Przywara <andre.przywara@arm.com>
> ---
>  tools/perf/util/arm-spe-decoder/arm-spe-pkt-decoder.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/tools/perf/util/arm-spe-decoder/arm-spe-pkt-decoder.c b/tools/perf/util/arm-spe-decoder/arm-spe-pkt-decoder.c
> index e633bb5b8e65..943e4155b246 100644
> --- a/tools/perf/util/arm-spe-decoder/arm-spe-pkt-decoder.c
> +++ b/tools/perf/util/arm-spe-decoder/arm-spe-pkt-decoder.c
> @@ -398,6 +398,10 @@ int arm_spe_pkt_desc(const struct arm_spe_pkt *packet, char *buf,
>  					buf += ret;
>  					blen -= ret;
>  				}
> +			} else if ((payload & 0xfe) == 0x30) {
> +				ret = snprintf(buf, buf_len, " NV-SYSREG");
> +				buf += ret;
> +				blen -= ret;

This change has been included in the patch "perf arm-spe: Add more sub
classes for operation packet" [1].

Thanks,
Leo

[1] https://lore.kernel.org/patchwork/patch/1288412/

>  			} else if (payload & 0x4) {
>  				ret = snprintf(buf, buf_len, " SIMD-FP");
>  				buf += ret;
> -- 
> 2.17.1
> 