linux-kernel - [PATCH v2 0/2] perf kvm: Add kvm stat support on riscv

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <20240415031131.23443-1-liangshenlin@eswincomputing.com>
Date: Mon, 15 Apr 2024 03:11:29 +0000
From: Shenlin Liang <liangshenlin@...incomputing.com>
To: anup@...infault.org,
	atishp@...shpatra.org,
	paul.walmsley@...ive.com,
	palmer@...belt.com,
	aou@...s.berkeley.edu,
	kvm@...r.kernel.org,
	kvm-riscv@...ts.infradead.org,
	linux-riscv@...ts.infradead.org,
	linux-kernel@...r.kernel.org,
	peterz@...radead.org,
	mingo@...hat.com,
	acme@...nel.org,
	namhyung@...nel.org,
	mark.rutland@....com,
	alexander.shishkin@...ux.intel.com,
	jolsa@...nel.org,
	irogers@...gle.com,
	adrian.hunter@...el.com,
	linux-perf-users@...r.kernel.org
Cc: Shenlin Liang <liangshenlin@...incomputing.com>
Subject: [PATCH v2 0/2] perf kvm: Add kvm stat support on riscv

Changes from v1->v2:
- Rebased on Linux 6.9-rc3.

'perf kvm stat report/record' generates a statistical analysis of KVM
events and can be used to analyze guest exit reasons. This patch tries
to add stat support on riscv.

Map the return value of trace_kvm_exit() to the specific cause of the 
exception, and export it to userspace.

It records on two available KVM tracepoints for riscv: "kvm:kvm_entry"
and "kvm:kvm_exit", and reports statistical data which includes events
handles time, samples, and so on.

Simple tests go below:

# ./perf kvm record -e "kvm:kvm_entry" -e "kvm:kvm_exit"
Lowering default frequency rate from 4000 to 2500.
Please consider tweaking /proc/sys/kernel/perf_event_max_sample_rate.
[ perf record: Woken up 18 times to write data ]
[ perf record: Captured and wrote 5.433 MB perf.data.guest (62519 samples) 

# ./perf kvm report
31K kvm:kvm_entry
31K kvm:kvm_exit

# ./perf kvm stat record -a
[ perf record: Woken up 3 times to write data ]
[ perf record: Captured and wrote 8.502 MB perf.data.guest (99338 samples) ]

# ./perf kvm stat report --event=vmexit
Event name                Samples   Sample%    Time (ns)     Time%   Max Time (ns)   Min Time (ns)  Mean Time (ns)
STORE_GUEST_PAGE_FAULT     26968     54.00%    2003031800    40.00%     3361400         27600          74274
LOAD_GUEST_PAGE_FAULT      17645     35.00%    1153338100    23.00%     2513400         30800          65363
VIRTUAL_INST_FAULT         1247      2.00%     340820800     6.00%      1190800         43300          273312
INST_GUEST_PAGE_FAULT      1128      2.00%     340645800     6.00%      2123200         30200          301990
SUPERVISOR_SYSCALL         1019      2.00%     245989900     4.00%      1851500         29300          241403
LOAD_ACCESS                986       1.00%     671556200     13.00%     4180200         100700         681091
INST_ACCESS                655       1.00%     170054800     3.00%      1808300         54600          259625
HYPERVISOR_SYSCALL         21        0.00%     4276400       0.00%      716500          116000         203638 

Shenlin Liang (2):
  RISCV: KVM: add tracepoints for entry and exit events
  perf kvm/riscv: Port perf kvm stat to RISC-V

 arch/riscv/kvm/trace.h                        | 67 ++++++++++++++++
 arch/riscv/kvm/vcpu.c                         |  7 ++
 tools/perf/arch/riscv/Makefile                |  1 +
 tools/perf/arch/riscv/util/Build              |  1 +
 tools/perf/arch/riscv/util/kvm-stat.c         | 78 +++++++++++++++++++
 .../arch/riscv/util/riscv_exception_types.h   | 41 ++++++++++
 6 files changed, 195 insertions(+)
 create mode 100644 arch/riscv/kvm/trace.h
 create mode 100644 tools/perf/arch/riscv/util/kvm-stat.c
 create mode 100644 tools/perf/arch/riscv/util/riscv_exception_types.h

-- 
2.37.2