perf, kvm/arm64: perf-kvm-stat to report VM TRAP

virt inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I4IZPY


CVE: NA

-------------------------------------------------

When guest exits due to "TRAP", we can analyze the guest exit reasons
deeplier. Enhance perf-kvm-stat to record and analyze VM TRAP events.

There is a mapping between guest's "trap_code" (ESR_ELx's bits[31:26])
and "trap_reason" - kvm_arm_exception_class. Copy it from kernel to
aarch64_guest_exits.h, export it to userspace.

This patch records two new KVM tracepoints: "kvm:kvm_trap_enter" and
"kvm:kvm_trap_exit", and reports statistical data between these two
tracepoints.

A simple test go below:

 # ./tools/perf/perf kvm stat record -p 20763
[ perf record: Woken up 92 times to write data ]
[ perf record: Captured and wrote 203.727 MB perf.data.guest (2601786 samples) ]

 # ./tools/perf/perf kvm stat report --event=vmexit

Analyze events for all VMs, all VCPUs:

             VM-EXIT    Samples  Samples%     Time%    Min Time    Max Time         Avg time

                TRAP     640931    97.12%   100.00%      2.44us  14683.86us   3446.49us ( +-   0.05% )
                 IRQ      19019     2.88%     0.00%      0.90us    461.94us      2.12us ( +-   2.09% )

Total Samples:659950, Total events handled time:2209005391.30us.

 # ./tools/perf/perf kvm stat report --event=trap

Analyze events for all VMs, all VCPUs:

          TRAP-EVENT    Samples  Samples%     Time%    Min Time    Max Time         Avg time

                 WFx     601194    93.80%    99.98%      0.90us   4294.04us   3671.01us ( +-   0.03% )
               SYS64      33714     5.26%     0.01%      1.10us     41.34us      5.68us ( +-   0.18% )
            DABT_LOW       6014     0.94%     0.00%      1.12us     18.04us      2.57us ( +-   0.91% )
            IABT_LOW         12     0.00%     0.01%  12597.76us  14679.96us  12893.61us ( +-   1.34% )

Total Samples:640934, Total events handled time:2207353434.56us.

Signed-off-by: Zenghui Yu <yuzenghui@huawei.com>
Reviewed-by: Hailiang Zhang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Zenghui Yu <yuzenghui@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Link: https://lore.kernel.org/r/1560330526-15468-6-git-send-email-yuzenghui@huawei.com
Link: https://gitee.com/openeuler/kernel/commit/59634497418b


Reviewed-by: Yanan Wang <wangyanan55@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>