The perf kvm still use the legacy interface.

Switch to the new perf_mmap__read_event() interface for perf kvm.

No functional change.

Committer notes:

Tested before and after running:

  # perf kvm stat record

On a machine with a kvm guest, then used:

  # perf kvm stat report

Before/after results match and look like:

  # perf kvm stat record -a sleep 5
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 2.132 MB perf.data.guest (1828 samples) ]
  # perf kvm stat report

  Analyze events for all VMs, all VCPUs:

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

      IO_INSTRUCTION     258   40.06%  0.08%   3.51us    122.54us     14.87us (+- 6.76%)
           MSR_WRITE     178   27.64%  0.01%   0.47us      6.34us      2.18us (+- 4.80%)
       EPT_MISCONFIG     148   22.98%  0.03%   3.76us     65.60us     11.22us (+- 8.14%)
                 HLT      47    7.30% 99.88% 181.69us 249988.06us 102061.36us (+-13.49%)
   PAUSE_INSTRUCTION       5    0.78%  0.00%   0.38us      0.79us      0.47us (+-17.05%)
            MSR_READ       4    0.62%  0.00%   1.14us      3.33us      2.67us (+-19.35%)
  EXTERNAL_INTERRUPT       2    0.31%  0.00%   2.15us      2.17us      2.16us (+- 0.30%)
   PENDING_INTERRUPT       1    0.16%  0.00%   2.56us      2.56us      2.56us (+- 0.00%)
    PREEMPTION_TIMER       1    0.16%  0.00%   3.21us      3.21us      3.21us (+- 0.00%)

  Total Samples:644, Total events handled time:4802790.72us.

  #
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1519945751-37786-1-git-send-email-kan.liang@linux.intel.com
[ Changed bool parameters from 0 to 'false', as per Jiri comment ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>