[RFC 4/4] perf kvm: Fix output fields instead of 'trace' for perf kvm report on powerpc

[Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>]

commit d49dadea7862 ("perf tools: Make 'trace' or 'trace_fields' sort key
default for tracepoint events") makes 'trace' sort key as a default
while displaying report for tracepoint.

Because tracepoint(kvm_hv:kvm_guest_exit) is used as a default event,
perf kvm report will display output as a list of tracepoint hits and
not with a normal report columns.

This patch will replace 'trace' field with 'overhead,comm,dso,sym' while
displaying perf kvm report of powerpc.

Before applying patch:

  $ ./perf kvm --guestkallsyms=guest.kallsyms --guestmodules=guest.modules report --stdio
  # To display the perf.data header info, please use --header/--header-only options.
  #
  #
  # Total Lost Samples: 0
  #
  # Samples: 181K of event 'kvm_hv:kvm_guest_exit'
  # Event count (approx.): 181061
  #
  # Overhead  Trace output
  # ........  .................................................................................
  #
       0.02%  VCPU 8: trap=HV_DECREMENTER pc=0xc000000000091924 msr=0x8000000000009032, ceded=0
       0.00%  VCPU 0: trap=HV_DECREMENTER pc=0xc000000000091924 msr=0x8000000000009032, ceded=0
       0.00%  VCPU 8: trap=HV_DECREMENTER pc=0x10005c7c msr=0x800000000280f032, ceded=0
       0.00%  VCPU 8: trap=HV_DECREMENTER pc=0x1001ef14 msr=0x800000000280f032, ceded=0
       0.00%  VCPU 8: trap=HV_DECREMENTER pc=0x3fff83398830 msr=0x800000000280f032, ceded=0
       0.00%  VCPU 8: trap=HV_DECREMENTER pc=0x3fff833a6fe4 msr=0x800000000280f032, ceded=0
       0.00%  VCPU 8: trap=HV_DECREMENTER pc=0x3fff833a7a64 msr=0x800000000280f032, ceded=0

After applying patch:

  $ ./perf kvm --guestkallsyms=guest.kallsyms --guestmodules=guest.modules report --stdio
  # To display the perf.data header info, please use --header/--header-only options.
  #
  #
  # Total Lost Samples: 0
  #
  # Samples: 181K of event 'kvm_hv:kvm_guest_exit'
  # Event count (approx.): 181061
  #
  # Overhead  Command  Shared Object            Symbol
  # ........  .......  .......................  ..............................
  #
       0.02%  :57276   [guest.kernel.kallsyms]  [g] .plpar_hcall_norets
       0.00%  :57274   [guest.kernel.kallsyms]  [g] .plpar_hcall_norets
       0.00%  :57276   [guest.kernel.kallsyms]  [g] .__copy_tofrom_user_power7
       0.00%  :57276   [guest.kernel.kallsyms]  [g] ._atomic_dec_and_lock
       0.00%  :57276   [guest.kernel.kallsyms]  [g] ._raw_spin_lock
       0.00%  :57276   [guest.kernel.kallsyms]  [g] ._switch
       0.00%  :57276   [guest.kernel.kallsyms]  [g] .bio_add_page
       0.00%  :57276   [guest.kernel.kallsyms]  [g] .kmem_cache_alloc

Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
---
 tools/perf/builtin-report.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index 31ec4ba..5d96882 100644
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -930,6 +930,11 @@ repeat:
 	else
 		use_browser = 0;
 
+	if (!field_order &&
+	    is_perf_data_reorded_on_ppc(session->evlist) &&
+	    perf_guest_only())
+		field_order = "overhead,comm,dso,sym";
+
 	if (setup_sorting(session->evlist) < 0) {
 		if (sort_order)
 			parse_options_usage(report_usage, options, "s", 1);
-- 
2.1.4