[PATCH v5 1/2] perf/kvm: Port perf kvm stat to powerpc
Hemant Kumar
hemant at linux.vnet.ibm.com
Fri Jul 17 02:04:51 AEST 2015
From: Srikar Dronamraju <srikar at linux.vnet.ibm.com>
perf kvm can be used to analyze guest exit reasons. This support already
exists in x86. Hence, porting it to powerpc.
- To trace KVM events :
perf kvm stat record
If many guests are running, we can track for a specific guest by using
--pid as in : perf kvm stat record --pid <pid>
- To see the results :
perf kvm stat report
The result shows the number of exits (from the guest context to
host/hypervisor context) grouped by their respective exit reasons with
their frequency.
To analyze the different exits, group them and present them (in a
slightly descriptive way) to the user, we need a mapping between the
"exit code" (dumped in the kvm_guest_exit tracepoint data) and to its
related Interrupt vector description (exit reason). This patch adds this
mapping in book3s_exits.h.
It records on two available KVM tracepoints :
"kvm_hv:kvm_guest_exit" and "kvm_hv:kvm_guest_enter".
Note that this patch has a direct dependency on
"perf,kvm/ppc: Add kvm_perf.h for powerpc" which adds kvm_perf.h, where
the required kvm tracpoints are defined for "perf kvm stat" to be used.
Here is a sample o/p:
# pgrep qemu
19378
60515
2 Guests are running on the host.
# perf kvm stat record -a
^C[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 4.153 MB perf.data.guest (39624 samples) ]
# perf kvm stat report -p 60515
Analyze events for pid(s) 60515, all VCPUs:
VM-EXIT Samples Samples% Time% Min Time Max Time Avg time
H_DATA_STORAGE 5006 35.30% 0.13% 1.94us 49.46us 12.37us ( +- 0.52% )
HV_DECREMENTER 4457 31.43% 0.02% 0.72us 16.14us 1.91us ( +- 0.96% )
SYSCALL 2690 18.97% 0.10% 2.84us 528.24us 18.29us ( +- 3.75% )
RETURN_TO_HOST 1789 12.61% 99.76% 1.58us 672791.91us 27470.23us ( +- 3.00% )
EXTERNAL 240 1.69% 0.00% 0.69us 10.67us 1.33us ( +- 5.34% )
Total Samples:14182, Total events handled time:49264158.30us.
Signed-off-by: Srikar Dronamraju <srikar at linux.vnet.ibm.com>
Signed-off-by: Hemant Kumar <hemant at linux.vnet.ibm.com>
---
This patch has a direct dependency on:
http://www.mail-archive.com/linuxppc-dev@lists.ozlabs.org/msg91603.html
Changes :
- Added exit reasons definitions(unlikely to change) in the userspace side.
tools/perf/arch/powerpc/Makefile | 1 +
tools/perf/arch/powerpc/util/Build | 1 +
tools/perf/arch/powerpc/util/book3s_exits.h | 33 +++++++++++++++++++++++++++++
tools/perf/arch/powerpc/util/kvm-stat.c | 33 +++++++++++++++++++++++++++++
4 files changed, 68 insertions(+)
create mode 100644 tools/perf/arch/powerpc/util/book3s_exits.h
create mode 100644 tools/perf/arch/powerpc/util/kvm-stat.c
diff --git a/tools/perf/arch/powerpc/Makefile b/tools/perf/arch/powerpc/Makefile
index 7fbca17..21322e0 100644
--- a/tools/perf/arch/powerpc/Makefile
+++ b/tools/perf/arch/powerpc/Makefile
@@ -1,3 +1,4 @@
ifndef NO_DWARF
PERF_HAVE_DWARF_REGS := 1
endif
+HAVE_KVM_STAT_SUPPORT := 1
diff --git a/tools/perf/arch/powerpc/util/Build b/tools/perf/arch/powerpc/util/Build
index 7b8b0d1..c8fe207 100644
--- a/tools/perf/arch/powerpc/util/Build
+++ b/tools/perf/arch/powerpc/util/Build
@@ -1,5 +1,6 @@
libperf-y += header.o
libperf-y += sym-handling.o
+libperf-y += kvm-stat.o
libperf-$(CONFIG_DWARF) += dwarf-regs.o
libperf-$(CONFIG_DWARF) += skip-callchain-idx.o
diff --git a/tools/perf/arch/powerpc/util/book3s_exits.h b/tools/perf/arch/powerpc/util/book3s_exits.h
new file mode 100644
index 0000000..94c58f4
--- /dev/null
+++ b/tools/perf/arch/powerpc/util/book3s_exits.h
@@ -0,0 +1,33 @@
+#ifndef ARCH_PERF_BOOK3S_EXITS_H
+#define ARCH_PERF_BOOK3S_EXITS_H
+
+/*
+ * PowerPC Interrupt vectors : exit code to name mapping
+ */
+
+#define kvm_trace_symbol_exit \
+ {0x0, "RETURN_TO_HOST"}, \
+ {0x100, "SYSTEM_RESET"}, \
+ {0x200, "MACHINE_CHECK"}, \
+ {0x300, "DATA_STORAGE"}, \
+ {0x380, "DATA_SEGMENT"}, \
+ {0x400, "INST_STORAGE"}, \
+ {0x480, "INST_SEGMENT"}, \
+ {0x500, "EXTERNAL"}, \
+ {0x501, "EXTERNAL_LEVEL"}, \
+ {0x502, "EXTERNAL_HV"}, \
+ {0x600, "ALIGNMENT"}, \
+ {0x700, "PROGRAM"}, \
+ {0x800, "FP_UNAVAIL"}, \
+ {0x900, "DECREMENTER"}, \
+ {0x980, "HV_DECREMENTER"}, \
+ {0xc00, "SYSCALL"}, \
+ {0xd00, "TRACE"}, \
+ {0xe00, "H_DATA_STORAGE"}, \
+ {0xe20, "H_INST_STORAGE"}, \
+ {0xe40, "H_EMUL_ASSIST"}, \
+ {0xf00, "PERFMON"}, \
+ {0xf20, "ALTIVEC"}, \
+ {0xf40, "VSX"}
+
+#endif
diff --git a/tools/perf/arch/powerpc/util/kvm-stat.c b/tools/perf/arch/powerpc/util/kvm-stat.c
new file mode 100644
index 0000000..d0e1930
--- /dev/null
+++ b/tools/perf/arch/powerpc/util/kvm-stat.c
@@ -0,0 +1,33 @@
+#include "../../util/kvm-stat.h"
+#include "book3s_exits.h"
+
+define_exit_reasons_table(hv_exit_reasons, kvm_trace_symbol_exit);
+
+static struct kvm_events_ops exit_events = {
+ .is_begin_event = exit_event_begin,
+ .is_end_event = exit_event_end,
+ .decode_key = exit_event_decode_key,
+ .name = "VM-EXIT"
+};
+
+const char *const kvm_events_tp[] = {
+ "kvm_hv:kvm_guest_exit",
+ "kvm_hv:kvm_guest_enter",
+ NULL,
+};
+
+struct kvm_reg_events_ops kvm_reg_events_ops[] = {
+ { .name = "vmexit", .ops = &exit_events },
+ { NULL, NULL },
+};
+
+const char * const kvm_skip_events[] = {
+ NULL,
+};
+
+int cpu_isa_init(struct perf_kvm_stat *kvm, const char *cpuid __maybe_unused)
+{
+ kvm->exit_reasons = hv_exit_reasons;
+ kvm->exit_reasons_isa = "HV";
+ return 0;
+}
--
1.9.3
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