'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_riscv.h | 60 ++++++++++++++
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, 188 insertions(+)
create mode 100644 arch/riscv/kvm/trace_riscv.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
'perf kvm stat report/record' generates a statistical analysis of KVM
events and can be used to analyze guest exit reasons.
"report" reports statistical analysis of guest exit events.
To record kvm events on the host:
# perf kvm stat record -a
To report kvm VM EXIT events:
# perf kvm stat report --event=vmexit
Signed-off-by: Shenlin Liang <[email protected]>
---
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 ++++++++++
4 files changed, 121 insertions(+)
create mode 100644 tools/perf/arch/riscv/util/kvm-stat.c
create mode 100644 tools/perf/arch/riscv/util/riscv_exception_types.h
diff --git a/tools/perf/arch/riscv/Makefile b/tools/perf/arch/riscv/Makefile
index a8d25d005207..e1e445615536 100644
--- a/tools/perf/arch/riscv/Makefile
+++ b/tools/perf/arch/riscv/Makefile
@@ -3,3 +3,4 @@ PERF_HAVE_DWARF_REGS := 1
endif
PERF_HAVE_ARCH_REGS_QUERY_REGISTER_OFFSET := 1
PERF_HAVE_JITDUMP := 1
+HAVE_KVM_STAT_SUPPORT := 1
\ No newline at end of file
diff --git a/tools/perf/arch/riscv/util/Build b/tools/perf/arch/riscv/util/Build
index 603dbb5ae4dc..d72b04f8d32b 100644
--- a/tools/perf/arch/riscv/util/Build
+++ b/tools/perf/arch/riscv/util/Build
@@ -1,5 +1,6 @@
perf-y += perf_regs.o
perf-y += header.o
+perf-$(CONFIG_LIBTRACEEVENT) += kvm-stat.o
perf-$(CONFIG_DWARF) += dwarf-regs.o
perf-$(CONFIG_LIBDW_DWARF_UNWIND) += unwind-libdw.o
diff --git a/tools/perf/arch/riscv/util/kvm-stat.c b/tools/perf/arch/riscv/util/kvm-stat.c
new file mode 100644
index 000000000000..db7183e0f09f
--- /dev/null
+++ b/tools/perf/arch/riscv/util/kvm-stat.c
@@ -0,0 +1,78 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Arch specific functions for perf kvm stat.
+ *
+ * Copyright 2024 Beijing ESWIN Computing Technology Co., Ltd.
+ *
+ */
+#include <errno.h>
+#include <memory.h>
+#include "../../../util/evsel.h"
+#include "../../../util/kvm-stat.h"
+#include "riscv_exception_types.h"
+#include "debug.h"
+
+define_exit_reasons_table(riscv_exit_reasons, kvm_riscv_exception_class);
+
+const char *kvm_exit_reason = "scause";
+const char *kvm_entry_trace = "kvm:kvm_entry";
+const char *kvm_exit_trace = "kvm:kvm_exit";
+
+const char *kvm_events_tp[] = {
+ "kvm:kvm_entry",
+ "kvm:kvm_exit",
+ NULL,
+};
+
+static void event_get_key(struct evsel *evsel,
+ struct perf_sample *sample,
+ struct event_key *key)
+{
+ key->info = 0;
+ key->key = evsel__intval(evsel, sample, kvm_exit_reason);
+ key->key = (int)key->key;
+ key->exit_reasons = riscv_exit_reasons;
+}
+
+static bool event_begin(struct evsel *evsel,
+ struct perf_sample *sample __maybe_unused,
+ struct event_key *key __maybe_unused)
+{
+ return evsel__name_is(evsel, kvm_entry_trace);
+}
+
+static bool event_end(struct evsel *evsel,
+ struct perf_sample *sample,
+ struct event_key *key)
+{
+ if (evsel__name_is(evsel, kvm_exit_trace)) {
+ event_get_key(evsel, sample, key);
+ return true;
+ }
+ return false;
+}
+
+static struct kvm_events_ops exit_events = {
+ .is_begin_event = event_begin,
+ .is_end_event = event_end,
+ .decode_key = exit_event_decode_key,
+ .name = "VM-EXIT"
+};
+
+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_isa = "riscv64";
+ return 0;
+}
diff --git a/tools/perf/arch/riscv/util/riscv_exception_types.h b/tools/perf/arch/riscv/util/riscv_exception_types.h
new file mode 100644
index 000000000000..2e42150f72b2
--- /dev/null
+++ b/tools/perf/arch/riscv/util/riscv_exception_types.h
@@ -0,0 +1,41 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * RISCV exception types
+ *
+ * Copyright 2024 Beijing ESWIN Computing Technology Co., Ltd.
+ *
+ */
+#ifndef ARCH_PERF_RISCV_EXCEPTION_TYPES_H
+#define ARCH_PERF_RISCV_EXCEPTION_TYPES_H
+
+#define EXC_INST_MISALIGNED 0
+#define EXC_INST_ACCESS 1
+#define EXC_INST_ILLEGAL 2
+#define EXC_BREAKPOINT 3
+#define EXC_LOAD_MISALIGNED 4
+#define EXC_LOAD_ACCESS 5
+#define EXC_STORE_MISALIGNED 6
+#define EXC_STORE_ACCESS 7
+#define EXC_SYSCALL 8
+#define EXC_HYPERVISOR_SYSCALL 9
+#define EXC_SUPERVISOR_SYSCALL 10
+#define EXC_INST_PAGE_FAULT 12
+#define EXC_LOAD_PAGE_FAULT 13
+#define EXC_STORE_PAGE_FAULT 15
+#define EXC_INST_GUEST_PAGE_FAULT 20
+#define EXC_LOAD_GUEST_PAGE_FAULT 21
+#define EXC_VIRTUAL_INST_FAULT 22
+#define EXC_STORE_GUEST_PAGE_FAULT 23
+
+#define EXC(x) {EXC_##x, #x }
+
+#define kvm_riscv_exception_class \
+ (EXC(INST_MISALIGNED), EXC(INST_ACCESS), EXC(INST_ILLEGAL), \
+ EXC(BREAKPOINT), EXC(LOAD_MISALIGNED), EXC(LOAD_ACCESS), \
+ EXC(STORE_MISALIGNED), EXC(STORE_ACCESS), EXC(SYSCALL), \
+ EXC(HYPERVISOR_SYSCALL), EXC(SUPERVISOR_SYSCALL), \
+ EXC(INST_PAGE_FAULT), EXC(LOAD_PAGE_FAULT), EXC(STORE_PAGE_FAULT), \
+ EXC(INST_GUEST_PAGE_FAULT), EXC(LOAD_GUEST_PAGE_FAULT), \
+ EXC(VIRTUAL_INST_FAULT), EXC(STORE_GUEST_PAGE_FAULT))
+
+#endif /* ARCH_PERF_RISCV_EXCEPTION_TYPES_H */
--
2.37.2
Gentle ping...
>
> '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_riscv.h | 60 ++++++++++++++
> 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, 188 insertions(+)
> create mode 100644 arch/riscv/kvm/trace_riscv.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