[PATCH 2/2] perf kvm/riscv: Port perf kvm stat to RISC-V

Shenlin Liang
2024-03-28T03:20:28Z

'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 <liangshenlin@eswincomputing.com>
---
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