[PATCHv4] perf kvm: add kvm-stat for arm64

From: Sergey Senozhatsky
Date: Thu Sep 17 2020 - 06:02:53 EST

Add support for perf kvm stat on arm64 platform.

Example:
# perf kvm stat report

Analyze events for all VMs, all VCPUs:

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

DABT_LOW 661867 98.91% 40.45% 2.19us 3364.65us 6.24us ( +- 0.34% )
IRQ 4598 0.69% 57.44% 2.89us 3397.59us 1276.27us ( +- 1.61% )
WFx 1475 0.22% 1.71% 2.22us 3388.63us 118.31us ( +- 8.69% )
IABT_LOW 1018 0.15% 0.38% 2.22us 2742.07us 38.29us ( +- 12.55% )
SYS64 180 0.03% 0.01% 2.07us 112.91us 6.57us ( +- 14.95% )
HVC64 17 0.00% 0.01% 2.19us 322.35us 42.95us ( +- 58.98% )

Total Samples:669155, Total events handled time:10216387.86us.

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx>
Reviewed-by: Leo Yan <leo.yan@xxxxxxxxxx>
Tested-by: Leo Yan <leo.yan@xxxxxxxxxx>

---

v4: rebased (Leo)
v3: report ARM_EXCEPTION_IL exceptions (Leo)
v2: reworked the patch after offline discussion with Suleiman

tools/perf/arch/arm64/Makefile | 1 +
tools/perf/arch/arm64/util/Build | 1 +
.../arch/arm64/util/arm64_exception_types.h | 92 +++++++++++++++++++
tools/perf/arch/arm64/util/kvm-stat.c | 85 +++++++++++++++++
4 files changed, 179 insertions(+)
create mode 100644 tools/perf/arch/arm64/util/arm64_exception_types.h
create mode 100644 tools/perf/arch/arm64/util/kvm-stat.c

diff --git a/tools/perf/arch/arm64/Makefile b/tools/perf/arch/arm64/Makefile
index dbef716a1913..fab3095fb5d0 100644
--- a/tools/perf/arch/arm64/Makefile
+++ b/tools/perf/arch/arm64/Makefile
@@ -4,6 +4,7 @@ PERF_HAVE_DWARF_REGS := 1
endif
PERF_HAVE_JITDUMP := 1
PERF_HAVE_ARCH_REGS_QUERY_REGISTER_OFFSET := 1
+HAVE_KVM_STAT_SUPPORT := 1

#
# Syscall table generation for perf
diff --git a/tools/perf/arch/arm64/util/Build b/tools/perf/arch/arm64/util/Build
index 5c13438c7bd4..4cba12f4b741 100644
--- a/tools/perf/arch/arm64/util/Build
+++ b/tools/perf/arch/arm64/util/Build
@@ -1,6 +1,7 @@
perf-y += header.o
perf-y += machine.o
perf-y += perf_regs.o
+perf-y += kvm-stat.o
perf-$(CONFIG_DWARF) += dwarf-regs.o
perf-$(CONFIG_LOCAL_LIBUNWIND) += unwind-libunwind.o
perf-$(CONFIG_LIBDW_DWARF_UNWIND) += unwind-libdw.o
diff --git a/tools/perf/arch/arm64/util/arm64_exception_types.h b/tools/perf/arch/arm64/util/arm64_exception_types.h
new file mode 100644
index 000000000000..27c981ebe401
--- /dev/null
+++ b/tools/perf/arch/arm64/util/arm64_exception_types.h
@@ -0,0 +1,92 @@
+// SPDX-License-Identifier: GPL-2.0
+#ifndef ARCH_PERF_ARM64_EXCEPTION_TYPES_H
+#define ARCH_PERF_ARM64_EXCEPTION_TYPES_H
+
+/* Per asm/virt.h */
+#define HVC_STUB_ERR 0xbadca11
+
+/* Per asm/kvm_asm.h */
+#define ARM_EXCEPTION_IRQ 0
+#define ARM_EXCEPTION_EL1_SERROR 1
+#define ARM_EXCEPTION_TRAP 2
+#define ARM_EXCEPTION_IL 3
+/* The hyp-stub will return this for any kvm_call_hyp() call */
+#define ARM_EXCEPTION_HYP_GONE HVC_STUB_ERR
+
+#define kvm_arm_exception_type \
+ {ARM_EXCEPTION_IRQ, "IRQ" }, \
+ {ARM_EXCEPTION_EL1_SERROR, "SERROR" }, \
+ {ARM_EXCEPTION_TRAP, "TRAP" }, \
+ {ARM_EXCEPTION_IL, "ILLEGAL" }, \
+ {ARM_EXCEPTION_HYP_GONE, "HYP_GONE" }
+
+/* Per asm/esr.h */
+#define ESR_ELx_EC_UNKNOWN (0x00)
+#define ESR_ELx_EC_WFx (0x01)
+/* Unallocated EC: 0x02 */
+#define ESR_ELx_EC_CP15_32 (0x03)
+#define ESR_ELx_EC_CP15_64 (0x04)
+#define ESR_ELx_EC_CP14_MR (0x05)
+#define ESR_ELx_EC_CP14_LS (0x06)
+#define ESR_ELx_EC_FP_ASIMD (0x07)
+#define ESR_ELx_EC_CP10_ID (0x08) /* EL2 only */
+#define ESR_ELx_EC_PAC (0x09) /* EL2 and above */
+/* Unallocated EC: 0x0A - 0x0B */
+#define ESR_ELx_EC_CP14_64 (0x0C)
+/* Unallocated EC: 0x0d */
+#define ESR_ELx_EC_ILL (0x0E)
+/* Unallocated EC: 0x0F - 0x10 */
+#define ESR_ELx_EC_SVC32 (0x11)
+#define ESR_ELx_EC_HVC32 (0x12) /* EL2 only */
+#define ESR_ELx_EC_SMC32 (0x13) /* EL2 and above */
+/* Unallocated EC: 0x14 */
+#define ESR_ELx_EC_SVC64 (0x15)
+#define ESR_ELx_EC_HVC64 (0x16) /* EL2 and above */
+#define ESR_ELx_EC_SMC64 (0x17) /* EL2 and above */
+#define ESR_ELx_EC_SYS64 (0x18)
+#define ESR_ELx_EC_SVE (0x19)
+#define ESR_ELx_EC_ERET (0x1a) /* EL2 only */
+/* Unallocated EC: 0x1b - 0x1E */
+#define ESR_ELx_EC_IMP_DEF (0x1f) /* EL3 only */
+#define ESR_ELx_EC_IABT_LOW (0x20)
+#define ESR_ELx_EC_IABT_CUR (0x21)
+#define ESR_ELx_EC_PC_ALIGN (0x22)
+/* Unallocated EC: 0x23 */
+#define ESR_ELx_EC_DABT_LOW (0x24)
+#define ESR_ELx_EC_DABT_CUR (0x25)
+#define ESR_ELx_EC_SP_ALIGN (0x26)
+/* Unallocated EC: 0x27 */
+#define ESR_ELx_EC_FP_EXC32 (0x28)
+/* Unallocated EC: 0x29 - 0x2B */
+#define ESR_ELx_EC_FP_EXC64 (0x2C)
+/* Unallocated EC: 0x2D - 0x2E */
+#define ESR_ELx_EC_SERROR (0x2F)
+#define ESR_ELx_EC_BREAKPT_LOW (0x30)
+#define ESR_ELx_EC_BREAKPT_CUR (0x31)
+#define ESR_ELx_EC_SOFTSTP_LOW (0x32)
+#define ESR_ELx_EC_SOFTSTP_CUR (0x33)
+#define ESR_ELx_EC_WATCHPT_LOW (0x34)
+#define ESR_ELx_EC_WATCHPT_CUR (0x35)
+/* Unallocated EC: 0x36 - 0x37 */
+#define ESR_ELx_EC_BKPT32 (0x38)
+/* Unallocated EC: 0x39 */
+#define ESR_ELx_EC_VECTOR32 (0x3A) /* EL2 only */
+/* Unallocated EC: 0x3B */
+#define ESR_ELx_EC_BRK64 (0x3C)
+/* Unallocated EC: 0x3D - 0x3F */
+#define ESR_ELx_EC_MAX (0x3F)
+
+#define ECN(x) { ESR_ELx_EC_##x, #x }
+
+#define kvm_arm_exception_class \
+ ECN(UNKNOWN), ECN(WFx), ECN(CP15_32), ECN(CP15_64), ECN(CP14_MR), \
+ ECN(CP14_LS), ECN(FP_ASIMD), ECN(CP10_ID), ECN(PAC), ECN(CP14_64), \
+ ECN(SVC64), ECN(HVC64), ECN(SMC64), ECN(SYS64), ECN(SVE), \
+ ECN(IMP_DEF), ECN(IABT_LOW), ECN(IABT_CUR), \
+ ECN(PC_ALIGN), ECN(DABT_LOW), ECN(DABT_CUR), \
+ ECN(SP_ALIGN), ECN(FP_EXC32), ECN(FP_EXC64), ECN(SERROR), \
+ ECN(BREAKPT_LOW), ECN(BREAKPT_CUR), ECN(SOFTSTP_LOW), \
+ ECN(SOFTSTP_CUR), ECN(WATCHPT_LOW), ECN(WATCHPT_CUR), \
+ ECN(BKPT32), ECN(VECTOR32), ECN(BRK64)
+
+#endif /* ARCH_PERF_ARM64_EXCEPTION_TYPES_H */
diff --git a/tools/perf/arch/arm64/util/kvm-stat.c b/tools/perf/arch/arm64/util/kvm-stat.c
new file mode 100644
index 000000000000..50376b9062c1
--- /dev/null
+++ b/tools/perf/arch/arm64/util/kvm-stat.c
@@ -0,0 +1,85 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <errno.h>
+#include <memory.h>
+#include "../../util/evsel.h"
+#include "../../util/kvm-stat.h"
+#include "arm64_exception_types.h"
+#include "debug.h"
+
+define_exit_reasons_table(arm64_exit_reasons, kvm_arm_exception_type);
+define_exit_reasons_table(arm64_trap_exit_reasons, kvm_arm_exception_class);
+
+const char *kvm_trap_exit_reason = "esr_ec";
+const char *vcpu_id_str = "id";
+const int decode_str_len = 20;
+const char *kvm_exit_reason = "ret";
+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->exit_reasons = arm64_exit_reasons;
+
+ /*
+ * TRAP exceptions carry exception class info in esr_ec field
+ * and, hence, we need to use a different exit_reasons table to
+ * properly decode event's est_ec.
+ */
+ if (key->key == ARM_EXCEPTION_TRAP) {
+ key->key = evsel__intval(evsel, sample, kvm_trap_exit_reason);
+ key->exit_reasons = arm64_trap_exit_reasons;
+ }
+}
+
+static bool event_begin(struct evsel *evsel,
+ struct perf_sample *sample __maybe_unused,
+ struct event_key *key __maybe_unused)
+{
+ return !strcmp(evsel->name, kvm_entry_trace);
+}
+
+static bool event_end(struct evsel *evsel,
+ struct perf_sample *sample,
+ struct event_key *key)
+{
+ if (!strcmp(evsel->name, 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 },
+};
+
+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 = "arm64";
+ return 0;
+}
--
2.28.0