From 066d3593e1b14690dc1131d50cacbb0b7eb3f160 Mon Sep 17 00:00:00 2001 From: Hemant Kumar Date: Thu, 28 Jan 2016 12:03:06 +0530 Subject: [PATCH] perf kvm/powerpc: Port perf kvm stat to powerpc 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 - 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. Since, different powerpc machines have different KVM tracepoints, this patch discovers the available tracepoints dynamically and accordingly looks for them. If any single tracepoint is not present, this support won't be enabled for reporting. To record, this will fail if any of the events we are looking to record isn't available. Right now, its only supported on PowerPC Book3S_HV architectures. To analyze the different exits, group them and present them (in a slight 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_hv_exits.h. It records on two available KVM tracepoints for book3s_hv: "kvm_hv:kvm_guest_exit" and "kvm_hv:kvm_guest_enter". 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% MinTime MaxTime Avg time SYSCALL 9141 63.67% 7.49% 1.26us 5782.39us 9.87us (+- 6.46%) H_DATA_STORAGE 4114 28.66% 5.07% 1.72us 4597.68us 14.84us (+-20.06%) HV_DECREMENTER 418 2.91% 4.26% 0.70us 30002.22us 122.58us (+-70.29%) EXTERNAL 392 2.73% 0.06% 0.64us 104.10us 1.94us (+-18.83%) RETURN_TO_HOST 287 2.00% 83.11% 1.53us 124240.15us 3486.52us (+-16.81%) H_INST_STORAGE 5 0.03% 0.00% 1.88us 3.73us 2.39us (+-14.20%) Total Samples:14357, Total events handled time:1203918.42us. Signed-off-by: Hemant Kumar Cc: Alexander Yarygin Cc: David Ahern Cc: Michael Ellerman Cc: Naveen N. Rao Cc: Paul Mackerras Cc: Scott Wood Cc: Srikar Dronamraju Cc: linuxppc-dev@lists.ozlabs.org Link: http://lkml.kernel.org/r/1453962787-15376-3-git-send-email-hemant@linux.vnet.ibm.com Signed-off-by: Srikar Dronamraju Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/arch/powerpc/Makefile | 2 + tools/perf/arch/powerpc/util/Build | 1 + .../perf/arch/powerpc/util/book3s_hv_exits.h | 33 ++++++ tools/perf/arch/powerpc/util/kvm-stat.c | 107 ++++++++++++++++++ tools/perf/builtin-kvm.c | 18 +++ tools/perf/util/kvm-stat.h | 1 + 6 files changed, 162 insertions(+) create mode 100644 tools/perf/arch/powerpc/util/book3s_hv_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 7fbca175099e..9f9cea3478fd 100644 --- a/tools/perf/arch/powerpc/Makefile +++ b/tools/perf/arch/powerpc/Makefile @@ -1,3 +1,5 @@ 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 7b8b0d1a1b62..c8fe2074d217 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_hv_exits.h b/tools/perf/arch/powerpc/util/book3s_hv_exits.h new file mode 100644 index 000000000000..e68ba2da8970 --- /dev/null +++ b/tools/perf/arch/powerpc/util/book3s_hv_exits.h @@ -0,0 +1,33 @@ +#ifndef ARCH_PERF_BOOK3S_HV_EXITS_H +#define ARCH_PERF_BOOK3S_HV_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 000000000000..27bc559b8b3a --- /dev/null +++ b/tools/perf/arch/powerpc/util/kvm-stat.c @@ -0,0 +1,107 @@ +#include "util/kvm-stat.h" +#include "util/parse-events.h" + +#include "book3s_hv_exits.h" + +#define NR_TPS 2 + +const char *vcpu_id_str = "vcpu_id"; +const int decode_str_len = 40; +const char *kvm_entry_trace = "kvm_hv:kvm_guest_enter"; +const char *kvm_exit_trace = "kvm_hv:kvm_guest_exit"; + +define_exit_reasons_table(hv_exit_reasons, kvm_trace_symbol_exit); + +/* Tracepoints specific to ppc_book3s_hv */ +const char *ppc_book3s_hv_kvm_tp[] = { + "kvm_hv:kvm_guest_enter", + "kvm_hv:kvm_guest_exit", +}; + +/* 1 extra placeholder for NULL */ +const char *kvm_events_tp[NR_TPS + 1]; +const char *kvm_exit_reason; + +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" +}; + +struct kvm_reg_events_ops kvm_reg_events_ops[] = { + { .name = "vmexit", .ops = &exit_events }, + { NULL, NULL }, +}; + +const char * const kvm_skip_events[] = { + NULL, +}; + + +static int is_tracepoint_available(const char *str, struct perf_evlist *evlist) +{ + struct parse_events_error err; + int ret; + + err.str = NULL; + ret = parse_events(evlist, str, &err); + if (err.str) + pr_err("%s : %s\n", str, err.str); + return ret; +} + +static int ppc__setup_book3s_hv(struct perf_kvm_stat *kvm, + struct perf_evlist *evlist) +{ + const char **events_ptr; + int i, nr_tp = 0, err = -1; + + /* Check for book3s_hv tracepoints */ + for (events_ptr = ppc_book3s_hv_kvm_tp; *events_ptr; events_ptr++) { + err = is_tracepoint_available(*events_ptr, evlist); + if (err) + return -1; + nr_tp++; + } + + for (i = 0; i < nr_tp; i++) + kvm_events_tp[i] = ppc_book3s_hv_kvm_tp[i]; + + kvm_events_tp[i] = NULL; + kvm_exit_reason = "trap"; + kvm->exit_reasons = hv_exit_reasons; + kvm->exit_reasons_isa = "HV"; + + return 0; +} + +/* Wrapper to setup kvm tracepoints */ +static int ppc__setup_kvm_tp(struct perf_kvm_stat *kvm) +{ + struct perf_evlist *evlist = perf_evlist__new(); + + if (evlist == NULL) + return -ENOMEM; + + /* Right now, only supported on book3s_hv */ + return ppc__setup_book3s_hv(kvm, evlist); +} + +int setup_kvm_events_tp(struct perf_kvm_stat *kvm) +{ + return ppc__setup_kvm_tp(kvm); +} + +int cpu_isa_init(struct perf_kvm_stat *kvm, const char *cpuid __maybe_unused) +{ + int ret; + + ret = ppc__setup_kvm_tp(kvm); + if (ret) { + kvm->exit_reasons = NULL; + kvm->exit_reasons_isa = NULL; + } + + return ret; +} diff --git a/tools/perf/builtin-kvm.c b/tools/perf/builtin-kvm.c index ab5645cf39d2..bff666458b28 100644 --- a/tools/perf/builtin-kvm.c +++ b/tools/perf/builtin-kvm.c @@ -1132,6 +1132,11 @@ exit: _p; \ }) +int __weak setup_kvm_events_tp(struct perf_kvm_stat *kvm __maybe_unused) +{ + return 0; +} + static int kvm_events_record(struct perf_kvm_stat *kvm, int argc, const char **argv) { @@ -1148,7 +1153,14 @@ kvm_events_record(struct perf_kvm_stat *kvm, int argc, const char **argv) NULL }; const char * const *events_tp; + int ret; + events_tp_size = 0; + ret = setup_kvm_events_tp(kvm); + if (ret < 0) { + pr_err("Unable to setup the kvm tracepoints\n"); + return ret; + } for (events_tp = kvm_events_tp; *events_tp; events_tp++) events_tp_size++; @@ -1377,6 +1389,12 @@ static int kvm_events_live(struct perf_kvm_stat *kvm, /* * generate the event list */ + err = setup_kvm_events_tp(kvm); + if (err < 0) { + pr_err("Unable to setup the kvm tracepoints\n"); + return err; + } + kvm->evlist = kvm_live_event_list(); if (kvm->evlist == NULL) { err = -1; diff --git a/tools/perf/util/kvm-stat.h b/tools/perf/util/kvm-stat.h index c965dc844df3..d01e73592f6e 100644 --- a/tools/perf/util/kvm-stat.h +++ b/tools/perf/util/kvm-stat.h @@ -122,6 +122,7 @@ void exit_event_decode_key(struct perf_kvm_stat *kvm, bool kvm_exit_event(struct perf_evsel *evsel); bool kvm_entry_event(struct perf_evsel *evsel); +int setup_kvm_events_tp(struct perf_kvm_stat *kvm); #define define_exit_reasons_table(name, symbols) \ static struct exit_reasons_table name[] = { \ -- 2.30.2