diff options
Diffstat (limited to 'accel/tcg/perf.c')
| -rw-r--r-- | accel/tcg/perf.c | 386 |
1 files changed, 0 insertions, 386 deletions
diff --git a/accel/tcg/perf.c b/accel/tcg/perf.c deleted file mode 100644 index cd1aa99a7e..0000000000 --- a/accel/tcg/perf.c +++ /dev/null @@ -1,386 +0,0 @@ -/* - * Linux perf perf-<pid>.map and jit-<pid>.dump integration. - * - * The jitdump spec can be found at [1]. - * - * [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/plain/tools/perf/Documentation/jitdump-specification.txt - * - * SPDX-License-Identifier: GPL-2.0-or-later - */ - -#include "qemu/osdep.h" -#include "elf.h" -#include "exec/exec-all.h" -#include "qemu/timer.h" -#include "tcg/tcg.h" - -#include "debuginfo.h" -#include "perf.h" - -static FILE *safe_fopen_w(const char *path) -{ - int saved_errno; - FILE *f; - int fd; - - /* Delete the old file, if any. */ - unlink(path); - - /* Avoid symlink attacks by using O_CREAT | O_EXCL. */ - fd = open(path, O_RDWR | O_CREAT | O_EXCL, S_IRUSR | S_IWUSR); - if (fd == -1) { - return NULL; - } - - /* Convert fd to FILE*. */ - f = fdopen(fd, "w"); - if (f == NULL) { - saved_errno = errno; - close(fd); - errno = saved_errno; - return NULL; - } - - return f; -} - -static FILE *perfmap; - -void perf_enable_perfmap(void) -{ - char map_file[32]; - - snprintf(map_file, sizeof(map_file), "/tmp/perf-%d.map", getpid()); - perfmap = safe_fopen_w(map_file); - if (perfmap == NULL) { - warn_report("Could not open %s: %s, proceeding without perfmap", - map_file, strerror(errno)); - } -} - -/* Get PC and size of code JITed for guest instruction #INSN. */ -static void get_host_pc_size(uintptr_t *host_pc, uint16_t *host_size, - const void *start, size_t insn) -{ - uint16_t start_off = insn ? tcg_ctx->gen_insn_end_off[insn - 1] : 0; - - if (host_pc) { - *host_pc = (uintptr_t)start + start_off; - } - if (host_size) { - *host_size = tcg_ctx->gen_insn_end_off[insn] - start_off; - } -} - -static const char *pretty_symbol(const struct debuginfo_query *q, size_t *len) -{ - static __thread char buf[64]; - int tmp; - - if (!q->symbol) { - tmp = snprintf(buf, sizeof(buf), "guest-0x%"PRIx64, q->address); - if (len) { - *len = MIN(tmp + 1, sizeof(buf)); - } - return buf; - } - - if (!q->offset) { - if (len) { - *len = strlen(q->symbol) + 1; - } - return q->symbol; - } - - tmp = snprintf(buf, sizeof(buf), "%s+0x%"PRIx64, q->symbol, q->offset); - if (len) { - *len = MIN(tmp + 1, sizeof(buf)); - } - return buf; -} - -static void write_perfmap_entry(const void *start, size_t insn, - const struct debuginfo_query *q) -{ - uint16_t host_size; - uintptr_t host_pc; - - get_host_pc_size(&host_pc, &host_size, start, insn); - fprintf(perfmap, "%"PRIxPTR" %"PRIx16" %s\n", - host_pc, host_size, pretty_symbol(q, NULL)); -} - -static FILE *jitdump; -static size_t perf_marker_size; -static void *perf_marker = MAP_FAILED; - -#define JITHEADER_MAGIC 0x4A695444 -#define JITHEADER_VERSION 1 - -struct jitheader { - uint32_t magic; - uint32_t version; - uint32_t total_size; - uint32_t elf_mach; - uint32_t pad1; - uint32_t pid; - uint64_t timestamp; - uint64_t flags; -}; - -enum jit_record_type { - JIT_CODE_LOAD = 0, - JIT_CODE_DEBUG_INFO = 2, -}; - -struct jr_prefix { - uint32_t id; - uint32_t total_size; - uint64_t timestamp; -}; - -struct jr_code_load { - struct jr_prefix p; - - uint32_t pid; - uint32_t tid; - uint64_t vma; - uint64_t code_addr; - uint64_t code_size; - uint64_t code_index; -}; - -struct debug_entry { - uint64_t addr; - int lineno; - int discrim; - const char name[]; -}; - -struct jr_code_debug_info { - struct jr_prefix p; - - uint64_t code_addr; - uint64_t nr_entry; - struct debug_entry entries[]; -}; - -static uint32_t get_e_machine(void) -{ - Elf64_Ehdr elf_header; - FILE *exe; - size_t n; - - QEMU_BUILD_BUG_ON(offsetof(Elf32_Ehdr, e_machine) != - offsetof(Elf64_Ehdr, e_machine)); - - exe = fopen("/proc/self/exe", "r"); - if (exe == NULL) { - return EM_NONE; - } - - n = fread(&elf_header, sizeof(elf_header), 1, exe); - fclose(exe); - if (n != 1) { - return EM_NONE; - } - - return elf_header.e_machine; -} - -void perf_enable_jitdump(void) -{ - struct jitheader header; - char jitdump_file[32]; - - if (!use_rt_clock) { - warn_report("CLOCK_MONOTONIC is not available, proceeding without jitdump"); - return; - } - - snprintf(jitdump_file, sizeof(jitdump_file), "jit-%d.dump", getpid()); - jitdump = safe_fopen_w(jitdump_file); - if (jitdump == NULL) { - warn_report("Could not open %s: %s, proceeding without jitdump", - jitdump_file, strerror(errno)); - return; - } - - /* - * `perf inject` will see that the mapped file name in the corresponding - * PERF_RECORD_MMAP or PERF_RECORD_MMAP2 event is of the form jit-%d.dump - * and will process it as a jitdump file. - */ - perf_marker_size = qemu_real_host_page_size(); - perf_marker = mmap(NULL, perf_marker_size, PROT_READ | PROT_EXEC, - MAP_PRIVATE, fileno(jitdump), 0); - if (perf_marker == MAP_FAILED) { - warn_report("Could not map %s: %s, proceeding without jitdump", - jitdump_file, strerror(errno)); - fclose(jitdump); - jitdump = NULL; - return; - } - - header.magic = JITHEADER_MAGIC; - header.version = JITHEADER_VERSION; - header.total_size = sizeof(header); - header.elf_mach = get_e_machine(); - header.pad1 = 0; - header.pid = getpid(); - header.timestamp = get_clock(); - header.flags = 0; - fwrite(&header, sizeof(header), 1, jitdump); -} - -void perf_report_prologue(const void *start, size_t size) -{ - if (perfmap) { - fprintf(perfmap, "%"PRIxPTR" %zx tcg-prologue-buffer\n", - (uintptr_t)start, size); - } -} - -/* Write a JIT_CODE_DEBUG_INFO jitdump entry. */ -static void write_jr_code_debug_info(const void *start, - const struct debuginfo_query *q, - size_t icount) -{ - struct jr_code_debug_info rec; - struct debug_entry ent; - uintptr_t host_pc; - int insn; - - /* Write the header. */ - rec.p.id = JIT_CODE_DEBUG_INFO; - rec.p.total_size = sizeof(rec) + sizeof(ent) + 1; - rec.p.timestamp = get_clock(); - rec.code_addr = (uintptr_t)start; - rec.nr_entry = 1; - for (insn = 0; insn < icount; insn++) { - if (q[insn].file) { - rec.p.total_size += sizeof(ent) + strlen(q[insn].file) + 1; - rec.nr_entry++; - } - } - fwrite(&rec, sizeof(rec), 1, jitdump); - - /* Write the main debug entries. */ - for (insn = 0; insn < icount; insn++) { - if (q[insn].file) { - get_host_pc_size(&host_pc, NULL, start, insn); - ent.addr = host_pc; - ent.lineno = q[insn].line; - ent.discrim = 0; - fwrite(&ent, sizeof(ent), 1, jitdump); - fwrite(q[insn].file, strlen(q[insn].file) + 1, 1, jitdump); - } - } - - /* Write the trailing debug_entry. */ - ent.addr = (uintptr_t)start + tcg_ctx->gen_insn_end_off[icount - 1]; - ent.lineno = 0; - ent.discrim = 0; - fwrite(&ent, sizeof(ent), 1, jitdump); - fwrite("", 1, 1, jitdump); -} - -/* Write a JIT_CODE_LOAD jitdump entry. */ -static void write_jr_code_load(const void *start, uint16_t host_size, - const struct debuginfo_query *q) -{ - static uint64_t code_index; - struct jr_code_load rec; - const char *symbol; - size_t symbol_size; - - symbol = pretty_symbol(q, &symbol_size); - rec.p.id = JIT_CODE_LOAD; - rec.p.total_size = sizeof(rec) + symbol_size + host_size; - rec.p.timestamp = get_clock(); - rec.pid = getpid(); - rec.tid = qemu_get_thread_id(); - rec.vma = (uintptr_t)start; - rec.code_addr = (uintptr_t)start; - rec.code_size = host_size; - rec.code_index = code_index++; - fwrite(&rec, sizeof(rec), 1, jitdump); - fwrite(symbol, symbol_size, 1, jitdump); - fwrite(start, host_size, 1, jitdump); -} - -void perf_report_code(uint64_t guest_pc, TranslationBlock *tb, - const void *start) -{ - struct debuginfo_query *q; - size_t insn, start_words; - uint64_t *gen_insn_data; - - if (!perfmap && !jitdump) { - return; - } - - q = g_try_malloc0_n(tb->icount, sizeof(*q)); - if (!q) { - return; - } - - debuginfo_lock(); - - /* Query debuginfo for each guest instruction. */ - gen_insn_data = tcg_ctx->gen_insn_data; - start_words = tcg_ctx->insn_start_words; - - for (insn = 0; insn < tb->icount; insn++) { - /* FIXME: This replicates the restore_state_to_opc() logic. */ - q[insn].address = gen_insn_data[insn * start_words + 0]; - if (tb_cflags(tb) & CF_PCREL) { - q[insn].address |= (guest_pc & TARGET_PAGE_MASK); - } else { -#if defined(TARGET_I386) - q[insn].address -= tb->cs_base; -#endif - } - q[insn].flags = DEBUGINFO_SYMBOL | (jitdump ? DEBUGINFO_LINE : 0); - } - debuginfo_query(q, tb->icount); - - /* Emit perfmap entries if needed. */ - if (perfmap) { - flockfile(perfmap); - for (insn = 0; insn < tb->icount; insn++) { - write_perfmap_entry(start, insn, &q[insn]); - } - funlockfile(perfmap); - } - - /* Emit jitdump entries if needed. */ - if (jitdump) { - flockfile(jitdump); - write_jr_code_debug_info(start, q, tb->icount); - write_jr_code_load(start, tcg_ctx->gen_insn_end_off[tb->icount - 1], - q); - funlockfile(jitdump); - } - - debuginfo_unlock(); - g_free(q); -} - -void perf_exit(void) -{ - if (perfmap) { - fclose(perfmap); - perfmap = NULL; - } - - if (perf_marker != MAP_FAILED) { - munmap(perf_marker, perf_marker_size); - perf_marker = MAP_FAILED; - } - - if (jitdump) { - fclose(jitdump); - jitdump = NULL; - } -} |