On 2015-08-03 10:14, Alex Bennée wrote:
> This allows the perf tool to map samples to each individual translation
> block. This could be expanded for user space but currently it gives
> enough information to find any hotblocks by other means.
>
> Signed-off-by: Alex Bennée <alex.ben...@linaro.org>
>
> ---
>
> v2:
> - hoist up into translate-all.c
> - don't use pointless glib wrappers
> - use proper format types for portability
> - mark prologue/epilog area
> - rebase
>
> v3:
> - fix bracket for perf-map
> - find an include for the tb_enable_perfmap() declaration
> - checkpatch clean-ups
> ---
> include/qemu-common.h | 2 ++
> qemu-options.hx | 9 +++++++++
> translate-all.c | 26 ++++++++++++++++++++++++++
> vl.c | 4 ++++
> 4 files changed, 41 insertions(+)
>
> diff --git a/include/qemu-common.h b/include/qemu-common.h
> index fb3da6c..60b87d0 100644
> --- a/include/qemu-common.h
> +++ b/include/qemu-common.h
> @@ -382,6 +382,8 @@ typedef struct PCIHostDeviceAddress {
> void tcg_exec_init(unsigned long tb_size);
> bool tcg_enabled(void);
>
> +void tb_enable_perfmap(void);
> +
> void cpu_exec_init_all(void);
>
> /* CPU save/load. */
> diff --git a/qemu-options.hx b/qemu-options.hx
> index 77f5853..ae53346 100644
> --- a/qemu-options.hx
> +++ b/qemu-options.hx
> @@ -3572,6 +3572,15 @@ to the RNG daemon.
>
> ETEXI
>
> +DEF("perfmap", 0, QEMU_OPTION_PERFMAP, \
> + "-perfmap generate a /tmp/perf-${pid}.map file for perf\n",
> + QEMU_ARCH_ALL)
> +STEXI
> +@item -perfmap
> +@findex -perfmap
> +This will cause QEMU to generate a map file for Linux perf tools that will
> allow
> +basic profiling information to be broken down into basic blocks.
> +ETEXI
>
> HXCOMM This is the last statement. Insert new options before this line!
> STEXI
> diff --git a/translate-all.c b/translate-all.c
> index 60a3d8b..c05e2a5 100644
> --- a/translate-all.c
> +++ b/translate-all.c
> @@ -27,6 +27,7 @@
> #include <stdio.h>
> #include <string.h>
> #include <inttypes.h>
> +#include <glib.h>
>
> #include "config.h"
>
> @@ -133,6 +134,24 @@ static void tb_link_page(TranslationBlock *tb,
> tb_page_addr_t phys_pc,
> tb_page_addr_t phys_page2);
> static TranslationBlock *tb_find_pc(uintptr_t tc_ptr);
>
> +static FILE *tb_perfmap;
> +
> +void tb_enable_perfmap(void)
> +{
> + gchar *map_file = g_strdup_printf("/tmp/perf-%d.map", getpid());
> + tb_perfmap = fopen(map_file, "w");
What about symlink attacks there?
> + g_free(map_file);
> +}
> +
> +static void tb_write_perfmap(tcg_insn_unit *start, int size, target_ulong pc)
> +{
> + if (tb_perfmap) {
> + fprintf(tb_perfmap,
> + "%"PRIxPTR" %x subject-"TARGET_FMT_lx"\n",
> + (uintptr_t) start, size, pc);
> + }
> +}
> +
> void cpu_gen_init(void)
> {
> tcg_context_init(&tcg_ctx);
> @@ -190,6 +209,7 @@ int cpu_gen_code(CPUArchState *env, TranslationBlock *tb,
> int *gen_code_size_ptr
> s->code_out_len += gen_code_size;
> #endif
>
> + tb_write_perfmap(gen_code_buf, gen_code_size, tb->pc);
> #ifdef DEBUG_DISAS
> if (qemu_loglevel_mask(CPU_LOG_TB_OUT_ASM)) {
> qemu_log("OUT: [size=%d]\n", gen_code_size);
> @@ -669,6 +689,12 @@ static inline void code_gen_alloc(size_t tb_size)
> tcg_ctx.code_gen_buffer_size - 1024;
> tcg_ctx.code_gen_buffer_size -= 1024;
>
> + if (tb_perfmap) {
> + fprintf(tb_perfmap,
> + "%"PRIxPTR" %x tcg-prologue-buffer\n",
> + (uintptr_t) tcg_ctx.code_gen_prologue, 1024);
> + }
> +
> tcg_ctx.code_gen_buffer_max_size = tcg_ctx.code_gen_buffer_size -
> (TCG_MAX_OP_SIZE * OPC_BUF_SIZE);
> tcg_ctx.code_gen_max_blocks = tcg_ctx.code_gen_buffer_size /
> diff --git a/vl.c b/vl.c
> index 0adbbd6..1d2de4f 100644
> --- a/vl.c
> +++ b/vl.c
> @@ -122,6 +122,7 @@ int main(int argc, char **argv)
> #include "qapi-event.h"
> #include "exec/semihost.h"
> #include "crypto/init.h"
> +#include "qemu-common.h"
>
> #define MAX_VIRTIO_CONSOLES 1
> #define MAX_SCLP_CONSOLES 1
> @@ -3348,6 +3349,9 @@ int main(int argc, char **argv, char **envp)
> case QEMU_OPTION_D:
> log_file = optarg;
> break;
> + case QEMU_OPTION_PERFMAP:
> + tb_enable_perfmap();
> + break;
> case QEMU_OPTION_s:
> add_device_config(DEV_GDB, "tcp::" DEFAULT_GDBSTUB_PORT);
> break;
> --
> 2.5.0
>
>
--
Aurelien Jarno GPG: 4096R/1DDD8C9B
aurel...@aurel32.net http://www.aurel32.net
