diff options
Diffstat (limited to 'accel/tcg/translate-all.c')
| -rw-r--r-- | accel/tcg/translate-all.c | 63 |
1 files changed, 20 insertions, 43 deletions
diff --git a/accel/tcg/translate-all.c b/accel/tcg/translate-all.c index 9061c0508c..f99bfd9309 100644 --- a/accel/tcg/translate-all.c +++ b/accel/tcg/translate-all.c @@ -606,15 +606,13 @@ static inline void *alloc_code_gen_buffer(void) { void *buf = static_code_gen_buffer; void *end = static_code_gen_buffer + sizeof(static_code_gen_buffer); - size_t full_size, size; + size_t size; /* page-align the beginning and end of the buffer */ buf = QEMU_ALIGN_PTR_UP(buf, qemu_real_host_page_size); end = QEMU_ALIGN_PTR_DOWN(end, qemu_real_host_page_size); - /* Reserve a guard page. */ - full_size = end - buf; - size = full_size - qemu_real_host_page_size; + size = end - buf; /* Honor a command-line option limiting the size of the buffer. */ if (size > tcg_ctx->code_gen_buffer_size) { @@ -633,9 +631,6 @@ static inline void *alloc_code_gen_buffer(void) if (qemu_mprotect_rwx(buf, size)) { abort(); } - if (qemu_mprotect_none(buf + size, qemu_real_host_page_size)) { - abort(); - } qemu_madvise(buf, size, QEMU_MADV_HUGEPAGE); return buf; @@ -644,22 +639,16 @@ static inline void *alloc_code_gen_buffer(void) static inline void *alloc_code_gen_buffer(void) { size_t size = tcg_ctx->code_gen_buffer_size; - void *buf1, *buf2; - - /* Perform the allocation in two steps, so that the guard page - is reserved but uncommitted. */ - buf1 = VirtualAlloc(NULL, size + qemu_real_host_page_size, - MEM_RESERVE, PAGE_NOACCESS); - if (buf1 != NULL) { - buf2 = VirtualAlloc(buf1, size, MEM_COMMIT, PAGE_EXECUTE_READWRITE); - assert(buf1 == buf2); - } + void *buf; - return buf1; + buf = VirtualAlloc(NULL, size, MEM_RESERVE | MEM_COMMIT, + PAGE_EXECUTE_READWRITE); + return buf; } #else static inline void *alloc_code_gen_buffer(void) { + int prot = PROT_WRITE | PROT_READ | PROT_EXEC; int flags = MAP_PRIVATE | MAP_ANONYMOUS; uintptr_t start = 0; size_t size = tcg_ctx->code_gen_buffer_size; @@ -693,8 +682,7 @@ static inline void *alloc_code_gen_buffer(void) # endif # endif - buf = mmap((void *)start, size + qemu_real_host_page_size, - PROT_NONE, flags, -1, 0); + buf = mmap((void *)start, size, prot, flags, -1, 0); if (buf == MAP_FAILED) { return NULL; } @@ -704,24 +692,23 @@ static inline void *alloc_code_gen_buffer(void) /* Try again, with the original still mapped, to avoid re-acquiring that 256mb crossing. This time don't specify an address. */ size_t size2; - void *buf2 = mmap(NULL, size + qemu_real_host_page_size, - PROT_NONE, flags, -1, 0); + void *buf2 = mmap(NULL, size, prot, flags, -1, 0); switch ((int)(buf2 != MAP_FAILED)) { case 1: if (!cross_256mb(buf2, size)) { /* Success! Use the new buffer. */ - munmap(buf, size + qemu_real_host_page_size); + munmap(buf, size); break; } /* Failure. Work with what we had. */ - munmap(buf2, size + qemu_real_host_page_size); + munmap(buf2, size); /* fallthru */ default: /* Split the original buffer. Free the smaller half. */ buf2 = split_cross_256mb(buf, size); size2 = tcg_ctx->code_gen_buffer_size; if (buf == buf2) { - munmap(buf + size2 + qemu_real_host_page_size, size - size2); + munmap(buf + size2, size - size2); } else { munmap(buf, size - size2); } @@ -732,10 +719,6 @@ static inline void *alloc_code_gen_buffer(void) } #endif - /* Make the final buffer accessible. The guard page at the end - will remain inaccessible with PROT_NONE. */ - mprotect(buf, size, PROT_WRITE | PROT_READ | PROT_EXEC); - /* Request large pages for the buffer. */ qemu_madvise(buf, size, QEMU_MADV_HUGEPAGE); @@ -916,13 +899,8 @@ static void do_tb_flush(CPUState *cpu, run_on_cpu_data tb_flush_count) size_t host_size = 0; g_tree_foreach(tb_ctx.tb_tree, tb_host_size_iter, &host_size); - printf("qemu: flush code_size=%td nb_tbs=%zu avg_tb_size=%zu\n", - tcg_ctx->code_gen_ptr - tcg_ctx->code_gen_buffer, nb_tbs, - nb_tbs > 0 ? host_size / nb_tbs : 0); - } - if ((unsigned long)(tcg_ctx->code_gen_ptr - tcg_ctx->code_gen_buffer) - > tcg_ctx->code_gen_buffer_size) { - cpu_abort(cpu, "Internal error: code buffer overflow\n"); + printf("qemu: flush code_size=%zu nb_tbs=%zu avg_tb_size=%zu\n", + tcg_code_size(), nb_tbs, nb_tbs > 0 ? host_size / nb_tbs : 0); } CPU_FOREACH(cpu) { @@ -936,7 +914,7 @@ static void do_tb_flush(CPUState *cpu, run_on_cpu_data tb_flush_count) qht_reset_size(&tb_ctx.htable, CODE_GEN_HTABLE_SIZE); page_flush_tb(); - tcg_ctx->code_gen_ptr = tcg_ctx->code_gen_buffer; + tcg_region_reset_all(); /* XXX: flush processor icache at this point if cache flush is expensive */ atomic_mb_set(&tb_ctx.tb_flush_count, tb_ctx.tb_flush_count + 1); @@ -1274,9 +1252,9 @@ TranslationBlock *tb_gen_code(CPUState *cpu, phys_pc = get_page_addr_code(env, pc); + buffer_overflow: tb = tb_alloc(pc); if (unlikely(!tb)) { - buffer_overflow: /* flush must be done */ tb_flush(cpu); mmap_unlock(); @@ -1380,9 +1358,9 @@ TranslationBlock *tb_gen_code(CPUState *cpu, } #endif - tcg_ctx->code_gen_ptr = (void *) + atomic_set(&tcg_ctx->code_gen_ptr, (void *) ROUND_UP((uintptr_t)gen_code_buf + gen_code_size + search_size, - CODE_GEN_ALIGN); + CODE_GEN_ALIGN)); /* init jump list */ assert(((uintptr_t)tb & 3) == 0); @@ -1908,9 +1886,8 @@ void dump_exec_info(FILE *f, fprintf_function cpu_fprintf) * otherwise users might think "-tb-size" is not honoured. * For avg host size we use the precise numbers from tb_tree_stats though. */ - cpu_fprintf(f, "gen code size %td/%zd\n", - tcg_ctx->code_gen_ptr - tcg_ctx->code_gen_buffer, - tcg_ctx->code_gen_highwater - tcg_ctx->code_gen_buffer); + cpu_fprintf(f, "gen code size %zu/%zu\n", + tcg_code_size(), tcg_code_capacity()); cpu_fprintf(f, "TB count %zu\n", nb_tbs); cpu_fprintf(f, "TB avg target size %zu max=%zu bytes\n", nb_tbs ? tst.target_size / nb_tbs : 0, |