diff options
| -rw-r--r-- | exec.c | 59 | ||||
| -rw-r--r-- | qemu-options.hx | 2 | ||||
| -rw-r--r-- | vl.c | 4 |
3 files changed, 47 insertions, 18 deletions
@@ -904,6 +904,13 @@ static long gethugepagesize(const char *path) return fs.f_bsize; } +static sigjmp_buf sigjump; + +static void sigbus_handler(int signal) +{ + siglongjmp(sigjump, 1); +} + static void *file_ram_alloc(RAMBlock *block, ram_addr_t memory, const char *path) @@ -913,9 +920,6 @@ static void *file_ram_alloc(RAMBlock *block, char *c; void *area; int fd; -#ifdef MAP_POPULATE - int flags; -#endif unsigned long hpagesize; hpagesize = gethugepagesize(path); @@ -963,21 +967,52 @@ static void *file_ram_alloc(RAMBlock *block, if (ftruncate(fd, memory)) perror("ftruncate"); -#ifdef MAP_POPULATE - /* NB: MAP_POPULATE won't exhaustively alloc all phys pages in the case - * MAP_PRIVATE is requested. For mem_prealloc we mmap as MAP_SHARED - * to sidestep this quirk. - */ - flags = mem_prealloc ? MAP_POPULATE | MAP_SHARED : MAP_PRIVATE; - area = mmap(0, memory, PROT_READ | PROT_WRITE, flags, fd, 0); -#else area = mmap(0, memory, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0); -#endif if (area == MAP_FAILED) { perror("file_ram_alloc: can't mmap RAM pages"); close(fd); return (NULL); } + + if (mem_prealloc) { + int ret, i; + struct sigaction act, oldact; + sigset_t set, oldset; + + memset(&act, 0, sizeof(act)); + act.sa_handler = &sigbus_handler; + act.sa_flags = 0; + + ret = sigaction(SIGBUS, &act, &oldact); + if (ret) { + perror("file_ram_alloc: failed to install signal handler"); + exit(1); + } + + /* unblock SIGBUS */ + sigemptyset(&set); + sigaddset(&set, SIGBUS); + pthread_sigmask(SIG_UNBLOCK, &set, &oldset); + + if (sigsetjmp(sigjump, 1)) { + fprintf(stderr, "file_ram_alloc: failed to preallocate pages\n"); + exit(1); + } + + /* MAP_POPULATE silently ignores failures */ + for (i = 0; i < (memory/hpagesize)-1; i++) { + memset(area + (hpagesize*i), 0, 1); + } + + ret = sigaction(SIGBUS, &oldact, NULL); + if (ret) { + perror("file_ram_alloc: failed to reinstall signal handler"); + exit(1); + } + + pthread_sigmask(SIG_SETMASK, &oldset, NULL); + } + block->fd = fd; return area; } diff --git a/qemu-options.hx b/qemu-options.hx index 8b9426484d..eafc022ad0 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -228,7 +228,6 @@ STEXI Allocate guest RAM from a temporarily created file in @var{path}. ETEXI -#ifdef MAP_POPULATE DEF("mem-prealloc", 0, QEMU_OPTION_mem_prealloc, "-mem-prealloc preallocate guest memory (use with -mem-path)\n", QEMU_ARCH_ALL) @@ -237,7 +236,6 @@ STEXI @findex -mem-prealloc Preallocate memory when using -mem-path. ETEXI -#endif DEF("k", HAS_ARG, QEMU_OPTION_k, "-k language use keyboard layout (for example 'fr' for French)\n", @@ -188,9 +188,7 @@ static int display_remote; const char* keyboard_layout = NULL; ram_addr_t ram_size; const char *mem_path = NULL; -#ifdef MAP_POPULATE int mem_prealloc = 0; /* force preallocation of physical target memory */ -#endif int nb_nics; NICInfo nd_table[MAX_NICS]; int autostart; @@ -3206,11 +3204,9 @@ int main(int argc, char **argv, char **envp) case QEMU_OPTION_mempath: mem_path = optarg; break; -#ifdef MAP_POPULATE case QEMU_OPTION_mem_prealloc: mem_prealloc = 1; break; -#endif case QEMU_OPTION_d: log_mask = optarg; break; |