On Mon, 10 Feb 2014 18:38:59 +0100 Laszlo Ersek <ler...@redhat.com> wrote:
> comments below > > On 02/06/14 09:16, Igor Mammedov wrote: > > Adds option to -m > > "mem" - startup memory amount > > > > For compatibility with legacy CLI if suffix-less number is passed, > > it assumes amount in Mb. > > > > Otherwise user is free to use suffixed number using suffixes b,k/K,M,G > > > > Signed-off-by: Igor Mammedov <imamm...@redhat.com> > > Signed-off-by: Paolo Bonzini <pbonz...@redhat.com> > > --- > > qemu-options.hx | 7 +++++-- > > vl.c | 53 > > ++++++++++++++++++++++++++++++++++++++++++----------- > > 2 files changed, 47 insertions(+), 13 deletions(-) > > > > diff --git a/qemu-options.hx b/qemu-options.hx > > index 56e5fdf..4d7ef52 100644 > > --- a/qemu-options.hx > > +++ b/qemu-options.hx > > @@ -210,8 +210,11 @@ use is discouraged as it may be removed from future > > versions. > > ETEXI > > > > DEF("m", HAS_ARG, QEMU_OPTION_m, > > - "-m megs set virtual RAM size to megs MB [default=" > > - stringify(DEFAULT_RAM_SIZE) "]\n", QEMU_ARCH_ALL) > > + "-m [mem=]megs\n" > > + " configure guest RAM\n" > > "configure guest RAM size" fixed > > > + " mem: initial amount of guest memory (default: " > > + stringify(DEFAULT_RAM_SIZE) "Mb)\n", > > I wonder if it should rather say "MB" -- small "b" has this "bits" > connotation for me. But I could be wrong. fixed > > Also, again, I believe explaining the default used to mean something > else, but I'm OK with that part as-is. > > > + QEMU_ARCH_ALL) > > STEXI > > @item -m @var{megs} > > @findex -m > > diff --git a/vl.c b/vl.c > > index 7f2595c..fe5dae3 100644 > > --- a/vl.c > > +++ b/vl.c > > @@ -532,6 +532,20 @@ static QemuOptsList qemu_msg_opts = { > > }, > > }; > > (this could conflict with Alan's series -- modifies the same spot) I'll put it in the beginning of list to avoid conflict. > > +static QemuOptsList qemu_mem_opts = { > > + .name = "memory-opts", > > + .implied_opt_name = "mem", > > + .head = QTAILQ_HEAD_INITIALIZER(qemu_mem_opts.head), > > + .merge_lists = true, > > OK, so we've set merge_list to true here as well, same as for "machine". > Further support for simplifying qemu_find_opts_singleton(); see patch #1. I believe it's not good for generic function to depend on merge_lists. > > > + .desc = { > > + { > > + .name = "mem", > > + .type = QEMU_OPT_SIZE, > > QEMU_OPT_SIZE implies (in parse_option_size()) that "no suffix" means > "unit==byte" (); I'll check lower down how that's solved. it's(i.e. legacy behavior) taken care of later at -m parsing time > > > + }, > > + { /* end of list */ } > > + }, > > +}; > > + > > /** > > * Get machine options > > * > > @@ -2868,6 +2882,7 @@ int main(int argc, char **argv, char **envp) > > }; > > const char *trace_events = NULL; > > const char *trace_file = NULL; > > + const ram_addr_t default_ram_size = DEFAULT_RAM_SIZE * 1024 * 1024; > > I'd feel safer if the multiplications were done in ram_addr_t. Currently > they are done in "int". It's unlikely that we'll make 2GB+ the default > ram size, but still. fixed > > > > > atexit(qemu_run_exit_notifiers); > > error_set_progname(argv[0]); > > @@ -2906,6 +2921,7 @@ int main(int argc, char **argv, char **envp) > > qemu_add_opts(&qemu_tpmdev_opts); > > qemu_add_opts(&qemu_realtime_opts); > > qemu_add_opts(&qemu_msg_opts); > > + qemu_add_opts(&qemu_mem_opts); > > > > runstate_init(); > > > > @@ -2921,7 +2937,7 @@ int main(int argc, char **argv, char **envp) > > module_call_init(MODULE_INIT_MACHINE); > > machine = find_default_machine(); > > cpu_model = NULL; > > - ram_size = 0; > > + ram_size = default_ram_size; > > snapshot = 0; > > cyls = heads = secs = 0; > > translation = BIOS_ATA_TRANSLATION_AUTO; > > @@ -3198,16 +3214,32 @@ int main(int argc, char **argv, char **envp) > > exit(0); > > break; > > case QEMU_OPTION_m: { > > - int64_t value; > > uint64_t sz; > > - char *end; > > + const char *mem_str; > > > > - value = strtosz(optarg, &end); > > - if (value < 0 || *end) { > > - fprintf(stderr, "qemu: invalid ram size: %s\n", > > optarg); > > + opts = qemu_opts_parse(qemu_find_opts("memory-opts"), > > + optarg, 1); > > This can set "opts" to NULL if parsing fails, and then the > qemu_opt_get() just below will SIGSEGV. You need to check if "opts" > becomes NULL here, and exit if so (see other calls to qemu_opts_parse() > in main()). fixed > > In particular, see commit f46e720a. > > Also, unfortunately, this conversion kind of relaxes the error checking > that happens during parsing. The pre-patch version ends up in > strtosz_suffix_unit(), which rejects the empty string, for example. The > new version, which ends up in parse_option_size(), is not that smart > about strtod(). I think it will simply return zero for > > -m mem="" > > However it's not the fault of this patch. parse_option_size() does return 0, but following code fixes it, look for comment: /* backward compatibility behavior for case "-m 0" */ but as you pointed below empty mem option causes undefined behavior later so fix by checking that string is not empty. > > > + > > + mem_str = qemu_opt_get(opts, "mem"); > > + if (!mem_str) { > > + fprintf(stderr, "qemu: invalid -m option, missing " > > + " 'mem' option\n"); > > Double space. (There's one at the end of the first string literal, and > another at the beginning of the second literal.) fixed > > > exit(1); > > } > > - sz = QEMU_ALIGN_UP((uint64_t)value, 8192); > > + > > + sz = qemu_opt_get_size(opts, "mem", ram_size); > > + > > + /* Fix up legacy suffix-less format */ > > + if (g_ascii_isdigit(mem_str[strlen(mem_str) - 1])) { > > Undefined behavior if mem_str is the emptry string. (I think it is > possible, but I didn't test it.) indeed, fixed. > > > + sz <<= 20; > > + } > > We could check for overflow here, if we wanted. fixed > > > + > > + /* backward compatibility behaviour for case "-m 0" */ > > + if (sz == 0) { > > + sz = default_ram_size; > > + } > > + > > + sz = QEMU_ALIGN_UP(sz, 8192); > > ram_size = sz; > > if (ram_size != sz) { > > fprintf(stderr, "qemu: ram size too large\n"); > > @@ -4056,10 +4088,9 @@ int main(int argc, char **argv, char **envp) > > exit(1); > > } > > > > - /* init the memory */ > > - if (ram_size == 0) { > > - ram_size = DEFAULT_RAM_SIZE * 1024 * 1024; > > - } > > + /* store value for the future use */ > > + qemu_opt_set_number(qemu_find_opts_singleton("memory-opts"), > > + "mem", ram_size); > > Slight possibility here to overflow the int64_t "val" parameter with the > potentially uint64_t "ram_size" argument. I guess we don't care. yep, everywhere in API *_number is treated as uint64_t and only qemu_opt_set_number() treats it as int64_t, perhaps this function should be fixed. > > Also, I wonder what happens when we have passed a non-default memory > size on the command line. In that case, qemu_opt_set_number() seems to > create a second QemuOpt here. I guess that's maybe expected though? which appends it to the tail, and following lookup finds it first. > > > > > if (qemu_opts_foreach(qemu_find_opts("device"), device_help_func, > > NULL, 0) > > != 0) { > > > > It's your call what you'd like to address from the above. > > Thanks > Laszlo