vl: convert -m to QemuOpts

Adds option to -m
 "size" - 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 <imammedo@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

qemu-options.hx

@@ -210,10 +210,13 @@ 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 [size=]megs\n"
+    "                configure guest RAM\n"
+    "                size: initial amount of guest memory (default: "
+    stringify(DEFAULT_RAM_SIZE) "MiB)\n",
+    QEMU_ARCH_ALL)
 STEXI
-@item -m @var{megs}
+@item -m [size=]@var{megs}
 @findex -m
 Set virtual RAM size to @var{megs} megabytes. Default is 128 MiB.  Optionally,
 a suffix of ``M'' or ``G'' can be used to signify a value in megabytes or

vl.c

@@ -510,6 +510,20 @@ static QemuOptsList qemu_name_opts = {
     },
 };
 
+static QemuOptsList qemu_mem_opts = {
+    .name = "memory",
+    .implied_opt_name = "size",
+    .head = QTAILQ_HEAD_INITIALIZER(qemu_mem_opts.head),
+    .merge_lists = true,
+    .desc = {
+        {
+            .name = "size",
+            .type = QEMU_OPT_SIZE,
+        },
+        { /* end of list */ }
+    },
+};
+
 /**
  * Get machine options
  *
@@ -2955,6 +2969,8 @@ 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 = (ram_addr_t)DEFAULT_RAM_SIZE *
+                                        1024 * 1024;
 
     atexit(qemu_run_exit_notifiers);
     error_set_progname(argv[0]);
@@ -2978,6 +2994,7 @@ int main(int argc, char **argv, char **envp)
     qemu_add_opts(&qemu_trace_opts);
     qemu_add_opts(&qemu_option_rom_opts);
     qemu_add_opts(&qemu_machine_opts);
+    qemu_add_opts(&qemu_mem_opts);
     qemu_add_opts(&qemu_smp_opts);
     qemu_add_opts(&qemu_boot_opts);
     qemu_add_opts(&qemu_sandbox_opts);
@@ -3002,7 +3019,7 @@ int main(int argc, char **argv, char **envp)
     module_call_init(MODULE_INIT_MACHINE);
     machine_class = 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;
@@ -3289,20 +3306,48 @@ 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);
-                    exit(1);
+                opts = qemu_opts_parse(qemu_find_opts("memory"),
+                                       optarg, 1);
+                if (!opts) {
+                    exit(EXIT_FAILURE);
+                }
+
+                mem_str = qemu_opt_get(opts, "size");
+                if (!mem_str) {
+                    error_report("invalid -m option, missing 'size' option");
+                    exit(EXIT_FAILURE);
+                }
+                if (!*mem_str) {
+                    error_report("missing 'size' option value");
+                    exit(EXIT_FAILURE);
+                }
+
+                sz = qemu_opt_get_size(opts, "size", ram_size);
+
+                /* Fix up legacy suffix-less format */
+                if (g_ascii_isdigit(mem_str[strlen(mem_str) - 1])) {
+                    uint64_t overflow_check = sz;
+
+                    sz <<= 20;
+                    if ((sz >> 20) != overflow_check) {
+                        error_report("too large 'size' option value");
+                        exit(EXIT_FAILURE);
+                    }
+                }
+
+                /* backward compatibility behaviour for case "-m 0" */
+                if (sz == 0) {
+                    sz = default_ram_size;
                 }
-                sz = QEMU_ALIGN_UP((uint64_t)value, 8192);
+
+                sz = QEMU_ALIGN_UP(sz, 8192);
                 ram_size = sz;
                 if (ram_size != sz) {
-                    fprintf(stderr, "qemu: ram size too large\n");
-                    exit(1);
+                    error_report("ram size too large");
+                    exit(EXIT_FAILURE);
                 }
                 break;
             }
@@ -4145,10 +4190,8 @@ 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"), "size", ram_size);
 
     if (qemu_opts_foreach(qemu_find_opts("device"), device_help_func, NULL, 0)
         != 0) {