qemu-io: allow specifying image as a set of options args

Currently qemu-io allows an image filename to be passed on the
command line, but unless using the JSON format, it does not have
a way to set any options except the format eg

 qemu-io https://127.0.0.1/images/centos7.iso
 qemu-io /home/berrange/demo.qcow2

By contrast when using the interactive shell, it is possible to
use --option with the 'open' command, or to omit the filename.

This adds a --image-opts arg that indicates that the positional
filename should be interpreted as a full option string, not
just a filename.

 qemu-io --image-opts driver=https,url=https://127.0.0.1/images,sslverify=off
 qemu-io --image-opts driver=qcow2,file.filename=/home/berrange/demo.qcow2

This flag is mutually exclusive with the '-f' flag and with
the '-o' flag to the 'open' command

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

qemu-io.c

@@ -32,6 +32,7 @@ static BlockBackend *qemuio_blk;
 /* qemu-io commands passed using -c */
 static int ncmdline;
 static char **cmdline;
+static bool imageOpts;
 
 static ReadLineState *readline_state;
 
@@ -151,6 +152,10 @@ static int open_f(BlockBackend *blk, int argc, char **argv)
             readonly = 1;
             break;
         case 'o':
+            if (imageOpts) {
+                printf("--image-opts and 'open -o' are mutually exclusive\n");
+                return 0;
+            }
             if (!qemu_opts_parse_noisily(&empty_opts, optarg, false)) {
                 qemu_opts_reset(&empty_opts);
                 return 0;
@@ -166,6 +171,14 @@ static int open_f(BlockBackend *blk, int argc, char **argv)
         flags |= BDRV_O_RDWR;
     }
 
+    if (imageOpts && (optind == argc - 1)) {
+        if (!qemu_opts_parse_noisily(&empty_opts, argv[optind], false)) {
+            qemu_opts_reset(&empty_opts);
+            return 0;
+        }
+        optind++;
+    }
+
     qopts = qemu_opts_find(&empty_opts, NULL);
     opts = qopts ? qemu_opts_to_qdict(qopts, NULL) : NULL;
     qemu_opts_reset(&empty_opts);
@@ -366,6 +379,7 @@ static void reenable_tty_echo(void)
 
 enum {
     OPTION_OBJECT = 256,
+    OPTION_IMAGE_OPTS = 257,
 };
 
 static QemuOptsList qemu_object_opts = {
@@ -378,6 +392,16 @@ static QemuOptsList qemu_object_opts = {
 };
 
 
+static QemuOptsList file_opts = {
+    .name = "file",
+    .implied_opt_name = "file",
+    .head = QTAILQ_HEAD_INITIALIZER(file_opts.head),
+    .desc = {
+        /* no elements => accept any params */
+        { /* end of list */ }
+    },
+};
+
 int main(int argc, char **argv)
 {
     int readonly = 0;
@@ -397,6 +421,7 @@ int main(int argc, char **argv)
         { "cache", 1, NULL, 't' },
         { "trace", 1, NULL, 'T' },
         { "object", 1, NULL, OPTION_OBJECT },
+        { "image-opts", 0, NULL, OPTION_IMAGE_OPTS },
         { NULL, 0, NULL, 0 }
     };
     int c;
@@ -404,6 +429,7 @@ int main(int argc, char **argv)
     int flags = BDRV_O_UNMAP;
     Error *local_error = NULL;
     QDict *opts = NULL;
+    const char *format = NULL;
 
 #ifdef CONFIG_POSIX
     signal(SIGPIPE, SIG_IGN);
@@ -431,10 +457,7 @@ int main(int argc, char **argv)
             }
             break;
         case 'f':
-            if (!opts) {
+            format = optarg;
-                opts = qdict_new();
-            }
-            qdict_put(opts, "driver", qstring_from_str(optarg));
             break;
         case 'c':
             add_user_command(optarg);
@@ -466,13 +489,16 @@ int main(int argc, char **argv)
             usage(progname);
             exit(0);
         case OPTION_OBJECT: {
-            QemuOpts *qopts = NULL;
+            QemuOpts *qopts;
             qopts = qemu_opts_parse_noisily(&qemu_object_opts,
                                             optarg, true);
             if (!qopts) {
                 exit(1);
             }
         }   break;
+        case OPTION_IMAGE_OPTS:
+            imageOpts = true;
+            break;
         default:
             usage(progname);
             exit(1);
@@ -484,6 +510,11 @@ int main(int argc, char **argv)
         exit(1);
     }
 
+    if (format && imageOpts) {
+        error_report("--image-opts and -f are mutually exclusive");
+        exit(1);
+    }
+
     if (qemu_init_main_loop(&local_error)) {
         error_report_err(local_error);
         exit(1);
@@ -516,7 +547,21 @@ int main(int argc, char **argv)
     }
 
     if ((argc - optind) == 1) {
-        openfile(argv[optind], flags, opts);
+        if (imageOpts) {
+            QemuOpts *qopts = NULL;
+            qopts = qemu_opts_parse_noisily(&file_opts, argv[optind], false);
+            if (!qopts) {
+                exit(1);
+            }
+            opts = qemu_opts_to_qdict(qopts, NULL);
+            openfile(NULL, flags, opts);
+        } else {
+            if (format) {
+                opts = qdict_new();
+                qdict_put(opts, "driver", qstring_from_str(format));
+            }
+            openfile(argv[optind], flags, opts);
+        }
     }
     command_loop();