os-posix: Allow 'chroot' via '-run-with' and deprecate the old '-chroot' option

We recently introduced "-run-with" for options that influence the
runtime behavior of QEMU. This option has the big advantage that it
can group related options (so that it is easier for the users to spot
them) and that the options become introspectable via QMP this way.
So let's start moving more switches into this option group, starting
with "-chroot" now.

Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: Michael Tokarev <mjt@tls.msk.ru>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Message-Id: <20230703074447.17044-1-thuth@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>

1 files changed, 34 insertions, 1 deletions

diff --git a/os-posix.c b/os-posix.c
index 90ea71725f..cfcb96533c 100644
--- a/os-posix.c
+++ b/os-posix.c
@@ -38,6 +38,7 @@
 #include "qemu/cutils.h"
 #include "qemu/config-file.h"
 #include "qemu/option.h"
+#include "qemu/module.h"
 
 #ifdef CONFIG_LINUX
 #include <sys/prctl.h>
@@ -148,6 +149,7 @@ int os_parse_cmd_args(int index, const char *optarg)
         }
         break;
     case QEMU_OPTION_chroot:
+        warn_report("option is deprecated, use '-run-with chroot=...' instead");
         chroot_dir = optarg;
         break;
     case QEMU_OPTION_daemonize:
@@ -158,18 +160,25 @@ int os_parse_cmd_args(int index, const char *optarg)
     case QEMU_OPTION_asyncteardown:
         init_async_teardown();
         break;
+#endif
     case QEMU_OPTION_run_with: {
+        const char *str;
         QemuOpts *opts = qemu_opts_parse_noisily(qemu_find_opts("run-with"),
                                                  optarg, false);
         if (!opts) {
             exit(1);
         }
+#if defined(CONFIG_LINUX)
         if (qemu_opt_get_bool(opts, "async-teardown", false)) {
             init_async_teardown();
         }
+#endif
+        str = qemu_opt_get(opts, "chroot");
+        if (str) {
+            chroot_dir = str;
+        }
         break;
     }
-#endif
     default:
         return -1;
     }
@@ -348,3 +357,27 @@ int os_mlock(void)
     return -ENOSYS;
 #endif
 }
+
+static QemuOptsList qemu_run_with_opts = {
+    .name = "run-with",
+    .head = QTAILQ_HEAD_INITIALIZER(qemu_run_with_opts.head),
+    .desc = {
+#if defined(CONFIG_LINUX)
+        {
+            .name = "async-teardown",
+            .type = QEMU_OPT_BOOL,
+        },
+#endif
+        {
+            .name = "chroot",
+            .type = QEMU_OPT_STRING,
+        },
+        { /* end of list */ }
+    },
+};
+
+static void register_runwith(void)
+{
+    qemu_add_opts(&qemu_run_with_opts);
+}
+opts_init(register_runwith);