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>
diff --git a/docs/about/deprecated.rst b/docs/about/deprecated.rst
index ddc1e48..02ea5a8 100644
--- a/docs/about/deprecated.rst
+++ b/docs/about/deprecated.rst
@@ -116,6 +116,11 @@
Use ``-run-with async-teardown=on`` instead.
+``-chroot`` (since 8.1)
+'''''''''''''''''''''''
+
+Use ``-run-with chroot=dir`` instead.
+
``-singlestep`` (since 8.1)
'''''''''''''''''''''''''''
diff --git a/os-posix.c b/os-posix.c
index 90ea717..cfcb965 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 @@
}
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 @@
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 @@
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);
diff --git a/qemu-options.hx b/qemu-options.hx
index 9608750..f8f384e 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -4677,11 +4677,12 @@
#ifndef _WIN32
DEF("chroot", HAS_ARG, QEMU_OPTION_chroot, \
- "-chroot dir chroot to dir just before starting the VM\n",
+ "-chroot dir chroot to dir just before starting the VM (deprecated)\n",
QEMU_ARCH_ALL)
#endif
SRST
``-chroot dir``
+ Deprecated, use '-run-with chroot=...' instead.
Immediately before starting guest execution, chroot to the specified
directory. Especially useful in combination with -runas.
ERST
@@ -4868,13 +4869,16 @@
This option is deprecated and should no longer be used. The new option
``-run-with async-teardown=on`` is a replacement.
ERST
+#endif
+#ifdef CONFIG_POSIX
DEF("run-with", HAS_ARG, QEMU_OPTION_run_with,
- "-run-with async-teardown[=on|off]\n"
- " misc QEMU process lifecycle options\n"
- " async-teardown=on enables asynchronous teardown\n",
+ "-run-with [async-teardown=on|off][,chroot=dir]\n"
+ " Set miscellaneous QEMU process lifecycle options:\n"
+ " async-teardown=on enables asynchronous teardown (Linux only)\n"
+ " chroot=dir chroot to dir just before starting the VM\n",
QEMU_ARCH_ALL)
SRST
-``-run-with``
+``-run-with [async-teardown=on|off][,chroot=dir]``
Set QEMU process lifecycle options.
``async-teardown=on`` enables asynchronous teardown. A new process called
@@ -4887,6 +4891,10 @@
performed correctly. This only works if the cleanup process is not
forcefully killed with SIGKILL before the main QEMU process has
terminated completely.
+
+ ``chroot=dir`` can be used for doing a chroot to the specified directory
+ immediately before starting the guest execution. This is especially useful
+ in combination with -runas.
ERST
#endif
diff --git a/util/async-teardown.c b/util/async-teardown.c
index 3ab19c8..62cdeb0 100644
--- a/util/async-teardown.c
+++ b/util/async-teardown.c
@@ -12,9 +12,6 @@
*/
#include "qemu/osdep.h"
-#include "qemu/config-file.h"
-#include "qemu/option.h"
-#include "qemu/module.h"
#include <dirent.h>
#include <sys/prctl.h>
#include <sched.h>
@@ -147,21 +144,3 @@
clone(async_teardown_fn, new_stack_for_clone(), CLONE_VM, NULL);
sigprocmask(SIG_SETMASK, &old_signals, NULL);
}
-
-static QemuOptsList qemu_run_with_opts = {
- .name = "run-with",
- .head = QTAILQ_HEAD_INITIALIZER(qemu_run_with_opts.head),
- .desc = {
- {
- .name = "async-teardown",
- .type = QEMU_OPT_BOOL,
- },
- { /* end of list */ }
- },
-};
-
-static void register_teardown(void)
-{
- qemu_add_opts(&qemu_run_with_opts);
-}
-opts_init(register_teardown);
