[PATCH v2] qemu-options: Deprecate "-runas" and introduce "-run-with user=..." instead

The old "-runas" option has the disadvantage that it is not visible in the QAPI schema, so it is not available via the normal introspection mechanisms. We've recently introduced the "-run-with" option for exactly this purpose, which is meant to handle the options that affect the runtime behavior. Thus let's introduce a "user=..." parameter here now and deprecate the old "-runas" option. Signed-off-by: Thomas Huth <thuth@redhat.com> --- v2: Add missing part in qemu-options.hx as suggested by Philippe docs/about/deprecated.rst | 6 ++++++ system/vl.c | 15 +++++++++++++++ qemu-options.hx | 15 +++++++++++---- 3 files changed, 32 insertions(+), 4 deletions(-) diff --git a/docs/about/deprecated.rst b/docs/about/deprecated.rst index 3310df3274..fe69e2d44c 100644 --- a/docs/about/deprecated.rst +++ b/docs/about/deprecated.rst @@ -61,6 +61,12 @@ configurations (e.g. -smp drawers=1,books=1,clusters=1 for x86 PC machine) is marked deprecated since 9.0, users have to ensure that all the topology members described with -smp are supported by the target machine. +``-runas`` (since 9.1) +---------------------- + +Use ``-run-with user=..`` instead. + + User-mode emulator command line arguments ----------------------------------------- diff --git a/system/vl.c b/system/vl.c index 7756eac81e..b031427440 100644 --- a/system/vl.c +++ b/system/vl.c @@ -773,6 +773,10 @@ static QemuOptsList qemu_run_with_opts = { .name = "chroot", .type = QEMU_OPT_STRING, }, + { + .name = "user", + .type = QEMU_OPT_STRING, + }, { /* end of list */ } }, }; @@ -3586,6 +3590,7 @@ void qemu_init(int argc, char **argv) break; #if defined(CONFIG_POSIX) case QEMU_OPTION_runas: + warn_report("-runas is deprecated, use '-run-with user=...' instead"); if (!os_set_runas(optarg)) { error_report("User \"%s\" doesn't exist" " (and is not <uid>:<gid>)", @@ -3612,6 +3617,16 @@ void qemu_init(int argc, char **argv) if (str) { os_set_chroot(str); } + str = qemu_opt_get(opts, "user"); + if (str) { + if (!os_set_runas(str)) { + error_report("User \"%s\" doesn't exist" + " (and is not <uid>:<gid>)", + optarg); + exit(1); + } + } + break; } #endif /* CONFIG_POSIX */ diff --git a/qemu-options.hx b/qemu-options.hx index cf61f6b863..3031479a15 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -4824,7 +4824,8 @@ DEF("runas", HAS_ARG, QEMU_OPTION_runas, \ SRST ``-runas user`` Immediately before starting guest execution, drop root privileges, - switching to the specified user. + switching to the specified user. This option is deprecated, use + ``-run-with user=...`` instead. ERST DEF("prom-env", HAS_ARG, QEMU_OPTION_prom_env, @@ -4990,13 +4991,15 @@ DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "", QEMU_ARCH_ALL) #ifdef CONFIG_POSIX DEF("run-with", HAS_ARG, QEMU_OPTION_run_with, - "-run-with [async-teardown=on|off][,chroot=dir]\n" + "-run-with [async-teardown=on|off][,chroot=dir][user=username|uid:gid]\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", + " chroot=dir chroot to dir just before starting the VM\n" + " user=username switch to the specified user before starting the VM\n" + " user=uid:gid dito, but use specified user-ID and group-ID instead\n", QEMU_ARCH_ALL) SRST -``-run-with [async-teardown=on|off][,chroot=dir]`` +``-run-with [async-teardown=on|off][,chroot=dir][user=username|uid:gid]`` Set QEMU process lifecycle options. ``async-teardown=on`` enables asynchronous teardown. A new process called @@ -5013,6 +5016,10 @@ SRST ``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. + + ``user=username`` or ``user=uid:gid`` can be used to drop root privileges + by switching to the specified user (via username) or user and group + (via uid:gid) immediately before starting guest execution. ERST #endif -- 2.45.0

On 6/5/24 13:20, Thomas Huth wrote:
The old "-runas" option has the disadvantage that it is not visible in the QAPI schema, so it is not available via the normal introspection mechanisms. We've recently introduced the "-run-with" option for exactly this purpose, which is meant to handle the options that affect the runtime behavior. Thus let's introduce a "user=..." parameter here now and deprecate the old "-runas" option.
Signed-off-by: Thomas Huth <thuth@redhat.com> --- v2: Add missing part in qemu-options.hx as suggested by Philippe
docs/about/deprecated.rst | 6 ++++++ system/vl.c | 15 +++++++++++++++ qemu-options.hx | 15 +++++++++++---- 3 files changed, 32 insertions(+), 4 deletions(-)
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>

On Mon, May 6, 2024 at 1:21 PM Thomas Huth <thuth@redhat.com> wrote:
The old "-runas" option has the disadvantage that it is not visible in the QAPI schema, so it is not available via the normal introspection mechanisms. We've recently introduced the "-run-with" option for exactly this purpose, which is meant to handle the options that affect the runtime behavior. Thus let's introduce a "user=..." parameter here now and deprecate the old "-runas" option.
No need to deprecate it, there are other shortcut options that are just a couple lines of code to implement: case QEMU_OPTION_watchdog_action: { opts = qemu_opts_create(qemu_find_opts("action"), NULL, 0, &error_abort); qemu_opt_set(opts, "watchdog", optarg, &error_abort); break; However that would be a larger patch, basically moving all of the --run-with handling to qemu_process_early_options() (and, as an aside, setting .merge_lists = true in qemu_run_with_opts). No objections to your patch, but also no objections to cleaning all of --run-with; I should have caught it and proposed the shortcut options when it was introduced or when --chroot was removed. Paolo
if (!os_set_runas(optarg)) { error_report("User \"%s\" doesn't exist" " (and is not <uid>:<gid>)", @@ -3612,6 +3617,16 @@ void qemu_init(int argc, char **argv) if (str) { os_set_chroot(str); } + str = qemu_opt_get(opts, "user"); + if (str) { + if (!os_set_runas(str)) { + error_report("User \"%s\" doesn't exist" + " (and is not <uid>:<gid>)", + optarg); + exit(1); + } + } + break; } #endif /* CONFIG_POSIX */ diff --git a/qemu-options.hx b/qemu-options.hx index cf61f6b863..3031479a15 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -4824,7 +4824,8 @@ DEF("runas", HAS_ARG, QEMU_OPTION_runas, \ SRST ``-runas user`` Immediately before starting guest execution, drop root privileges, - switching to the specified user. + switching to the specified user. This option is deprecated, use + ``-run-with user=...`` instead. ERST
DEF("prom-env", HAS_ARG, QEMU_OPTION_prom_env, @@ -4990,13 +4991,15 @@ DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "", QEMU_ARCH_ALL)
#ifdef CONFIG_POSIX DEF("run-with", HAS_ARG, QEMU_OPTION_run_with, - "-run-with [async-teardown=on|off][,chroot=dir]\n" + "-run-with [async-teardown=on|off][,chroot=dir][user=username|uid:gid]\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", + " chroot=dir chroot to dir just before starting the VM\n" + " user=username switch to the specified user before starting the VM\n" + " user=uid:gid dito, but use specified user-ID and group-ID instead\n", QEMU_ARCH_ALL) SRST -``-run-with [async-teardown=on|off][,chroot=dir]`` +``-run-with [async-teardown=on|off][,chroot=dir][user=username|uid:gid]`` Set QEMU process lifecycle options.
``async-teardown=on`` enables asynchronous teardown. A new process called @@ -5013,6 +5016,10 @@ SRST ``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. + + ``user=username`` or ``user=uid:gid`` can be used to drop root privileges + by switching to the specified user (via username) or user and group + (via uid:gid) immediately before starting guest execution. ERST #endif
-- 2.45.0 M

On 5/6/24 13:20, Thomas Huth wrote:
The old "-runas" option has the disadvantage that it is not visible in the QAPI schema, so it is not available via the normal introspection mechanisms. We've recently introduced the "-run-with" option for exactly this purpose, which is meant to handle the options that affect the runtime behavior. Thus let's introduce a "user=..." parameter here now and deprecate the old "-runas" option.
Signed-off-by: Thomas Huth <thuth@redhat.com> --- v2: Add missing part in qemu-options.hx as suggested by Philippe
docs/about/deprecated.rst | 6 ++++++ system/vl.c | 15 +++++++++++++++ qemu-options.hx | 15 +++++++++++---- 3 files changed, 32 insertions(+), 4 deletions(-)
diff --git a/docs/about/deprecated.rst b/docs/about/deprecated.rst index 3310df3274..fe69e2d44c 100644 --- a/docs/about/deprecated.rst +++ b/docs/about/deprecated.rst @@ -61,6 +61,12 @@ configurations (e.g. -smp drawers=1,books=1,clusters=1 for x86 PC machine) is marked deprecated since 9.0, users have to ensure that all the topology members described with -smp are supported by the target machine.
+``-runas`` (since 9.1) +---------------------- + +Use ``-run-with user=..`` instead. + + User-mode emulator command line arguments -----------------------------------------
diff --git a/system/vl.c b/system/vl.c index 7756eac81e..b031427440 100644 --- a/system/vl.c +++ b/system/vl.c @@ -773,6 +773,10 @@ static QemuOptsList qemu_run_with_opts = { .name = "chroot", .type = QEMU_OPT_STRING, }, + { + .name = "user", + .type = QEMU_OPT_STRING, + }, { /* end of list */ } }, }; @@ -3586,6 +3590,7 @@ void qemu_init(int argc, char **argv) break; #if defined(CONFIG_POSIX) case QEMU_OPTION_runas: + warn_report("-runas is deprecated, use '-run-with user=...' instead"); if (!os_set_runas(optarg)) { error_report("User \"%s\" doesn't exist" " (and is not <uid>:<gid>)", @@ -3612,6 +3617,16 @@ void qemu_init(int argc, char **argv) if (str) { os_set_chroot(str); } + str = qemu_opt_get(opts, "user"); + if (str) { + if (!os_set_runas(str)) { + error_report("User \"%s\" doesn't exist" + " (and is not <uid>:<gid>)", + optarg); + exit(1); + } + } + break; } #endif /* CONFIG_POSIX */ diff --git a/qemu-options.hx b/qemu-options.hx index cf61f6b863..3031479a15 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -4824,7 +4824,8 @@ DEF("runas", HAS_ARG, QEMU_OPTION_runas, \ SRST ``-runas user`` Immediately before starting guest execution, drop root privileges, - switching to the specified user. + switching to the specified user. This option is deprecated, use + ``-run-with user=...`` instead. ERST
DEF("prom-env", HAS_ARG, QEMU_OPTION_prom_env, @@ -4990,13 +4991,15 @@ DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "", QEMU_ARCH_ALL)
#ifdef CONFIG_POSIX DEF("run-with", HAS_ARG, QEMU_OPTION_run_with, - "-run-with [async-teardown=on|off][,chroot=dir]\n" + "-run-with [async-teardown=on|off][,chroot=dir][user=username|uid:gid]\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", + " chroot=dir chroot to dir just before starting the VM\n" + " user=username switch to the specified user before starting the VM\n" + " user=uid:gid dito, but use specified user-ID and group-ID instead\n",
nit: ditto? Ciao, C
QEMU_ARCH_ALL) SRST -``-run-with [async-teardown=on|off][,chroot=dir]`` +``-run-with [async-teardown=on|off][,chroot=dir][user=username|uid:gid]`` Set QEMU process lifecycle options.
``async-teardown=on`` enables asynchronous teardown. A new process called @@ -5013,6 +5016,10 @@ SRST ``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. + + ``user=username`` or ``user=uid:gid`` can be used to drop root privileges + by switching to the specified user (via username) or user and group + (via uid:gid) immediately before starting guest execution. ERST #endif

On 08/05/2024 15.20, Claudio Fontana wrote:
On 5/6/24 13:20, Thomas Huth wrote:
The old "-runas" option has the disadvantage that it is not visible in the QAPI schema, so it is not available via the normal introspection mechanisms. We've recently introduced the "-run-with" option for exactly this purpose, which is meant to handle the options that affect the runtime behavior. Thus let's introduce a "user=..." parameter here now and deprecate the old "-runas" option.
Signed-off-by: Thomas Huth <thuth@redhat.com> --- v2: Add missing part in qemu-options.hx as suggested by Philippe
docs/about/deprecated.rst | 6 ++++++ system/vl.c | 15 +++++++++++++++ qemu-options.hx | 15 +++++++++++---- 3 files changed, 32 insertions(+), 4 deletions(-)
diff --git a/docs/about/deprecated.rst b/docs/about/deprecated.rst index 3310df3274..fe69e2d44c 100644 --- a/docs/about/deprecated.rst +++ b/docs/about/deprecated.rst @@ -61,6 +61,12 @@ configurations (e.g. -smp drawers=1,books=1,clusters=1 for x86 PC machine) is marked deprecated since 9.0, users have to ensure that all the topology members described with -smp are supported by the target machine.
+``-runas`` (since 9.1) +---------------------- + +Use ``-run-with user=..`` instead. + + User-mode emulator command line arguments -----------------------------------------
diff --git a/system/vl.c b/system/vl.c index 7756eac81e..b031427440 100644 --- a/system/vl.c +++ b/system/vl.c @@ -773,6 +773,10 @@ static QemuOptsList qemu_run_with_opts = { .name = "chroot", .type = QEMU_OPT_STRING, }, + { + .name = "user", + .type = QEMU_OPT_STRING, + }, { /* end of list */ } }, }; @@ -3586,6 +3590,7 @@ void qemu_init(int argc, char **argv) break; #if defined(CONFIG_POSIX) case QEMU_OPTION_runas: + warn_report("-runas is deprecated, use '-run-with user=...' instead"); if (!os_set_runas(optarg)) { error_report("User \"%s\" doesn't exist" " (and is not <uid>:<gid>)", @@ -3612,6 +3617,16 @@ void qemu_init(int argc, char **argv) if (str) { os_set_chroot(str); } + str = qemu_opt_get(opts, "user"); + if (str) { + if (!os_set_runas(str)) { + error_report("User \"%s\" doesn't exist" + " (and is not <uid>:<gid>)", + optarg); + exit(1); + } + } + break; } #endif /* CONFIG_POSIX */ diff --git a/qemu-options.hx b/qemu-options.hx index cf61f6b863..3031479a15 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -4824,7 +4824,8 @@ DEF("runas", HAS_ARG, QEMU_OPTION_runas, \ SRST ``-runas user`` Immediately before starting guest execution, drop root privileges, - switching to the specified user. + switching to the specified user. This option is deprecated, use + ``-run-with user=...`` instead. ERST
DEF("prom-env", HAS_ARG, QEMU_OPTION_prom_env, @@ -4990,13 +4991,15 @@ DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "", QEMU_ARCH_ALL)
#ifdef CONFIG_POSIX DEF("run-with", HAS_ARG, QEMU_OPTION_run_with, - "-run-with [async-teardown=on|off][,chroot=dir]\n" + "-run-with [async-teardown=on|off][,chroot=dir][user=username|uid:gid]\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", + " chroot=dir chroot to dir just before starting the VM\n" + " user=username switch to the specified user before starting the VM\n" + " user=uid:gid dito, but use specified user-ID and group-ID instead\n",
nit: ditto?
Thanks, I'll fix it! Thomas
participants (4)
-
Claudio Fontana
-
Paolo Bonzini
-
Philippe Mathieu-Daudé
-
Thomas Huth