On Wed, Jul 01, 2026 at 03:19:53PM +0200, Markus Armbruster wrote: > Daniel P. Berrangé <[email protected]> writes: > > > On Tue, Jun 30, 2026 at 01:55:52PM +0200, Markus Armbruster wrote: > >> Daniel P. Berrangé <[email protected]> writes: > >> > >> > This introduces a Monitor QOM object, with MonitorHMP and > >> > MonitorQMP subclasses. This is the bare minimum conversion > >> > of just the type declarations and replacing g_new/g_free > >> > with object_new/object_unref. > >> > > >> > Reviewed-by: Marc-André Lureau <[email protected]> > >> > Tested-by: Peter Krempa <[email protected]> > >> > Signed-off-by: Daniel P. Berrangé <[email protected]> > >> > --- > >> > include/monitor/monitor.h | 11 ++++++++++- > >> > monitor/hmp.c | 29 +++++++++++++++++++++++++++-- > >> > monitor/monitor-internal.h | 18 ++++++++++++++++-- > >> > monitor/monitor.c | 18 ++++++++++++++++-- > >> > monitor/qmp-cmds.c | 15 ++++++++------- > >> > monitor/qmp.c | 29 +++++++++++++++++++++++++++-- > >> > 6 files changed, 104 insertions(+), 16 deletions(-) > >> > > >> > diff --git a/include/monitor/monitor.h b/include/monitor/monitor.h > >> > index b9642b58ba..2e9f9e12e9 100644 > >> > --- a/include/monitor/monitor.h > >> > +++ b/include/monitor/monitor.h > >> > @@ -5,8 +5,17 @@ > >> > #include "qapi/qapi-types-misc.h" > >> > #include "qemu/readline.h" > >> > #include "exec/hwaddr.h" > >> > +#include "qom/object.h" > >> > + > >> > +#define TYPE_MONITOR "monitor" > >> > +OBJECT_DECLARE_TYPE(Monitor, MonitorClass, MONITOR); > >> > + > >> > +#define TYPE_MONITOR_HMP "monitor-hmp" > >> > +OBJECT_DECLARE_TYPE(MonitorHMP, MonitorHMPClass, MONITOR_HMP); > >> > + > >> > +#define TYPE_MONITOR_QMP "monitor-qmp" > >> > +OBJECT_DECLARE_TYPE(MonitorQMP, MonitorQMPClass, MONITOR_QMP); > >> > > >> > -typedef struct MonitorHMP MonitorHMP; > >> > typedef struct MonitorOptions MonitorOptions; > >> > > >> > #define QMP_REQ_QUEUE_LEN_MAX 8 > >> > diff --git a/monitor/hmp.c b/monitor/hmp.c > >> > index 4e4468424a..81047d2513 100644 > >> > --- a/monitor/hmp.c > >> > +++ b/monitor/hmp.c > >> > @@ -43,6 +43,20 @@ > >> > #include "system/block-backend.h" > >> > #include "trace.h" > >> > > >> > +OBJECT_DEFINE_TYPE(MonitorHMP, monitor_hmp, MONITOR_HMP, MONITOR); > >> > + > >> > +static void monitor_hmp_finalize(Object *obj) > >> > +{ > >> > +} > >> > + > >> > +static void monitor_hmp_class_init(ObjectClass *cls, const void *data) > >> > +{ > >> > +} > >> > + > >> > +static void monitor_hmp_init(Object *obj) > >> > +{ > >> > +} > >> > + > >> > static void monitor_command_cb(void *opaque, const char *cmdline, > >> > void *readline_opaque) > >> > { > >> > @@ -1526,10 +1540,21 @@ static void monitor_readline_flush(void *opaque) > >> > > >> > void monitor_new_hmp(Chardev *chr, bool use_readline, Error **errp) > >> > { > >> > - MonitorHMP *mon = g_new0(MonitorHMP, 1); > >> > + MonitorHMP *mon; > >> > + static int counter; > >> > + g_autofree char *id = g_strdup_printf("hmpcompat%d", counter++); > >> > >> Hmm. The system picking IDs is problematic when they can clash with the > >> user's IDs. If we had an ounce of common sense, we'd restrict both > >> across the board so they cannot clash. But we don't. > >> > >> We need an ID here, because we need to make the new object the child of > >> something (actually: child of /objects/), which requires a child name. > >> > >> Non-problem with -object / object-add, because @id is mandatory there. > >> > >> Non-problem with -device / device_add, because we use separate parents > >> for devices with and without @id (/machine/peripheral/ and > >> /machine/peripheral-anon/, plus the /machine/unattached/ orphanage). > >> > >> Example for an existing problem: > >> > >> $ qemu-system-x86_64 -nodefaults -monitor stdio -chardev null,id=chr0 > >> -mon id=compat_monitor0,chardev=chr0 > >> qemu-system-x86_64: -mon id=compat_monitor0,chardev=chr0: Duplicate ID > >> 'compat_monitor0' for mon > >> > >> Example for a problem created by this series: > >> > >> $ qemu-system-x86_64 -nodefaults -display none -S -monitor stdio > >> -chardev null,id=chr0 -object monitor-hmp,id=hmpcompat0,chardev=chr0 > >> qemu-system-x86_64: -monitor stdio: attempt to add duplicate property > >> 'hmpcompat0' to object (type 'container') > >> > >> I readily admit that these clashes are *unlikely*. Still, do we really > >> want to define an interface that claims to let you pick any ID, then > >> rejects some of them sometimes? Feels rather 1990s to me. At the very > >> least, cover the wart in the commit message. > > > > The way I looked at it was aything using -object with the new > > monitor-qmp/monitor-hmp types is new code. They can: > > > > 1. Trivially abide the warning about "hmpcompatNN" / "qmpcompatNN" > > being internal usage for compat syntax > > A wart you can easily cope with is still a wart. Oh well, we'll live. > However, the wart should be documented. > > > 2. Not use both -monitor and -object on the same QEMU instance > > so not have a clash between the two to begin with > > Management applications aware of the monitor QOM types should use > -object / object-add exclusively. > > Human users will use -monitor to save typing. If they then need to plug > an additional one at run time, they have no choice but use object-add. > Again, we'll live. > > > The remaining danger where is some existing code using -object with > > a *non-monitor* type, and calling it "hmpcompatNN" / "qmpcompatNN", > > which would be insanity. Never say never, but I think that's an > > acceptable risk. > > The risk is acceptable. The documentation complexity that comes with > the wart bothers me. > > Could we use id_generate()?
Since we want to re-use the QemuOpts ID present in -monitor/-qmp, I'm going to stick with "compat_monitorNNN" and get rid of use of 'hmpcompatNN' and 'qmpcompatNN'. id_generate() does not help here because it forces a "#" prefix onto the ID which then (intentionally) violates id_wellformed() which object_new_xxx() validates. With regards, Daniel -- |: https://berrange.com ~~ https://hachyderm.io/@berrange :| |: https://libvirt.org ~~ https://entangle-photo.org :| |: https://pixelfed.art/berrange ~~ https://fstop138.berrange.com :|
