Re: [RFC V1 11/14] monitor: connect in precreate

[Paolo Bonzini <pbonzini@redhat.com>]

On 10/17/24 17:14, Steve Sistare wrote:
> Complete monitor connections as early as possible, prior to
> qemu_create_early_backends, so the user can issue commands during the
> precreate phase.
> 
> Make a list of the chardev's referenced by all monitors.  Create the
> chardevs, then create the monitors.  Exclude monitor chardevs and
> monitors from the later creation phases.
> 
> Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
> ---
>   system/vl.c | 81 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++---
>   1 file changed, 77 insertions(+), 4 deletions(-)
> 
> diff --git a/system/vl.c b/system/vl.c
> index 3c592b9..a985ab8 100644
> --- a/system/vl.c
> +++ b/system/vl.c
> @@ -1939,6 +1939,11 @@ static bool object_create_early(const ObjectOption *opt)
>           return false;
>       }
>   
> +    /* Reason: already created. */
> +    if (g_str_equal(type, "mon")) {
> +        return false;
> +    }

This is incorrect as mentioned by Peter.

>       return true;
>   }
>   
> @@ -1956,6 +1961,68 @@ static void qemu_apply_machine_options(QDict *qdict)
>       }
>   }
>   
> +typedef struct NamedElement {
> +    char *name;
> +    QTAILQ_ENTRY(NamedElement) next;
> +} NamedElement;
> +
> +static QTAILQ_HEAD(, NamedElement) monitor_chardevs =
> +    QTAILQ_HEAD_INITIALIZER(monitor_chardevs);
> +
> +static void chardev_add(const char *name)
> +{
> +    NamedElement *elem = g_new0(NamedElement, 1);
> +
> +    elem->name = g_strdup(name);
> +    QTAILQ_INSERT_TAIL(&monitor_chardevs, elem, next);
> +}
> +
> +static bool chardev_find(const char *name)
> +{
> +    NamedElement *elem;
> +
> +    QTAILQ_FOREACH(elem, &monitor_chardevs, next) {
> +        if (g_str_equal(elem->name, name)) {
> +            return true;
> +        }
> +    }
> +    return false;
> +}

No new special casing and no tricky differentiation of how a single 
command line option is processed.  If you need to create monitors so 
early, create _all_ chardevs and _all_ monitors; same for qtest.

Paolo