Re: [PATCH 08/11] mos6522: add "info via" HMP command for debugging

["Daniel P. Berrangé" <berrange@redhat.com>]

On Thu, Jan 27, 2022 at 08:54:02PM +0000, Mark Cave-Ayland wrote:
> This displays detailed information about the device registers and timers to aid
> debugging problems with timers and interrupts.
> 
> Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
> ---
>  hmp-commands-info.hx | 12 ++++++
>  hw/misc/mos6522.c    | 92 ++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 104 insertions(+)
> 
> diff --git a/hmp-commands-info.hx b/hmp-commands-info.hx
> index e90f20a107..4e714e79a2 100644
> --- a/hmp-commands-info.hx
> +++ b/hmp-commands-info.hx
> @@ -879,3 +879,15 @@ SRST
>    ``info sgx``
>      Show intel SGX information.
>  ERST
> +
> +    {
> +        .name       = "via",
> +        .args_type  = "",
> +        .params     = "",
> +        .help       = "show guest 6522 VIA devices",
> +    },
> +
> +SRST
> +  ``info via``
> +    Show guest 6522 VIA devices.
> +ERST
> diff --git a/hw/misc/mos6522.c b/hw/misc/mos6522.c
> index aaae195d63..cfa6a9c44b 100644
> --- a/hw/misc/mos6522.c
> +++ b/hw/misc/mos6522.c
> @@ -30,6 +30,8 @@
>  #include "hw/misc/mos6522.h"
>  #include "hw/qdev-properties.h"
>  #include "migration/vmstate.h"
> +#include "monitor/monitor.h"
> +#include "qapi/type-helpers.h"
>  #include "qemu/timer.h"
>  #include "qemu/cutils.h"
>  #include "qemu/log.h"
> @@ -415,6 +417,95 @@ void mos6522_write(void *opaque, hwaddr addr, uint64_t val, unsigned size)
>      }
>  }
>  
> +static int qmp_x_query_via_foreach(Object *obj, void *opaque)


> +
> +static HumanReadableText *qmp_x_query_via(Error **errp)
> +{
> +    g_autoptr(GString) buf = g_string_new("");
> +
> +    object_child_foreach_recursive(object_get_root(),
> +                                   qmp_x_query_via_foreach, buf);
> +
> +    return human_readable_text_from_str(buf);
> +}

This provides a code handler for a QMP command which is good,
but doesn't ever define the QMP command in the qapi/ schema.


>  static const MemoryRegionOps mos6522_ops = {
>      .read = mos6522_read,
>      .write = mos6522_write,
> @@ -547,6 +638,7 @@ static const TypeInfo mos6522_type_info = {
>  static void mos6522_register_types(void)
>  {
>      type_register_static(&mos6522_type_info);
> +    monitor_register_hmp_info_hrt("via", qmp_x_query_via);

This only registers the HMP counterpart.

The idea of the HumanReadableText handler is that it is calling
a QMP command that is exposed to apps.

>  }

Regards,
Daniel
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