Re: [Qemu-devel] [Xen-devel] qemu mainline regression with xen-unstable: unable to start QMP

[Don Slutz <don.slutz@gmail.com>]

On 06/04/15 17:59, Don Slutz wrote:
> On 06/04/15 11:04, Fabio Fantoni wrote:
>> Today after trying xen-unstable build (tested many hours) of some days
>> ago I tried update qemu to latest development version (from git master
>> commit 6fa6b312765f698dc81b2c30e7eeb9683804a05b) and seems that there is
>> a regression:
>>> xl create /etc/xen/W7.cfg
>>> Parsing config from /etc/xen/W7.cfg
>>> libxl: error: libxl_qmp.c:287:qmp_handle_error_response: received an
>>> error message from QMP server: QMP input object member 'id' is unexpected
>>> libxl: error: libxl_qmp.c:715:libxl__qmp_initialize: Failed to connect
>>> to QMP
>>
> 
> This is caused by:
> 
> commit 65207c59d99f2260c5f1d3b9c491146616a522aa
> Author: Markus Armbruster <armbru@redhat.com>
> Date:   Thu Mar 5 14:35:26 2015 +0100
> 
>     monitor: Drop broken, unused asynchronous command interface
> 
> 
>> DomU is working but operations that require QMP not (for example
>> save/restore).
>>
>> Thanks for any reply and sorry for my bad english.
>>
> 

I have created a bug -- Bug #1462131 for this.

   -Don Slutz

> The patch:
> 
> From 1b0221078353870fe530e49de158cae205f9bce5 Mon Sep 17 00:00:00 2001
> From: Don Slutz <dslutz@verizon.com>
> Date: Thu, 4 Jun 2015 17:04:42 -0400
> Subject: [PATCH 01/14] monitor: Allow Xen's (broken) usage of asynchronous
>  command interface.
> 
> commit 65207c59d99f2260c5f1d3b9c491146616a522aa
> Author: Markus Armbruster <armbru@redhat.com>
> Date:   Thu Mar 5 14:35:26 2015 +0100
> 
>     monitor: Drop broken, unused asynchronous command interface
> 
> Breaks Xen.  Add a hack un unbreak it.
> 
> Xen is only doing synchronous commands, but is including an id.
> 
> Signed-off-by: Don Slutz <dslutz@verizon.com>
> ---
>  monitor.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/monitor.c b/monitor.c
> index c7baa91..e9a0747 100644
> --- a/monitor.c
> +++ b/monitor.c
> @@ -4955,6 +4955,15 @@ static QDict *qmp_check_input_obj(QObject
> *input_obj, Error **errp)
>                            "arguments", "object");
>                  return NULL;
>              }
> +        } else if (!strcmp(arg_name, "id")) {
> +            /*
> +             * Fixup Xen's usage. Just ignore the "id". See point #5
> +             * above.  This was an attempt at an asynchronous
> +             * command interface.  However commit
> +             * 65207c59d99f2260c5f1d3b9c491146616a522aa is
> +             * wrong. Xen does not expect an error when it passes in
> +             * "id":1, so just continue to ignore it.
> +             */
>          } else {
>              error_set(errp, QERR_QMP_EXTRA_MEMBER, arg_name);
>              return NULL;
>