[libvirt] [PATCH] virsh: Increase device-detach intelligence

[Michal Prívozník]

On 04/05/2011 12:14 AM, Eric Blake wrote:
> On 03/25/2011 09:09 AM, Michal Privoznik wrote:
>> Up to now users have to give a full XML description on input when
>> device-detaching. If they omited something it lead to unclear
>> error messages (like generated MAC wasn't found, etc.).
>> With this patch users can specify only those information which
>> specify one device sufficiently precise. Remaining information is
>> completed from domain.
>> ---
>>   tools/virsh.c |  260 +++++++++++++++++++++++++++++++++++++++++++++++++++++----
>>   1 files changed, 245 insertions(+), 15 deletions(-)
>
> Not forgotten, but not quite yet to the top of my queue, either :(  I
> guess having too many patches to review is a good sign that there is a
> lot of contribution going on.
>
>>
>> diff --git a/tools/virsh.c b/tools/virsh.c
>> index 50ca50f..95d27f7 100644
>> --- a/tools/virsh.c
>> +++ b/tools/virsh.c
>> @@ -8702,6 +8702,224 @@ cmdAttachDevice(vshControl *ctl, const vshCmd *cmd)
>>       return TRUE;
>>   }
>>
>> +/**
>> + * Check if n1 is superset of n2, meaning n1 contains all elements and
>> + * attributes as n2 at lest. Including children.
>> + * @n1 first node
>> + * @n2 second node
>> + * return 1 in case n1 covers n2, 0 otherwise.
>> + */
>> +static int
>> +vshNodeIsSuperset(xmlNodePtr n1, xmlNodePtr n2) {
>
> Are there any xml library functions that can already do this without you
> rewriting it from scratch?
No, there are not. I consulted this issue with Daniel Veillard.
>
>> +/**
>> + * To given domain and (probably incomplete) device XML specification try to
>> + * find such device in domain and complete missing parts. This is however
>> + * possible when given device XML is sufficiently precise so it addresses only
>> + * one device.
>> + * @ctl vshControl for error messages printing
>> + * @dom domain
>> + * @oldXML device XML before
>> + * @newXML and after completion
>> + * Returns -2 when no such device exists in domain, -3 when given XML selects many
>> + *          (is too ambiguous), 0 in case of success. Otherwise returns -1. @newXML
>> + *          is touched only in case of success.
>> + */
>> +static int
>> +vshCompleteXMLFromDomain(vshControl *ctl, virDomainPtr dom, char *oldXML,
>> +                         char **newXML) {
>
> My quick glance of just the documentation says that this looks like a
> nice helper, but I haven't reviewed it in depth.
>