On Tue, Dec 23, 2014 at 07:33:30AM +0100, Alexander Graf wrote: > > > > > Am 23.12.2014 um 04:14 schrieb David Gibson <da...@gibson.dropbear.id.au>: > > > >> On Tue, Dec 23, 2014 at 01:26:58AM +0100, Alexander Graf wrote: > >> > >> > >>> On 23.12.14 01:17, David Gibson wrote: > >>> On x86, the guest's RTC can be read with QMP, either from the RTC device's > >>> "date" property or via the "rtc-time" property on the machine (which is an > >>> alias to the former). This is set up in the mc146818rtc driver, and > >>> doesn't work on other targets. > >>> > >>> This patch adds a similar "date" property to the pseries machine's RTAS > >>> RTC > >>> and adds a compatible alias to the machine. > >>> > >>> Signed-off-by: David Gibson <da...@gibson.dropbear.id.au> > >> > >> Very nice, can we somehow get rid of an exported spapr_rtc_read() with > >> this as well? > > > > Uhhh.. we could, but I really don't like the idea. > > > > It seems perverse to encode the current time into JSON, just so we can > > decode it into a struct tm again in the events code. > > I don't understand - what does JSON have to do with it?
My misunderstanding, it doesn't actually deal with JSON here. But if
I'm following how this would work, it would be a way of getting a
struct tm from point A to point B, by:
1. building a temporary visitor object (object_property_get_qobject)
2. finding and calling the general property getter callback
(object_property_get)
3. Making multiple callbacks into the visitor with pieces of point
A's struct tm (property_get_tm)
4. In those visitor callbacks building an associative array
(qmp_output_start_struct), then filling it with object wrappers
around integers (qmp_output_type_int)
5. Digging through the nested qobject thus constructed to extract
the various ints and put them into point B's struct tm
(hypothetical object_property_get_tm)
6. Cleaning up the various temporaries created during the process
Seriously, w. t. f.!?
Maybe there's a simpler way of doing this via the object property
mechanism, but it's sure as hell not obvious to me.
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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