| Message ID | 1419293824-2654-9-git-send-email-david@gibson.dropbear.id.au |
|---|---|
| State | New |
| Headers | show |
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 <david@gibson.dropbear.id.au> Very nice, can we somehow get rid of an exported spapr_rtc_read() with this as well? Alex
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 <david@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.
> Am 23.12.2014 um 04:14 schrieb David Gibson <david@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 <david@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? Alex
On Tue, Dec 23, 2014 at 07:33:30AM +0100, Alexander Graf wrote: > > > > > Am 23.12.2014 um 04:14 schrieb David Gibson <david@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 <david@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.
diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c index 3070be0..88fabc8 100644 --- a/hw/ppc/spapr.c +++ b/hw/ppc/spapr.c @@ -961,6 +961,9 @@ static void spapr_rtc_create(sPAPREnvironment *spapr) qdev_init_nofail(dev); spapr->rtc = dev; + + object_property_add_alias(qdev_get_machine(), "rtc-time", + OBJECT(spapr->rtc), "date", NULL); } /* Returns whether we want to use VGA or not */ diff --git a/hw/ppc/spapr_rtc.c b/hw/ppc/spapr_rtc.c index 5ad0823..83eb7c1 100644 --- a/hw/ppc/spapr_rtc.c +++ b/hw/ppc/spapr_rtc.c @@ -152,6 +152,11 @@ static void rtas_set_time_of_day(PowerPCCPU *cpu, sPAPREnvironment *spapr, rtas_st(rets, 0, RTAS_OUT_SUCCESS); } +static void spapr_rtc_qom_date(Object *obj, struct tm *current_tm, Error **errp) +{ + spapr_rtc_read(DEVICE(obj), current_tm, NULL); +} + static void spapr_rtc_realize(DeviceState *dev, Error **errp) { sPAPRRTCState *rtc = SPAPR_RTC(dev); @@ -165,6 +170,8 @@ static void spapr_rtc_realize(DeviceState *dev, Error **errp) host_s = mktimegm(&tm); rtc_ns = qemu_clock_get_ns(rtc_clock); rtc->ns_offset = host_s * NSEC_PER_SEC - rtc_ns; + + object_property_add_tm(OBJECT(rtc), "date", spapr_rtc_qom_date, NULL); } static const VMStateDescription vmstate_spapr_rtc = {
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 <david@gibson.dropbear.id.au> --- hw/ppc/spapr.c | 3 +++ hw/ppc/spapr_rtc.c | 7 +++++++ 2 files changed, 10 insertions(+)