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pseries: Make RTAS time of day functions respect -rtc options 

In the 'pseries' machine the real time clock is provided by a
paravirtualized firmware interface rather than a device per se; the RTAS
get-time-of-day and set-time-of-day calls.

Out current implementations of those work directly off host time (with
an offset), not respecting options such as clock=vm which can be
specified in the -rtc command line option.

This patch reworks the RTAS RTC code to respect those options, primarily
by basing them on the qemu_clock_get_ns(rtc_clock) function instead of
directly on qemu_get_timedate() (which essentially handles host time, not
virtual rtc time).

As a bonus, this means our get-time-of-day function now also returns
nanoseconds.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Alexander Graf <agraf@suse.de>
This commit is contained in:
David Gibson 2015-02-06 14:55:50 +11:00 committed by Alexander Graf
parent e5dad1d7d1
commit f01c5d8477
1 changed files with 36 additions and 4 deletions
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40
hw/ppc/spapr_rtc.c
View File

@ -26,14 +26,24 @@
*
*/
#include "cpu.h"
#include "sysemu/sysemu.h"
#include "hw/ppc/spapr.h"
#include "qapi-event.h"
#define NSEC_PER_SEC 1000000000LL
void spapr_rtc_read(sPAPREnvironment *spapr, struct tm *tm, uint32_t *ns)
{
qemu_get_timedate(tm, spapr->rtc_offset);
int64_t host_ns = qemu_clock_get_ns(rtc_clock);
time_t guest_s;
guest_s = host_ns / NSEC_PER_SEC + spapr->rtc_offset;
if (tm) {
gmtime_r(&guest_s, tm);
}
if (ns) {
*ns = 0; /* we don't do nanoseconds, yet */
*ns = host_ns % NSEC_PER_SEC;
}
}
@ -68,6 +78,8 @@ static void rtas_set_time_of_day(PowerPCCPU *cpu, sPAPREnvironment *spapr,
uint32_t nret, target_ulong rets)
{
struct tm tm;
time_t new_s;
int64_t host_ns;
if ((nargs != 7) || (nret != 1)) {
rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR);
@ -81,15 +93,35 @@ static void rtas_set_time_of_day(PowerPCCPU *cpu, sPAPREnvironment *spapr,
tm.tm_min = rtas_ld(args, 4);
tm.tm_sec = rtas_ld(args, 5);
/* Just generate a monitor event for the change */
new_s = mktimegm(&tm);
if (new_s == -1) {
rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR);
return;
}
/* Generate a monitor event for the change */
qapi_event_send_rtc_change(qemu_timedate_diff(&tm), &error_abort);
spapr->rtc_offset = qemu_timedate_diff(&tm);
host_ns = qemu_clock_get_ns(rtc_clock);
spapr->rtc_offset = new_s - host_ns / NSEC_PER_SEC;
rtas_st(rets, 0, RTAS_OUT_SUCCESS);
}
void spapr_rtc_init(void)
{
struct tm tm;
time_t host_s;
int64_t rtc_ns;
/* Initialize the RTAS RTC from host time */
qemu_get_timedate(&tm, 0);
host_s = mktimegm(&tm);
rtc_ns = qemu_clock_get_ns(rtc_clock);
spapr->rtc_offset = host_s - rtc_ns / NSEC_PER_SEC;
spapr_rtas_register(RTAS_GET_TIME_OF_DAY, "get-time-of-day",
rtas_get_time_of_day);
spapr_rtas_register(RTAS_SET_TIME_OF_DAY, "set-time-of-day",