motorhead/qemu
1
0
Fork 0
mirror of https://github.com/Motorhead1991/qemu.git synced 2025-08-01 23:03:54 -06:00
Code Issues Projects Releases Packages Wiki Activity Actions

Introduce QEMU_CLOCK_HOST

Browse source 
Despite its name QEMU_CLOCK_REALTIME is (normally) not using
CLOCK_REALTIME / the host system time as base. In order to allow also
non-trivial RTC emulations (MC146818) to follow the host time instead of
the virtual guest time, introduce the new clock type QEMU_CLOCK_HOST. It
is unconditionally based on CLOCK_REALTIME, thus will follow system time
changes of the host.

The only limitation of its current implementation is that pending
host_clock timers may not fire early if the host time is pushed forward
beyond their expiry. So far no urgent need to overcome this limitation
was identified, so it's left as simple as it is (expiry on next alarm
timer tick).

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
This commit is contained in:
Jan Kiszka 2009-09-15 13:36:04 +02:00 • committed by Anthony Liguori
parent f64382bad8
commit 21d5d12bb0
2 changed files with 42 additions and 11 deletions
Download patch file Download diff file Expand all files Collapse all files

7
qemu-timer.h
View file

@ -17,6 +17,13 @@ extern QEMUClock *rt_clock;
precision clock, usually cpu cycles (use ticks_per_sec). */
extern QEMUClock *vm_clock;
/* The host clock should be use for device models that emulate accurate
real time sources. It will continue to run when the virtual machine
is suspended, and it will reflect system time changes the host may
undergo (e.g. due to NTP). The host clock has the same precision as
the virtual clock. */
extern QEMUClock *host_clock;
int64_t qemu_get_clock(QEMUClock *clock);
QEMUTimer *qemu_new_timer(QEMUClock *clock, QEMUTimerCB *cb, void *opaque);