Jeremy Fitzhardinge wrote: > Gerd Hoffmann wrote: >> Wall clock is off a few hours though. Oops. >> >> I think the way wall clock and system clock work together in xen (Jeremy >> correct me if I'm wrong) is that the wall clock specifies the point in >> time where the system clock started going. As kvm fills in host system >> time into the guest system time fields the guest wall clock fields >> should be filled with the host boot time timestamp I'd say. >> > > Yes. The wallclock field in the shared info structure is the wallclock > time at boot; you compute the current time by adding the system > timestamp to it. System time changes are effected by retroactively > changing the boot time of the machine, though that can also change > because of suspend/resume/migrate. > > In general the kernel only reads the wallclock time at boot, and then > maintains it for itself from then on. I think.
Thanks. I'm looking at the guest side of the issue right now, trying to identify common code, and while doing so noticed that xen does the version-check-loop in both get_time_values_from_xen(void) and xen_clocksource_read(void), and I can't see any obvious reason for that. The loop in xen_clocksource_read(void) is not needed IMHO. Can I drop it? cheers, Gerd -- http://kraxel.fedorapeople.org/xenner/ ------------------------------------------------------------------------- This SF.net email is sponsored by the 2008 JavaOne(SM) Conference Don't miss this year's exciting event. There's still time to save $100. Use priority code J8TL2D2. http://ad.doubleclick.net/clk;198757673;13503038;p?http://java.sun.com/javaone _______________________________________________ kvm-devel mailing list kvm-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/kvm-devel
