Anthony Liguori wrote: > Avi Kivity wrote: >> The fourth is probably impossible from userspace (and very >> difficult in the kernel). > > What makes it impossible to do in userspace? If you managed a > tsc_offset in userspace, you would of course need to adjust that > tsc_offset within the kernel for the particular PCPU that you were on. >
In the kernel you can to tricks like local_irq_disable(); rdtsc(); ktime_get(); local_irq_enable() to get a sense where the tsc is. Take a look at kvm_inject_pit_timer_irqs() and kvm_pit_timer_intr_post(). An attempt to have a accurate userspace pit needs to take into account what those functions do. I believe it's doable, but will require careful design of the interface (which should be usable for rtc and hpet as well). -- error compiling committee.c: too many arguments to function ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ kvm-devel mailing list kvm-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/kvm-devel
