Jeremy Fitzhardinge wrote: > Anthony Liguori wrote: > >> Except that I wanted to change the hypercall to allow querying of real >> time or "available" time as VMI puts it. >> > > I see. You could have an interface like Xen's runstate interface, which > gives you a breakdown of how long each vcpu spends in each state > (running, runnable, paused or blocked). The sum of all of them gives > you real time, or you can use a subset to work out stolen time > (runnable+paused), busyness (blocked / (running+runnable+blocked)), etc. >
I'll look at that. Since the vmca is per-vcpu, that may work well. >> Right now, I'm relying on the PIT but it would be nice to eliminate >> that. I'd like to move to something PV so that I can make use of >> tickless guest kernels. I'm very open to suggestion and even more >> open to reusing other people's code :-) >> > > A simple hypercall interface which says "raise irq X after N ns" is > probably the easiest way to go. That's what I was thinking. The current bit that makes that ugly is that you can't really raise an interrupt in the host kernel yet (although it will be possible when the in-kernel apic code is merged). I could, in theory, implement that interface in userspace but that may be ugly. > Try to avoid the pitfalls of VMI's > interface in this area, which tries to recycle existing architectural > interrupt sources for hypervisor timers, and gets into a bit of mess. > Xen is relatively clean, but I'm not sure how it would fit into the > mostly-emulated kvm model. If you keep things simple, most of the Xen > clockevent code could be reused with little change. > I think it should work out well. Thanks for the feedback! Regards, Anthony Liguori > J > > ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ _______________________________________________ kvm-devel mailing list kvm-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/kvm-devel
