On 19 Jun 2015, at 17:50, Justin Cormack <[email protected]> wrote: > > On 19 June 2015 at 17:42, Martin Lucina <[email protected]> wrote: >> Also note that I have no idea what the stability of TSC is under KVM and >> the current code makes no attempt to figure out if TSC is invariant, >> constant, or anything else. So option 3) would also be a safe(r) bet in >> that the PIT should "just work". > > KVM has a PV clock, see summary of how it works here > https://rwmj.wordpress.com/tag/kvmclock/ > > Because clocks under virtualization are problematic, using this is > probably the best solution longer term.
On Xen HVM, you can still use the PV hypercall to map the shared_info page and get the PV clock from there. Does all of that "just work" from the NetBSD Xen PCI bridge device driver and Rump/Xen? -anil
