On Sun, Aug 05, 2012 at 04:33:02PM +0300, Avi Kivity wrote: > On 08/05/2012 03:58 PM, Gleb Natapov wrote: > > APIC code has a lot of checks for apic presence and apic HW/SW enable > > state. Most common configuration is when each vcpu has in kernel apic > > and it is fully enabled. This path series uses jump labels to turn checks > > to nops in the common case. > > > > Gleb Natapov (8): > > KVM: clean up kvm_(set|get)_apic_base > > KVM: use kvm_lapic_set_base() to change apic_base > > KVM: mark apic enabled on start up. > > Export jump_label_rate_limit() > > KVM: use jump label to optimize checking for HW enabled APIC in > > APIC_BASE MSR. > > KVM: use jump label to optimize checking for SW enabled apic in > > spurious interrupt register > > KVM: use jump label to optimize checking for in kernel local apic > > presence. > > KVM: inline kvm_apic_present() and kvm_lapic_enabled() > > Neat. > > During guest boot up, some of these jump keys will change, no? Does > this mean a stop_machine() or equivalent? I'm worried about real-time > response or one guest being affected by another. > Yes, SW enable bit changes during boot. The jump label triggerable by a guest are rate limited though. So stop machine will not happen more then once per second even with malicious guests. -- Gleb. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
