2016-11-03 17:00+0100, Paolo Bonzini: > On 03/11/2016 16:03, Radim Krčmář wrote: >> 2016-11-03 14:30+0100, Paolo Bonzini: >>> On 26/10/2016 21:59, Radim Krčmář wrote: >>>> 2016-10-14 20:21+0200, Paolo Bonzini: >>>>> Calling apic_find_highest_irr results in IRR being scanned twice, >>>>> once in vmx_sync_pir_from_irr and once in apic_search_irr. Change >>>>> sync_pir_from_irr to do the RVI write and kvm_apic_update_irr to >>>>> compute the new RVI on the fly. >>>>> >>>>> Signed-off-by: Paolo Bonzini <[email protected]> >>>>> --- >>>> >>>> Reviewed-by: Radim Krčmář <[email protected]> >>> >>> Nope, this breaks nested VMX exit on external interrupt. For now I'm >>> testing only patch 1 and will push that one only to kvm/next.
Which hypervisor is being nested? >> Hm, does it also happen with this change? > > Probably not but I wanted to understand why. :) Yeah, I'm also looking forward to knowing the funny coincidence. I think a bug is likely for hypervisors that don't enable PIN_BASED_EXT_INTR_MASK. The bug would trigger when kvm_cpu_has_interrupt() in vmx_check_nested_events() in kvm_arch_vcpu_runnable() queues the interrupt ... but I didn't see how this would have caused a problem. :)
