Messages in this thread | | | From | Vitaly Kuznetsov <> | Subject | Re: [PATCH RFC] KVM: x86: vmx: throttle immediate exit through preemtion timer to assist buggy guests | Date | Mon, 01 Apr 2019 12:41:51 +0200 |
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Liran Alon <liran.alon@oracle.com> writes:
> So to sum-up: This matches what I mentioned in my previous emails right? > That vector 96 is not related, and the only issue here is that level-triggered interrupt handler for vector 80 is doing EOI before lowering the irq-line. > Which cause vector 80 to be injected in infinite loop. > And this is not even related to being a nested virtualization > workload. It’s just an issue in Hyper-V (L1) interrupt handler for > vector 80.
Yes, it may be related to how communications between Hyper-V and Windows partition are organized but it's a pure speculation.
> > Therefore the only action-items are: > 1) Microsoft to fix Hyper-V vector 80 interrupt handler to lower irq-line before EOI. > 2) Patch QEMU IOAPIC implementation to have a mechanism similar to KVM to delay injection of level-triggered interrupt > in case we are injecting the same interrupt for X times in a row.
I'm intended to do 2) and we already let MS know there's an issue.
Thanks for your help with the investigation guys!
-- Vitaly
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