2014-01-09 17:05:39

by Hu Yaohui

[permalink] [raw]
Subject: Emulated Guest TLB flush IPIs in qemu-kvm

Hi all.
If the hardware does not support APIC virtualization: kvm_vcpu_kick sends an
host-IPI to the remote vcpu if that vcpu is in guest mode, a VM-exit
(exit reason: external interrupt) will be triggered due to the host-IPI.
Then on VM-entry (inject_pending_event) the guest-IPI is injected. If
that IPI is a TLB flush IPI,
what will happen if the target vcpu access the stale tlb entry before
the host-IPI arrives?
Thanks for your time!

Best Wishes,
Yaohui Hu