On Wed, May 12, 2021 at 02:41:56PM +0000, Sean Christopherson wrote: > On Tue, May 11, 2021, Marcelo Tosatti wrote: > > > The KVM_REQ_UNBLOCK patch will resume execution even any such event > > > > even without any such event > > > > > occuring. So the behaviour would be different from baremetal. > > I agree with Marcelo, we don't want to spuriously unhalt the vCPU. It's legal, > albeit risky, to do something like > > hlt > /* #UD to triple fault if this CPU is awakened. */ > ud2 > > when offlining a CPU, in which case the spurious wake event will crash the guest. We can avoid that by moving the check+clear of KVM_REQ_UNBLOCK from kvm_vcpu_has_events() into kvm_vcpu_check_block() as replied in the other thread. But I also agree Marcelo's series should work already to fix the bug, hence no strong opinion on this. Thanks, -- Peter Xu
