Re: [PATCH 0/4] KVM: nVMX: Fix migration of nested guests when eVMCS is in use

[Paolo Bonzini]

On 03/05/21 17:08, Vitaly Kuznetsov wrote:
> Win10 guests with WSL2 enabled sometimes crash on migration when
> enlightened VMCS was used. The condition seems to be induced by the
> situation when L2->L1 exit is caused immediately after migration and
> before L2 gets a chance to run (e.g. when there's an interrupt pending).

Interesting, I think it gets to nested_vmx_vmexit before

                if (kvm_check_request(KVM_REQ_GET_NESTED_STATE_PAGES, vcpu)) {
                        if (unlikely(!kvm_x86_ops.nested_ops->get_nested_state_pages(vcpu))) {
                                r = 0;
                                goto out;
                        }
                }

due to the infamous calls to check_nested_events that are scattered
through KVM?

Paolo