RE: [PATCH v1 12/23] KVM: VMX: Handle FRED event data

Li, Xin3
2023-11-20T08:16:52Z

> >> IIUC, L1 KVM can inject a nested exception whose vector isn't #DB, or
> >> #NM or #PF with a non-zero event_data to L2.
> >
> >No, this is not allowed.
>
> How do you interpret the last sentence:
>
> Section 5.2.1 specifies the event data that FRED event delivery of
> certain events saves on the stack. When FRED event delivery is used
> for an event injected by VM entry, the event data saved is the value
> of the injected-event-data field in the VMCS. This value is used
> instead of what is specified in Section 5.2.1 and is done for __ALL__
> injected events using FRED event delivery

To me, it means FRED event injection during VM entry simply pushes the
value in the injected-event-data field of the VMCS as event data. But
the event data definition should comply with Section 5.2.1. It is a
forward compatibility issue otherwise.