Re: [PATCH v4 3/3] KVM: nVMX: Emulate EPTP switching for the L1 hypervisor

From: Bandan Das
Date: Tue Jul 11 2017 - 14:35:42 EST

Jim Mattson <jmattson@xxxxxxxxxx> writes:
>>> I can find the definition for an vmexit in case of index >=
>>> VMFUNC_EPTP_ENTRIES, but not for !vmcs12->eptp_list_address in the SDM.
>>> Can you give me a hint?
>> I don't think there is. Since, we are basically emulating eptp switching
>> for L2, this is a good check to have.
> There is nothing wrong with a hypervisor using physical page 0 for
> whatever purpose it likes, including an EPTP list.

Right, but of all the things, a l1 hypervisor wanting page 0 for a eptp list
address most likely means it forgot to initialize it. Whatever damage it does will
still end up with vmfunc vmexit anyway.