KVM: nVMX: fix nested EPT detection

KVM: nVMX: fix nested EPT detection

The nested_ept_enabled flag introduced in commit 7ca29de2136 was not
computed correctly. We are interested only in L1's EPT state, not the
the combined L0+L1 value.

In particular, if L0 uses EPT but L1 does not, nested_ept_enabled must
be false to make sure that PDPSTRs are loaded based on CR3 as usual,
because the special case described in 26.3.2.4 Loading Page-Directory-
Pointer-Table Entries does not apply.

Fixes: 7ca29de21362 ("KVM: nVMX: fix CR3 load if L2 uses PAE paging and EPT")
Cc: qemu-stable@nongnu.org
Reported-by: Wanpeng Li <wanpeng.li@hotmail.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Ladi Prosek <lprosek@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit 7ad658b693536741c37b16aeb07840a2ce75f5b9)
OraBug: 26628813 KVM: nVMX: fix CR3 load if L2 uses PAE paging and EPT - backport+regression fix
Signed-off-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Reviewed-by: Jack Vogel <jack.vogel@oracle.com>
Tested-by: Eyal Moscovici <eyal.moscovici@oracle.com>
Tested-by: Chris Kenna <chris.kenna@oracle.com>
Acked-by: Konrad Wilk <konrad.wilk@oracle.com>