>>> On 26.05.17 at 16:37, <rcojoc...@bitdefender.com> wrote: > On 05/26/17 17:29, Jan Beulich wrote: >>>>> On 25.05.17 at 11:40, <rcojoc...@bitdefender.com> wrote: >>> I've noticed that, with pages marked NX and vm_event emulation, we can >>> end up emulating an ud2, for which hvm_emulate_one() returns >>> X86EMUL_EXCEPTION in hvm_emulate_one_vm_event(). >> >> Could you explain what would lead to emulation of UD2? > > If you mean in which cases does our engine mark pages NX, I'll have to > ask and get back to you. If you mean why generally would an UD2 end up > being the instruction where RIP causes an execute violation fault, I'll > have to check.
The question was more for the latter, as I don't understand what good could come from executing UD2 intentionally, unless the entity doing so knows there is an emulator around to do something sensible with it. Jan _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org https://lists.xen.org/xen-devel
