Xen devel - Feb 2013 - What is do_ni_hypercall() for

Hi everyone,
I traced pv hypercalls and found that the vector "do_ni_hypercall" is
invoked a lot. But this hypercall function does nothing (from the source
code). So I am very confused what is do_ni_hypercall for? Why do guests
invoke it ?
Thanks a lot,
-- 
Xinxin


_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
http://lists.xen.org/xen-devel

On 19/02/2013 23:09, Xinxin Jin wrote:
> Hi everyone,
> I traced pv hypercalls and found that the vector
"do_ni_hypercall" is
> invoked a lot. But this hypercall function does nothing (from the
> source code). So I am very confused what is do_ni_hypercall for? Why
> do guests invoke it ?
> Thanks a lot,
> -- 
> Xinxin
As expected.  It is the "Not Implemented" hypercall.  This means that
your PV guest is erroneously asking for hypercalls which are in the
permitted range (0-63) but not implemented by the hypervisor.

See xen/arch/x86/x86_64/entry.S:hypercall_table

~Andrew