Messages in this thread | | | Subject | Re: [Xen-devel] [PATCH] xen/apic: implement io apic read with hypercall | From | Ian Campbell <> | Date | Fri, 20 Apr 2012 14:12:46 +0100 |
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On Fri, 2012-04-20 at 13:53 +0100, Andrew Cooper wrote: > > > > Under what circumstances can these hypercalls fail? Would a BUG_ON be > > appropriate/ > > -EFAULT, -EPERM, anything xsm_apic() could return (which looks only to > be -EPERM).
So either the guest has called a hypercall which it is not permitted to or it has called it with invalid parameters of one sort or another. Both of these would be a code bug in the guest and therefore asserting that no failure occurred is reasonable?
What could the caller do with the error other than log it and collapse?
> The call into Xen itself will return 0 as a value if an > invalid physbase is passed in the hypercall.
> So a BUG_ON() is not safe/sensible for domU.
I think you have successfully argued that it is ;-)
Ian.
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