Re: [Xen-devel] [PATCH v2 15/15] xen/arm: arm64: Document Cortex-A57 erratum 834220

[Julien Grall <julien.grall@xxxxxxx>]

On 30/05/2016 17:19, Stefano Stabellini wrote:
> > "Erratum #834220: Xen needs to check that the Stage 1 translation does not
> > generate a fault before handling Stage 2 fault. If it is a stage 1 translation
> > fault, return to the guest to let the project injecting the correct fault.
> >
> > XXX: This can be optimized to avoid some unnecessary translation."
> What about adding a lengthy and detailed description of the erratum
> elsewhere and just having a one liner at the call sites, such as:
I don't see any problem to have "lengthy" comment twice. It could 
actually be 3 lines because the last one is a TODO.
I thought about merging some bits of do_trap_instr_abort_guest and 
do_trap_data_abort_guest, but at first glance it is not that simple.
> /* Erratum #834220: check Stage1 translation does not generate faults first! */
>
> so that developers can easily grep for #834220 through the code to have
> the full explanation?
Where would you put the full explanation? do_trap_hypervisor does not 
make sense because it does not deal with the erratum. When we will come 
back in few months time, we will wonder why the comment is there.
Regards,

--
Julien Grall

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