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Re: [Xen-devel] [PATCH 1/2] xen: Introduce PHYSDEVOP_pirq_eoi_gmfn_new

On Thu, 26 Jan 2012, Keir Fraser wrote:
> On 26/01/2012 16:45, "Stefano Stabellini" <stefano.stabellini@xxxxxxxxxxxxx>
> wrote:
> >> If that's the case then there is precedent (e.g. sched_op, physdev_op,
> >> evtchn_op) for renaming the existing thing FOO_compat and taking over
> >> the name with the new semantics.
> >> 
> >> That's certainly better than _new->_newer->really_new etc. If you must
> >> go down that route then adding a number seems preferable.
> > 
> > In that case, I vote for taking over the existing name with the new
> > hypercall.
> Agreed, but you have to be careful because other codebases expect to be able
> to sync with our public headers without subtle side effects.
> The correct thing to do here is probably to rename the old command to
> PHYSDEVOP_pirq_eoi_gmfn_v1, and your new one ..._v2.
> Then you bump XEN_LATEST_INTERFACE_VERSION to 0x00040200 (somewhat
> arbitrarily!), and at the end of physdev.h you put something like:
> #if __XEN_INTERFACE_VERSION < 0x00040200
> #define PHYSDEVOP_pirq_eoi_gmfn PHYSDEVOP_pirq_eoi_gmfn_v1
> #else
> #define PHYSDEVOP_pirq_eoi_gmfn PHYSDEVOP_pirq_eoi_gmfn_v2
> #endif
> Perfect, those who want the explicitly versioned command can use it. Old
> codebases can sync with new headers safely. Or codebases can be updated for
> latest XEN_INTERFACE_VERSION and default to the latest sanest command
> versions.

Great, I'll make the change and repost.

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