HYBRID naming [Was: Re: [HYBRID]: status update...]

[Matt Wilson <msw@amazon.com>]

On Wed, Aug 01, 2012 at 09:21:57AM -0700, George Dunlap wrote:
> On Wed, Aug 1, 2012 at 5:05 PM, Konrad Rzeszutek Wilk
> <konrad.wilk@oracle.com> wrote:
> > On Wed, Aug 01, 2012 at 04:59:58PM +0100, George Dunlap wrote:
> >> On Wed, Aug 1, 2012 at 4:25 PM, Konrad Rzeszutek Wilk
> >> <konrad.wilk@oracle.com> wrote:
> >> > On Wed, Aug 01, 2012 at 04:25:01PM +0100, George Dunlap wrote:
> >> >> I hope this isn't bikeshedding; but I don't like "Hybrid" as a name
> >> >> for this feature, mainly for "marketing" reasons.  I think it will
> >> >> probably give people the wrong idea about what the technology does.
> >> >> PV domains is one of Xen's really distinct advantages -- much simpler
> >> >> interface, lighter-weight (no qemu, legacy boot), &c &c.  As I
> >> >> understand it, the mode you've been calling "hybrid" still has all of
> >> >> these advantages -- it just uses some of the HVM hardware extensions
> >> >> to make the interface even simpler / faster.  I'm afraid "hybrid" may
> >> >> be seen as, "Even Xen has had to give up on PV."
> >> >>
> >> >> Can I suggest something like "PVH" instead?  That (at least to me)
> >> >> makes it clear that PV domains are still fully PV, but just use some
> >> >> HVM extensions.
> >> >
> >> > if (xen_pvh_domain()?
> >> >
> >> > if (xen_pv_h_domain()?
> >> >
> >> > if (xen_h_domain()) ?
> >> >
> >> > if (xen_pvplus_domain()) ?
> >> >
> >> > if (xen_pv_ext_domain()) ?
> >> >
> >> > I think I like 'pv+'?
> >>
> >> I could deal with pv+.  However, in general I dislike that kind of
> >> "now even better!" marketing.  PV+, EPV (Enhanced / extended PV), PVX
> >> (Extreme PV!) -- they all sound cool when they come out, but five
> >> years later, when they're not so new or sexy anymore, they all sound
> >> lame.  PVH is just descriptive -- it will always be PV with HVM
> >> extensions, so it will age much better. :-)
> >
> > How about pv_with_mmu_in_hvm_container_domain() ?
> >
> > Ok, that is a bit to lengthy. How about then:
> >
> > if (xen_pvhvm_ext_domain()) ?
> >
> > The 'if (xen_pvh_domain())' is just one characer short of 'xen_pv_domain()'
> > and one might not notice it. Perhaps then 'if (xen_pv_h_domain()' ?
> 
> Hmm -- that's an interesting issue I hadn't thought of.  "PVHVM" has
> already been sort of taken by Stefano's extensions to allow Linux
> kernels booted in HVM mode to use some of the PV extensions.  I tend
> to think "xen_pvh_domain()" is probably OK, but maybe calling it
> "pvext" (or "pvhext") in the code, and "PVH" in documentation /
> stories?  Just using "pvext" everywhere could work as well; it's a
> little bit "now even better!", but not as much as pvplus.

How about HAPV, for "Hardware Assisted Paravirtualization"? It's
nicely pronounceable as "hap-vee" and follows the general
"hardware-assisted paging" (HAP) Xen terminology that spans both Intel
EPT and AMD RVI. 'if (xen_hapv_domain())'

Matt