Re: [HYBRID]: status update...

[Mukesh Rathor <mukesh.rathor@oracle.com>]

On Wed, 1 Aug 2012 16:25:01 +0100
George Dunlap <George.Dunlap@eu.citrix.com> 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.
> 
> Thoughts?

Hi George,

We gave some thought looking for name. I figured pure PV will be around for 
a while at least. So there's PV on one side and HVM on the other, hybrid
somewhere in between. 

The issue with PV in HVM is that it limits PV to HVM container only. The
vision I had was that hybrid, a PV ops kernel that is somewhere in between
PV and HVM, could be configured with options. So, one could run hybrid
with say EPT off (altho, won't be supported this anymore). But generic name
like hybrid allows it in future to be flexible, instead of confined to a
specific. I suppose a PV guest could just be started with various options.

As for name in code, 'pvh' was confusing, as PVHVM is now routinely used to
refer to HVM with PV drivers. 'hpv' for HVM/hybrid PV, well, thats a certain
virus ;). So I just used hybrid in the code to refer to PV guest that runs
in HVM container. I suppose I could change the flag to pv_in_hvm or
something.

In the end, I am flexible on whatever we wanna call it :).

thanks,
Mukesh