Re: [PATCH -tip] x86: move vmware to hypervisor

Alok Kataria
2009-03-25T17:24:23Z

On Wed, 2009-03-25 at 10:07 -0700, Jaswinder Singh Rajput wrote:
> On Wed, 2009-03-25 at 09:52 -0700, Alok Kataria wrote:
> > >
> > > vmware can be considered a CPU here, so i think making the disabling
> > > also depend on PROCESSOR_SELECT.
> >
> > Ingo, this code is not just to be used by VMware, the reason we did this
> > generically was so that a guest could run unaltered on *any* fully
> > virtualized hypervisor.
> > And give that this code is just a boot setup thing, the only thing this
> > patch saves over here is not running the detection code on native
> > systems. All the rest of the code is guarded by the
> > "boot_cpu_data.x86_hyper_vendor" checks anyways.
> >
> > I don't really see the point of adding one more config option just for
> > this.
> >
>
> Can you please explain what is the point of adding this support all the
> time if this is useless for 99.9% of cases. IMHO, it should be optional.

First of all, I don't know how did you get to the 99.9% number, though I
think its not a point worth debating, just like to share some info with
you. More and more people are adopting virtualization now a days and
give the trend i don't see just 0.1% people running Linux on virtualized
hardware. So though its not a common case there is still a large user
base.
I am not saying we should not hide this behind a config at all. The
point is there is nothing that we save by adding a new config, so what's
the point at all. If you can give me a solid reason like, say, you save
1% code space with this config option, or 'n' sec in the boottime, I am
all ears for such an argument.

Thanks,
Alok

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> JSR
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