Re: [RFC PATCH 0/3] generic hypercall support

[Avi Kivity]

Gregory Haskins wrote:
> Avi Kivity wrote:
>   
> > Gregory Haskins wrote:
> >     
> > > I guess technically mmio can just be a simple access of the page which
> > > would be problematic to trap locally without a PF.  However it seems
> > > that most mmio always passes through a ioread()/iowrite() call so this
> > > is perhaps the hook point.  If we set the stake in the ground that mmios
> > > that go through some other mechanism like PFs can just hit the "slow
> > > path" are an acceptable casualty, I think we can make that work.
> > >   
> > >       
> > That's my thinking exactly.
> >     
>
> Cool,  I will code this up and submit it.  While Im at it, Ill run it
> through the "nullio" ringer, too. ;)  It would be cool to see the
> pv-mmio hit that 2.07us number.  I can't think of any reason why this
> will not be the case.
>   

Don't - it's broken.  It will also catch device assignment mmio and 
hypercall them.

--
Do not meddle in the internals of kernels, for they are subtle and quick to panic.

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