Re: [Qemu-devel] [PATCH 2/5] target-ppc: Register and handle HCALL to receive updated RTAS region

[Benjamin Herrenschmidt]

On Tue, 2014-08-26 at 15:39 +1000, David Gibson wrote:
> On Mon, Aug 25, 2014 at 07:15:26PM +0530, Aravinda Prasad wrote:
> > Receive updates from SLOF about the updated rtas-base.
> > A separate patch for SLOF [1] adds functionality to invoke a
> > a private HCALL whenever OS issues instantiate-rtas with
> > a new rtas-base.
> > 
> > This is required as qemu needs to know the updated rtas-base
> > as it allocates error reporting structure in RTAS space upon
> > a machine check exception.
> 
> This also seems really awkward.  Specifically it seems like a rather
> arbitrary and complex division of what qemu's responsible for and what
> SLOF is responsible for.
> 
> Instead I'd suggest that we add an H_INSTANTIATE_RTAS hcall, and we
> move the loading of the spapr-rtas blob from normal reset to when that
> hcall is invoked.

Beware that SLOF needs to call RTAS for its own reasons...

So it would be instanciated twice.

Cheers,
Ben.