Re: [Qemu-devel] ppc: regression in 2.7.0-rc3 on rfi/rfid/hrfi instructions

[Benjamin Herrenschmidt]

On Thu, 2016-08-25 at 11:31 +1000, Benjamin Herrenschmidt wrote:
> On Wed, 2016-08-24 at 20:39 +0200, Hervé Poussineau wrote:
> > 
> > Hi,
> > 
> > Following patch regresses Linux boot on PReP machine:
> > 
> > commit a2e71b28e832346409efc795ecd1f0a2bcb705a3
> > Author: Benjamin Herrenschmidt <address@hidden>
> > Date:   Tue Jun 21 23:48:46 2016 +0200
> > 
> >      ppc: Fix rfi/rfid/hrfi/... emulation
> > 
> >      This reworks emulation of the various "rfi" variants. I
> > removed
> >      some masking bits that I couldn't make sense of, the only bit
> > that
> 
> Interesting, the problem is only with 603, not 604. I think I might
> have broken something with the 603 SW TLB loading stuff which is
> a bit weird, I'll have a look. Thanks.

Actually it's trickier than that...

PReP seems to default to 602 ! Linux never supported the 602 so that's
really strange.

If I use 603 instead, I quickly hit a bad SPR, looks like we are trying
to hit the DABR which is ... odd. Probably getting into xmon but your
kernel is trying to get to the video rather than the serial port so I
can't see it.

I need that kernel source, we dropped PReP support from Linux ages
ago...

Cheers,
Ben.