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

[Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>]

On 24/08/16 19:39, Hervé Poussineau wrote:

> Hi,
> 
> Following patch regresses Linux boot on PReP machine:
> 
> commit a2e71b28e832346409efc795ecd1f0a2bcb705a3
> Author: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> 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
>     I am aware we should mask here is POW, the CPU's MSR mask should
>     take care of the rest.
> 
>     This also fixes some problems when running 32-bit userspace under
>     a 64-bit kernel.
> 
>     This patch broke 32bit OpenBIOS when run under a 970 cpu. A fix was
>     proposed here :
> 
>         https://www.coreboot.org/pipermail/openbios/2016-June/009452.html
> 
>     Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
>     Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
>     [clg: updated the commit log with the reference of the openbios fix ]
>     Signed-off-by: Cédric Le Goater <clg@kaod.org>
>     [dwg: Remove hunk which disabled rfi on 64-bit CPUS.  The change was
>      correct, but we need to fix OpenBIOS before applying it]
>     Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
> 
> Test case:
> - Download: http://www.juneau-lug.org/zImage.initrd.sandalfoot
> - Run: qemu-system-ppc -M prep -kernel zImage.initrd.sandalfoot
> 
> Firmware starts, loads kernel, but seems to error out just after PS/2
> detection.
> 
> Reverting the commit and fixing the conflict makes it work again, up to
> shell.

I can at least confirm that the v4 patch was applied to OpenBIOS for the
last update:
http://git.qemu.org/?p=openbios.git;a=commit;h=b747b6acc272f6ab839728193042455c9b36e26a.


ATB,

Mark.