Re: [Qemu-ppc] [PATCH 0/3] ppc: complete the new HV mode

[Mark Cave-Ayland]

On 06/06/16 05:20, Benjamin Herrenschmidt wrote:

> On Mon, 2016-06-06 at 13:55 +1000, Benjamin Herrenschmidt wrote:
>>
>> I'm not sure that 32-bit patch is correct. We shouldn't have to flush
>> on IR/DR transitions at all, that's the whole point of the split I/D
>> code.
>>
>> I think something else is wrong.
> 
> Note: With whatever's in this branch, OpenBIOS won't start at all

Yeah, there's a patch currently pending upstream to fix the serial port
which hangs OpenBIOS upon startup:
https://lists.nongnu.org/archive/html/qemu-devel/2016-06/msg00035.html.

The best reproducer is to run from David's ppc-for-2.7 branch with the
above patch applied manually and then try booting the following ISOs
which now panic on boot with the split I/D MMU mode enabled:

Darwin/ppc: https://opensource.apple.com/static/iso/darwinppc-602.cdr.gz
HelenOS:    http://www.helenos.org/releases/HelenOS-0.6.0-ppc32.iso

I've seen some DMA coherence issues related to macio in some of my local
tests and so I'm also testing with my beta patch to switch macio over to
use the DMA helpers here:
https://lists.nongnu.org/archive/html/qemu-devel/2016-05/msg04907.html.


ATB,

Mark.