Re: [Qemu-devel] [PATCH 00/17] ppc: preparing pnv landing

[Cédric Le Goater]

On 03/16/2016 02:19 AM, David Gibson wrote:
> On Tue, Mar 15, 2016 at 09:11:31AM +0100, Cédric Le Goater wrote:
>> On 03/15/2016 01:39 AM, David Gibson wrote:
>>> On Mon, Mar 14, 2016 at 05:56:23PM +0100, Cédric Le Goater wrote:
>>>> Hello,
>>>>
>>>> This is a first mini-serie of patches adding support for new ppc SPRs.
>>>> They were taken from Ben's larger patchset adding the ppc powernv
>>>> platform and they should already be useful for the pseries guest
>>>> migration.
>>>>
>>>> Initial patches come from :
>>>>
>>>>    https://github.com/ozbenh/qemu/commits/powernv
>>>>
>>>> The changes are mostly due to the rebase on Dave's 2.6 branch:
>>>>
>>>>    https://github.com/dgibson/qemu/commits/ppc-for-2.6
>>>>
>>>> A couple more are bisect and checkpatch fixes and finally some patches
>>>> were merge to reduce the noise.
>>>>
>>>>       
>>>>
>>>> The patchset is also available here: 
>>>>
>>>>    https://github.com/legoater/qemu/commits/for-2.6
>>>>
>>>> It was quickly tested with a pseries guest using KVM and TCG.
>>>
>>> Hmm.. do these all fix bugs with migration, or only some of them?
>>
>> Probably only some. 
>>
>> Initially, Thomas gave a shorter list which I expanded to a larger one 
>> because of dependencies between patches and I didn't want to change too
>> much what Ben had sent. You had also reviewed a few.
>>
>>> The relevance is that things to fix migration should go into 2.6, but
>>> preparation work for powernv that doesn't fix bug shouldn't really be
>>> going in now, after the soft freeze and will need to wait for 2.7.
>>
>> OK. I will rework and keep the rest for 2.7. 
> 
> So, I'm ok with including (low risk) patches that aren't directly
> relevant to 2.6 if they're prereqs for patches that are relevant to
> 2.6.  After all, reworking the patches isn't risk free either.  Please
> mention why these patches are being included in the commit messages
> though.

Sure.  

>> Thomas, thanks for the review. I have identified a few things I need 
>> to work on but may be, the patchset is still too large for 2.6 ?
> 
> It's not really a question of being too large, it's that I'm nervous
> about applying patches which touch the core translation code
> (e.g. fixes to HV mode tests) during soft freeze if they're not
> addressing a bug that's relevant to 2.6.

Could you please take a look at these two patches to see if they are 
relevant for 2.6 ? From my readings, they seem to be the only ones on 
the edge.

        06/17  ppc: Create cpu_ppc_set_papr() helper 
        11/17  ppc: Initialize AMOR in PAPR mode  

but it makes sense to take them if we take :

        12/17  ppc: Fix writing to AMR/UAMOR (move hunk to 13)
        13/17  ppc: Add POWER8 IAMR register (rework hunk)

Thanks for the review,

C.