[Skiboot] [PATCH v2] xive: Add calls to save/restore the queues and VPs HW state

[Cédric Le Goater]

On 3/29/19 5:04 AM, Stewart Smith wrote:
> Cédric Le Goater <clg at kaod.org> writes:
>> To be able to support migration of guests using the XIVE native
>> exploitation mode, (where the queue is effectively owned by the
>> guest), KVM needs to be able to save and restore the HW-modified
>> fields of the queue, such as the current queue producer pointer and
>> generation bit, and to retrieve the modified thread context registers
>> of the VP from the NVT structure : the VP interrupt pending bits.
>>
>> However, there is no need to set back the NVT structure on P9. P10
>> should be the same.
>>
>> Based on previous work from BenH.
>>
>> Signed-off-by: Cédric Le Goater <clg at kaod.org>
>> ---
>>  include/opal-api.h |   7 +--
>>  hw/xive.c          | 130 +++++++++++++++++++++++++++++++++++++++++++++
>>  doc/xive.rst       |  51 ++++++++++++++++++
>>  3 files changed, 185 insertions(+), 3 deletions(-)
> 
> Thanks for this, merged to master as of
> bbcbbd3e071ffe654596ce19ddf8d99b4176bbc3 and in v6.3-rc1.
> 
> I wish I knew more XIVE deep details to provide better review, or had
> the time to get deep enough to provide deeper review, but hey, you're
> smart and have spent a lot of time around it, so it's probably right :)

The XIVE interrupt controller model for QEMU should help (a bit) to 
understand the internals.

https://git.qemu.org/?p=qemu.git;a=blob;f=include/hw/ppc/xive.h;h=ec23253ba448e25c621356b55a7777119a738f8e;hb=HEAD

But this is big and it takes time.

Thanks,

C.