Re: [Qemu-devel] [PATCH v7 01/19] ppc/xive: add support for the END Event State Buffers

[Cédric Le Goater]

On 12/10/18 5:16 AM, David Gibson wrote:
> On Sun, Dec 09, 2018 at 08:45:52PM +0100, Cédric Le Goater wrote:
>> The Event Notification Descriptor (END) XIVE structure also contains
>> two Event State Buffers providing further coalescing of interrupts,
>> one for the notification event (ESn) and one for the escalation events
>> (ESe). A MMIO page is assigned for each to control the EOI through
>> loads only. Stores are not allowed.
>>
>> The END ESBs are modeled through an object resembling the 'XiveSource'
>> It is stateless as the END state bits are backed into the XiveEND
>> structure under the XiveRouter and the MMIO accesses follow the same
>> rules as for the XiveSource ESBs.
>>
>> END ESBs are not supported by the Linux drivers neither on OPAL nor on
>> sPAPR. Nevetherless, it provides a mean to study the question in the
>> future and validates a bit more the XIVE model.
>>
>> Signed-off-by: Cédric Le Goater <address@hidden>
>> ---
>>
>>  Changes since v6:
>>
>>  - removed the 'chip-id' field from XiveRouter
>>  - introduced a 'block-id' field in XiveENDSource to lookup the XIVE
>>    END structure when doing a load in the MMIO ESB
>>  - removed reset XiveENDSource handler
>>
>>  include/hw/ppc/xive.h |  21 ++++++
>>  hw/intc/xive.c        | 160 +++++++++++++++++++++++++++++++++++++++++-
>>  2 files changed, 179 insertions(+), 2 deletions(-)
> 
> Applied to ppc-for-4.0.
> 
> I had some thoughts about maybe-nicer arrangements of things here, but
> nothing important enough to delay this (the things I'm mulling over
> wouldn't break migration, so it's fixable later).

OK. No problem for me to do it afterwards. 

It's a bit of pain to maintain a pile of 30/40 patches and changing stuff   
in the first ones. 

C.