Re: [PATCH 1/7] spapr, xics: Get number of servers with a XICSFabricClass method

[Cédric Le Goater]

On 03/10/2019 15:02, Greg Kurz wrote:
> On Thu, 3 Oct 2019 14:58:45 +0200
> Cédric Le Goater <address@hidden> wrote:
> 
>> On 03/10/2019 14:49, Greg Kurz wrote:
>>> On Thu, 3 Oct 2019 14:24:06 +0200
>>> Cédric Le Goater <address@hidden> wrote:
>>>
>>>> On 03/10/2019 14:00, Greg Kurz wrote:
>>>>> The number of servers, ie. upper bound of the highest VCPU id, is
>>>>> currently only needed to generate the "interrupt-controller" node
>>>>> in the DT. Soon it will be needed to inform the XICS-on-XIVE KVM
>>>>> device that it can allocates less resources in the XIVE HW.
>>>>>
>>>>> Add a method to XICSFabricClass for this purpose. 
>>>>
>>>> This is sPAPR code and PowerNV does not care.
>>>>
>>>
>>> Then PowerNV doesn't need to implement the method.
>>>
>>>> why can not we simply call spapr_max_server_number(spapr) ?
>>>>
>>>
>>> Because the backend shouldn't reach out to sPAPR machine
>>> internals. XICSFabric is the natural interface for ICS/ICP
>>> if they need something from the machine.
>>
>> From what I can see, xics_nr_servers() is only called by : 
>>
>>   spapr_dt_xics(SpaprMachineState *spapr ...)
>>   xics_kvm_connect(SpaprMachineState *spapr ...)
>>
> 
> Yes... and ?

so it is spapr only and we can use spapr_max_server_number(spapr)
without the need of a new XICSFabric handler.

C. 

>> C. 
>>
>>>>
>>>>> Implement it
>>>>> for sPAPR and use it to generate the "interrupt-controller" node.
>>>>>
>>>>> Signed-off-by: Greg Kurz <address@hidden>
>>>>> ---
>>>>>  hw/intc/xics.c        |    7 +++++++
>>>>>  hw/intc/xics_spapr.c  |    3 ++-
>>>>>  hw/ppc/spapr.c        |    8 ++++++++
>>>>>  include/hw/ppc/xics.h |    2 ++
>>>>>  4 files changed, 19 insertions(+), 1 deletion(-)
>>>>>
>>>>> diff --git a/hw/intc/xics.c b/hw/intc/xics.c
>>>>> index dfe7dbd254ab..f82072935266 100644
>>>>> --- a/hw/intc/xics.c
>>>>> +++ b/hw/intc/xics.c
>>>>> @@ -716,6 +716,13 @@ ICPState *xics_icp_get(XICSFabric *xi, int server)
>>>>>      return xic->icp_get(xi, server);
>>>>>  }
>>>>>  
>>>>> +uint32_t xics_nr_servers(XICSFabric *xi)
>>>>> +{
>>>>> +    XICSFabricClass *xic = XICS_FABRIC_GET_CLASS(xi);
>>>>> +
>>>>> +    return xic->nr_servers(xi);
>>>>> +}
>>>>> +
>>>>>  void ics_set_irq_type(ICSState *ics, int srcno, bool lsi)
>>>>>  {
>>>>>      assert(!(ics->irqs[srcno].flags & XICS_FLAGS_IRQ_MASK));
>>>>> diff --git a/hw/intc/xics_spapr.c b/hw/intc/xics_spapr.c
>>>>> index 6e5eb24b3cca..aa568ed0dc0d 100644
>>>>> --- a/hw/intc/xics_spapr.c
>>>>> +++ b/hw/intc/xics_spapr.c
>>>>> @@ -311,8 +311,9 @@ static void ics_spapr_realize(DeviceState *dev, Error 
>>>>> **errp)
>>>>>  void spapr_dt_xics(SpaprMachineState *spapr, uint32_t nr_servers, void 
>>>>> *fdt,
>>>>>                     uint32_t phandle)
>>>>>  {
>>>>> +    ICSState *ics = spapr->ics;
>>>>>      uint32_t interrupt_server_ranges_prop[] = {
>>>>> -        0, cpu_to_be32(nr_servers),
>>>>> +        0, cpu_to_be32(xics_nr_servers(ics->xics)),
>>>>>      };
>>>>>      int node;
>>>>>  
>>>>> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
>>>>> index 514a17ae74d6..b8b9796c88e4 100644
>>>>> --- a/hw/ppc/spapr.c
>>>>> +++ b/hw/ppc/spapr.c
>>>>> @@ -4266,6 +4266,13 @@ static ICPState *spapr_icp_get(XICSFabric *xi, int 
>>>>> vcpu_id)
>>>>>      return cpu ? spapr_cpu_state(cpu)->icp : NULL;
>>>>>  }
>>>>>  
>>>>> +static uint32_t spapr_nr_servers(XICSFabric *xi)
>>>>> +{
>>>>> +    SpaprMachineState *spapr = SPAPR_MACHINE(xi);
>>>>> +
>>>>> +    return spapr_max_server_number(spapr);
>>>>> +}
>>>>> +
>>>>>  static void spapr_pic_print_info(InterruptStatsProvider *obj,
>>>>>                                   Monitor *mon)
>>>>>  {
>>>>> @@ -4423,6 +4430,7 @@ static void spapr_machine_class_init(ObjectClass 
>>>>> *oc, void *data)
>>>>>      xic->ics_get = spapr_ics_get;
>>>>>      xic->ics_resend = spapr_ics_resend;
>>>>>      xic->icp_get = spapr_icp_get;
>>>>> +    xic->nr_servers = spapr_nr_servers;
>>>>>      ispc->print_info = spapr_pic_print_info;
>>>>>      /* Force NUMA node memory size to be a multiple of
>>>>>       * SPAPR_MEMORY_BLOCK_SIZE (256M) since that's the granularity
>>>>> diff --git a/include/hw/ppc/xics.h b/include/hw/ppc/xics.h
>>>>> index 1e6a9300eb2b..e6bb1239e8f8 100644
>>>>> --- a/include/hw/ppc/xics.h
>>>>> +++ b/include/hw/ppc/xics.h
>>>>> @@ -151,9 +151,11 @@ typedef struct XICSFabricClass {
>>>>>      ICSState *(*ics_get)(XICSFabric *xi, int irq);
>>>>>      void (*ics_resend)(XICSFabric *xi);
>>>>>      ICPState *(*icp_get)(XICSFabric *xi, int server);
>>>>> +    uint32_t (*nr_servers)(XICSFabric *xi);
>>>>>  } XICSFabricClass;
>>>>>  
>>>>>  ICPState *xics_icp_get(XICSFabric *xi, int server);
>>>>> +uint32_t xics_nr_servers(XICSFabric *xi);
>>>>>  
>>>>>  /* Internal XICS interfaces */
>>>>>  void icp_set_cppr(ICPState *icp, uint8_t cppr);
>>>>>
>>>>
>>>
>>
>