Re: [Qemu-devel] [Qemu-ppc] [RFC PATCH v2 04/21] ppc/xive: provide a link to the sPAPR ICS object under XIVE

[Cédric Le Goater]

On 09/12/2017 12:04 AM, Greg Kurz wrote:
> On Mon, 11 Sep 2017 19:12:18 +0200
> Cédric Le Goater <address@hidden> wrote:
> 
>> The sPAPR machine first starts with a XICS interrupt model and
>> depending on the guest capabilities, the XIVE exploitation mode is
>> negotiated during CAS. A reset should then be performed to rebuild the
>> device tree but the same IRQ numbers which were allocated by the
>> devices prior to reset, when the XICS model was operating, are still
>> in use.
>>
>> For this purpose, we need a common IRQ number allocator for both the
>> interrupt models: XICS legacy or XIVE exploitation. This is what the
>> ICSIRQState array of the XICS interrupt source is used for. It also
>> contains the LSI/MSI flag of an interrupt which will we need later on.
>>
>> So, let's provide a link to the sPAPR ICS object under XIVE to make
>> use of it.
>>
>> Signed-off-by: Cédric Le Goater <address@hidden>
>> ---
>>  hw/intc/spapr_xive.c        | 12 ++++++++++++
>>  include/hw/ppc/spapr_xive.h |  4 ++++
>>  2 files changed, 16 insertions(+)
>>
>> diff --git a/hw/intc/spapr_xive.c b/hw/intc/spapr_xive.c
>> index 6d98528fae68..1681affb0848 100644
>> --- a/hw/intc/spapr_xive.c
>> +++ b/hw/intc/spapr_xive.c
>> @@ -56,6 +56,8 @@ void spapr_xive_reset(void *dev)
>>  static void spapr_xive_realize(DeviceState *dev, Error **errp)
>>  {
>>      sPAPRXive *xive = SPAPR_XIVE(dev);
>> +    Object *obj;
>> +    Error *err = NULL;
>>  
>>      if (!xive->nr_targets) {
>>          error_setg(errp, "Number of interrupt targets needs to be greater 
>> 0");
>> @@ -68,6 +70,16 @@ static void spapr_xive_realize(DeviceState *dev, Error 
>> **errp)
>>          return;
>>      }
>>  
>> +    /* Retrieve SPAPR ICS source to share the IRQ number allocator */
>> +    obj = object_property_get_link(OBJECT(dev), "ics", &err);
>> +    if (!obj) {
>> +        error_setg(errp, "%s: required link 'ics' not found: %s",
>> +                   __func__, error_get_pretty(err));
>> +        return;
> 
> err is leaked if you do this way. Please do this instead:
> 
>         error_propagate(errp, err);
>         error_prepend(errp, "required link 'ics' not found: ");

ok. I will fix. 

C.

> Note: I've just sent a patch to fix the same error in XICS :)
>
>> +    }
>> +
>> +    xive->ics = ICS_BASE(obj);
>> +
>>      /* Allocate SBEs (State Bit Entry). 2 bits, so 4 entries per byte */
>>      xive->sbe_size = DIV_ROUND_UP(xive->nr_irqs, 4);
>>      xive->sbe = g_malloc0(xive->sbe_size);
>> diff --git a/include/hw/ppc/spapr_xive.h b/include/hw/ppc/spapr_xive.h
>> index b17dd4f17b0b..29112589b37f 100644
>> --- a/include/hw/ppc/spapr_xive.h
>> +++ b/include/hw/ppc/spapr_xive.h
>> @@ -24,6 +24,7 @@
>>  typedef struct sPAPRXive sPAPRXive;
>>  typedef struct XiveIVE XiveIVE;
>>  typedef struct XiveEQ XiveEQ;
>> +typedef struct ICSState ICSState;
>>  
>>  #define TYPE_SPAPR_XIVE "spapr-xive"
>>  #define SPAPR_XIVE(obj) OBJECT_CHECK(sPAPRXive, (obj), TYPE_SPAPR_XIVE)
>> @@ -35,6 +36,9 @@ struct sPAPRXive {
>>      uint32_t     nr_targets;
>>      uint32_t     nr_irqs;
>>  
>> +    /* IRQ */
>> +    ICSState     *ics;  /* XICS source inherited from the SPAPR machine */
>> +
>>      /* XIVE internal tables */
>>      uint8_t      *sbe;
>>      uint32_t     sbe_size;
>