Re: [PATCH 2/4] ppc/xive: Introduce a new XiveRouter end_notify() handler

[Frederic Barrat <fbarrat@linux.ibm.com>]

On 29/08/2023 16:32, Cédric Le Goater wrote:
> It will help us model the END triggers on the PowerNV machine, which
> can be rerouted to another interrupt controller.
> 
> Signed-off-by: Cédric Le Goater <clg@kaod.org>
> ---



> diff --git a/hw/intc/xive.c b/hw/intc/xive.c
> index 56670b2cac6e..df3ee0496fe7 100644
> --- a/hw/intc/xive.c
> +++ b/hw/intc/xive.c
> @@ -1518,6 +1518,13 @@ static void xive_router_realize(DeviceState *dev, Error **errp)
>       assert(xrtr->xfb);
>   }
>   
> +static void xive_router_end_notify_handler(XiveRouter *xrtr, XiveEAS *eas)
> +{
> +    XiveRouterClass *xrc = XIVE_ROUTER_GET_CLASS(xrtr);
> +
> +    return xrc->end_notify(xrtr, eas);
> +}
> +
>   /*
>    * Encode the HW CAM line in the block group mode format :
>    *
> @@ -1664,8 +1671,7 @@ static bool xive_router_end_es_notify(XiveRouter *xrtr, uint8_t end_blk,
>    * another chip. We don't model the PowerBus but the END trigger
>    * message has the same parameters than in the function below.
>    */
> -static void xive_router_end_notify(XiveRouter *xrtr, uint8_t end_blk,
> -                                   uint32_t end_idx, uint32_t end_data)
> +void xive_router_end_notify(XiveRouter *xrtr, XiveEAS *eas)
>   {
>       XiveEND end;
>       uint8_t priority;
> @@ -1675,6 +1681,10 @@ static void xive_router_end_notify(XiveRouter *xrtr, uint8_t end_blk,
>       XiveNVT nvt;
>       bool found;
>   
> +    uint8_t end_blk = xive_get_field64(EAS_END_BLOCK, eas->w);
> +    uint32_t end_idx = xive_get_field64(EAS_END_INDEX, eas->w);
> +    uint32_t end_data = xive_get_field64(EAS_END_DATA,  eas->w);
> +
>       /* END cache lookup */
>       if (xive_router_get_end(xrtr, end_blk, end_idx, &end)) {
>           qemu_log_mask(LOG_GUEST_ERROR, "XIVE: No END %x/%x\n", end_blk,
> @@ -1817,10 +1827,7 @@ do_escalation:
>       /*
>        * The END trigger becomes an Escalation trigger
>        */
> -    xive_router_end_notify(xrtr,
> -                           xive_get_field32(END_W4_ESC_END_BLOCK, end.w4),
> -                           xive_get_field32(END_W4_ESC_END_INDEX, end.w4),
> -                           xive_get_field32(END_W5_ESC_END_DATA,  end.w5));
> +    xive_router_end_notify_handler(xrtr, (XiveEAS *) &end.w4);


I didn't like the cast, but I can see why you're doing it this way. We 
should be fine as long as the notify handler is not testing the validity 
bit of the EAS structure.

Reviewed-by: Frederic Barrat <fbarrat@linux.ibm.com>

   Fred


>   }
>   
>   void xive_router_notify(XiveNotifier *xn, uint32_t lisn, bool pq_checked)
> @@ -1871,10 +1878,7 @@ void xive_router_notify(XiveNotifier *xn, uint32_t lisn, bool pq_checked)
>       /*
>        * The event trigger becomes an END trigger
>        */
> -    xive_router_end_notify(xrtr,
> -                           xive_get_field64(EAS_END_BLOCK, eas.w),
> -                           xive_get_field64(EAS_END_INDEX, eas.w),
> -                           xive_get_field64(EAS_END_DATA,  eas.w));
> +    xive_router_end_notify_handler(xrtr, &eas);
>   }
>   
>   static Property xive_router_properties[] = {
> @@ -1887,12 +1891,16 @@ static void xive_router_class_init(ObjectClass *klass, void *data)
>   {
>       DeviceClass *dc = DEVICE_CLASS(klass);
>       XiveNotifierClass *xnc = XIVE_NOTIFIER_CLASS(klass);
> +    XiveRouterClass *xrc = XIVE_ROUTER_CLASS(klass);
>   
>       dc->desc    = "XIVE Router Engine";
>       device_class_set_props(dc, xive_router_properties);
>       /* Parent is SysBusDeviceClass. No need to call its realize hook */
>       dc->realize = xive_router_realize;
>       xnc->notify = xive_router_notify;
> +
> +    /* By default, the router handles END triggers locally */
> +    xrc->end_notify = xive_router_end_notify;
>   }
>   
>   static const TypeInfo xive_router_info = {