xive: Use the XIVE fabric link under the XIVE router

Now that the spapr and pnv machines do set the "xive-fabric" link, the
use of the XIVE fabric pointer becomes mandatory. This is checked with
an assert() in a new realize hook. Since the XIVE router is realized at
machine init for the all the machine's life time, no risk to abort an
already running guest (ie. not a hotplug path).

This gets rid of a qdev_get_machine() call.
Signed-off-by: NGreg Kurz <groug@kaod.org>
Signed-off-by: NCédric Le Goater <clg@kaod.org>
Message-Id: <20200106145645.4539-6-clg@kaod.org>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

hw/intc/xive.c

@@ -1378,6 +1378,13 @@ static int xive_router_get_block_id(XiveRouter *xrtr)
    return xrc->get_block_id(xrtr);
 }
 
+static void xive_router_realize(DeviceState *dev, Error **errp)
+{
+    XiveRouter *xrtr = XIVE_ROUTER(dev);
+
+    assert(xrtr->xfb);
+}
+
 /*
  * Encode the HW CAM line in the block group mode format :
  *
@@ -1470,12 +1477,11 @@ int xive_presenter_tctx_match(XivePresenter *xptr, XiveTCTX *tctx,
  *
  * The parameters represent what is sent on the PowerBus
  */
-static bool xive_presenter_notify(uint8_t format,
+static bool xive_presenter_notify(XiveFabric *xfb, uint8_t format,
                                   uint8_t nvt_blk, uint32_t nvt_idx,
                                   bool cam_ignore, uint8_t priority,
                                   uint32_t logic_serv)
 {
-    XiveFabric *xfb = XIVE_FABRIC(qdev_get_machine());
     XiveFabricClass *xfc = XIVE_FABRIC_GET_CLASS(xfb);
     XiveTCTXMatch match = { .tctx = NULL, .ring = 0 };
     int count;
@@ -1607,7 +1613,7 @@ static void xive_router_end_notify(XiveRouter *xrtr, uint8_t end_blk,
         return;
     }
 
-    found = xive_presenter_notify(format, nvt_blk, nvt_idx,
+    found = xive_presenter_notify(xrtr->xfb, format, nvt_blk, nvt_idx,
                           xive_get_field32(END_W7_F0_IGNORE, end.w7),
                           priority,
                           xive_get_field32(END_W7_F1_LOG_SERVER_ID, end.w7));
@@ -1727,6 +1733,8 @@ static void xive_router_class_init(ObjectClass *klass, void *data)
 
     dc->desc    = "XIVE Router Engine";
     dc->props   = xive_router_properties;
+    /* Parent is SysBusDeviceClass. No need to call its realize hook */
+    dc->realize = xive_router_realize;
     xnc->notify = xive_router_notify;
 }