ppc/xive: Provide escalation support

If the XIVE presenter can not find the NVT dispatched on any of the HW
threads, it can not deliver the interrupt. XIVE offers an escalation
mechanism to handle such scenarios and inform the hypervisor that an
action should be taken.

Escalation is configured by setting the 'e' bit and the EAS in word 4
& 5 to let the HW look for the escalation END on which to trigger a
new event.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190718115420.19919-6-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

hw/intc/xive.c

@@ -1549,6 +1549,22 @@ static void xive_router_end_notify(XiveRouter *xrtr, uint8_t end_blk,
          * On HW, follows a "Broadcast Backlog" to IVPEs
          */
     }
+
+    /*
+     * If activated, escalate notification using the ESe PQ bits and
+     * the EAS in w4-5
+     */
+    if (!xive_end_is_escalate(&end)) {
+        return;
+    }
+
+    /*
+     * 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));
 }
 
 void xive_router_notify(XiveNotifier *xn, uint32_t lisn)