ppc: Reset the interrupt presenter from the CPU reset handler

On the sPAPR machine and PowerNV machine, the interrupt presenters are
created by a machine handler at the core level and are reset
independently. This is not consistent and it raises issues when it
comes to handle hot-plugged CPUs. In that case, the presenters are not
reset. This is less of an issue in XICS, although a zero MFFR could
be a concern, but in XIVE, the OS CAM line is not set and this breaks
the presenting algorithm. The current code has workarounds which need
a global cleanup.

Extend the sPAPR IRQ backend and the PowerNV Chip class with a new
cpu_intc_reset() handler called by the CPU reset handler and remove
the XiveTCTX reset handler which is now redundant.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20191022163812.330-6-clg@kaod.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
diff --git a/hw/intc/spapr_xive.c b/hw/intc/spapr_xive.c
index ba32d2c..20a8d82 100644
--- a/hw/intc/spapr_xive.c
+++ b/hw/intc/spapr_xive.c
@@ -553,6 +553,14 @@
     return 0;
 }
 
+static void spapr_xive_cpu_intc_reset(SpaprInterruptController *intc,
+                                     PowerPCCPU *cpu)
+{
+    XiveTCTX *tctx = spapr_cpu_state(cpu)->tctx;
+
+    xive_tctx_reset(tctx);
+}
+
 static void spapr_xive_set_irq(SpaprInterruptController *intc, int irq, int val)
 {
     SpaprXive *xive = SPAPR_XIVE(intc);
@@ -697,6 +705,7 @@
     sicc->activate = spapr_xive_activate;
     sicc->deactivate = spapr_xive_deactivate;
     sicc->cpu_intc_create = spapr_xive_cpu_intc_create;
+    sicc->cpu_intc_reset = spapr_xive_cpu_intc_reset;
     sicc->claim_irq = spapr_xive_claim_irq;
     sicc->free_irq = spapr_xive_free_irq;
     sicc->set_irq = spapr_xive_set_irq;