[Qemu-devel] [RFC PATCH] spapr/irq: force XICS interrupt mode on non P9 machines

[Cédric Le Goater]

There is no need to propose the 'dual' interrupt mode interrupt device
on POWER7/8 machines and the XIVE mode will not operate. Simply force
XICS in this case.

This makes the check in spapr_machine_init() redundant on XIVE-only
machines.

Signed-off-by: Cédric Le Goater <c...@kaod.org>
---
 hw/ppc/spapr_irq.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/hw/ppc/spapr_irq.c b/hw/ppc/spapr_irq.c
index f2ca1bb66c9d..d27ae68915a1 100644
--- a/hw/ppc/spapr_irq.c
+++ b/hw/ppc/spapr_irq.c
@@ -16,6 +16,7 @@
 #include "hw/ppc/spapr_xive.h"
 #include "hw/ppc/xics.h"
 #include "hw/ppc/xics_spapr.h"
+#include "cpu-models.h"
 #include "sysemu/kvm.h"
 
 #include "trace.h"
@@ -655,6 +656,7 @@ SpaprIrq spapr_irq_dual = {
 void spapr_irq_init(SpaprMachineState *spapr, Error **errp)
 {
     MachineState *machine = MACHINE(spapr);
+    Error *local_err = NULL;
 
     if (machine_kernel_irqchip_split(machine)) {
         error_setg(errp, "kernel_irqchip split mode not supported on pseries");
@@ -667,6 +669,14 @@ void spapr_irq_init(SpaprMachineState *spapr, Error **errp)
         return;
     }
 
+    /* Force XICS on non P9 machines */
+    if (!ppc_type_check_compat(machine->cpu_type, CPU_POWERPC_LOGICAL_3_00,
+                              0, spapr->max_compat_pvr)) {
+        error_setg(&local_err, "forcing XICS interrupt controller");
+        warn_report_err(local_err);
+        spapr->irq = &spapr_irq_xics;
+    }
+
     /* Initialize the MSI IRQ allocator. */
     if (!SPAPR_MACHINE_GET_CLASS(spapr)->legacy_irq_allocation) {
         spapr_irq_msi_init(spapr, spapr->irq->nr_msis);
-- 
2.20.1