spapr: enable XIVE MMIOs at reset

Depending on the interrupt mode of the machine, enable or disable the
XIVE MMIOs.

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

2 files changed, 18 insertions, 0 deletions

diff --git a/hw/intc/spapr_xive.c b/hw/intc/spapr_xive.c
index eea28337e8..d391177ab8 100644
--- a/hw/intc/spapr_xive.c
+++ b/hw/intc/spapr_xive.c
@@ -179,6 +179,15 @@ static void spapr_xive_map_mmio(sPAPRXive *xive)
     sysbus_mmio_map(SYS_BUS_DEVICE(xive), 2, xive->tm_base);
 }
 
+void spapr_xive_mmio_set_enabled(sPAPRXive *xive, bool enable)
+{
+    memory_region_set_enabled(&xive->source.esb_mmio, enable);
+    memory_region_set_enabled(&xive->tm_mmio, enable);
+
+    /* Disable the END ESBs until a guest OS makes use of them */
+    memory_region_set_enabled(&xive->end_source.esb_mmio, false);
+}
+
 /*
  * When a Virtual Processor is scheduled to run on a HW thread, the
  * hypervisor pushes its identifier in the OS CAM line. Emulate the
diff --git a/hw/ppc/spapr_irq.c b/hw/ppc/spapr_irq.c
index d110b8cdee..5fce72fe0f 100644
--- a/hw/ppc/spapr_irq.c
+++ b/hw/ppc/spapr_irq.c
@@ -375,6 +375,9 @@ static void spapr_irq_reset_xive(sPAPRMachineState *spapr, Error **errp)
         /* (TCG) Set the OS CAM line of the thread interrupt context. */
         spapr_xive_set_tctx_os_cam(cpu->tctx);
     }
+
+    /* Activate the XIVE MMIOs */
+    spapr_xive_mmio_set_enabled(spapr->xive, true);
 }
 
 static void spapr_irq_set_irq_xive(void *opaque, int srcno, int val)
@@ -549,6 +552,12 @@ static int spapr_irq_post_load_dual(sPAPRMachineState *spapr, int version_id)
 
 static void spapr_irq_reset_dual(sPAPRMachineState *spapr, Error **errp)
 {
+    /*
+     * Deactivate the XIVE MMIOs. The XIVE backend will reenable them
+     * if selected.
+     */
+    spapr_xive_mmio_set_enabled(spapr->xive, false);
+
     spapr_irq_current(spapr)->reset(spapr, errp);
 }