spapr: add a 'reset' method to the sPAPR IRQ backend

For the time being, the XIVE reset handler updates the OS CAM line of
the vCPU as it is done under a real hypervisor when a vCPU is
scheduled to run on a HW thread. This will let the XIVE presenter
engine find a match among the NVTs dispatched on the HW threads.

This handler will become even more useful when we introduce the
machine supporting both interrupt modes, XIVE and XICS. In this
machine, the interrupt mode is chosen by the CAS negotiation process
and activated after a reset.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
[dwg: Fix style nits]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

1 files changed, 6 insertions, 0 deletions

diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index 0b09a88753..487f80e940 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -1619,6 +1619,12 @@ static void spapr_machine_reset(void)
 
     qemu_devices_reset();
 
+    /*
+     * This is fixing some of the default configuration of the XIVE
+     * devices. To be called after the reset of the machine devices.
+     */
+    spapr_irq_reset(spapr, &error_fatal);
+
     /* DRC reset may cause a device to be unplugged. This will cause troubles
      * if this device is used by another device (eg, a running vhost backend
      * will crash QEMU if the DIMM holding the vring goes away). To avoid such