spapr: Don't use spapr_drc_needed() in CAS code

We currently don't support hotplug of devices between boot and CAS. If
this happens a CAS reboot is triggered. We detect this during CAS using
the spapr_drc_needed() function which is essentially a VMStateDescription
.needed callback. Even if the condition for CAS reboot happens to be the
same as for DRC migration, it looks wrong to piggyback a migration helper
for this.

Introduce a helper with slightly more explicit name and use it in both CAS
and DRC migration code. Since a subsequent patch will enhance this helper
to cover the case of hot unplug, let's go for spapr_drc_transient(). While
here convert spapr_hotplugged_dev_before_cas() to the "transient" wording as
well.

This doesn't change any behaviour.

Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <158169248180.3465937.9531405453362718771.stgit@bahia.lan>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

1 files changed, 14 insertions, 6 deletions

diff --git a/hw/ppc/spapr_drc.c b/hw/ppc/spapr_drc.c
index fc62e04901..4c35ce7c5c 100644
--- a/hw/ppc/spapr_drc.c
+++ b/hw/ppc/spapr_drc.c
@@ -456,23 +456,31 @@ void spapr_drc_reset(SpaprDrc *drc)
     }
 }
 
-bool spapr_drc_needed(void *opaque)
+bool spapr_drc_transient(SpaprDrc *drc)
 {
-    SpaprDrc *drc = (SpaprDrc *)opaque;
     SpaprDrcClass *drck = SPAPR_DR_CONNECTOR_GET_CLASS(drc);
 
-    /* If no dev is plugged in there is no need to migrate the DRC state */
+    /*
+     * If no dev is plugged in there is no need to migrate the DRC state
+     * nor to reset the DRC at CAS.
+     */
     if (!drc->dev) {
         return false;
     }
 
     /*
-     * We need to migrate the state if it's not equal to the expected
-     * long-term state, which is the same as the coldplugged initial
-     * state */
+     * We need to reset the DRC at CAS or to migrate the DRC state if it's
+     * not equal to the expected long-term state, which is the same as the
+     * coldplugged initial state.
+     */
     return (drc->state != drck->ready_state);
 }
 
+static bool spapr_drc_needed(void *opaque)
+{
+    return spapr_drc_transient(opaque);
+}
+
 static const VMStateDescription vmstate_spapr_drc = {
     .name = "spapr_drc",
     .version_id = 1,