spapr_drc: fix aborts during DRC-count based hotplug

CPU/memory resources can be signalled en-masse via
spapr_hotplug_req_add_by_count(), and when doing so, actually change
the meaning of the 'drc' parameter passed to
spapr_hotplug_req_event() to be a count rather than an index.

f40eb92 added a hook in spapr_hotplug_req_event() to record when a
device had been 'signalled' to the guest, but that code assumes that
drc is always an index. In cases where it's a count, such as memory
hotplug, the DRC lookup will fail, leading to an assert.

Fix this by only explicitly setting the signalled state for cases where
we are doing PCI hotplug.

For other resources types, since we cannot selectively track whether a
resource has been signalled in cases where we signal attach as a count,
set the 'signalled' state to true immediately upon making the
resource available via drck->attach().

Reported-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
Cc: Bharata B Rao <bharata@linux.vnet.ibm.com>
Cc: david@gibson.dropbear.id.au
Cc: qemu-ppc@nongnu.org
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

1 files changed, 3 insertions, 4 deletions

diff --git a/hw/ppc/spapr_events.c b/hw/ppc/spapr_events.c
index 269ab7e61c..049fb1b325 100644
--- a/hw/ppc/spapr_events.c
+++ b/hw/ppc/spapr_events.c
@@ -442,6 +442,9 @@ static void spapr_hotplug_req_event(uint8_t hp_id, uint8_t hp_action,
     switch (drc_type) {
     case SPAPR_DR_CONNECTOR_TYPE_PCI:
         hp->hotplug_type = RTAS_LOG_V6_HP_TYPE_PCI;
+        if (hp->hotplug_action == RTAS_LOG_V6_HP_ACTION_ADD) {
+            spapr_hotplug_set_signalled(drc);
+        }
         break;
     case SPAPR_DR_CONNECTOR_TYPE_LMB:
         hp->hotplug_type = RTAS_LOG_V6_HP_TYPE_MEMORY;
@@ -462,10 +465,6 @@ static void spapr_hotplug_req_event(uint8_t hp_id, uint8_t hp_action,
 
     rtas_event_log_queue(RTAS_LOG_TYPE_HOTPLUG, new_hp, true);
 
-    if (hp->hotplug_action == RTAS_LOG_V6_HP_ACTION_ADD) {
-        spapr_hotplug_set_signalled(drc);
-    }
-
     qemu_irq_pulse(xics_get_qirq(spapr->icp, spapr->check_exception_irq));
 }