[PATCH] spapr/xive: skip partially initialized vCPUs in presenter

[Cédric Le Goater]

When vCPUs are hotplugged, they are added to the QEMU CPU list before
being fully realized. This can crash the XIVE presenter because the
'tctx' pointer is not necessarily initialized when looking for a
matching target.

These vCPUs are not valid targets for the presenter. Skip them.

Signed-off-by: Cédric Le Goater <address@hidden>
---
 hw/intc/xive.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/hw/intc/xive.c b/hw/intc/xive.c
index b7417210d817..29df06df1136 100644
--- a/hw/intc/xive.c
+++ b/hw/intc/xive.c
@@ -1396,6 +1396,14 @@ static bool xive_presenter_match(XiveRouter *xrtr, 
uint8_t format,
         XiveTCTX *tctx = xive_router_get_tctx(xrtr, cs);
         int ring;
 
+        /*
+         * Skip partially initialized vCPUs. This can happen when
+         * vCPUs are hotplugged.
+         */
+        if (!tctx) {
+            continue;
+        }
+
         /*
          * HW checks that the CPU is enabled in the Physical Thread
          * Enable Register (PTER).
-- 
2.21.0