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From: "Cédric Le Goater" <clg@kaod.org>
To: David Gibson <david@gibson.dropbear.id.au>
Cc: "Cédric Le Goater" <clg@kaod.org>,
	qemu-ppc@nongnu.org, qemu-devel@nongnu.org,
	"Greg Kurz" <groug@kaod.org>
Subject: [PATCH] spapr/xive: skip partially initialized vCPUs in presenter
Date: Tue,  1 Oct 2019 10:57:22 +0200	[thread overview]
Message-ID: <20191001085722.32755-1-clg@kaod.org> (raw)

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 <clg@kaod.org>
---
 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



             reply	other threads:[~2019-10-01  8:59 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-01  8:57 Cédric Le Goater [this message]
2019-10-01 11:06 ` [PATCH] spapr/xive: skip partially initialized vCPUs in presenter Greg Kurz
2019-10-01 11:56   ` Cédric Le Goater
2019-10-01 16:56     ` Greg Kurz
2019-10-02  1:02       ` David Gibson
2019-10-02 14:21         ` Greg Kurz
2019-10-02 14:47           ` Cédric Le Goater
2019-10-02 22:37             ` David Gibson
2019-10-03  8:02               ` Cédric Le Goater

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