From: Greg Kurz <gr...@kaod.org>
If the host has 8 threads/core and the guest is started with:
-smp cores=1,threads=4,maxcpus=12
It is possible to crash QEMU by doing:
(qemu) device_add host-spapr-cpu-core,core-id=16,id=foo
(qemu) device_del foo
Segmentation fault
This happens because spapr_core_unplug() assumes cpu_dt_id == core_id.
As long as cpu_dt_id is derived from the non-table cpu_index, this is
only true when you plug cores with contiguous ids.
It is safer to be consistent: the DR connector was created with an
index that is immediately written to cc->core_id, and spapr_core_plug()
also relies on cc->core_id.
Let's use it also in spapr_core_unplug().
Signed-off-by: Greg Kurz <gr...@kaod.org>
Reviewed-by: Bharata B Rao <bhar...@linux.vnet.ibm.com>
Signed-off-by: David Gibson <da...@gibson.dropbear.id.au>
---
hw/ppc/spapr_cpu_core.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/hw/ppc/spapr_cpu_core.c b/hw/ppc/spapr_cpu_core.c
index 9347f07..bc52b3c 100644
--- a/hw/ppc/spapr_cpu_core.c
+++ b/hw/ppc/spapr_cpu_core.c
@@ -126,11 +126,9 @@ static void spapr_core_release(DeviceState *dev, void
*opaque)
void spapr_core_unplug(HotplugHandler *hotplug_dev, DeviceState *dev,
Error **errp)
{
- sPAPRCPUCore *core = SPAPR_CPU_CORE(OBJECT(dev));
- PowerPCCPU *cpu = POWERPC_CPU(core->threads);
- int id = ppc_get_vcpu_dt_id(cpu);
+ CPUCore *cc = CPU_CORE(dev);
sPAPRDRConnector *drc =
- spapr_dr_connector_by_id(SPAPR_DR_CONNECTOR_TYPE_CPU, id);
+ spapr_dr_connector_by_id(SPAPR_DR_CONNECTOR_TYPE_CPU, cc->core_id);
sPAPRDRConnectorClass *drck;
Error *local_err = NULL;
--
2.7.4
