s->smmu_pcibus_by_bus_num is a SMMUPciBus pointer cache indexed
by bus number, bus number may not always be a fixed value,
i.e., guest reboot to different kernel which set bus number with
different algorithm.

This could lead to smmu_iommu_mr() providing the wrong iommu MR.

Suggested-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
---
 hw/arm/smmu-common.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/hw/arm/smmu-common.c b/hw/arm/smmu-common.c
index 9a8ac45431..f58261bb81 100644
--- a/hw/arm/smmu-common.c
+++ b/hw/arm/smmu-common.c
@@ -675,6 +675,8 @@ static void smmu_base_reset_hold(Object *obj)
 {
     SMMUState *s = ARM_SMMU(obj);
 
+    memset(s->smmu_pcibus_by_bus_num, 0, sizeof(s->smmu_pcibus_by_bus_num));
+
     g_hash_table_remove_all(s->configs);
     g_hash_table_remove_all(s->iotlb);
 }
-- 
2.34.1