KVM: s390: Zero out current VMDB of STSI before including level3 data.

[ Upstream commit b75f4c9a ]

s390 documentation requires words 0 and 10-15 to be reserved and stored as
zeros. As we fill out all other fields, we can memset the full structure.
Signed-off-by: Ekaterina Tumanova <tumanova@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

arch/s390/kvm/priv.c

@@ -470,6 +470,7 @@ static void handle_stsi_3_2_2(struct kvm_vcpu *vcpu, struct sysinfo_3_2_2 *mem)
 	for (n = mem->count - 1; n > 0 ; n--)
 		memcpy(&mem->vm[n], &mem->vm[n - 1], sizeof(mem->vm[0]));
 
+	memset(&mem->vm[0], 0, sizeof(mem->vm[0]));
 	mem->vm[0].cpus_total = cpus;
 	mem->vm[0].cpus_configured = cpus;
 	mem->vm[0].cpus_standby = 0;