Re: [PATCH 3/3 v2] kvm common: verify that cpu slot is available when creating new vcpu

[Carsten Otte <cotte@de.ibm.com>]

KVM common code should'nt try to create the same virtual cpu twice.
In case of s390, it crashes badly in kvm_arch_vcpu_create.

Reported-by: Mijo Safradin <mijo@linux.vnet.ibm.com>
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
---
 virt/kvm/kvm_main.c |    3 +++
 1 file changed, 3 insertions(+)

Index: kvm/virt/kvm/kvm_main.c
===================================================================
--- kvm.orig/virt/kvm/kvm_main.c
+++ kvm/virt/kvm/kvm_main.c
@@ -1605,6 +1605,9 @@ static int kvm_vm_ioctl_create_vcpu(stru
 	if (!valid_vcpu(n))
 		return -EINVAL;
 
+	if (kvm->vcpus[n])
+		return -EEXIST;
+
 	vcpu = kvm_arch_vcpu_create(kvm, n);
 	if (IS_ERR(vcpu))
 		return PTR_ERR(vcpu);