KVM: s390: Verify memory in kvm run

This check verifies that the guest we're trying to run in KVM_RUN
has some memory assigned to it. It enters an endless exception
loop if this is not the case.

Reported-by: Mijo Safradin <mijo@linux.vnet.ibm.com>
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Christian Ehrhardt <ehrhardt@de.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 628494a4342..10bccd1f8ae 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -487,6 +487,12 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
 
         vcpu_load(vcpu);
 
+        /* verify, that memory has been registered */
+        if (!vcpu->kvm->arch.guest_memsize) {
+                vcpu_put(vcpu);
+                return -EINVAL;
+        }
+
         if (vcpu->sigset_active)
                 sigprocmask(SIG_SETMASK, &vcpu->sigset, &sigsaved);