| From | Luis Henriques <> | Subject | [PATCH 3.16.y-ckt 087/183] KVM: s390: floating irqs: fix user triggerable endless loop | Date | Fri, 6 Mar 2015 09:56:18 +0000 |
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3.16.7-ckt8 -stable review patch. If anyone has any objections, please let me know.
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From: David Hildenbrand <dahi@linux.vnet.ibm.com>
commit 8e2207cdd087ebb031e9118d1fd0902c6533a5e5 upstream.
If a vm with no VCPUs is created, the injection of a floating irq leads to an endless loop in the kernel.
Let's skip the search for a destination VCPU for a floating irq if no VCPUs were created.
Reviewed-by: Dominik Dingel <dingel@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Luis Henriques <luis.henriques@canonical.com> --- arch/s390/kvm/interrupt.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c index e2354f97264e..f19702fc89ec 100644 --- a/arch/s390/kvm/interrupt.c +++ b/arch/s390/kvm/interrupt.c @@ -925,6 +925,8 @@ static int __inject_vm(struct kvm *kvm, struct kvm_s390_interrupt_info *inti) list_add_tail(&inti->list, &iter->list); } atomic_set(&fi->active, 1); + if (atomic_read(&kvm->online_vcpus) == 0) + goto unlock_fi; sigcpu = find_first_bit(fi->idle_mask, KVM_MAX_VCPUS); if (sigcpu == KVM_MAX_VCPUS) { do {
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