| From 8e2207cdd087ebb031e9118d1fd0902c6533a5e5 Mon Sep 17 00:00:00 2001 |
| From: David Hildenbrand <dahi@linux.vnet.ibm.com> |
| Date: Thu, 15 Jan 2015 17:56:18 +0100 |
| Subject: KVM: s390: floating irqs: fix user triggerable endless loop |
| |
| 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: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| arch/s390/kvm/interrupt.c | 2 ++ |
| 1 file changed, 2 insertions(+) |
| |
| --- a/arch/s390/kvm/interrupt.c |
| +++ b/arch/s390/kvm/interrupt.c |
| @@ -1197,6 +1197,8 @@ static int __inject_vm(struct kvm *kvm, |
| 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 { |
