KVM: PIT: fix kpit_elapsed division by zero
Fix division by zero triggered by latch count command on uninitialized
counter.
Cc: stable@kernel.org
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/x86/kvm/i8254.c b/arch/x86/kvm/i8254.c
index 4d6f0d2..21f68e0 100644
--- a/arch/x86/kvm/i8254.c
+++ b/arch/x86/kvm/i8254.c
@@ -104,6 +104,9 @@
ktime_t remaining;
struct kvm_kpit_state *ps = &kvm->arch.vpit->pit_state;
+ if (!ps->pit_timer.period)
+ return 0;
+
/*
* The Counter does not stop when it reaches zero. In
* Modes 0, 1, 4, and 5 the Counter ``wraps around'' to