From: Avi Kivity <avi@qumranet.com>
Date: Sun, 24 Feb 2008 12:37:50 +0000 (+0200)
Subject: KVM: Avoid infinite-frequency local apic timer
X-Git-Tag: v2.6.25-rc4~97^2~4
X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=0b975a3c2d53829fa978e18fabae7d99031f588f;p=linux-2.6-omap-h63xx.git

KVM: Avoid infinite-frequency local apic timer

If the local apic initial count is zero, don't start a an hrtimer with infinite
frequency, locking up the host.

Signed-off-by: Avi Kivity <avi@qumranet.com>
---

diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 2cbee9479ce..68a6b151193 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -647,6 +647,10 @@ static void start_apic_timer(struct kvm_lapic *apic)
 	apic->timer.period = apic_get_reg(apic, APIC_TMICT) *
 		    APIC_BUS_CYCLE_NS * apic->timer.divide_count;
 	atomic_set(&apic->timer.pending, 0);
+
+	if (!apic->timer.period)
+		return;
+
 	hrtimer_start(&apic->timer.dev,
 		      ktime_add_ns(now, apic->timer.period),
 		      HRTIMER_MODE_ABS);