KVM guest: Move a printk that's using the clock before it's ready
Fix a hang during SMP kernel boot on KVM that showed up
after commit 489fb490dbf8dab0249ad82b56688ae3842a79e8
(2.6.35) and 59aab522154a2f17b25335b63c1cf68a51fb6ae0
(2.6.34.1). The problem only occurs when
CONFIG_PRINTK_TIME is set.
KVM-Stable-Tag.
Signed-off-by: Arjan Koers <0h61vkll2ly8@xutrox.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c
index eb9b76c..ca43ce3 100644
--- a/arch/x86/kernel/kvmclock.c
+++ b/arch/x86/kernel/kvmclock.c
@@ -128,13 +128,15 @@
static int kvm_register_clock(char *txt)
{
int cpu = smp_processor_id();
- int low, high;
+ int low, high, ret;
+
low = (int)__pa(&per_cpu(hv_clock, cpu)) | 1;
high = ((u64)__pa(&per_cpu(hv_clock, cpu)) >> 32);
+ ret = native_write_msr_safe(msr_kvm_system_time, low, high);
printk(KERN_INFO "kvm-clock: cpu %d, msr %x:%x, %s\n",
cpu, high, low, txt);
- return native_write_msr_safe(msr_kvm_system_time, low, high);
+ return ret;
}
#ifdef CONFIG_X86_LOCAL_APIC