From ca242ac9960dc61530e25a2c190e4e13fd5f1ecb Mon Sep 17 00:00:00 2001
From: Avi Kivity <avi@redhat.com>
Date: Tue, 21 Sep 2010 19:59:43 +0200
Subject: [PATCH] KVM: Fix reboot on Intel hosts
When we reboot, we disable vmx extensions or otherwise INIT gets blocked.
If a task on another cpu hits a vmx instruction, it will fault if vmx is
disabled. We trap that to avoid a nasty oops and spin until the reboot
completes.
Problem is, we sleep with interrupts disabled. This blocks smp_send_stop()
from running, and the reboot process halts.
Fix by enabling interrupts before spinning.
KVM-Stable-Tag.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
---
virt/kvm/kvm_main.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index d4853a54771a0..5186e728c53ed 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1970,10 +1970,12 @@ static int kvm_cpu_hotplug(struct notifier_block *notifier, unsigned long val,
asmlinkage void kvm_handle_fault_on_reboot(void)
{
- if (kvm_rebooting)
+ if (kvm_rebooting) {
/* spin while reset goes on */
+ local_irq_enable();
while (true)
;
+ }
/* Fault while not rebooting. We want the trace. */
BUG();
}