KVM: Fix reboot on Intel hosts

ca242ac9 · Avi Kivity <[email protected]> · 2010-09-21 19:59:43 +02:00

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 <[email protected]>
Signed-off-by: Marcelo Tosatti <[email protected]>

Commit: ca242ac9960dc61530e25a2c190e4e13fd5f1ecb
Parents: 6bbfb265

Changes

1 files changed · +3 −1

File	Status	Add	Del	Content
virt/kvm/kvm_main.c	modified	+3	−1	View file

virt/kvm/kvm_main.c

View file

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index d4853a5..5186e72 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();
 }