Commit ca242ac9 authored Sep 21, 2010 by Avi Kivity Committed by Marcelo Tosatti Sep 23, 2010

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>

parent 6bbfb265

virt/kvm/kvm_main.c

+3 −1

Original line number	Original line	Diff line number	Diff line
	@@ -1970,10 +1970,12 @@ static int kvm_cpu_hotplug(struct notifier_block *notifier, unsigned long val,

	asmlinkage void kvm_handle_fault_on_reboot(void)		asmlinkage void kvm_handle_fault_on_reboot(void)
	{		{
	if (kvm_rebooting)		if (kvm_rebooting) {
	/* spin while reset goes on */		/* spin while reset goes on */
			local_irq_enable();
	while (true)		while (true)
	;		;
			}
	/* Fault while not rebooting. We want the trace. */		/* Fault while not rebooting. We want the trace. */
	BUG();		BUG();
	}		}