From b7c4145ba2eb0717db0ddac1b5f7f48012189c53 Mon Sep 17 00:00:00 2001 From: Avi Kivity Date: Thu, 2 Dec 2010 17:52:50 +0200 Subject: KVM: Don't spin on virt instruction faults during reboot Since vmx blocks INIT signals, we disable virtualization extensions during reboot. This leads to virtualization instructions faulting; we trap these faults and spin while the reboot continues. Unfortunately spinning on a non-preemptible kernel may block a task that reboot depends on; this causes the reboot to hang. Fix by skipping over the instruction and hoping for the best. Signed-off-by: Avi Kivity --- virt/kvm/kvm_main.c | 13 ++++--------- 1 file changed, 4 insertions(+), 9 deletions(-) (limited to 'virt') diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index ee99b77e4451..7f686251f711 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -90,7 +90,8 @@ static void hardware_disable_all(void); static void kvm_io_bus_destroy(struct kvm_io_bus *bus); -static bool kvm_rebooting; +bool kvm_rebooting; +EXPORT_SYMBOL_GPL(kvm_rebooting); static bool largepages_enabled = true; @@ -2171,18 +2172,12 @@ static int kvm_cpu_hotplug(struct notifier_block *notifier, unsigned long val, } -asmlinkage void kvm_handle_fault_on_reboot(void) +asmlinkage void kvm_spurious_fault(void) { - if (kvm_rebooting) { - /* spin while reset goes on */ - local_irq_enable(); - while (true) - cpu_relax(); - } /* Fault while not rebooting. We want the trace. */ BUG(); } -EXPORT_SYMBOL_GPL(kvm_handle_fault_on_reboot); +EXPORT_SYMBOL_GPL(kvm_spurious_fault); static int kvm_reboot(struct notifier_block *notifier, unsigned long val, void *v) -- cgit v1.2.3-59-g8ed1b