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authorAvi Kivity <avi@redhat.com>2010-12-02 17:52:50 +0200
committerAvi Kivity <avi@redhat.com>2011-01-12 11:30:18 +0200
commitb7c4145ba2eb0717db0ddac1b5f7f48012189c53 (patch)
tree9b259970f56451ecb0f5d84ecd81d67386f63224 /virt/kvm
parent4cc703100b1fd97c71804e2fa5c9c377c5b37dc5 (diff)
downloadlinux-b7c4145ba2eb0717db0ddac1b5f7f48012189c53.tar.gz
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 <avi@redhat.com>
Diffstat (limited to 'virt/kvm')
-rw-r--r--virt/kvm/kvm_main.c13
1 files changed, 4 insertions, 9 deletions
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)