KVM: Convert vm lock to a mutex

This allows the kvm mmu to perform sleepy operations, such as memory
allocation.

Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
diff --git a/drivers/kvm/vmx.c b/drivers/kvm/vmx.c
index 8c87d20..5b77d9b 100644
--- a/drivers/kvm/vmx.c
+++ b/drivers/kvm/vmx.c
@@ -1711,19 +1711,19 @@
 	if (is_page_fault(intr_info)) {
 		cr2 = vmcs_readl(EXIT_QUALIFICATION);
 
-		spin_lock(&vcpu->kvm->lock);
+		mutex_lock(&vcpu->kvm->lock);
 		r = kvm_mmu_page_fault(vcpu, cr2, error_code);
 		if (r < 0) {
-			spin_unlock(&vcpu->kvm->lock);
+			mutex_unlock(&vcpu->kvm->lock);
 			return r;
 		}
 		if (!r) {
-			spin_unlock(&vcpu->kvm->lock);
+			mutex_unlock(&vcpu->kvm->lock);
 			return 1;
 		}
 
 		er = emulate_instruction(vcpu, kvm_run, cr2, error_code);
-		spin_unlock(&vcpu->kvm->lock);
+		mutex_unlock(&vcpu->kvm->lock);
 
 		switch (er) {
 		case EMULATE_DONE: