KVM: Convert kvm_lock to raw_spinlock

Code under this lock requires non-preemptibility. Ensure this also over
-rt by converting it to raw spinlock.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index ffd7f8d..a58aebe 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -85,7 +85,7 @@
 
 #define ASYNC_PF_PER_VCPU 64
 
-extern spinlock_t kvm_lock;
+extern raw_spinlock_t kvm_lock;
 extern struct list_head vm_list;
 
 struct kvm_vcpu;
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index ccacf0b..b6a9963 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -3587,7 +3587,7 @@
 	if (nr_to_scan == 0)
 		goto out;
 
-	spin_lock(&kvm_lock);
+	raw_spin_lock(&kvm_lock);
 
 	list_for_each_entry(kvm, &vm_list, vm_list) {
 		int idx, freed_pages;
@@ -3610,7 +3610,7 @@
 	if (kvm_freed)
 		list_move_tail(&kvm_freed->vm_list, &vm_list);
 
-	spin_unlock(&kvm_lock);
+	raw_spin_unlock(&kvm_lock);
 
 out:
 	return percpu_counter_read_positive(&kvm_total_used_mmu_pages);
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index bd59e8e..d9855b8 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4557,7 +4557,7 @@
 
 	smp_call_function_single(freq->cpu, tsc_khz_changed, freq, 1);
 
-	spin_lock(&kvm_lock);
+	raw_spin_lock(&kvm_lock);
 	list_for_each_entry(kvm, &vm_list, vm_list) {
 		kvm_for_each_vcpu(i, vcpu, kvm) {
 			if (vcpu->cpu != freq->cpu)
@@ -4567,7 +4567,7 @@
 				send_ipi = 1;
 		}
 	}
-	spin_unlock(&kvm_lock);
+	raw_spin_unlock(&kvm_lock);
 
 	if (freq->old < freq->new && send_ipi) {
 		/*