powerpc/kvm/book3s: switch from raw_spin_*lock to arch_spin_lock.

These functions can get called in realmode. Hence use low level
arch_spin_lock which is safe to be called in realmode.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200505071729.54912-9-aneesh.kumar@linux.ibm.com

arch/powerpc/kvm/book3s_hv_rm_mmu.c

@@ -948,7 +948,7 @@ static long kvmppc_do_h_page_init_zero(struct kvm_vcpu *vcpu,
 		return ret;
 
 	/* Check if we've been invalidated */
-	raw_spin_lock(&kvm->mmu_lock.rlock);
+	arch_spin_lock(&kvm->mmu_lock.rlock.raw_lock);
 	if (mmu_notifier_retry(kvm, mmu_seq)) {
 		ret = H_TOO_HARD;
 		goto out_unlock;
@@ -960,7 +960,7 @@ static long kvmppc_do_h_page_init_zero(struct kvm_vcpu *vcpu,
 	kvmppc_update_dirty_map(memslot, dest >> PAGE_SHIFT, PAGE_SIZE);
 
 out_unlock:
-	raw_spin_unlock(&kvm->mmu_lock.rlock);
+	arch_spin_unlock(&kvm->mmu_lock.rlock.raw_lock);
 	return ret;
 }
 
@@ -984,7 +984,7 @@ static long kvmppc_do_h_page_init_copy(struct kvm_vcpu *vcpu,
 		return ret;
 
 	/* Check if we've been invalidated */
-	raw_spin_lock(&kvm->mmu_lock.rlock);
+	arch_spin_lock(&kvm->mmu_lock.rlock.raw_lock);
 	if (mmu_notifier_retry(kvm, mmu_seq)) {
 		ret = H_TOO_HARD;
 		goto out_unlock;
@@ -996,7 +996,7 @@ static long kvmppc_do_h_page_init_copy(struct kvm_vcpu *vcpu,
 	kvmppc_update_dirty_map(dest_memslot, dest >> PAGE_SHIFT, PAGE_SIZE);
 
 out_unlock:
-	raw_spin_unlock(&kvm->mmu_lock.rlock);
+	arch_spin_unlock(&kvm->mmu_lock.rlock.raw_lock);
 	return ret;
 }