1 files changed, 11 insertions, 7 deletions

diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 2598cf243b86..1371dff2b90d 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -769,7 +769,7 @@ static void kvm_s390_sync_request_broadcast(struct kvm *kvm, int req)
 
 /*
  * Must be called with kvm->srcu held to avoid races on memslots, and with
- * kvm->lock to avoid races with ourselves and kvm_s390_vm_stop_migration.
+ * kvm->slots_lock to avoid races with ourselves and kvm_s390_vm_stop_migration.
  */
 static int kvm_s390_vm_start_migration(struct kvm *kvm)
 {
@@ -825,7 +825,7 @@ static int kvm_s390_vm_start_migration(struct kvm *kvm)
 }
 
 /*
- * Must be called with kvm->lock to avoid races with ourselves and
+ * Must be called with kvm->slots_lock to avoid races with ourselves and
  * kvm_s390_vm_start_migration.
  */
 static int kvm_s390_vm_stop_migration(struct kvm *kvm)
@@ -840,6 +840,8 @@ static int kvm_s390_vm_stop_migration(struct kvm *kvm)
 
         if (kvm->arch.use_cmma) {
                 kvm_s390_sync_request_broadcast(kvm, KVM_REQ_STOP_MIGRATION);
+                /* We have to wait for the essa emulation to finish */
+                synchronize_srcu(&kvm->srcu);
                 vfree(mgs->pgste_bitmap);
         }
         kfree(mgs);
@@ -849,14 +851,12 @@ static int kvm_s390_vm_stop_migration(struct kvm *kvm)
 static int kvm_s390_vm_set_migration(struct kvm *kvm,
                                      struct kvm_device_attr *attr)
 {
-        int idx, res = -ENXIO;
+        int res = -ENXIO;
 
-        mutex_lock(&kvm->lock);
+        mutex_lock(&kvm->slots_lock);
         switch (attr->attr) {
         case KVM_S390_VM_MIGRATION_START:
-                idx = srcu_read_lock(&kvm->srcu);
                 res = kvm_s390_vm_start_migration(kvm);
-                srcu_read_unlock(&kvm->srcu, idx);
                 break;
         case KVM_S390_VM_MIGRATION_STOP:
                 res = kvm_s390_vm_stop_migration(kvm);
@@ -864,7 +864,7 @@ static int kvm_s390_vm_set_migration(struct kvm *kvm,
         default:
                 break;
         }
-        mutex_unlock(&kvm->lock);
+        mutex_unlock(&kvm->slots_lock);
 
         return res;
 }
@@ -1754,7 +1754,9 @@ long kvm_arch_vm_ioctl(struct file *filp,
                 r = -EFAULT;
                 if (copy_from_user(&args, argp, sizeof(args)))
                         break;
+                mutex_lock(&kvm->slots_lock);
                 r = kvm_s390_get_cmma_bits(kvm, &args);
+                mutex_unlock(&kvm->slots_lock);
                 if (!r) {
                         r = copy_to_user(argp, &args, sizeof(args));
                         if (r)
@@ -1768,7 +1770,9 @@ long kvm_arch_vm_ioctl(struct file *filp,
                 r = -EFAULT;
                 if (copy_from_user(&args, argp, sizeof(args)))
                         break;
+                mutex_lock(&kvm->slots_lock);
                 r = kvm_s390_set_cmma_bits(kvm, &args);
+                mutex_unlock(&kvm->slots_lock);
                 break;
         }
         default: