1 files changed, 32 insertions, 13 deletions

diff --git a/virt/kvm/vfio.c b/virt/kvm/vfio.c
index ce1b01d02c51..495ceabffe88 100644
--- a/virt/kvm/vfio.c
+++ b/virt/kvm/vfio.c
@@ -24,6 +24,9 @@
 struct kvm_vfio_group {
 	struct list_head node;
 	struct file *file;
+#ifdef CONFIG_SPAPR_TCE_IOMMU
+	struct iommu_group *iommu_group;
+#endif
 };
 
 struct kvm_vfio {
@@ -61,6 +64,23 @@ static bool kvm_vfio_file_enforced_coherent(struct file *file)
 	return ret;
 }
 
+static bool kvm_vfio_file_is_group(struct file *file)
+{
+	bool (*fn)(struct file *file);
+	bool ret;
+
+	fn = symbol_get(vfio_file_is_group);
+	if (!fn)
+		return false;
+
+	ret = fn(file);
+
+	symbol_put(vfio_file_is_group);
+
+	return ret;
+}
+
+#ifdef CONFIG_SPAPR_TCE_IOMMU
 static struct iommu_group *kvm_vfio_file_iommu_group(struct file *file)
 {
 	struct iommu_group *(*fn)(struct file *file);
@@ -77,16 +97,15 @@ static struct iommu_group *kvm_vfio_file_iommu_group(struct file *file)
 	return ret;
 }
 
-#ifdef CONFIG_SPAPR_TCE_IOMMU
 static void kvm_spapr_tce_release_vfio_group(struct kvm *kvm,
 					     struct kvm_vfio_group *kvg)
 {
-	struct iommu_group *grp = kvm_vfio_file_iommu_group(kvg->file);
-
-	if (WARN_ON_ONCE(!grp))
+	if (WARN_ON_ONCE(!kvg->iommu_group))
 		return;
 
-	kvm_spapr_tce_release_iommu_group(kvm, grp);
+	kvm_spapr_tce_release_iommu_group(kvm, kvg->iommu_group);
+	iommu_group_put(kvg->iommu_group);
+	kvg->iommu_group = NULL;
 }
 #endif
 
@@ -136,7 +155,7 @@ static int kvm_vfio_group_add(struct kvm_device *dev, unsigned int fd)
 		return -EBADF;
 
 	/* Ensure the FD is a vfio group FD.*/
-	if (!kvm_vfio_file_iommu_group(filp)) {
+	if (!kvm_vfio_file_is_group(filp)) {
 		ret = -EINVAL;
 		goto err_fput;
 	}
@@ -236,19 +255,19 @@ static int kvm_vfio_group_set_spapr_tce(struct kvm_device *dev,
 	mutex_lock(&kv->lock);
 
 	list_for_each_entry(kvg, &kv->group_list, node) {
-		struct iommu_group *grp;
-
 		if (kvg->file != f.file)
 			continue;
 
-		grp = kvm_vfio_file_iommu_group(kvg->file);
-		if (WARN_ON_ONCE(!grp)) {
-			ret = -EIO;
-			goto err_fdput;
+		if (!kvg->iommu_group) {
+			kvg->iommu_group = kvm_vfio_file_iommu_group(kvg->file);
+			if (WARN_ON_ONCE(!kvg->iommu_group)) {
+				ret = -EIO;
+				goto err_fdput;
+			}
 		}
 
 		ret = kvm_spapr_tce_attach_iommu_group(dev->kvm, param.tablefd,
-						       grp);
+						       kvg->iommu_group);
 		break;
 	}