diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index 98940d1392cb..b17536d6e69b 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -3202,7 +3202,7 @@ static void amd_iommu_get_resv_regions(struct device *dev,
 
 	region = iommu_alloc_resv_region(MSI_RANGE_START,
 					 MSI_RANGE_END - MSI_RANGE_START + 1,
-					 0, IOMMU_RESV_RESERVED);
+					 0, IOMMU_RESV_MSI);
 	if (!region)
 		return;
 	list_add_tail(&region->list, head);
diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
index 5806a6acc94e..591bb96047c9 100644
--- a/drivers/iommu/arm-smmu-v3.c
+++ b/drivers/iommu/arm-smmu-v3.c
@@ -1888,7 +1888,7 @@ static void arm_smmu_get_resv_regions(struct device *dev,
 	int prot = IOMMU_WRITE | IOMMU_NOEXEC | IOMMU_MMIO;
 
 	region = iommu_alloc_resv_region(MSI_IOVA_BASE, MSI_IOVA_LENGTH,
-					 prot, IOMMU_RESV_MSI);
+					 prot, IOMMU_RESV_SW_MSI);
 	if (!region)
 		return;
 
diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index abf6496843a6..b493c99e17f7 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -1608,7 +1608,7 @@ static void arm_smmu_get_resv_regions(struct device *dev,
 	int prot = IOMMU_WRITE | IOMMU_NOEXEC | IOMMU_MMIO;
 
 	region = iommu_alloc_resv_region(MSI_IOVA_BASE, MSI_IOVA_LENGTH,
-					 prot, IOMMU_RESV_MSI);
+					 prot, IOMMU_RESV_SW_MSI);
 	if (!region)
 		return;
 
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 91d60493b57c..d412a313a372 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -5249,7 +5249,7 @@ static void intel_iommu_get_resv_regions(struct device *device,
 
 	reg = iommu_alloc_resv_region(IOAPIC_RANGE_START,
 				      IOAPIC_RANGE_END - IOAPIC_RANGE_START + 1,
-				      0, IOMMU_RESV_RESERVED);
+				      0, IOMMU_RESV_MSI);
 	if (!reg)
 		return;
 	list_add_tail(&reg->list, head);
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 8ea14f41a979..3b67144dead2 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -72,6 +72,7 @@ static const char * const iommu_group_resv_type_string[] = {
 	[IOMMU_RESV_DIRECT]	= "direct",
 	[IOMMU_RESV_RESERVED]	= "reserved",
 	[IOMMU_RESV_MSI]	= "msi",
+	[IOMMU_RESV_SW_MSI]	= "msi",
 };
 
 #define IOMMU_GROUP_ATTR(_name, _mode, _show, _store)		\
@@ -1743,8 +1744,8 @@ void iommu_put_resv_regions(struct device *dev, struct list_head *list)
 }
 
 struct iommu_resv_region *iommu_alloc_resv_region(phys_addr_t start,
-						  size_t length,
-						  int prot, int type)
+						  size_t length, int prot,
+						  enum iommu_resv_type type)
 {
 	struct iommu_resv_region *region;
 
diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index c26fa1f3ed86..32d2633092a3 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -1182,8 +1182,7 @@ static struct vfio_group *find_iommu_group(struct vfio_domain *domain,
 	return NULL;
 }
 
-static bool vfio_iommu_has_resv_msi(struct iommu_group *group,
-				    phys_addr_t *base)
+static bool vfio_iommu_has_sw_msi(struct iommu_group *group, phys_addr_t *base)
 {
 	struct list_head group_resv_regions;
 	struct iommu_resv_region *region, *next;
@@ -1192,7 +1191,7 @@ static bool vfio_iommu_has_resv_msi(struct iommu_group *group,
 	INIT_LIST_HEAD(&group_resv_regions);
 	iommu_get_group_resv_regions(group, &group_resv_regions);
 	list_for_each_entry(region, &group_resv_regions, list) {
-		if (region->type & IOMMU_RESV_MSI) {
+		if (region->type == IOMMU_RESV_SW_MSI) {
 			*base = region->start;
 			ret = true;
 			goto out;
@@ -1283,7 +1282,7 @@ static int vfio_iommu_type1_attach_group(void *iommu_data,
 	if (ret)
 		goto out_domain;
 
-	resv_msi = vfio_iommu_has_resv_msi(iommu_group, &resv_msi_base);
+	resv_msi = vfio_iommu_has_sw_msi(iommu_group, &resv_msi_base);
 
 	INIT_LIST_HEAD(&domain->group_list);
 	list_add(&group->next, &domain->group_list);
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 6a6de187ddc0..2e4de0deee53 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -125,9 +125,16 @@ enum iommu_attr {
 };
 
 /* These are the possible reserved region types */
-#define IOMMU_RESV_DIRECT	(1 << 0)
-#define IOMMU_RESV_RESERVED	(1 << 1)
-#define IOMMU_RESV_MSI		(1 << 2)
+enum iommu_resv_type {
+	/* Memory regions which must be mapped 1:1 at all times */
+	IOMMU_RESV_DIRECT,
+	/* Arbitrary "never map this or give it to a device" address ranges */
+	IOMMU_RESV_RESERVED,
+	/* Hardware MSI region (untranslated) */
+	IOMMU_RESV_MSI,
+	/* Software-managed MSI translation window */
+	IOMMU_RESV_SW_MSI,
+};
 
 /**
  * struct iommu_resv_region - descriptor for a reserved memory region
@@ -142,7 +149,7 @@ struct iommu_resv_region {
 	phys_addr_t		start;
 	size_t			length;
 	int			prot;
-	int			type;
+	enum iommu_resv_type	type;
 };
 
 #ifdef CONFIG_IOMMU_API
@@ -288,7 +295,8 @@ extern void iommu_get_resv_regions(struct device *dev, struct list_head *list);
 extern void iommu_put_resv_regions(struct device *dev, struct list_head *list);
 extern int iommu_request_dm_for_dev(struct device *dev);
 extern struct iommu_resv_region *
-iommu_alloc_resv_region(phys_addr_t start, size_t length, int prot, int type);
+iommu_alloc_resv_region(phys_addr_t start, size_t length, int prot,
+			enum iommu_resv_type type);
 extern int iommu_get_group_resv_regions(struct iommu_group *group,
 					struct list_head *head);