@@ -721,6 +721,21 @@ qemu_vfio_find_temp_iova(QEMUVFIOState *s, size_t size, uint64_t *iova)
return -ENOMEM;
}
+/**
+ * qemu_vfio_water_mark_reached:
+ *
+ * Returns %true if high watermark has been reached, %false otherwise.
+ */
+static bool qemu_vfio_water_mark_reached(QEMUVFIOState *s, size_t size,
+ Error **errp)
+{
+ if (s->high_water_mark - s->low_water_mark + 1 < size) {
+ error_setg(errp, "iova exhausted (water mark reached)");
+ return true;
+ }
+ return false;
+}
+
/* Map [host, host + size) area into a contiguous IOVA address space, and store
* the result in @iova if not NULL. The caller need to make sure the area is
* aligned to page size, and mustn't overlap with existing mapping areas (split
@@ -742,7 +757,7 @@ int qemu_vfio_dma_map(QEMUVFIOState *s, void *host, size_t size,
if (mapping) {
iova0 = mapping->iova + ((uint8_t *)host - (uint8_t *)mapping->host);
} else {
- if (s->high_water_mark - s->low_water_mark + 1 < size) {
+ if (qemu_vfio_water_mark_reached(s, size, errp)) {
ret = -ENOMEM;
goto out;
}