diff --git a/xen/drivers/passthrough/vtd/intremap.c b/xen/drivers/passthrough/vtd/intremap.c
index afa8eb3756..dd2788efd7 100644
--- a/xen/drivers/passthrough/vtd/intremap.c
+++ b/xen/drivers/passthrough/vtd/intremap.c
@@ -513,13 +513,13 @@ static int msi_msg_to_remap_entry(
 
         if ( rc )
             return rc;
+
+        if ( msi_desc->msi_attrib.type == PCI_CAP_ID_MSI )
+            nr = msi_desc->msi.nvec;
     }
     else
         set_hpet_source_id(msi_desc->hpet_id, &new_ire);
 
-    if ( msi_desc->msi_attrib.type == PCI_CAP_ID_MSI )
-        nr = msi_desc->msi.nvec;
-
     spin_lock_irqsave(&iommu->intremap.lock, flags);
 
     if ( msg == NULL )