diff --git a/sys/amd64/vmm/amd/amdvi_hw.c b/sys/amd64/vmm/amd/amdvi_hw.c
--- a/sys/amd64/vmm/amd/amdvi_hw.c
+++ b/sys/amd64/vmm/amd/amdvi_hw.c
@@ -274,6 +274,8 @@
 
 	tail = (struct amdvi_cmd *)((uint8_t *)softc->cmd +
 	    ctrl->cmd_tail);
+	if (tail != NULL)
+		memset(tail, 0, sizeof(*tail));
 
 	return (tail);
 }
@@ -420,10 +422,6 @@
 static void
 amdvi_inv_domain(struct amdvi_softc *softc, uint16_t domain_id)
 {
-	struct amdvi_cmd *cmd __diagused;
-
-	cmd = amdvi_get_cmd_tail(softc);
-	KASSERT(cmd != NULL, ("Cmd is NULL"));
 
 	/*
 	 * See section 3.3.3 of IOMMU spec rev 2.0, software note