[Qemu-devel] [PULL 5/9] vfio: Generalize vfio_listener_region_add failure path

[Alex Williamson <alex.williamson@redhat.com>]

From: David Gibson <david@gibson.dropbear.id.au>

If a DMA mapping operation fails in vfio_listener_region_add() it
checks to see if we've already completed initial setup of the
container.  If so it reports an error so the setup code can fail
gracefully, otherwise throws a hw_error().

There are other potential failure cases in vfio_listener_region_add()
which could benefit from the same logic, so move it to its own
fail: block.  Later patches can use this to extend other failure cases
to fail as gracefully as possible under the circumstances.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Laurent Vivier <lvivier@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
---
 hw/vfio/common.c |   26 +++++++++++++++-----------
 1 file changed, 15 insertions(+), 11 deletions(-)

diff --git a/hw/vfio/common.c b/hw/vfio/common.c
index 1545f62..95a4850 100644
--- a/hw/vfio/common.c
+++ b/hw/vfio/common.c
@@ -399,19 +399,23 @@ static void vfio_listener_region_add(MemoryListener *listener,
         error_report("vfio_dma_map(%p, 0x%"HWADDR_PRIx", "
                      "0x%"HWADDR_PRIx", %p) = %d (%m)",
                      container, iova, end - iova, vaddr, ret);
+        goto fail;
+    }
 
-        /*
-         * On the initfn path, store the first error in the container so we
-         * can gracefully fail.  Runtime, there's not much we can do other
-         * than throw a hardware error.
-         */
-        if (!container->initialized) {
-            if (!container->error) {
-                container->error = ret;
-            }
-        } else {
-            hw_error("vfio: DMA mapping failed, unable to continue");
+    return;
+
+fail:
+    /*
+     * On the initfn path, store the first error in the container so we
+     * can gracefully fail.  Runtime, there's not much we can do other
+     * than throw a hardware error.
+     */
+    if (!container->initialized) {
+        if (!container->error) {
+            container->error = ret;
         }
+    } else {
+        hw_error("vfio: DMA mapping failed, unable to continue");
     }
 }