vdpa: Add vhost_vdpa_section_end

Abstract this operation, that will be reused when validating the region
against the iova range that the device supports.

Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20211014141236.923287-3-eperezma@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>

1 files changed, 15 insertions, 7 deletions

diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
index ea1aa71ad8..be7c63b4ba 100644
--- a/hw/virtio/vhost-vdpa.c
+++ b/hw/virtio/vhost-vdpa.c
@@ -24,6 +24,19 @@
 #include "trace.h"
 #include "qemu-common.h"
 
+/*
+ * Return one past the end of the end of section. Be careful with uint64_t
+ * conversions!
+ */
+static Int128 vhost_vdpa_section_end(const MemoryRegionSection *section)
+{
+    Int128 llend = int128_make64(section->offset_within_address_space);
+    llend = int128_add(llend, section->size);
+    llend = int128_and(llend, int128_exts64(TARGET_PAGE_MASK));
+
+    return llend;
+}
+
 static bool vhost_vdpa_listener_skipped_section(MemoryRegionSection *section)
 {
     return (!memory_region_is_ram(section->mr) &&
@@ -160,10 +173,7 @@ static void vhost_vdpa_listener_region_add(MemoryListener *listener,
     }
 
     iova = TARGET_PAGE_ALIGN(section->offset_within_address_space);
-    llend = int128_make64(section->offset_within_address_space);
-    llend = int128_add(llend, section->size);
-    llend = int128_and(llend, int128_exts64(TARGET_PAGE_MASK));
-
+    llend = vhost_vdpa_section_end(section);
     if (int128_ge(int128_make64(iova), llend)) {
         return;
     }
@@ -221,9 +231,7 @@ static void vhost_vdpa_listener_region_del(MemoryListener *listener,
     }
 
     iova = TARGET_PAGE_ALIGN(section->offset_within_address_space);
-    llend = int128_make64(section->offset_within_address_space);
-    llend = int128_add(llend, section->size);
-    llend = int128_and(llend, int128_exts64(TARGET_PAGE_MASK));
+    llend = vhost_vdpa_section_end(section);
 
     trace_vhost_vdpa_listener_region_del(v, iova, int128_get64(llend));