vfio/common: Fix a small boundary issue of a trace

It uses [offset, offset + size - 1] to indicate that the length of range is
size in most places in vfio trace code (such as
trace_vfio_region_region_mmap()) execpt trace_vfio_region_sparse_mmap_entry().
So change it for trace_vfio_region_sparse_mmap_entry(), but if size is zero,
the trace will be weird with an underflow, so move the trace and trace it
only if size is not zero.

Signed-off-by: Xiang Chen <chenxiang66@hisilicon.com>
Link: https://lore.kernel.org/r/1650100104-130737-1-git-send-email-chenxiang66@hisilicon.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

diff --git a/hw/vfio/common.c b/hw/vfio/common.c
index 2b1f78f..6065834 100644 (file)
--- a/hw/vfio/common.c
+++ b/hw/vfio/common.c
@@ -1544,11 +1544,10 @@ static int vfio_setup_region_sparse_mmaps(VFIORegion *region,
     region->mmaps = g_new0(VFIOMmap, sparse->nr_areas);
 
     for (i = 0, j = 0; i < sparse->nr_areas; i++) {
-        trace_vfio_region_sparse_mmap_entry(i, sparse->areas[i].offset,
-                                            sparse->areas[i].offset +
-                                            sparse->areas[i].size);
-
         if (sparse->areas[i].size) {
+            trace_vfio_region_sparse_mmap_entry(i, sparse->areas[i].offset,
+                                            sparse->areas[i].offset +
+                                            sparse->areas[i].size - 1);
             region->mmaps[j].offset = sparse->areas[i].offset;
             region->mmaps[j].size = sparse->areas[i].size;
             j++;