migration: Make sure that we pass the right cache size
Instead of passing silently round down the number of pages, make it an
error that the cache size is not a power of 2.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
diff --git a/migration/page_cache.c b/migration/page_cache.c
index 9a9d13d..96268c3 100644
--- a/migration/page_cache.c
+++ b/migration/page_cache.c
@@ -58,6 +58,13 @@
return NULL;
}
+ /* round down to the nearest power of 2 */
+ if (!is_power_of_2(num_pages)) {
+ error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "cache size",
+ "is not a power of two number of pages");
+ return NULL;
+ }
+
/* We prefer not to abort if there is no memory */
cache = g_try_malloc(sizeof(*cache));
if (!cache) {
@@ -65,11 +72,6 @@
"Failed to allocate cache");
return NULL;
}
- /* round down to the nearest power of 2 */
- if (!is_power_of_2(num_pages)) {
- num_pages = pow2floor(num_pages);
- DPRINTF("rounding down to %" PRId64 "\n", num_pages);
- }
cache->page_size = page_size;
cache->num_items = 0;
cache->max_num_items = num_pages;
