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>
This commit is contained in:
Juan Quintela 2017-10-06 22:58:44 +02:00
parent a93ece47fd
commit bab01ed4e8
1 changed files with 7 additions and 5 deletions

View File

@ -58,6 +58,13 @@ PageCache *cache_init(int64_t new_size, size_t page_size, Error **errp)
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 @@ PageCache *cache_init(int64_t new_size, size_t page_size, Error **errp)
"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;