From: Fabiano Rosas Date: Thu, 21 Mar 2024 20:12:42 +0000 (-0300) Subject: migration/multifd: Fix clearing of mapped-ram zero pages X-Git-Tag: v9.0.0-rc1~6^2 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=8fa1a21c6edc2bf7de85984944848ab9ac49e937;p=thirdparty%2Fqemu.git migration/multifd: Fix clearing of mapped-ram zero pages When the zero page detection is done in the multifd threads, we need to iterate the second part of the pages->offset array and clear the file bitmap for each zero page. The piece of code we merged to do that is wrong. The reason this has passed all the tests is because the bitmap is initialized with zeroes already, so clearing the bits only really has an effect during live migration and when a data page goes from having data to no data. Fixes: 303e6f54f9 ("migration/multifd: Implement zero page transmission on the multifd thread.") Signed-off-by: Fabiano Rosas Link: https://lore.kernel.org/r/20240321201242.6009-1-farosas@suse.de Signed-off-by: Peter Xu --- diff --git a/migration/multifd.c b/migration/multifd.c index d2f0238f70f..2802afe79d0 100644 --- a/migration/multifd.c +++ b/migration/multifd.c @@ -111,7 +111,6 @@ void multifd_send_channel_created(void) static void multifd_set_file_bitmap(MultiFDSendParams *p) { MultiFDPages_t *pages = p->pages; - uint32_t zero_num = p->pages->num - p->pages->normal_num; assert(pages->block); @@ -119,7 +118,7 @@ static void multifd_set_file_bitmap(MultiFDSendParams *p) ramblock_set_file_bmap_atomic(pages->block, pages->offset[i], true); } - for (int i = p->pages->num; i < zero_num; i++) { + for (int i = p->pages->normal_num; i < p->pages->num; i++) { ramblock_set_file_bmap_atomic(pages->block, pages->offset[i], false); } }