From: David Hildenbrand <da...@redhat.com>
If something goes wrong during uffd_change_protection(), we would miss
to unregister uffd-wp and not release our reference. Fix it by
performing the uffd_change_protection(true) last.
Note that a uffd_change_protection(false) on the recovery path without a
prior uffd_change_protection(false) is fine.
Fixes: 278e2f551a09 ("migration: support UFFD write fault processing in
ram_save_iterate()")
Cc: qemu-sta...@nongnu.org
Reviewed-by: Peter Xu <pet...@redhat.com>
Reviewed-by: Juan Quintela <quint...@redhat.com>
Signed-off-by: David Hildenbrand <da...@redhat.com>
Signed-off-by: Juan Quintela <quint...@redhat.com>
---
migration/ram.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/migration/ram.c b/migration/ram.c
index ba228eead4..73e5ca93e5 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -1896,13 +1896,14 @@ int ram_write_tracking_start(void)
block->max_length, UFFDIO_REGISTER_MODE_WP, NULL)) {
goto fail;
}
+ block->flags |= RAM_UF_WRITEPROTECT;
+ memory_region_ref(block->mr);
+
/* Apply UFFD write protection to the block memory range */
if (uffd_change_protection(rs->uffdio_fd, block->host,
block->max_length, true, false)) {
goto fail;
}
- block->flags |= RAM_UF_WRITEPROTECT;
- memory_region_ref(block->mr);
trace_ram_write_tracking_ramblock_start(block->idstr, block->page_size,
block->host, block->max_length);
--
2.39.1
