On 02/08/2017 11:28 AM, Ashijeet Acharya wrote:
Migration of a "none" machine with no RAM crashes abruptly as
bitmap_new() fails and thus aborts. Instead place zero RAM checks at
appropriate places to skip migration of RAM in this case and complete
migration successfully for devices only.
Signed-off-by: Ashijeet Acharya <ashijeetacha...@gmail.com>
Reviewed-by: Philippe Mathieu-Daudé <f4...@amsat.org>
---
Changes in v3:
- handle migration cleanup appropriately (Dave)
Changes in v2:
- try to migrate successfully by skipping RAM (Paolo, Greg)
- drop the idea of erroring out and failing nicely
---
migration/ram.c | 22 +++++++++++++++-------
1 file changed, 15 insertions(+), 7 deletions(-)
diff --git a/migration/ram.c b/migration/ram.c
index ef8fadf..faff5ab 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -1325,6 +1325,11 @@ static int ram_find_and_save_block(QEMUFile *f, bool
last_stage,
ram_addr_t dirty_ram_abs; /* Address of the start of the dirty page in
ram_addr_t space */
+ /* No dirty page as there is zero RAM */
+ if (!ram_bytes_total()) {
+ return pages;
+ }
+
pss.block = last_seen_block;
pss.offset = last_offset;
pss.complete_round = false;
@@ -1912,14 +1917,17 @@ static int ram_save_init_globals(void)
bytes_transferred = 0;
reset_ram_globals();
- ram_bitmap_pages = last_ram_offset() >> TARGET_PAGE_BITS;
migration_bitmap_rcu = g_new0(struct BitmapRcu, 1);
- migration_bitmap_rcu->bmap = bitmap_new(ram_bitmap_pages);
- bitmap_set(migration_bitmap_rcu->bmap, 0, ram_bitmap_pages);
-
- if (migrate_postcopy_ram()) {
- migration_bitmap_rcu->unsentmap = bitmap_new(ram_bitmap_pages);
- bitmap_set(migration_bitmap_rcu->unsentmap, 0, ram_bitmap_pages);
+ /* Skip setting bitmap if there is no RAM */
+ if (ram_bytes_total()) {
+ ram_bitmap_pages = last_ram_offset() >> TARGET_PAGE_BITS;
+ migration_bitmap_rcu->bmap = bitmap_new(ram_bitmap_pages);
+ bitmap_set(migration_bitmap_rcu->bmap, 0, ram_bitmap_pages);
+
+ if (migrate_postcopy_ram()) {
+ migration_bitmap_rcu->unsentmap = bitmap_new(ram_bitmap_pages);
+ bitmap_set(migration_bitmap_rcu->unsentmap, 0, ram_bitmap_pages);
+ }
}
/*
