On 03/02/2017 02:36, 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> > --- > 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..2f19566 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); > + /* Skip setting bitmap if there is no RAM */ > + if (ram_bytes_total()) { > + 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); > + if (migrate_postcopy_ram()) { > + migration_bitmap_rcu->unsentmap = bitmap_new(ram_bitmap_pages); > + bitmap_set(migration_bitmap_rcu->unsentmap, 0, ram_bitmap_pages); > + } > } > > /* >
I didn't test it, but it looks good. Paolo