* Peter Xu (pet...@redhat.com) wrote: > The calculation on size of received bitmap is incorrect for postcopy > recovery. Here we wanted to let the size to cover all the valid bits in > the bitmap, we should use DIV_ROUND_UP() instead of a division. > > For example, a RAMBlock with size=4K (which contains only one single 4K > page) will have nbits=1, then nbits/8=0, then the real bitmap won't be > sent to source at all. > > Signed-off-by: Peter Xu <pet...@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilb...@redhat.com> > --- > migration/ram.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/migration/ram.c b/migration/ram.c > index fbeb23f750..203c691ded 100644 > --- a/migration/ram.c > +++ b/migration/ram.c > @@ -235,7 +235,7 @@ int64_t ramblock_recv_bitmap_send(QEMUFile *file, > bitmap_to_le(le_bitmap, block->receivedmap, nbits); > > /* Size of the bitmap, in bytes */ > - size = nbits / 8; > + size = DIV_ROUND_UP(nbits, 8); > > /* > * size is always aligned to 8 bytes for 64bit machines, but it > @@ -3944,7 +3944,7 @@ int ram_dirty_bitmap_reload(MigrationState *s, RAMBlock > *block) > int ret = -EINVAL; > QEMUFile *file = s->rp_state.from_dst_file; > unsigned long *le_bitmap, nbits = block->used_length >> TARGET_PAGE_BITS; > - uint64_t local_size = nbits / 8; > + uint64_t local_size = DIV_ROUND_UP(nbits, 8); > uint64_t size, end_mark; > > trace_ram_dirty_bitmap_reload_begin(block->idstr); > -- > 2.17.1 > -- Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
