Re: [Qemu-devel] [PATCH v11 11/13] migration: add postcopy migration of dirty bitmaps

[Vladimir Sementsov-Ogievskiy]

13.03.2018 21:22, Dr. David Alan Gilbert wrote:
> * Vladimir Sementsov-Ogievskiy (address@hidden) wrote:
> > Postcopy migration of dirty bitmaps. Only named dirty bitmaps are migrated.
> >
> > If destination qemu is already containing a dirty bitmap with the same name
> > as a migrated bitmap (for the same node), then, if their granularities are
> > the same the migration will be done, otherwise the error will be generated.
> >
> > If destination qemu doesn't contain such bitmap it will be created.
> >
> > Signed-off-by: Vladimir Sementsov-Ogievskiy <address@hidden>
> > ---

[...]

> > +
> > +static int dirty_bitmap_load_bits(QEMUFile *f, DirtyBitmapLoadState *s)
> > +{
> > +    uint64_t first_byte = qemu_get_be64(f) << BDRV_SECTOR_BITS;
> > +    uint64_t nr_bytes = (uint64_t)qemu_get_be32(f) << BDRV_SECTOR_BITS;
> > +    trace_dirty_bitmap_load_bits_enter(first_byte >> BDRV_SECTOR_BITS,
> > +                                       nr_bytes >> BDRV_SECTOR_BITS);
> > +
> > +    if (s->flags & DIRTY_BITMAP_MIG_FLAG_ZEROES) {
> > +        trace_dirty_bitmap_load_bits_zeroes();
> > +        bdrv_dirty_bitmap_deserialize_zeroes(s->bitmap, first_byte, nr_bytes,
> > +                                             false);
> > +    } else {
> > +        size_t ret;
> > +        uint8_t *buf;
> > +        uint64_t buf_size = qemu_get_be64(f);
> > +        uint64_t needed_size =
> > +            bdrv_dirty_bitmap_serialization_size(s->bitmap,
> > +                                                 first_byte, nr_bytes);
> > +
> > +        if (needed_size > buf_size ||
> > +            buf_size > QEMU_ALIGN_UP(needed_size, 4 + sizeof(long))
> I think you meant '4 * sizeof(long)';  other than that, from the
> migration side I'm OK, so with that fixed, and someone from the block
> side checking the block code:
>
>
> Reviewed-by: Dr. David Alan Gilbert <address@hidden>

Ohh, yes, 4 * sizeof(long).
Who will finally pull it? Should I respin, or you fix it inflight?

--
Best regards,
Vladimir