[Qemu-devel] An issue in block-migration

[Yaodong Yang]

Hi all,

In block-migration.c file, line 435, if (bdrv_get_dirty(bmds->bs, sector)) {

It looks like this "if statement" is used to check whether a chunk is dirty or not. If it is dirty, system will migrate a whole chunk, 1MB data, to the destination. Otherwise, the cur_dirty will increase by 1MB/512B sectors.

However, in my understanding, this function, bdrv_get_dirty(bmds->bs, sector), only check this sector (512B) is dirty or not, rather than a whole chunk (1MB). Could someone tell me the reason?

Thanks!

Yaodong