[Qemu-commits] [qemu/qemu] 3fd3c4: Fix xbzrle vs last_sent_block update

[GitHub]

  Branch: refs/heads/master
  Home:   https://github.com/qemu/qemu
  Commit: 3fd3c4b37c116cce7e9810fcc15a0a2cf15115a5
      
https://github.com/qemu/qemu/commit/3fd3c4b37c116cce7e9810fcc15a0a2cf15115a5
  Author: Dr. David Alan Gilbert <address@hidden>
  Date:   2015-12-11 (Fri, 11 Dec 2015)

  Changed paths:
    M migration/ram.c

  Log Message:
  -----------
  Fix xbzrle vs last_sent_block update

My fix (84e7b80a) replaced the last_sent_block update that I'd
removed earlier; however it was too aggressive in the xbzrle case.

save_xbzrle_page might return '0' to mean that the page didn't
need sending since it was the same as the last sent version;
in this case we can't update 'last_sent_block' since we didn't
actually send it.

Symptom: 'Illegal RAM offset 1018000' as we try and send a page
  to the wrong RAMBlock;  potentially that could be a data
  corruption if you were really unlucky.

Fixes: 84e7b80a05c0c44b90533c6cd2f1db5c932ccf77

Signed-off-by: Dr. David Alan Gilbert <address@hidden>
Reviewed-by: Juan Quintela <address@hidden>
Message-id: address@hidden
Signed-off-by: Peter Maydell <address@hidden>