On 04/27/2018 05:31 PM, Peter Xu wrote:
On Fri, Apr 27, 2018 at 11:15:37AM +0800, Xiao Guangrong wrote:
On 04/26/2018 10:01 PM, Eric Blake wrote:
On 04/26/2018 04:15 AM, guangrong.xiao@xxxxxxxxx wrote:
From: Xiao Guangrong <xiaoguangrong@xxxxxxxxxxx>
QEMU 2.13 enables strict check for compression & decompression to
make the migration more robuster, that depends on the source to fix
s/robuster/robust/
Will fix, thank you for pointing it out.
the internal design which triggers the unexpected error conditions
2.13 hasn't been released yet. Why do we need a knob to explicitly turn
off strict checking? Can we not instead make 2.13 automatically smart
enough to tell if the incoming stream is coming from an older qemu
(which might fail if the strict checks are enabled) vs. a newer qemu
(the sender gave us what we need to ensure the strict checks are
worthwhile)?
Really smart.
How about introduce a new command, MIG_CMD_DECOMPRESS_ERR_CHECK,
the destination will do strict check if got this command (i.e, new
QEMU is running on the source), otherwise, turn the check off.
Why not we just introduce a compat bit for that? I mean something
like: 15c3850325 ("migration: move skip_section_footers",
2017-06-28). Then we turn that check bit off for <=2.12.
Would that work?
I am afraid it can not. :(
The compat bit only impacts local behavior, however, in this case, we
need the source QEMU to tell the destination if it supports strict
error check.
