Commit 00a4b65f85 Sep 7 2010
"libxc: provide notification of final checkpoint to restore end"
broke migration from any version of Xen using tools from prior to that commit
Older tools have no idea about an XC_SAVE_ID_LAST_CHECKPOINT, causing newer
tools xc_domain_restore() to start reading the qemu save record, as
ctx->last_checkpoint is 0.
The failure looks like:
xc: error: Max batch size exceeded (1970103633). Giving up.
where 1970103633 = 0x756d6551 = *(uint32_t*)"Qemu"
With this fix in place, the behaviour for normal migrations is reverted to how
it was before the regression; the migration is considered non-checkpointed
right from the start. A XC_SAVE_ID_LAST_CHECKPOINT chunk seen in the
migration stream is a nop. For checkpointed migrations the behaviour is
unchanged.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Ian Campbell <Ian.Campbell@citrix.com>
CC: Ian Jackson <Ian.Jackson@eu.citrix.com>
Acked-by: Shriram Rajagopalan <rshriram@cs.ubc.ca> (Remus bits)
Andrew Cooper
7051d5c872