Re: [Qemu-devel] [PATCH 0/4] Add section footers to detect corrupted migration streams

[Amit Shah <amit.shah@redhat.com>]

On (Tue) 19 May 2015 [08:13:52], Eric Blake wrote:
> On 05/19/2015 08:06 AM, Dr. David Alan Gilbert wrote:
> 
> >> Does it let us detect a corrupted
> >> stream earlier in the process?  Or is the main benefit that it gives
> >> better error messages at the point corruption is first detected?
> > 
> > Both; there are two cases that often happen; both triggered by a section
> > reading too little or too much, and it gets back to the main loop and
> > we read the next byte:
> >    1) the next byte on the stream is a 0x00 - that's read as an end-of-migration
> >       marker, we start the VM  and you get a hung VM with no errors.
> > 
> >    2) the next byte is between 0x01..0x04 - and it looks like a section header,
> >       then we try and read the next few bytes to figure out which section;
> >       this could a) result in an error saying it's an unknown section or
> >       b) Happen to match a section ID and then get an error about a problem
> >       in that section.  In either case you don't get an error pointing to
> >       the previous section which was the actual problem.
> 
> Probably worth incorporating into the commit body then :)

How about docs/migration.txt?  The 00/NN message gets lost..



		Amit