On Tue, Nov 04, 2014 at 10:19:15AM +0000, Dr. David Alan Gilbert wrote: > * David Gibson (da...@gibson.dropbear.id.au) wrote: > > On Fri, Oct 03, 2014 at 06:47:28PM +0100, Dr. David Alan Gilbert (git) > > wrote: > > > From: "Dr. David Alan Gilbert" <dgilb...@redhat.com> > > > > > > QEMU_VM_CMD_PACKAGED is a migration command that allows a chunk > > > of migration stream to be sent in one go, and be received by > > > a separate instance of the loadvm loop while not interacting > > > with the migration stream. > > > > > > This is used by postcopy to load device state (from the package) > > > while loading memory pages from the main stream. > > > > > > Signed-off-by: Dr. David Alan Gilbert <dgilb...@redhat.com> > > > > Reviewed-by: David Gibson <da...@gibson.dropbear.id.au> > > > > Though one minor comment: > > > > [snip] > > > +/* We have a buffer of data to send; we don't want that all to be loaded > > > + * by the command itself, so the command contains just the length of the > > > + * extra buffer that we then send straight after it. > > > + * TODO: Must be a better way to organise that > > > > I'm not quite understanding what that comment's getting at. > > We have these VM Commands; and they are a command type, and a length: > CMD_whatever > length: whatever > data for whatever > > This comment is describing that, to make things easier for this code it's > ended up as: > > CMD_PACKAGED > CMD length: 4 <--- i.e. just enough to hold the next 'length' field > package length > --------------- > The package > > Which is a little different, hence i thought it needed the comment.
Ah.. right. That seems.. gratuitously easy to get wrong further down the track. Why not just use the cmd length as the package length. -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson
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