[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Xen-devel] [PATCH V2] Add flag to start info regarding virtual mapped p2m list



On 03/04/2015 12:18 PM, Tim Deegan wrote:
At 10:52 +0000 on 04 Mar (1425462776), Ian Campbell wrote:
On Wed, 2015-03-04 at 11:20 +0100, Juergen Gross wrote:
I'd like to do an appropriate change in xl, but I've been told this
would make sense only for migration protocol V2. OTOH I don't want to
wait for an undefined amount of time until this will be posted, so I
sent the ABI change first.

I could, of course, wait with the flag bit until xl is ready and post
another kernel patch then. Unfortunately this would delay Linux support
for automatically be able to run as a pv-domain >500GB further, so I
strongly recommend accepting the interface change now.

Please at least sketch out a design/description of what this flag means
to the guest and/or tools and what eventual tools support you expect
will be needed, and perhaps some ideas regarding what that support might
look like.

Without this your proposed ABI change is just a random bit in a data
structure with no context.

If this is just an ordering constraint between kernel and tools work,
maybe we could just define the bit as reserved for now, while the dev work
finishes, and give it a proper name when the toolstack bits go in.

I don't think this will be a proper solution. Using this bit in the
kernel would either be okay in case the interface is added later to Xen,
or it would be not okay making it impossible later to use that bit for
other purposes. In both cases we could easily name the bit like I did.
It would either be used like intended, or it would never be set thus
doing no harm.

Juergen


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel


 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.