[Xen-devel] Re: [PATCH] Allow guest to register a secondary vcpu_time_info structure

[Keir Fraser <keir.fraser@xxxxxxxxxxxxx>]

On 06/10/2009 01:10, "Jeremy Fitzhardinge" <jeremy@xxxxxxxx> wrote:

> The second vcpu_time_info structure is updated by copy, rather than
> being a shared page between the guest and Xen.  It is not directly
> updated by copy; instead, Xen preserves and increments the existing
> version number in place.  This allows the guest to also update the
> version number (useful to indicate vcpu context switches to usermode).
> This assumes that the guest will only ever update the structure for a
> given vcpu on that vcpu (as Xen does, so there are never any cross-cpu
> accesses).

How do you feel about the 32-bit version number? We have space to easily
expand it to 64 bits, and now would be the time to do it while we're
extending the ABI.

 -- Keir



_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel