Subject: Re: save/restore for xbd
To: Jed Davis <>
From: Manuel Bouyer <>
List: port-xen
Date: 04/25/2006 22:18:16
On Mon, Apr 24, 2006 at 01:15:00AM -0400, Jed Davis wrote:
> I've modified xbd to keep a private copy of outstanding requests,
> except with the pseudo-physical addresses of the buffer pages instead
> of machine addresses, to allow replaying any that were lost on
> suspension.  This is, modulo some minor details (and the presence of
> an explanatory block comment), what the Linux blkfront does, as part
> of support for save/restore of a domU (under Xen 2).
> The attached diff has been tested as far as it affects regular disk
> I/O (actual save/restore is still missing a few other pieces) but it's
> nontrivial enough that I felt I should have it looked at.
> The xbd_suspend and xbd_resume functions are dead code at the moment,
> but won't stay that way.

This looks good. Thanks for working on this !

Manuel Bouyer <>
     NetBSD: 26 ans d'experience feront toujours la difference