Andreas Bach Aaen (AH/TED)
2005-Nov-02 10:12 UTC
[Xen-users] kexec into a new Dom0 Xen kernel possible?
I have puzzled with the idea if it''s possible to upgrade a Dom0 XEN kernel by using kexec. Of cause the x86-xen architecture isn''t supported by kexec yet, but is it in principle possible? The XEN microkernel should continue to run, and the new Dom0 kernel should somehow be connected to XEN, so is will be able to manage it. If the table of user domains are kept inside XEN and not the dom0 kernel they should be able to continue to run during this kexec fastboot. Regards, -- Andreas Bach Aaen System Developer, M. Sc. Ericsson Danmark A/S tel: +45 89 38 51 00 Skanderborgvej 232 fax: +45 89 38 51 01 8260 Viby J Denmark andreas.bach.aaen@ericsson.com _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Mark Williamson
2005-Nov-02 12:17 UTC
Re: [Xen-users] kexec into a new Dom0 Xen kernel possible?
> I have puzzled with the idea if it''s possible to upgrade a Dom0 XEN kernel > by using kexec. Of cause the x86-xen architecture isn''t supported by kexec > yet, but is it in principle possible?Yep.> The XEN microkernel should continue to run, and the new Dom0 kernel should > somehow be connected to XEN, so is will be able to manage it. If the table > of user domains are kept inside XEN and not the dom0 kernel they should be > able to continue to run during this kexec fastboot.Well yes... You''ll have to reconnect the device channels though. This''ll also require the tools to save their state persistently across the dom0 reboot. When I worked on kexec my feeling was that it might be easier to build a kexec into Xen that restarts the whole host. If you really want to, restarting dom0 would be done by "failing over" to a standby domain 0 - we''d talked about having this feature for robustness to dom0 crashes anyhow. My kexec for domUs was nice in that it required (comparatively) minimal code duplication, since it was "assisted" by daemon in domain 0. The patch still exists but has rotted from being out-of-tree so long. HTH, Mark _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users