Re: [ANNOUNCE] kvm-56 release

Carlo Marcelo Arenas Belon
2007-12-16T08:54:11Z

On Thu, Dec 13, 2007 at 03:32:46PM +0200, Avi Kivity wrote:
> Notes:
> If you use the modules bundled with kvm-56, you can use any version
> of Linux from 2.6.9 upwards.

the external module (once patched) will only be able to build against 2.6.17
upwards because the in-kernel PIC/IOAPIC/LAPIC requires hrtimers and that
functionality was only made public to external modules during the stabilization
of 2.6.17 as seen by :

http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=8d16b76421f0b3216012ee2d7819355e1cb847e5

there are obviously 3 possible fixes :

1) rewrite the in-kernel PIC/IOAPIC/LAPIC not to use hrtimers (not worthy)
2) replicate the functionality needed in the compatibility header or with the
use of a helper (not that simple)
3) disable the functionality and ifdef the code for kernel < 2.6.17
(preferred)

but before, I would like to ask: is 2.6.9 upwards support really needed?, the
only reason why I would suspect that 2.6.9 was recommended was because of
RHEL4 but there is no kvm package available for it from Red Hat or in EPEL
and Full Support is due May 15, 2008 so there might not be one ever, specially
considering that Red Hat is focused on RHEL 5 Host for virtualization support
as can be seen by :

http://www.redhat.com/rhel/virtualization/

other Linux distributions that are still under support will be affected as
well (mainly because they are corporate linux focused and with longer
supported timelines than community oriented distributions) but AFAIK they
don't have yet a kvm package (and might never had one) :

* Ubuntu Dapper 6.06.1 LTS (2.6.15)
* SuSE Linux 10.1 (2.6.16)
* Mandriva Corporate 4 (2.6.12)

of course ALL community oriented distributions (fedora, ubuntu, gentoo) which
are currently packaging kvm are ok and won't be affected by a "2.6.17 upwards"
requirement.

Carlo

PS. shouldn't the 2.6.9 or higher requirement be in this page?