Re: call for testing: xen 4.1 packages

[Dustin Marquess <dmarquess%gmail.com@localhost>]

I just wanted to send a quick thanks to Christoph and everybody else
who worked on getting this working on NetBSD.  I know all too often
your hard work goes unappreciated.  I've been chomping at the bit to
give this a shot, and now's my chance!

-Dustin

On Wed, Mar 30, 2011 at 12:51 AM, Christoph Egger
<Christoph_Egger%gmx.de@localhost> wrote:
>
> Hi,
>
> I have packaged xen 4.1.
>
> Get the packages from
> http://www.netbsd.org/~cegger/xenkernel41.tar.gz
> http://www.netbsd.org/~cegger/xentools41.tar.gz
>
> Unpack them in pkgsrc/sysutils/
>
> Get the file http://www.netbsd.org/~cegger/buildlink3.mk
> and put it in pkgsrc/devel/ocaml-findlib/
> before you install the xentools41 package.
>
> In /etc/rc.conf add:
>
> xend=YES
>
> Differences to earlier xen versions:
>
> xenbackendd=YES is no longer needed in rc.conf.
>
>
> I highly recommend the use of 'xl'. xl is basically 'xm' rewritten in C.
> The syntax and usage of xl is equivalent to xm.
>
> xl does not require xend to run.
> xl requires xenstored and xenconsoled to run.
> xend no longer starts them automatically.
> The xencommon start script starts xenstored, xenconsoled and xenbackendd.
>
> xm is marked as supported but deprecated in Xen 4.1.
> Future versions of Xen no longer support xm (it will be removed).
>
> xl uses qemu-dm to handle accesses to the disks for both HVM and PV
> guests. qemu-dm uses aio internally. vnd(4) is no longer needed.
>
>
> Known-Bugs:
>
> * xm still invokes the scripts to make guests images available via
>  vnd(4). Now when starting an HVM guest, qemu's aio and vnd(4)
>  conflict and this results in a EBUSY error message from open(2). The
>  guests boots because whoever wins the race (either vnd or qemu) makes
>  the image available to the guest. If you run a DEBUG or DIAGNOSTIC
>  dom0 kernel then it panics on guest shutdown when it tries to
>  close(2) the image.
>  Note: This issue is related to xm only. User of xl don't have this
>  problem.
>
> * I put my focus in making xl to work on NetBSD.
>  xm hasn't got much testing because of that and you may find bugs.
>
> * xl is well tested to run HVM guests and is supposed to work
>  out-of-the box. This is not the case for PV guests and you may find
>  bugs.
>
> * When booting a HVM guest and the boot menu on the serial console
>  may not be shown. This is a longstanding bug in the xen tools and
>  has been only exposed with xl because it is much faster than xm.
>  The problem is that there is no communication infrastructure that
>  allows the guest to inform the tools when it is ready to start the
>  boot. If the guest is ready before the tools are then the boot menu
>  appears. If the tools are faster than the guest then output is
>  dropped. This is not fixable w/o deep infrastructure changes and is
>  planned to be fixed in future Xen versions.
>  A workaround is to refresh the boot menu manually in the guest.
>  BTW: How do I refresh the boot menu in NetBSD's bootloader?
>
>
> Christoph
>
>