Re: [OSSTEST PATCH 3/4] Add nested testcase of installing L2 guest VM

[Ian Campbell <Ian.Campbell@citrix.com>]

On Thu, 2015-01-08 at 19:22 +0800, Robert Hu wrote:
> On Thu, 2015-01-08 at 10:48 +0000, Wei Liu wrote:
> > On Thu, Jan 08, 2015 at 07:34:39AM +0000, Pang, LongtaoX wrote:
> > [...]
> > > > > ts-debian-install installs a L2 PV guest, which should work even
> > > > > without nested HVM enabled for your L1 HVM guest. You're testing
> > > > > nested HVM I think it makes more sense to install a L2 HVM guest.
> > > > >
> > > > [Pang, LongtaoX] Thanks Wei, I will try to re-use the script of
> > > > ts-debian-hvm-install as L2, maybe it will make this script become complicated.
> > > > If it works, there will not be necessary to modify and use ts-debian-install
> > > > anymore.
> > > [Pang, LongtaoX] Hi Wei, for script of ts-debian-hvm-install, as too many parameters, functions, structure and variables are not suit for L2 installing , 
> > > if I re-use and modify as L2, it will make the script become more convoluted and hard to maintain in later days. 
> > > So, I plant to write a new script similar to ts-debian-hvm-install, called ts-debian-hvm-install-L2 for L2 guest installing. 
> > > If you have any concern or other opinions, please tell me, thanks.
> > 
> > Some foreseeable variables I can think of are bios, disk size and ram
> > size, which can be easily grouped together.  Though you may also need
> > things like checking whether L2 guest is up and reachable etc.
> ts-debian-hvm-install has already been reused/modified to accommodate
> nested L1 installation.

I think this might be where the complication has come from.

ts-debian-hvm-install (and ts-debian-install) should be about installing
a basic guest with parameters (disk, memory, vcpus) and the basic OS
install, not about tailoring that guest for a particular use. Any
tailoring should be done by a separate step.

Take the L0 case, where we have ts-host-install to install the machine
with a basic OS and then ts-xen-install or ts-xen-build-prep depending
on what it is to be used for.

The L1 hypervisor should be handled similarly, install a basic OS with
ts-debian-hvm-install and then tailor, ideally with a ts-xen-install
which is enhanced to work for both L0 and L1.

In effect after ts-debian-hvm-install we should be treat the resulting
VM as if it were a host which was installed with ts-host-install.

Given that ts-debian-hvm-install is now only about installing a basic
guest OS, it now remains suitable for use as the L2 guest installer as
well.

I suppose there might be some differences in the result of
ts-debian-hvm-install and ts-host-install, which we should resolve by
making the results more similar by modifying one or both to use more
common/helper code.

Ian.