[Libguestfs] [PATCH v3] windows: delay installation of qemu-ga MSI

[Tomáš Golembiovský]

On Thu, Mar 05, 2020 at 08:49:04AM +0000, Richard W.M. Jones wrote:
> On Tue, Mar 03, 2020 at 03:45:49PM +0100, Tomáš Golembiovský wrote:
> > Instead of running firstboot script during early boot schedule a task
> > delayed for 2 minutes.
> > 
> > During the first boot, after virt-v2v conversion, Windows installs the
> > drivers injected by virt-v2v. When this installation is finished
> > Windows enforces some kind of internal reboot. This unfortunately
> > terminates any running firstboot scripts thus killing the installation
> > of qemu-ga MSI.
> > 
> > This is just a best-effort mitigation. It can still happen (e.g. with
> > slow disk drives) that the drivers are not yet installed when the
> > delayed installation starts. On the other hand we cannot delay it too
> > much otherwise we risk that the users logs in and will be doing some
> > work when the MSI installation starts. After MSI installation finishes
> > the VM needs to be rebooted which would be annoying if that would happen
> > under users hands. Although this is not a best fix (that may come later
> > as it is more complex, e.g. introducing waiting mechanism), the delay as
> > it is defined works in most cases. And it dramaticaly improves the
> > situations -- originaly I experienced more than 90% failure rate.
> > 
> > Signed-off-by: Tomáš Golembiovský <tgolembi at redhat.com>
> > ---
> >  common                 |  2 +-
> >  v2v/convert_windows.ml | 12 ++++--------
> >  2 files changed, 5 insertions(+), 9 deletions(-)
> > 
> > diff --git a/common b/common
> > index ea10827b..5371257c 160000
> > --- a/common
> > +++ b/common
> > @@ -1 +1 @@
> > -Subproject commit ea10827b4cfb3cfe5f782421c01d2902e5f73f90
> > +Subproject commit 5371257c3cf27fb09d5f2e31ba378b0e6ccf5df6
> > diff --git a/v2v/convert_windows.ml b/v2v/convert_windows.ml
> > index 0fda1d4e..bed5989a 100644
> > --- a/v2v/convert_windows.ml
> > +++ b/v2v/convert_windows.ml
> > @@ -429,14 +429,10 @@ popd
> >     List.iter (
> >       fun msi_path ->
> >         let fb_script = "\
> > -echo Installing qemu-ga from " ^ msi_path ^ "
> > -\"\\" ^ msi_path ^ "\" /norestart /qn /l+*vx \"%~dpn0.log\"
> > -set elvl=!errorlevel!
> > -echo Done installing qemu-ga error_level=!elvl!
> > -if !elvl! == 0 (
> > -  echo Restarting Windows...
> > -  shutdown /r /f /c \"rebooted by firstboot script\"
> > -)
> > +echo Removing any previously scheduled qemu-ga installation
> > +schtasks.exe /Delete /TN Firstboot-qemu-ga /F
> > +echo Scheduling delayed installation of qemu-ga from " ^ msi_path ^ "
> > +powershell.exe -command \"$d = (get-date).AddSeconds(120); schtasks.exe /Create /SC ONCE /ST $d.ToString('HH:mm') /SD $d.ToString('MM/dd/yyyy') /RU SYSTEM /TN Firstboot-qemu-ga /TR \\\"C:\\" ^ msi_path ^ " /forcerestart /qn /l+*vx C:\\" ^ msi_path ^ ".log\\\"\"
> >  " in
> >        Firstboot.add_firstboot_script g inspect.i_root
> >          ("install " ^ msi_path) fb_script;
> 
> It could be easier to follow if you use sprintf here, something like:
> 
> let fb_script = sprintf "\
> echo Removing any previously scheduled qemu-ga installation
> schtasks.exe /Delete /TN Firstboot-qemu-ga /F
> echo Scheduling delayed installation of qemu-ga from %s
> powershell.exe -command \"$d = (get-date).AddSeconds(120); schtasks.exe /Create /SC ONCE /ST $d.ToString('HH:mm') /SD $d.ToString('MM/dd/yyyy') /RU SYSTEM /TN Firstboot-qemu-ga /TR \\\"C:\\%s /forcerestart /qn /l+*vx C:\\%s.log\\\"\"
>   msi_path msi_path msi_path in

Ok, I can change that.

> 
> The other possible problem is this seems to install a firstboot script
> for every element of the list qemu_ga_files.  How long is this list?

At the moment it is just one. Until something changes in virtio-win ISO
or in our internal logic (like in virtio_iso_path_matches_qemu_ga()) it
will always be one.

> 
> Do filenames on this list need some kind of quoting?  The filenames
> don't, but they seem to contain a path that comes from the virtio-win
> ISO.

Those are really just file names without path. See 
https://github.com/libguestfs/virt-v2v/blob/master/v2v/windows_virtio.ml#L339

    Tomas

> 
> Rich.
> 
> -- 
> Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
> Read my programming and virtualization blog: http://rwmj.wordpress.com
> virt-builder quickly builds VMs from scratch
> http://libguestfs.org/virt-builder.1.html
> 

-- 
Tomáš Golembiovský <tgolembi at redhat.com>