[Libguestfs] [V2V PATCH 1/1] convert_windows: add firstboot script to install drivers with pnputil

[Richard W.M. Jones]

On Thu, Mar 09, 2023 at 03:47:10PM +0200, Andrey Drobyshev wrote:
> On 3/8/23 22:52, Richard W.M. Jones wrote:
> > On Wed, Mar 08, 2023 at 08:05:35PM +0200, Andrey Drobyshev wrote:
> >> During conversion we copy the necessary drivers to the directory
> >> "%systemroot%\Drivers\Virtio", adding it to the DevicePath registry
> >> value.  As documented in [1], this should be enough for Windows to find
> >> device drivers and successfully install them.
> >>
> >> However, it doesn't always happen.  Commit 73e009c04 ("v2v: windows:
> >> Document use of pnputil to install drivers.") describes such issues with
> >> Win2k12R2.  I'm seeing the same problem with Win2k16 and netkvm.sys
> >> driver not being installed.
> >>
> >> That same commit 73e009c04 suggests adding a firstboot script invoking
> >> pnputil at an early stage to install all the drivers we put into the
> >> drivers store.  So let's add such a script to make sure all the
> >> necessary drivers are installed.
> >>
> >> [1] https://learn.microsoft.com/en-us/windows-hardware/drivers/install/how-windows-selects-a-driver-for-a-device
> >>
> >> Signed-off-by: Andrey Drobyshev <andrey.drobyshev at virtuozzo.com>
> >> ---
> >>  convert/convert_windows.ml | 16 ++++++++++++++--
> >>  1 file changed, 14 insertions(+), 2 deletions(-)
> >>
> >> diff --git a/convert/convert_windows.ml b/convert/convert_windows.ml
> >> index 6bc2343b..e15a5e62 100644
> >> --- a/convert/convert_windows.ml
> >> +++ b/convert/convert_windows.ml
> >> @@ -295,9 +295,11 @@ let convert (g : G.guestfs) _ inspect i_firmware block_driver _ static_ips =
> >>      | Virt -> Virt
> >>  
> >>    and configure_firstboot () =
> >> -    (* Note that pnp_wait.exe must be the first firstboot script as it
> >> -     * suppresses PnP for all following scripts.
> >> +    (* Run the firstboot script with pnputil.exe before the one with
> >> +     * pnp_wait.exe as the latter suppresses PnP for all following scripts.
> >>       *)
> >> +    configure_pnputil_install ();
> >> +
> >>      let tool_path = virt_tools_data_dir () // "pnp_wait.exe" in
> >>      if Sys.file_exists tool_path then
> >>        configure_wait_pnp tool_path
> >> @@ -345,6 +347,16 @@ let convert (g : G.guestfs) _ inspect i_firmware block_driver _ static_ips =
> >>                        strkey name value
> >>      | None -> sprintf "reg delete \"%s\" /v %s /f" strkey name
> >>  
> >> +  and configure_pnputil_install () =
> >> +    let fb_script = "@echo off\n\
> >> +                     \n\
> >> +                     echo Wait for VirtIO drivers to be installed\n\
> >> +                     %systemroot%\\Sysnative\\PnPutil -i -a \
> >> +                     %systemroot%\\Drivers\\Virtio\\*.inf >\"%~dpn0.log\" 2>&1\
> >> +                    " in
> >> +    Firstboot.add_firstboot_script g inspect.i_root
> >> +      "pnputil install drivers" fb_script;
> >> +
> > 
> > I'm not sure I'm really qualified to comment on this, since Windows is
> > crazy.  I guess the worst this can do is fail to run, but that won't
> > stop anything else from happening.
> > 
> > Note that firstboot scripts already do logging, so I don't believe
> > writing to a separate log file is needed here.  All the output from
> > all firstboot scripts should go to
> > C:\Program Files\Guestfs\Firstboot\log.txt:
> > 
> > https://github.com/libguestfs/libguestfs-common/blob/7acf991a25b3fd625eb1ff1fbd8dc9fedf245942/mlcustomize/firstboot.ml#L276
> 
> Right, but apart from having the log common for all firstboot scripts,
> some of them also utilise separate log files in scripts-done directory,
> e.g.:
> 
> https://github.com/libguestfs/virt-v2v/blob/cb792fef27f/convert/convert_windows.ml#L381
> https://github.com/libguestfs/virt-v2v/blob/cb792fef27f/convert/convert_windows.ml#L168
> 
> So I did the same considering that pnputil's output is relatively long.

I think I'd probably get rid of those other scripts too.  It's helpful
to have everything go to one place.  I'm not actually sure where those
extra files end up.

> All in all, if there're no other concerns, can we give this script a go?

I think the patch is generally fine, so I'm just quibbling about
the logging.

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
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