Libguestfs - Apr 2017 - Re: [PATCH virt-v2v] v2v: windows: Install both legacy and modern virtio keys in the registry (RHBZ#1431579).

Hello Roman,

We have a bug with Windows 8 UEFI conversions failing with the usual
0x7B error:

  https://bugzilla.redhat.com/show_bug.cgi?id=1431579

There is a seemingly plausible theory that this happens because for
UEFI we use a qemu Q35 machine type.

Q35 machine type implies all-modern PCI-e devices, which implies the
use of virtio-1.0 and disabling of virtio legacy.

Virtio-1.0 uses different Windows registry keys: viostor changes from
VEN_1AF4&DEV_1001&SUBSYS_00021AF4&REV_00 ->
VEN_1AF4&DEV_1042&SUBSYS_11001AF4&REV_01, and vioscsi has a similar
change.

As we are only installing the virtio legacy key, but presenting
PCI-e virtio-1.0 (modern) devices to the guest, this may cause Windows
to fail to boot.

I have not gone beyond compile-testing the attached patch, but what do
you think?  I will try to actually test this tomorrow, but I wondered
if you have any comments.

Thanks,
Rich.

---
 v2v/windows_virtio.ml | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/v2v/windows_virtio.ml b/v2v/windows_virtio.ml
index 6c9708c03..9891a770c 100644
--- a/v2v/windows_virtio.ml
+++ b/v2v/windows_virtio.ml
@@ -36,8 +36,10 @@ let virtio_win        else Guestfs_config.datadir //
"virtio-win"
 
 let scsi_class_guid = "{4D36E97B-E325-11CE-BFC1-08002BE10318}"
-let viostor_pciid =
"VEN_1AF4&DEV_1001&SUBSYS_00021AF4&REV_00"
-let vioscsi_pciid =
"VEN_1AF4&DEV_1004&SUBSYS_00081AF4&REV_00"
+let viostor_legacy_pciid =
"VEN_1AF4&DEV_1001&SUBSYS_00021AF4&REV_00"
+let viostor_modern_pciid =
"VEN_1AF4&DEV_1042&SUBSYS_11001AF4&REV_01"
+let vioscsi_legacy_pciid =
"VEN_1AF4&DEV_1004&SUBSYS_00081AF4&REV_00"
+let vioscsi_modern_pciid =
"VEN_1AF4&DEV_1048&SUBSYS_11001AF4&REV_01"
 
 let rec install_drivers ((g, _) as reg) inspect rcaps    (* Copy the virtio
drivers to the guest. *)
@@ -104,7 +106,8 @@ let rec install_drivers ((g, _) as reg) inspect rcaps       
inspect.i_windows_systemroot driver_name in
         let target = g#case_sensitive_path target in
         g#cp source target;
-        add_guestor_to_registry reg inspect driver_name viostor_pciid;
+        add_guestor_to_registry reg inspect driver_name viostor_legacy_pciid;
+        add_guestor_to_registry reg inspect driver_name viostor_modern_pciid;
         Virtio_blk
 
       | Some Virtio_SCSI, _, true ->
@@ -115,7 +118,8 @@ let rec install_drivers ((g, _) as reg) inspect rcaps       
inspect.i_windows_systemroot in
         let target = g#case_sensitive_path target in
         g#cp source target;
-        add_guestor_to_registry reg inspect "vioscsi" vioscsi_pciid;
+        add_guestor_to_registry reg inspect "vioscsi"
vioscsi_legacy_pciid;
+        add_guestor_to_registry reg inspect "vioscsi"
vioscsi_modern_pciid;
         Virtio_SCSI
 
       | Some IDE, _, _ ->
-- 
2.12.0

On Thu, Apr 13, 2017 at 11:37:31AM +0300, Roman Kagan
wrote:
> Appears reasonable; however, I'm afraid it's only the experiment
that
> can tell if it can work or not, and I don't have a setup to test this
> right now.
Thanks.  I managed to test it now, and it does appear to
fix the problem, so I pushed this commit upstream.

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
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