[Libguestfs] [V2V PATCH v4] parse_libvirt_xml: look for manual firmware in "/domain/os/loader/@type"

[Andrey Drobyshev]

According to [1], there're different ways to specify which firmware is
to be used by a libvirt-driven VM.  Namely, there's an automatic
firmware selection, e.g.:

    ...
    <os firmware='(bios|efi)'>
    ...

and a manual one, e.g.:

    ...
    <os>
        <loader readonly='yes' type='pflash'>/usr/share/OVMF/OVMF_CODE.fd</loader>
        ...
    </os>
    ...

with the latter being a way to specify UEFI firmware.  So let's add this
search path as well when parsing source VM's libvirt xml.

[1] https://libvirt.org/formatdomain.html#bios-bootloader

Co-authored-by: Laszlo Ersek <lersek at redhat.com>
Signed-off-by: Andrey Drobyshev <andrey.drobyshev at virtuozzo.com>
Originally-by: Denis Plotnikov <dplotnikov at virtuozzo.com>
---
 input/parse_libvirt_xml.ml | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/input/parse_libvirt_xml.ml b/input/parse_libvirt_xml.ml
index 56ce1c22..ab72c0ce 100644
--- a/input/parse_libvirt_xml.ml
+++ b/input/parse_libvirt_xml.ml
@@ -446,12 +446,23 @@ let parse_libvirt_xml ?conn xml =
     done;
     List.rev !nics in
 
-  (* Firmware. *)
+  (* Firmware.
+   * If "/domain/os" node doesn't contain "firmware" attribute (automatic
+   * firmware), we look for the presence of "pflash" in
+   * "/domain/os/loader/@type" attribute (manual firmware), with the latter
+   * indicating the UEFI firmware.
+   * See https://libvirt.org/formatdomain.html#bios-bootloader
+   *)
   let firmware =
     match xpath_string "/domain/os/@firmware" with
     | Some "bios" -> BIOS
     | Some "efi" -> UEFI
-    | None | Some _ -> UnknownFirmware in
+    | Some _ -> UnknownFirmware
+    | None -> (
+        match xpath_string "/domain/os/loader/@type" with
+        | Some "pflash" -> UEFI
+        | _ -> UnknownFirmware
+      ) in
 
   (* Fallback to BIOS if we haven't found explicitly specified firmware.
    * This is VZ-specific since we're either using "/domain/os/loader" node
-- 
2.31.1