[Libguestfs] [PATCH common] mlcustomize: Add accessors for block driver priority list

[Richard W.M. Jones]

When injecting virtio-win drivers, allow the list of block drivers
that we search to be modified.
---
 mlcustomize/inject_virtio_win.ml  | 12 +++++++++---
 mlcustomize/inject_virtio_win.mli | 10 ++++++++++
 2 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/mlcustomize/inject_virtio_win.ml b/mlcustomize/inject_virtio_win.ml
index 4e977b3..2a7c742 100644
--- a/mlcustomize/inject_virtio_win.ml
+++ b/mlcustomize/inject_virtio_win.ml
@@ -49,6 +49,9 @@ type t = {
       of libosinfo.  Although this behaviour is documented, IMHO it has
       always been a bad idea.  We should change this in future to allow
       the user to select where they want to get drivers from. XXX *)
+
+  mutable block_driver_priority : string list
+  (** List of block drivers *)
 }
 
 type block_type = Virtio_blk | IDE
@@ -107,7 +110,11 @@ and get_inspection g root =
   { g; root;
     i_arch; i_major_version; i_minor_version; i_osinfo;
     i_product_variant; i_windows_current_control_set; i_windows_systemroot;
-    virtio_win = ""; was_set = false }
+    virtio_win = ""; was_set = false;
+    block_driver_priority = ["virtio_blk"; "vrtioblk"; "viostor"] }
+
+let get_block_driver_priority t   = t.block_driver_priority
+let set_block_driver_priority t v = t.block_driver_priority <- v
 
 let scsi_class_guid = "{4D36E97B-E325-11CE-BFC1-08002BE10318}"
 let viostor_legacy_pciid = "VEN_1AF4&DEV_1001&SUBSYS_00021AF4&REV_00"
@@ -176,14 +183,13 @@ let rec inject_virtio_win_drivers ({ g } as t) reg =
   else (
     (* Can we install the block driver? *)
     let block : block_type =
-      let filenames = ["virtio_blk"; "vrtioblk"; "viostor"] in
       let viostor_driver = try (
         Some (
           List.find (
             fun driver_file ->
               let source = driverdir // driver_file ^ ".sys" in
               g#exists source
-          ) filenames
+          ) t.block_driver_priority
         )
       ) with Not_found -> None in
       match viostor_driver with
diff --git a/mlcustomize/inject_virtio_win.mli b/mlcustomize/inject_virtio_win.mli
index 0ced02e..7bd9b9f 100644
--- a/mlcustomize/inject_virtio_win.mli
+++ b/mlcustomize/inject_virtio_win.mli
@@ -64,6 +64,16 @@ val from_environment : Guestfs.guestfs -> string -> string -> t
 
     This should only be used by [virt-v2v] and is considered a legacy method. *)
 
+val get_block_driver_priority : t -> string list
+val set_block_driver_priority : t -> string list -> unit
+(** Get or set the current block driver priority list.  This is
+    a list of virtio-win block driver names (eg. ["viostor"]) that
+    we search until we come to the first [name ^ ".sys"] that
+    we find, and that is the block driver which gets installed.
+
+    This module contains a default priority list which should
+    be suitable for most use cases. *)
+
 val inject_virtio_win_drivers : t -> Registry.t -> virtio_win_installed
 (** [inject_virtio_win_drivers t reg]
     installs virtio drivers from the driver directory or driver
-- 
2.39.2