[Qemu-devel] [v2][PATCH] libxl: add one machine property to support IGD GFX passthrough

[Tiejun Chen]

When we're working to support IGD GFX passthrough with qemu
upstream, instead of "-gfx_passthru" we'd like to make that
a machine option, "-machine xxx,-igd-passthru=on". This need
to bring a change on tool side.

Signed-off-by: Tiejun Chen <address@hidden>
---
v2:
 
* Based on some discussions with Wei we'd like to keep both old
  option, -gfx_passthru, and new machine property option,
  "-machine xxx,-igd-passthru=on" at the same time but deprecate
  the old one. Then finally we remove the old one at that point
  that to give downstream (in this case, Xen) time to cope with the
  change.

 tools/libxl/libxl_dm.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/tools/libxl/libxl_dm.c b/tools/libxl/libxl_dm.c
index c2b0487..8405f0b 100644
--- a/tools/libxl/libxl_dm.c
+++ b/tools/libxl/libxl_dm.c
@@ -701,6 +701,11 @@ static char ** 
libxl__build_device_model_args_new(libxl__gc *gc,
             flexarray_append(dm_args, "-net");
             flexarray_append(dm_args, "none");
         }
+        /*
+         * Although we already introduce 'igd-passthru', but we'd like
+         * to remove this until we give downstream time to cope with
+         * the change.
+         */
         if (libxl_defbool_val(b_info->u.hvm.gfx_passthru)) {
             flexarray_append(dm_args, "-gfx_passthru");
         }
@@ -748,6 +753,11 @@ static char ** 
libxl__build_device_model_args_new(libxl__gc *gc,
                                             machinearg, max_ram_below_4g);
             }
         }
+
+        if (libxl_defbool_val(b_info->u.hvm.gfx_passthru)) {
+            machinearg = libxl__sprintf(gc, "%s,igd-passthru=on", machinearg);
+        }
+
         flexarray_append(dm_args, machinearg);
         for (i = 0; b_info->extra_hvm && b_info->extra_hvm[i] != NULL; i++)
             flexarray_append(dm_args, b_info->extra_hvm[i]);
-- 
1.9.1