Re: [Qemu-devel] [v2][PATCH 2/2] libxl: introduce gfx_passthru_kind

["Chen, Tiejun" <tiejun.chen@intel.com>]

>>> If I remember the context correctly this is in the autodetect case,
>>> so I think shouldn't mention IGD. Something like "Unable to detect
>>> graphics passthru kind, please set gfx_passthru_kind. See xl.cfg(5)
>>> for more
>>
>> s/gfx_passthru_kind/gfx_passthru, right? Because actually we always get
>> 'gfx_passthru_kind' from 'gfx_passthru'.
>
> I think you have it backwards.
>
> In the case here gfx_passthru=1 has been set by the user, but
> gfx_passthru_kind=DEFAULT. So libxl has tried to autodetect but it has
> failed.
>
> So if the user wants to make progress they should set gfx_passthru_kind
> to whatever type of passthrough they were trying to do.

Looks you're saying 'gfx_passthru_kind' shouldn't reply on 
'gfx_passthru', so 'gfx_passthru_kind' can override that previous value 
parsed from 'gfx_passthru', right?

>
> Alternatively I suppose you could recommend removing gfx_passthru=1 (or

I'm still keep that currently.

> changing to=0), but given they've set =1 that doesn't seem to be the
> most productive suggestion.
>

So looks the whole policy should be something like this,

diff --git a/tools/libxl/xl_cmdimpl.c b/tools/libxl/xl_cmdimpl.c
index 5c40e84..5518759 100644
--- a/tools/libxl/xl_cmdimpl.c
+++ b/tools/libxl/xl_cmdimpl.c
@@ -1953,8 +1953,27 @@ skip_vfb:
          xlu_cfg_replace_string (config, "spice_streaming_video",
                                  &b_info->u.hvm.spice.streaming_video, 0);
          xlu_cfg_get_defbool(config, "nographic", 
&b_info->u.hvm.nographic, 0);
-        xlu_cfg_get_defbool(config, "gfx_passthru",
-                            &b_info->u.hvm.gfx_passthru, 0);
+        if (!xlu_cfg_get_long(config, "gfx_passthru", &l, 1)) {
+            libxl_defbool_set(&b_info->u.hvm.gfx_passthru, l);
+        } else if (!xlu_cfg_get_string(config, "gfx_passthru", &buf, 0)) {
+            if (libxl_gfx_passthru_kind_from_string(buf,
+ 
&b_info->u.hvm.gfx_passthru_kind)) {
+                fprintf(stderr,
+                        "ERROR: invalid value \"%s\" for 
\"gfx_passthru\"\n",
+                        buf);
+                exit (1);
+            }
+            libxl_defbool_set(&b_info->u.hvm.gfx_passthru, true);
+        }
+        if (!xlu_cfg_get_string(config, "gfx_passthru_kind", &buf, 0)) {
+            if (libxl_gfx_passthru_kind_from_string(buf,
+ 
&b_info->u.hvm.gfx_passthru_kind)) {
+                fprintf(stderr,
+                        "ERROR: invalid value \"%s\" for 
\"gfx_passthru_kind\"\n",
+                        buf);
+                exit (1);
+            }
+        }
          switch (xlu_cfg_get_list_as_string_list(config, "serial",
 
&b_info->u.hvm.serial_list,
                                                  1))

Thanks
Tiejun