On Mon, 2015-03-16 at 09:07 +0800, Chen, Tiejun wrote: > On 2015/3/13 18:11, Ian Campbell wrote: > > On Fri, 2015-03-13 at 09:39 +0800, Chen, Tiejun wrote: > >>> I don't think you can abort here, since a user can set > >>> b_info->u.hvm.gfx_passthru_kind to default. You would need to > >>> return an error. > >> > >> Then, looks I should do this, > >> > >> LOG(ERROR, "No supported IGD to passthru," " or please force set > >> gfx_passthru=\"igd\".\n"); return NULL; > > > > 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. Alternatively I suppose you could recommend removing gfx_passthru=1 (or changing to=0), but given they've set =1 that doesn't seem to be the most productive suggestion. Ian.
