On Mon, 2015-03-02 at 09:20 +0800, Chen, Tiejun wrote:
> Is this expected?
Yes. Can you post it as a proper patch please.
I suggest you split the basic stuff and the kind override discussed
below in to two patches.
> >> + (b_info->u.hvm.gfx_passthru &&
> >> + strncmp(b_info->u.hvm.gfx_passthru, "igd", 3) == 0) ) {
>
> But as you mentioned previously,
>
> "
> You might like to optionally consider add a forcing option somehow so
> that people with new devices not in the list can control things without
> the need to recompile (e.g. gfx_passthru_kind_override?).
> "
>
> Here I was trying to convert "gfx_passthru" to address this thing.
> According to your comment right now, you prefer we should introduce a
> new field instead of the original 'gfx_passthru' to enumerate such a
> type. So what about this?
>
> libxl_gfx_passthru_kind_type = Enumeration("gfx_passthru_kind_type", [
"kind_type" is redundant. I think just "kind" will do.
> (0, "unknown"),
"default" I think is better, i.e. if gfx_passthru is enabled then do the
probing from the PCI ID list thing.
> (1, "igd"),
> ])
You would then need to add a field of this type next to the gfx_passthru
one in b_config, lets say it's called gfx_passthru_kind.
> Then if we want to override this, just submit the following line into .cfg:
>
> gfx_passthru_kind_override = "igd"
So, while we cannot change the defbool in the libxl interface we do
actually have a little more freedom in the xl cfg parsing because we can
detect bool/integer vs string.
So I think it should be possible to arrange to support any of
gfx_passthru = 0 => sets build_info.u.gfx_passthru to false
gfx_passthru = 1 => sets build_info.u.gfx_passthru to false and
build_info.u.gfx_passthru_kind to DEFAULT
gfx_passthru = "igd" => sets build_info.u.gfx_passthru to false and
build_info.u.gfx_passthru_kind to IGD
Take a look at how the "timer_mode" option is handled in xl_cmdimpl.c
(except none of these variants are deprecated. You should be able to use
the libxl_..._from_string enum helper to do the parsing in the latter
case.
Ian.
