Re: VGA pass-through

[Michael Tokarev <mjt@tls.msk.ru>]

Han, Weidong wrote:
> Michael Tokarev wrote:
>> Han, Weidong wrote:
>>> Michael Tokarev wrote:
>> []
>>>> But how about using it as a "secondary" video card?  Like, I can
>>>> plug another add-on vga card into a free PCI slot and tell X to
>>>> use that one instead of "default" card.  Can kvm work like this?
>>> "secondary" means secondary video card in host, and will be
>>> "primary" in guest, right? As long as it's primary in guest, I think
>>> you still need most of above changes.  
>> No, I mean "secondary" on guest - no matter if it's secondary or
>> primary on host.  So that we'll have qemu-emulated VGA as primary
>> and a hardware-based secondary on *guest*.
> 
> Oh, for "secondary" in guest, it may needn't above changes. You can try it without any change.

I can't: ENOHARDWARE.

>> How much useful it is - it's another question.  For instance, I've
>> no idea how windows guest will be able to use such "secondary" vga
>> card on guest.
> 
> I don't know. Is there any interesting usage of this secondary VGA in guest?

I *guess* windows can be told to use non-primary display.  But I've no
idea how.

Also, it certainly supports multi-display configuration somehow.  Running
most stuff on "secondary" should be possible.

/mjt