Re: [Qemu-ppc] -vga std vs. -device VGA

[Alexander Graf]

Am 14.11.2013 um 04:37 schrieb Alexey Kardashevskiy <address@hidden>:

> On 11/14/2013 05:01 PM, Benjamin Herrenschmidt wrote:
>> On Thu, 2013-11-14 at 16:01 +1100, Alexey Kardashevskiy wrote:
>>> So the question is - is there any proper (i. e. qemu-upstreamable) way to
>>> detect a VGA device presence and create additional devices (OHCI, keyboard,
>>> mouse) as "-vga" does it now? The machine reset callback is too late for 
>>> that.
>>> 
>>> Or we should just print an error (in QEMU or SLOF) and do nothing and let
>>> the user configure all required devices in libvirt?
>> 
>> My opinion is that we should always create a PAPR vty...
>> 
>> libvirt creating VGA devices is stupid... I understand x86's get upset when
>> they don't have one but it's useless on power and adds its own problems.
> 
> The RHEL6.5 test mode installer is pretty limited compared to the graphical
> version. And, with libvirt, it is not always easy to use VNC provided by
> the installer. Having VGA is quite nice option.
> 
> 
>> So libvirt should be fixed not to do that
> 
> The user decided to use VGA, not libvirt (which does not create VGA by
> default).

In general we try to split cleverness between two different cases.

1) normal direct QEMU command line usage

Here we want to make life easy for a user and give him some help. That's why we 
automatically create a keyboard and USB controller when we see that he wants to 
use VGA.

2) -nodefaults

This mode is meant to pass full control to a management stack which wants to 
implement its own cleverness. The less QEMU tries to be smart, the more 
consistent we are in our interface. This mode really is meant as to tell QEMU 
to allow you to shoot yourself in the foot.

So in this case, the proper fix is to add the logic to libvirt. It asks for a 
machine without cleverness applied, so it needs to do all of the magic itself. 
It already does this for the mouse btw (-usbdevice tablet) to allow for an 
absolute pointer. It's only sensible to ask them to do the keyboard too. In 
this case, x86 is the inconsistent platform.


Alex