On 11/15/2013 10:03 AM, Peter Maydell wrote: > On 14 November 2013 22:32, Benjamin Herrenschmidt > <b...@kernel.crashing.org> wrote: >> On Thu, 2013-11-14 at 17:23 -0500, Alexander Graf wrote: >>> Yes. But I think it's the correct thing to do in this case. X86 also >>> doesn't create a USB controller like we would have to. Our pseries >>> platform just doesn't have a legacy PC/AT keyboard controller. >> >> Sure, but that implies that -nodefaults -device VGA creates a working >> usable machine on x86 and not on pseries... > > Sounds plausible. Anything using -nodefaults has to have > knowledge of every QEMU machine type it wants to use > so it can know which devices need adding in order to get > various functionality. ('-device VGA' doesn't work at all on > some, for instance). If you ask for full manual control, you > get full manual control :-)
That is ok and I asked our libvirt person to fix it (Hi Li :) ). What I still do not completely understand is the principle used about automatic device creation. Specifically, "-device VGA" creates only VGA (and that is understandable) but "-vga std" creates more devices, if if used together with "-nodefaults". Is it because "-device" must create only what it is told to create and others non-"-device" options (-usb? -vga? -machine ...? any!) can auto-create whatever they want (well, what seems reasonable to create for the specific arch)? -- Alexey