On Thu, Jun 7, 2012 at 11:00 AM, Benjamin Herrenschmidt <b...@au1.ibm.com>wrote:
> On Thu, 2012-06-07 at 09:15 +0800, Anthony Liguori wrote: > > > You misunderstand what I'm saying. > > > > -nodefault is a dumb option. It's semantics are poorly defined because > it > > depends on machine. Further complicating those semantics by adding more > magic > > for -M spapr just makes the situation worse. > > > > I'm suggesting to make use of the -machine option to allow usb to be > disabled. So: > > > > qemu-system-ppc64 -machine type=spapr,usb=off > > > > libvirt can still happily name the usb controller whatever it wants. > But the > > end result is a less magical command line. > > Allright, what I was missing is -machine option with arguments, I only > knew about -M <name> :-) > > That definitely sounds like the right way to go. However, I do wonder to > what extent we should still also support -nodefault because that's what > libvirt does today or we just don't give a shit ? > > Li, can you do something along the lines of what Anthony described ? By > default, you should have -vga std and usb OHCI with mouse and keyboard. > > OK. I will do it. > Feel free to replace the patches I currently have in our internal tree > for enabling -vga etc... and post the result publicly, however, please > note in the comments that for that stuff to work, there's a dependency > on the iommu patch series. > I see. Thanks. > > Cheers, > Ben. > > > Regards, > > > > Anthony Liguori > > > > > > > > The problem is that for things created "by default", libvirt then makes > > > horrible assumptions about the default 'names' and bus names as well, > > > which is why it's generally somewhat saner to let it create the machine > > > from scratch (well, sorry for putting "sane" and "libvirt" in the same > > > sentence but you get my idea I think :-) > > > > > >>> -vga should only affect vga (a shortcut for -device > > >>> pick_your_vga_poison) > > >> > > >> Ack. > > > > > > (Note: This is in reference to our current internal patch which > > > automagically adds OHCI and USB kbd + mouse when you do -vga, that's > not > > > something that should survive upstream). > > > > > >>> -usb should be essentially useless by default unless -nodefault is > > >>> passed in which case it is necessary to enable usb support, and > -device > > >>> (or equivalent) to manually add the keyboard and mouse (libvirt). > > >> > > >> If you want pseries to always have usb, just make it there by default > and yeah, > > >> -usb would be useless. If you want the option to not have usb, > introduce a > > >> machine option I guess. > > > > > > Ah, I'm not familiar with "machine options" ... or do you mean another > > > machine type ? ie -M pseries_nousb ? :-) > > > > > > The problem with things like USB by default is that libvirt will fuckup > > > (at least that's my understanding from what Li says) bcs it's going to > > > try to create a separate USB bus and can't seem to figure out how to > > > reference the existing one, etc... In fact it even tries to re-use the > > > PCI bus/dev where the original OHCI is created an that clashes. > > > > > >> I think it's over thinking it though. There's little harm in having > a usb > > >> controller present all the time. > > > > > > That makes more sense I agree, I'm just annoyed by the whole libvirt > > > business which seems to have some pretty hard assumptions that with > > > -nodefault you don't get anything by default, and I think it makes some > > > sense to keep that option around. > > > > > > Cheers, > > > Ben. > > > > > >> Regards, > > >> > > >> Anthony Liguori > > >> > > >>> > > >>> That's the best I can think of ... however it might be a bit tricky > > >>> seeing how qemu does things in vl.c at the moment, we might want to > > >>> introduce a default_usb variable which is used to set usb_enabled. > > >>> > > >>> BTW. The mac models should essentially behave the same, at least the > > >>> 64-bit one (32-bit supports CUDA for keyboard/mouse so USB isn't > > >>> strictly necessary). > > >>> > > >>> Cheers, > > >>> Ben. > > >>>> > > >>>> Thanks. > > >>>> > > >>>> On Tue, Jun 5, 2012 at 5:48 PM, li zhang<zhlci...@gmail.com> > wrote: > > >>>> Hi all, > > >>>> > > >>>> For pseries, when creating VMs with "-vga std", > > >>>> it requires usb mouse and usb kbd devices to be added. > > >>>> > > >>>> But with default options, vga is enabled and usb is > disabled. > > >>>> User may use default options as the following commands: > > >>>> > > >>>> $qemu -M pseries > > >>>> > > >>>> If vga is enabled, usb mouse and usb kbd is disabled, > > >>>> the mouse and kbd can't be used. So it's very hard for > > >>>> users to use. > > >>>> > > >>>> I think it's necessary to enable usb with default options. > > >>>> > > >>>> Any idea about that? > > >>>> Your comments are very appreciated. :) > > >>>> > > >>>> Thanks. > > >>>> -Li > > >>>> > > >>>> > > >>>> > > >>>> > > >>>> -- > > >>>> > > >>>> > > >>>> Best Regards > > >>>> -Li > > >>>> > > >>>> > > >>> > > >>> > > > > > > > > > -- Best Regards -Li
