Re: [Engine-devel] [Spice-devel] SPICE related features

On 02/09/2012 10:31 AM, Hans de Goede wrote:

>> so this means we need to ask the user for linux guests if they want >> single head or multiple heads when they choose multi monitor? > > We could ask the user, but I don't think that that is a good idea. > >> this will cause their (single) head to spin... > > With which you seem to agree :) > >> any better UX we can suggest users? > > Yes, no UI at all, the current solution using multiple single monitor > pci cards means using Xinerama, which disables Xrandr, and thus allows > no dynamic adjustment of the monitor settings of the guest, instead > an xorg.conf file must be written (the linux agent can generate one > based on the current client monitor info) and Xorg needs to be restarted. > > This is the result of the multiple pci cards which each 1 monitor model > we've been using for windows guests being a poor match for Linux guests. > > So we are working on adding support to drive multiple monitors from a > single qxl pci device. This requires changes on both the host and > guest side, but if both sides support it this configuration is much > better, so IMHO ovirt should just automatically enable it > if both the host (the cluster) and the guest support it. > > On the guest side, this is the current status: > > RHEL <= 6.1 no multi monitor support > RHEL 6.2(*) - 6.? multi monitor support using Xinerama (so 1 > monitor/card, multiple cards) > RHEL >= 6.? multi monitor support using a single card with multiple outputs > > Just like when exactly the new multi mon support will be available > for guests, it is a similar question mark for when it will be available for > the host. this is the ovirt mailing list, so upstream versions are more relevant here. in any case, I have the same issue with backward compatibilty. say you fix this in fedora 17. user started a guest VM when host was fedora 16. admin upgraded host and changed cluster level to utilize new features. suddenly on next boot guest will move from 4 heads to single head? I'm guessing it will break user configuration. i.e., user should be able to choose to move to utilize the new mode?