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

Hi, On 02/09/2012 09:33 AM, Itamar Heim wrote: > On 02/09/2012 10:31 AM, Hans de Goede wrote: <snip> >>> 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? I see this as something which gets decided at vm creation time, and then stored in the vm config. So if the vm gets created with a guest OS which does not support multiple monitors per qxl device, or when the cluster does not support it, it uses the old setup with 1 card / monitor. Even if the guest OS or the cluster gets upgraded later.