* Daniel P. Berrangé (berrange@xxxxxxxxxx) wrote: > On Fri, Oct 26, 2018 at 12:33:55PM +0530, P J P wrote: > > Hello Dan, all > > > > +-- On Thu, 25 Oct 2018, Daniel P. Berrangé wrote --+ > > | On Thu, Oct 25, 2018 at 10:52:56AM +0200, Gerd Hoffmann wrote: > > | > While being at it deprecate cirrus too. > > | > > > | > Reason (short version): use stdvga instead. > > | > Verbose version: > > | > https://www.kraxel.org/blog/2014/10/qemu-using-cirrus-considered-harmful > > | > > | > > | I don't debate the points in the blog post above that stdvga is a > > | better choice, but I don't think that's enough to justify deprecating > > | cirrus at this point in time, because when it then gets deleted it > > | will break way too many existing deployments. > > | > > | We need to socialize info in that blog post above more widely and > > | especially ensure that apps are not using that by default. I don't > > | see it being viable to formally deprecate it in QEMU any time soon > > | though given existing usage. > > > > To note, IMO there are other devices/sources in QEMU which are potential > > candidates for deprecation, similar to adlib etc. It'll help if we could > > device a process to deprecate/remove such code base. Other than maintenance it > > invariably also becomes source of security issues. > > > > Ex.(similar to Fedora) we could announce such candidate on qemu-devel list and > > after review over a period of say a month, candidate will be > > deprecated/expunged. (thinking aloud) > > QEMU has a deprecation process: > > https://qemu.weilnetz.de/doc/qemu-doc.html#Deprecated-features > > Most of the stuff deprecated is CLI args / monitor commands, etc where > mgmt apps just adjust the way they are calling QEMU, so end user's VMs > are largely not impacted. > > Deprecating a device type that is widely used is not desirable because > that will cause breakage of existing guests. Distros are free to disable > devices in their builds if they want to reduce the scope for CVEs in > packages they maintain, but again they should think carefully about how > many users they are going to break by doing so. I'm a bit mixed here; until recent guest kernels I've always treated Cirrus as the 'safe' one that's likely to work on anything - so losing it worries me. Having said that, I understand why we want to deprecate it; but we should give a much longer deprecation warning - a few years? I don't see any harm warning that it's deprecated and you really should try not to use it. Dave > Regards, > Daniel > -- > |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| > |: https://libvirt.org -o- https://fstop138.berrange.com :| > |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :| > -- Dr. David Alan Gilbert / dgilbert@xxxxxxxxxx / Manchester, UK -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list
