On Wed, Jan 16, 2019 at 06:54:38PM +0300, Ilya Maximets wrote: > On 16.01.2019 18:48, Daniel P. Berrangé wrote: > > On Wed, Jan 16, 2019 at 06:46:39PM +0300, Ilya Maximets wrote: > >> > >> > >> On 16.01.2019 18:30, Eduardo Habkost wrote: > >>> On Wed, Dec 12, 2018 at 07:49:36AM +0100, Gerd Hoffmann wrote: > >>>> On Tue, Dec 11, 2018 at 02:09:11PM +0300, Ilya Maximets wrote: > >>>>> On 11.12.2018 13:53, Daniel P. Berrangé wrote: > >>>>>>> > >>>>>>> Let's restrict memfd backend to systems with sealing support. > >>>>>> > >>>>>> I don't think we need todo that - sealing is optional in the QEMU code, > >>>>>> we simply have it set to the wrong default when sealing is not > >>>>>> available. > >>>>> > >>>>> That was literally what I've fixed in v1: > >>>>> > >>>>> https://lists.nongnu.org/archive/html/qemu-devel/2018-11/msg05483.html > >>>>> > >>>>> but 2 people suggested me to disable memfd entirely for this case. > >>>>> Do you think I need to get patch from v1 back ? > >>>>> > >>>>> Gerd, Marc-André, what do you think? > >>>> > >>>> I still think it makes sense to require sealing support. Sealing is > >>>> very useful, and there are only a few kernel versions with memfd but > >>>> without sealing. So finding such kernels in the wild will become more > >>>> rare over time. I wouldn't worry too much about them. > >>> > >>> -object memory-backend-memfd,id=mem,size=2M,seal=off still > >>> works on those systems, doesn't it? What's the rationale for > >>> breaking a working configuration without following the > >>> deprecation policy? > >>> > >> > >> See the commit message. > >> '.seal' property is not registered if sealing is not supported. > >> So, there is no way to disable sealing on the system that does not support > >> it. > > > > As I pointed out a few lines up, this is simply because QEMU has a bug > > setting seal=true as the built-in default value even when it isn't > > supported. > > So, do you think I need to return to the solution from my v1: > https://lists.nongnu.org/archive/html/qemu-devel/2018-11/msg05483.html
That is my preference, but we don't have universal agreement :-( 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 :|
