Jeremy Fitzhardinge wrote: > The XEN config option enables the Xen paravirt_ops interface, which is > installed when the kernel finds itself running under Xen. (By some > as-yet fully defined mechanism, implemented in a future patch.) > > Xen is no longer a sub-architecture, so the X86_XEN subarch config > option has gone. > > The disabled config options are: > - PREEMPT: Xen doesn't support it > - HZ: set to 100Hz for now, to cut down on VCPU context switch rate. > This will be adapted to use tickless later. > - kexec: not yet supported > > Signed-off-by: Jeremy Fitzhardinge <jeremy at xensource.com> > Signed-off-by: Ian Pratt <ian.pratt at xensource.com> > Signed-off-by: Christian Limpach <Christian.Limpach at cl.cam.ac.uk> > Signed-off-by: Chris Wright <chrisw at sous-sol.org> > We do support different HZ values, although 100HZ is actually preferable for us, so I don't object to that. PREEMPT is supported by us, but not as tested as I would like, so I also don't object to dropping it for generic paravirt guests - Rusty - Avi any objections to dropping preempt in terms of lguest/KVM paravirtualization? Paravirt-ops definitely needs a hook for kexec, although we should not disable kexec for the natively booted paravirt-ops. Eric - is there a way to disable it at runtime? We do support the doublefault task gate, and it would be good to keep it, but I can't complain so much if it is gone from generic paravirt kernels for now, because it is non-essential, and generally fatal anyway. We do need it for native boots of paravirt-ops kernels, however, so turning off the config option still needs to be revisited. Zach
