Re: [patch 14/21] Xen-paravirt: Add XEN config options and disable unsupported config options.

[ebiederm@xmission.com (Eric W. Biederman)]

Zachary Amsden <zach@vmware.com> writes:

>
> 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

Have machine_kexec_prepare fail.

I think your machine description or paravirt_ops or whatever it is needs
to hook both machine_kexec_prepare and machine_kexec.

I know there actually has been some work to get kexec actually working under
Xen but I don't know where that has gone.

Eric