xn ethernet issues as DOMU under NetBSD DOM0 FIXED!

[Roger Pau Monn?]

On Tue, May 17, 2016 at 01:17:00PM +0300, Konstantin Belousov wrote:
> On Tue, May 17, 2016 at 11:43:01AM +0200, Roger Pau Monn? wrote:
> > With previous FreeBSD 9.X versions, in order to get Xen support you had to 
> > compile a specific kernel (XENHVM), we wanted to remove this for FreeBSD 10, 
> > so we included the Xen components into the GENERIC kernel and made sure 
> > there were no weird interactions on bare metal. However, this change was 
> > too big to merge into 9, so in order to try to improve the situation on 9 
> > Colin decided to pack all the Xen support into a kernel module, in order to 
> > remove the need to compile a specific kernel for Xen VMs.
> 
> Why the module is a bad idea on HEAD/10.x ?

Because there are pieces of Xen support that AFAICT cannot be placed inside 
of a module. For example the Xen apic_enumerator cannot be placed inside of 
a modules because it's needed too early in the boot process. The same 
happens with the Xen specific entry point that's used by Dom0 and PVH mode, 
it cannot be moved into a module.

There are other parts/drivers that can certainly be moved into a kernel 
module, I just don't have enough time ATM to look into this.
 
> To explain further, I do not object against Xen code included into GENERIC.
> I am interested in the possibility of the stripped down kernel (without
> XEN options) which can be made operable on HVM with the module preloaded.

+1.

Roger.