Update to a newer longterm linux kernel / xen blktap2 driver

[pasikarkkainen]

Hello! I see there's some wip work for linux 5.4 (for el8) in #26

Current centos xen-kernel (4.9.x longterm) for el6 and el7 includes the blktap2 kernel driver patch (and centos xen rpms includes the blktap2.5 userland code as a patch).

I noticed xenserver/xcp-ng has updated to new longterm linux 4.19.x kernel, and thus xenserver folks have ported the blktap2 kernel driver patch for the linux 4.19.x kernel version ( https://github.com/xcp-ng-rpms/kernel/blob/XS-8.2/SOURCES/blktap2.patch ).

Should we update the centos xen-kernel rpm to linux 4.19.x longterm aswell, as it'd allow us to use/ship the available blktap2 driver patch easily?

Using same dom0 kernel as xenserver/xcp-ng would also give us the possibility of using fixes/patches from the xenserver/xcp-ng kernel patch queue ( https://github.com/xcp-ng-rpms/kernel/tree/XS-8.2/SOURCES ), if we happen to see any xen related problems/bugs when switching to that kernel version.. (they've obviously already done the work to get everything running smoothly).

thoughts?