Linux mainline contains all the Xen code bits for Dom0 and DomU support

Question

What does this mean?:

• "Linux mainline contains all the Xen code bits for Dom0 and DomU support"

does this means that I don't have to install a XEN kernel if I want to use it? Are there any updated howtos regarding this extremely good new "feature"? :)

Answer 1

This is correct. From the same page:

pvops, is a mode where the kernel can switch into pv, hvm or pvhvm at boot time. Instead of having multiple kernel binaries, there is just one and it will lay out its operations at boot time when it detects on what platform it runs.

Meaning that your standard kernel will automagically switch to DomU behavior if it detects Xen. I would guess the same happens when you use Linux for Dom0, based on that article.

And for many years, next to the hypervisor, there was a substantial linux kernel patch that had to be applied on top of a linux kernel to transform into this "Dom0".

[...]

Late last year in 2.6.37, we had a mainline kernel that was able to actually run as the "Dom0" for the Xen hypervisor.