On Thu, Mar 21, 2019 at 11:25:44AM -0700, Linus Torvalds wrote: > On Thu, Mar 21, 2019 at 11:21 AM Andy Lutomirski <l...@kernel.org> wrote: > > > > I dunno. Lots of people at least use to have serious commercial interest > > in it. > > Yes, it used to be a big deal. But full virtualization has gotten a > lot more common and better. > > > Hey Xen folks, how close are we to being able to say "if you want to > > run a new kernel, you need to switch to PVH or similar"? > > I'd also like to know if we could perhaps at least limit PV to just > the thing that people care most deeply about. > > For example, maybe people notice that they really deeply care about > the PV spinlocks because they help a lot for some loads, but don't > care so much about the low-level CPU PV stuff any more because modern > CPUs do _those_ things so well these days. > > So it might not be an all-or-nothing thing, but a gradual "let's stop > supporting xyz under PV, because it causes pain and isn't worth it".
So Juergen recently introduced PARAVIRT_XXL, which are exactly those bits of PV we can get rid of. This paravirt-me-harder config does indeed include the CR2 bits. I recently talked to Andrew Cooper about this, and he said Xen Dom0 still needs all this :/ But yes, I'd _love_ to delete all that in a hurry.
