Re: [PATCH v2 7/9] x86: Use current USER_CS to setup correct context on vmx entry

From: Sean Christopherson
Date: Mon Oct 05 2020 - 16:45:49 EST


On Sat, Oct 03, 2020 at 04:04:22PM -0700, Andy Lutomirski wrote:
> On Fri, Oct 2, 2020 at 5:15 PM Andy Lutomirski <luto@xxxxxxxxxx> wrote:
> > But it's also more subtly wrong -- this corrupts all the segment attributes
> > in the case where a segment points to the GDT and the GDT attributes are
> > non-default.

Part of me wants to ask if it's even possible to get into such a scenario,
but a much larger part of me doesn't want to think about segmentation any
more :-)

> > I would also be okay with making the KVM code match the context switch
> > code, but this may be distinctly nontrivial.

Ya.

> If you're okay waiting for a couple days, I'll just do this. I have
> it 2/3-done already, except I'm running into the utter catastrophe
> that is 32-bit stackprotector, so I'm going to fix that first. (Or
> delete it if I get toosick of it.)

By all means. I dragged my feet for several months, I can certainly do
nothing for a few more days.