On Tue, Oct 05, 2021 at 11:52:52AM +0200, Thomas Gleixner wrote:
> Jan,
>
> On Mon, Oct 04 2021 at 19:54, Jan Kiszka wrote:
> > what's the state of getting kvm working (again?) along RT? Seems
> > HAVE_POSIX_CPU_TIMERS_TASK_WORK is in conflict with KVM but a
> > precondition for RT on recent kernels. What's the story behind that?
>
> the ARM64 KVM implementation is incorrect vs. TIF handling before
> VMENTER which breaks the posix cpu timers task work assumptions and also
> violates a few other expectations. AFAICT the arm64 folks are working on
> that, but you have to ask them directly what the state of this is.
I think that was dealt with as of mainline commits:
* e1c6b9e1669e44fb ("entry: KVM: Allow use of generic KVM entry w/o full generic support")
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=e1c6b9e1669e44fb7f9688e34e460b759e3b9187
* 6caa5812e2d126a0 ("KVM: arm64: Use generic KVM xfer to guest work function")
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=6caa5812e2d126a0aa8a17816c1ba6f0a0c2b309
... unless I'm missing something.
Mark.
