Re: [PATCH v10 0/9] Linear Address Masking (LAM) KVM Enabling

[Binbin Wu]

On 8/17/2023 6:25 AM, Sean Christopherson wrote:
> On Wed, Jul 19, 2023, Binbin Wu wrote:
> > Binbin Wu (7):
> >    KVM: x86/mmu: Use GENMASK_ULL() to define __PT_BASE_ADDR_MASK
> >    KVM: x86: Add & use kvm_vcpu_is_legal_cr3() to check CR3's legality
> >    KVM: x86: Use KVM-governed feature framework to track "LAM enabled"
> >    KVM: x86: Virtualize CR3.LAM_{U48,U57}
> >    KVM: x86: Introduce get_untagged_addr() in kvm_x86_ops and call it in
> >      emulator
> >    KVM: VMX: Implement and wire get_untagged_addr() for LAM
> >    KVM: x86: Untag address for vmexit handlers when LAM applicable
> >
> > Robert Hoo (2):
> >    KVM: x86: Virtualize CR4.LAM_SUP
> >    KVM: x86: Expose LAM feature to userspace VMM
> Looks good, just needs a bit of re-organination.  Same goes for the LASS series.
>
> For the next version, can you (or Zeng) send a single series for LAM and LASS?
> They're both pretty much ready to go, i.e. I don't expect one to hold up the other
> at this point, and posting a single series will reduce the probability of me
> screwing up a conflict resolution or missing a dependency when applying.
>
> Lastly, a question: is there a pressing need to get LAM/LASS support merged _now_?
> E.g. are there are there any publicly available CPUs that support LAM and/or LASS?
AFAIK, there is no publicly available CPU supporting LAM and LASS yet.

> If not, I'll wait until v6.7 to grab these, e.g. so that you don't have to rush
> madly to turn around the next version, and so that I'm not trying to squeeze too
> much stuff in just before the merge window.