Re: [PATCH 0/5] KVM: SVM: nSVM: Implement Enlightened MSR-Bitmap for Hyper-V-on-KVM and fix it for KVM-on-Hyper-V

Paolo Bonzini
2022-02-01T13:49:15Z

On 12/20/21 16:21, Vitaly Kuznetsov wrote:
> Enlightened MSR-Bitmap feature implements a PV protocol for L0 and L1
> hypervisors to collaborate and skip unneeded updates to MSR-Bitmap.
> KVM implements the feature for KVM-on-Hyper-V but it seems there was
> a flaw in the implementation and the feature may not be fully functional.
> PATCHes 1-2 fix the problem. The rest of the series implements the same
> feature for Hyper-V-on-KVM.
>
> Vitaly Kuznetsov (5):
> KVM: SVM: Drop stale comment from
> svm_hv_vmcb_dirty_nested_enlightenments()
> KVM: SVM: hyper-v: Enable Enlightened MSR-Bitmap support for real
> KVM: nSVM: Track whether changes in L0 require MSR bitmap for L2 to be
> rebuilt
> KVM: x86: Make kvm_hv_hypercall_enabled() static inline
> KVM: nSVM: Implement Enlightened MSR-Bitmap feature
>
> arch/x86/kvm/hyperv.c | 12 +--------
> arch/x86/kvm/hyperv.h | 6 ++++-
> arch/x86/kvm/svm/nested.c | 47 ++++++++++++++++++++++++++++-----
> arch/x86/kvm/svm/svm.c | 3 ++-
> arch/x86/kvm/svm/svm.h | 16 +++++++----
> arch/x86/kvm/svm/svm_onhyperv.h | 12 +++------
> 6 files changed, 63 insertions(+), 33 deletions(-)
>

Queued 3-5 now, but it would be nice to have some testcases.

Paolo