Re: [PATCH 0/5] KVM: nSVM: few fixes for the nested migration

[Paolo Bonzini]

On 03/05/21 14:54, Maxim Levitsky wrote:
> Those are few fixes for issues I uncovered by doing variants of a
> synthetic migration test I just created:
>
> I modified the qemu, such that on each vm pause/resume cycle,
> just prior to resuming a vCPU, qemu reads its KVM state,
> then (optionaly) resets this state by uploading a
> dummy reset state to KVM, and then it uploads back to KVM,
> the state that this vCPU had before.
>
> I'll try to make this test upstreamable soon, pending few details
> I need to figure out.
>
> Last patch in this series is for false positive warning
> that I have seen lately when setting the nested state,
> in nested_svm_vmexit, where it expects the vmcb01 to have
> VMRUN vmexit, which is not true after nested migration,
> as it is not fully initialized.
> If you prefer the warning can be removed instead.
>
> Best regards,
> 	Maxim Levitsky
>
> Maxim Levitsky (5):
>    KVM: nSVM: fix a typo in svm_leave_nested
>    KVM: nSVM: fix few bugs in the vmcb02 caching logic
>    KVM: nSVM: leave the guest mode prior to loading a nested state
>    KVM: nSVM: force L1's GIF to 1 when setting the nested state
>    KVM: nSVM: set a dummy exit reason in L1 vmcb when loading the nested
>      state
>
>   arch/x86/include/asm/kvm_host.h |  1 +
>   arch/x86/kvm/svm/nested.c       | 29 ++++++++++++++++++++++++++---
>   arch/x86/kvm/svm/svm.c          |  4 ++--
>   3 files changed, 29 insertions(+), 5 deletions(-)

Queued patches 1-3.

Paolo