Re: [PATCH v2 0/7] x86/kvm/hyperv: stable clocksorce for L2 guests when running nested KVM on Hyper-V

[Paolo Bonzini <pbonzini@redhat.com>]

On 13/12/2017 16:09, Vitaly Kuznetsov wrote:
> Currently, KVM passes PVCLOCK_TSC_STABLE_BIT to its guests when running in
> so called 'masterclock' mode and this is only possible when the clocksource
> on the host is TSC. When running nested on Hyper-V we're using a different
> clocksource in L1 (Hyper-V TSC Page) which can actually be used for
> masterclock. This series brings the required support.
> 
> Making KVM work with TSC page clocksource is relatively easy, it is done in
> PATCH 5 of the series. All the rest is required to support L1 migration
  ^^^^^^^

Patch 6. :)

> when TSC frequency changes, we use a special feature from Hyper-V to do
> the job.

Patches 5-7 are

Acked-by: Paolo Bonzini <pbonzini@redhat.com>

I would appreciate if the Hyper-V folks can provide a topic branch to be
merged in both HV and KVM trees.

Thanks,

Paolo

> Vitaly Kuznetsov (7):
>   x86/hyper-v: check for required priviliges in hyperv_init()
>   x86/hyper-v: add a function to read both TSC and TSC page value
>     simulateneously
>   x86/hyper-v: reenlightenment notifications support
>   x86/hyper-v: redirect reenlightment notifications on CPU offlining
>   x86/irq: Count Hyper-V reenlightenment interrupts
>   x86/kvm: pass stable clocksource to guests when running nested on
>     Hyper-V
>   x86/kvm: support Hyper-V reenlightenment
> 
>  arch/x86/entry/entry_32.S          |   3 +
>  arch/x86/entry/entry_64.S          |   3 +
>  arch/x86/hyperv/hv_init.c          | 133 ++++++++++++++++++++++++++++++++++-
>  arch/x86/include/asm/hardirq.h     |   3 +
>  arch/x86/include/asm/irq_vectors.h |   7 +-
>  arch/x86/include/asm/mshyperv.h    |  32 +++++++--
>  arch/x86/include/uapi/asm/hyperv.h |  27 ++++++++
>  arch/x86/kernel/cpu/mshyperv.c     |   6 ++
>  arch/x86/kernel/irq.c              |   9 +++
>  arch/x86/kvm/x86.c                 | 138 ++++++++++++++++++++++++++++++-------
>  10 files changed, 329 insertions(+), 32 deletions(-)
>