Re: [PATCH v4 0/6] i386: Enable newly introduced KVM Hyper-V enlightenments

[Paolo Bonzini <pbonzini@redhat.com>]

On 5/25/22 13:59, Vitaly Kuznetsov wrote:
> Changes since v3:
> - Rebase, resolve merge conflict with 73d24074078a ("hyperv: Add support to
>    process syndbg commands")
> - Include "i386: docs:  Convert hyperv.txt to rST" patch which was previously
>    posted separately.

Thank you very much for reposting this.

Paolo

> Original description:
> 
> This series enables four new KVM Hyper-V enlightenmtes:
> 
> 'XMM fast hypercall input feature' is supported by KVM since v5.14,
> it allows for faster Hyper-V hypercall processing.
> 
> 'Enlightened MSR-Bitmap' is a new nested specific enlightenment speeds up
> L2 vmexits by avoiding unnecessary updates to L2 MSR-Bitmap. KVM support
> for the feature on Intel CPUs is in v5.17 and in  5.18 for AMD CPUs.
> 
> 'Extended GVA ranges for TLB flush hypercalls' indicates that extended GVA
> ranges are allowed to be passed to Hyper-V TLB flush hypercalls.
> 
> 'Direct TLB flush hypercall' features allows L0 (KVM) to directly handle
> L2's TLB flush hypercalls without the need to exit to L1 (Hyper-V).
> 
> The last two features are not merged in KVM yet:
> https://lore.kernel.org/kvm/20220525090133.1264239-1-vkuznets@redhat.com/
> however, there's no direct dependency on the kernel part as thanks to
> KVM_GET_SUPPORTED_HV_CPUID no new capabilities are introduced.
> 
> Vitaly Kuznetsov (6):
>    i386: Use hv_build_cpuid_leaf() for HV_CPUID_NESTED_FEATURES
>    i386: Hyper-V Enlightened MSR bitmap feature
>    i386: Hyper-V XMM fast hypercall input feature
>    i386: Hyper-V Support extended GVA ranges for TLB flush hypercalls
>    i386: Hyper-V Direct TLB flush hypercall
>    i386: docs:  Convert hyperv.txt to rST
> 
>   docs/hyperv.txt                | 270 -------------------------------
>   docs/system/i386/hyperv.rst    | 288 +++++++++++++++++++++++++++++++++
>   docs/system/target-i386.rst    |   1 +
>   target/i386/cpu.c              |   8 +
>   target/i386/cpu.h              |   5 +-
>   target/i386/kvm/hyperv-proto.h |   9 +-
>   target/i386/kvm/kvm.c          |  55 +++++--
>   7 files changed, 354 insertions(+), 282 deletions(-)
>   delete mode 100644 docs/hyperv.txt
>   create mode 100644 docs/system/i386/hyperv.rst
>