KVM: nSVM: Implement Enlightened MSR-Bitmap feature

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Similar to nVMX commit 502d2bf5f2 ("KVM: nVMX: Implement Enlightened MSR
Bitmap feature"), add support for the feature for nSVM (Hyper-V on KVM).

Notable differences from nVMX implementation:
- As the feature uses SW reserved fields in VMCB control, KVM needs to
make sure it's dealing with a Hyper-V guest (kvm_hv_hypercall_enabled()).

- 'msrpm_base_pa' needs to be always be overwritten in
nested_svm_vmrun_msrpm(), even when the update is skipped. As an
optimization, nested_vmcb02_prepare_control() copies it from VMCB01
so when MSR-Bitmap feature for L2 is disabled nothing needs to be done.

- 'struct vmcb_ctrl_area_cached' needs to be extended with clean
fields/sw reserved data and __nested_copy_vmcb_control_to_cache() needs to
copy it so nested_svm_vmrun_msrpm() can use it later.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20220202095100.129834-5-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

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This commit is contained in:

Vitaly Kuznetsov 2022-02-02 10:51:00 +01:00 • committed by Paolo Bonzini

parent 9e083ec7bb

commit 66c03a926f

3 changed files with 37 additions and 13 deletions

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7

arch/x86/kvm/hyperv.c

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43

arch/x86/kvm/svm/nested.c

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2

arch/x86/kvm/svm/svm.h

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