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| author | Vitaly Kuznetsov <vkuznets@redhat.com> | 2022-05-25 13:59:45 +0200 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2022-05-25 21:26:35 +0200 |
| commit | 869840d26c929b99694e31b1a18e83bdea6e97ca (patch) | |
| tree | 8d3be5755ce10f0b75bce56d99aa09de39dd6ca1 /docs | |
| parent | 7110fe56c1f69b9e1bdf838558fdcb75d1568964 (diff) | |
| download | qemu-869840d26c929b99694e31b1a18e83bdea6e97ca.zip qemu-869840d26c929b99694e31b1a18e83bdea6e97ca.tar.gz qemu-869840d26c929b99694e31b1a18e83bdea6e97ca.tar.bz2 | |
i386: Hyper-V Enlightened MSR bitmap feature
The newly introduced enlightenment allow L0 (KVM) and L1 (Hyper-V)
hypervisors to collaborate to avoid unnecessary updates to L2
MSR-Bitmap upon vmexits.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20220525115949.1294004-3-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'docs')
| -rw-r--r-- | docs/hyperv.txt | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/docs/hyperv.txt b/docs/hyperv.txt index 33588a0..5d85569 100644 --- a/docs/hyperv.txt +++ b/docs/hyperv.txt @@ -239,6 +239,15 @@ This enlightenment requires a VMBus device (-device vmbus-bridge,irq=15) and the follow enlightenments to work: hv-relaxed,hv_time,hv-vapic,hv-vpindex,hv-synic,hv-runtime,hv-stimer +3.22. hv-emsr-bitmap +===================== +The enlightenment is nested specific, it targets Hyper-V on KVM guests. When +enabled, it allows L0 (KVM) and L1 (Hyper-V) hypervisors to collaborate to +avoid unnecessary updates to L2 MSR-Bitmap upon vmexits. While the protocol is +supported for both VMX (Intel) and SVM (AMD), the VMX implementation requires +Enlightened VMCS ('hv-evmcs') feature to also be enabled. + +Recommended: hv-evmcs (Intel) 4. Supplementary features ========================= |