diff options
| author | Vitaly Kuznetsov <vkuznets@redhat.com> | 2021-09-02 11:35:26 +0200 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2021-10-01 19:04:45 +0200 |
| commit | 70367f091777419f42e5f68f4206deb641335877 (patch) | |
| tree | 99fc953aad6b0a2f8d998d3f640bcb873ab86f65 /docs/hyperv.txt | |
| parent | 988f7b8bfeffbf521814d1e48c321f7674277512 (diff) | |
i386: Support KVM_CAP_HYPERV_ENFORCE_CPUID
By default, KVM allows the guest to use all currently supported Hyper-V
enlightenments when Hyper-V CPUID interface was exposed, regardless of if
some features were not announced in guest visible CPUIDs. hv-enforce-cpuid
feature alters this behavior and only allows the guest to use exposed
Hyper-V enlightenments. The feature is supported by Linux >= 5.14 and is
not enabled by default in QEMU.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20210902093530.345756-5-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'docs/hyperv.txt')
| -rw-r--r-- | docs/hyperv.txt | 17 |
1 files changed, 14 insertions, 3 deletions
diff --git a/docs/hyperv.txt b/docs/hyperv.txt index 000638a2fd..072709a68f 100644 --- a/docs/hyperv.txt +++ b/docs/hyperv.txt @@ -203,8 +203,11 @@ When the option is set to 'on' QEMU will always enable the feature, regardless of host setup. To keep guests secure, this can only be used in conjunction with exposing correct vCPU topology and vCPU pinning. -4. Development features -======================== +4. Supplementary features +========================= + +4.1. hv-passthrough +=================== In some cases (e.g. during development) it may make sense to use QEMU in 'pass-through' mode and give Windows guests all enlightenments currently supported by KVM. This pass-through mode is enabled by "hv-passthrough" CPU @@ -215,8 +218,16 @@ values from KVM to QEMU. "hv-passthrough" overrides all other "hv-*" settings on the command line. Also, enabling this flag effectively prevents migration as the list of enabled enlightenments may differ between target and destination hosts. +4.2. hv-enforce-cpuid +===================== +By default, KVM allows the guest to use all currently supported Hyper-V +enlightenments when Hyper-V CPUID interface was exposed, regardless of if +some features were not announced in guest visible CPUIDs. 'hv-enforce-cpuid' +feature alters this behavior and only allows the guest to use exposed Hyper-V +enlightenments. + -4. Useful links +5. Useful links ================ Hyper-V Top Level Functional specification and other information: https://github.com/MicrosoftDocs/Virtualization-Documentation |