diff options
| author | Vitaly Kuznetsov <vkuznets@redhat.com> | 2021-09-02 11:35:28 +0200 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2021-10-01 19:04:45 +0200 |
| commit | e1f9a8e8c90ae54387922e33e5ac4fd759747d01 (patch) | |
| tree | be75154742d88bbf4c22d17d65d75958da14cabe /docs | |
| parent | 050716292a63f4969b32cac32b85774521738ef5 (diff) | |
| download | qemu-e1f9a8e8c90ae54387922e33e5ac4fd759747d01.zip | |
i386: Implement pseudo 'hv-avic' ('hv-apicv') enlightenment
The enlightenment allows to use Hyper-V SynIC with hardware APICv/AVIC
enabled. Normally, Hyper-V SynIC disables these hardware features and
suggests the guest to use paravirtualized AutoEOI feature. Linux-4.15
gains support for conditional APICv/AVIC disablement, the feature
stays on until the guest tries to use AutoEOI feature with SynIC. With
'HV_DEPRECATING_AEOI_RECOMMENDED' bit exposed, modern enough Windows/
Hyper-V versions should follow the recommendation and not use the
(unwanted) feature.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20210902093530.345756-7-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'docs')
| -rw-r--r-- | docs/hyperv.txt | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/docs/hyperv.txt b/docs/hyperv.txt index 072709a68f..cd1ea3bbe9 100644 --- a/docs/hyperv.txt +++ b/docs/hyperv.txt @@ -189,7 +189,15 @@ enabled. Requires: hv-vpindex, hv-synic, hv-time, hv-stimer -3.17. hv-no-nonarch-coresharing=on/off/auto +3.18. hv-avic (hv-apicv) +======================= +The enlightenment allows to use Hyper-V SynIC with hardware APICv/AVIC enabled. +Normally, Hyper-V SynIC disables these hardware feature and suggests the guest +to use paravirtualized AutoEOI feature. +Note: enabling this feature on old hardware (without APICv/AVIC support) may +have negative effect on guest's performace. + +3.19. hv-no-nonarch-coresharing=on/off/auto =========================================== This enlightenment tells guest OS that virtual processors will never share a physical core unless they are reported as sibling SMT threads. This information |