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Bug 1643887

Summary: [RFE] Default set of Hyper-V enlightenments for Windows guests on RHEL8 hosts
Product: Red Hat OpenStack Reporter: Vitaly Kuznetsov <vkuznets>
Component: openstack-novaAssignee: Artom Lifshitz <alifshit>
Status: CLOSED DEFERRED QA Contact: OSP DFG:Compute <osp-dfg-compute>
Severity: medium Docs Contact:
Priority: medium    
Version: 16.2 (Train)CC: ailan, alifshit, dasmith, egallen, eglynn, jhakimra, kchamart, ltamagno, lyarwood, mprivozn, sbauza, sgordon, smooney, vromanso, yvugenfi
Target Milestone: ---Keywords: FutureFeature, Patch, Performance, Triaged
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard:
Fixed In Version: Doc Type: Enhancement
Doc Text:
Story Points: ---
Clone Of:
: 1647745 2124291 (view as bug list) Environment:
Last Closed: 2023-04-14 13:53:26 UTC Type: Bug
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version: Zed
Embargoed:
Bug Depends On: 1620588    
Bug Blocks: 1647745    

Description Vitaly Kuznetsov 2018-10-29 10:59:53 UTC 
KVM and Qemu RHEL-8 will bring multiple improvements for Windows guests, in particular several new Hyper-V enlightenments got added. However, neither KVM/Qemu nor libvirt enable them by default (as there's no knowledge of the operating system running inside the guest) so it's up to the upper layer (RHEV, OpenStack) to enable them.

From BZ#1620588:

Currently, we have the following:
 hv-relaxed - windows activates it automatically when hypervisor CPU flag is present.
 hv-vapic - should speed things up in general (IRQs)
 hv-time - should speed things up significantly
 hv-crash - can we capture this info?
 hv-reset - rather redundant
 hv-vpindex - required for PV TLB flush/IPSs
 hv-runtime - for stats
 hv-synic - required for stimer
 hv-stimer - speed things up, especially with the latest Win10 update
 hv-frequencies - needed for Hyper-V on KVM (tsc page clocksource
 hv-reenlightenment - also needed for Hyper-V on KVM (tsc page clocksource)
 hv-tlbflush - speed things up in overcommited environments

I'll be updating this BZ as new enlightenments get merged upstream.
Comment 3 Artom Lifshitz 2022-03-30 16:14:31 UTC 
*** Bug 2068501 has been marked as a duplicate of this bug. ***
Comment 10 Artom Lifshitz 2023-04-14 13:53:26 UTC 
Tracked in https://issues.redhat.com/browse/OSPRH-58