[Bug 218267] [Sapphire Rapids][Upstream]Boot up multiple Windows VMs hang

bugzilla-daemon
2024-08-06T11:02:12Z

vkuznets@redhat.com changed:

What |Removed |Added
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CC| |vkuznets@redhat.com

--- Comment #5 from vkuznets@redhat.com ---
(In reply to Chao Gao from comment #3)

> Note that, APICv outperforms Hyper-V's synthetic MSRs; regardless of this
> bug, it is recommended to remove "hv-vapic" if KVM enables APICv.

'hv-vapic' is a prerequisite for some other Hyper-V features, e.g. Enlightened
VMCS so disabling it may not be desired.

Also, there's 'hv-apicv' (AKA 'hv-avic') feature which prevents AutoEOI
advertisement (can't work with APICv and this KVM inhibits it with
APICV_INHIBIT_REASON_HYPERV). AFAIR, newer Windows versions don't use AutoEOI
either way but Win8/Win7 may.