Messages in this thread | | | From | Vitaly Kuznetsov <> | Subject | Re: [PATCH] x86/hyperv: Suspend/resume the VP assist page for hibernation | Date | Fri, 17 Apr 2020 12:03:18 +0200 |
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Dexuan Cui <decui@microsoft.com> writes:
> Unlike the other CPUs, CPU0 is never offlined during hibernation. So in the > resume path, the "new" kernel's VP assist page is not suspended (i.e. > disabled), and later when we jump to the "old" kernel, the page is not > properly re-enabled for CPU0 with the allocated page from the old kernel. > > So far, the VP assist page is only used by hv_apic_eoi_write().
No, not only for that ('git grep hv_get_vp_assist_page')
KVM on Hyper-V also needs VP assist page to use Enlightened VMCS. In particular, Enlightened VMPTR is written there.
This makes me wonder: how does hibernation work with KVM in case we use Enlightened VMCS and we have VMs running? We need to make sure VP Assist page content is preserved.
-- Vitaly
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