[SRU][F/aws][PATCH 3/6] x86/kvm: Teardown PV features on boot CPU as well

[Krzysztof Kozlowski]

On 19/05/2021 11:15, Andrea Righi wrote:
> From: Vitaly Kuznetsov <vkuznets at redhat.com>
> 
> BugLink: https://bugs.launchpad.net/bugs/1920944
> 
> Various PV features (Async PF, PV EOI, steal time) work through memory
> shared with hypervisor and when we restore from hibernation we must
> properly teardown all these features to make sure hypervisor doesn't
> write to stale locations after we jump to the previously hibernated kernel
> (which can try to place anything there). For secondary CPUs the job is
> already done by kvm_cpu_down_prepare(), register syscore ops to do
> the same for boot CPU.
> 
> Signed-off-by: Vitaly Kuznetsov <vkuznets at redhat.com>
> Message-Id: <20210414123544.1060604-3-vkuznets at redhat.com>
> Signed-off-by: Paolo Bonzini <pbonzini at redhat.com>
> (backported from 8b79feffeca28c5459458fe78676b081e87c93a4)

This differs significantly against mainline kernel and
kvm_guest_cpu_offline() ends up in different section - under ifdef. Is
it on purpose?


Best regards,
Krzysztof