[SRU][F][PATCH 2/5] x86/kvm: Teardown PV features on boot CPU as well

Krzysztof Kozlowski krzysztof.kozlowski at canonical.com
Thu May 20 17:21:21 UTC 2021


On 20/05/2021 09:36, 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)

Same as for your v3 - this differs significantly against mainline, so it
should be mentioned what changed. The kvm_guest_cpu_offline() location
looks now wrong.



Best regards,
Krzysztof



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