On 20/05/2021 12:47, Paolo Bonzini wrote:
On 20/05/21 14:56, Krzysztof Kozlowski wrote:
From: Vitaly Kuznetsov vkuznets@redhat.com
commit 8b79feffeca28c5459458fe78676b081e87c93a4 upstream.
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.
Krzysztof: This fixes memory corruption visible after second resume from hibernation:
Hi, you should include a cover letter detailing the differences between the original patches and the backport.
(I'll review it anyway, but it would have helped).
My bad, I actually was not aware that backport differs that much. I can describe in v2.
The patch context looks quite a different and now I see kvm_guest_cpu_offline() ends up within CONFIG_SMP for unclear reasons. Let me try to fix it in v2.
Best regards, Krzysztof