On 20/05/2021 12:47, Paolo Bonzini wrote: > On 20/05/21 14:56, Krzysztof Kozlowski wrote: >> From: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx> >> >> 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