Re: [PATCH v12 00/18] KVM: s390: pv: implement lazy destroy for reboot

From: Janosch Frank
Date: Thu Jul 14 2022 - 02:59:26 EST


On 6/28/22 15:56, Claudio Imbrenda wrote:
Previously, when a protected VM was rebooted or when it was shut down,
its memory was made unprotected, and then the protected VM itself was
destroyed. Looping over the whole address space can take some time,
considering the overhead of the various Ultravisor Calls (UVCs). This
means that a reboot or a shutdown would take a potentially long amount
of time, depending on the amount of used memory.

This patchseries implements a deferred destroy mechanism for protected
guests. When a protected guest is destroyed, its memory can be cleared
in background, allowing the guest to restart or terminate significantly
faster than before.


Patches 1-12 have spent a considerable amount of time in the CI and I'd like to queue them to be able to focus on the rest of the series.

Patch 9 will need two small fixups since there are two conflicts where a line was introduced before your addition of the include and the struct kvm_s390_pv mmu_notifier member. I.e. it's more of a patch history problem than a real conflict.

I'd fix that up when queuing if you're ok with it?