[23.10 FEAT] KVM: Improve memory reclaiming for z15 Secure Execution guests - qemu part

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Feature Description:

Currently, Secure Execution guest memory needs to be exported or destroyed, when a secure guest is rebooted or shut down. On the z15 this currently happens in a serialized manner, which takes long and also causes the host system to become irresponsive for extended periods, if very large guests are terminated. Changes to the KVM memory management will be required to improve the scalability.

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------- Comment From <email address hidden> 2023-02-09 10:42 EDT-------
Please note: In addition to this qemu part, there is also a kernel and a libvirt part required to implement the feature "KVM: Improve memory reclaiming for z15 Secure Execution guests".

The two other parts (kernel and libvirt) are handled in the following bugs / LP entries:

Bug 193343 - LP1933180 : [23.04 FEAT] [VS2106] KVM: Improve memory reclaiming for z15 Secure Execution guests - kernel part
Bug 201598 - LP2006743 : [23.10 FEAT] [VS2106] KVM: Improve memory reclaiming for z15 Secure Execution guests - libvirt part

[Christian Ehrhardt (paelzer)]

Hi, we are working on qemu 8.0 right now, so I wanted to ask if it might by any chance be part of that already? If not - is there a known list of commits upstream after 8.0 to consider for this?

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------- Comment From <email address hidden> 2023-07-03 07:37 EDT-------
Hi,

most of the feature is in 8.0

you will need the following patches on top of 8.0:

80bd81cadd127c1e2fc784612a52abe392670ba4
2ca10faeb85e3c1b87e10bb46786445a5a879bbd (optional)
88693ab2a53f2f3d25cb39a7b5034ab391bc5a81

[Sergio Durigan Junior (sergiodj)]

Hi,

It seems that all patches mentioned in comment #3 are present in the latest qemu version that's shipped in Mantic (8.0.2). The hashes are a bit different because the ones provided in the comment belong to a development branch; these are the official hashes in the same order:

8ad637881f6ddf404bd554e149450a98ba8f5446
 2ca10faeb85e3c1b87e10bb46786445a5a879bbd (optional)
21b54a683d14c0c6f9af35536d9059c60b7449ca

@IBM, could you please double check and confirm that there is nothing else to be done here? I'll mark this bug as In Progress for now. Thanks.

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------- Comment From <email address hidden> 2023-07-11 08:09 EDT-------
the commit IDs I provided are in master, the ones you provided are in stable-8.0, but it's indeed the same code.

if that's already integrated, there is nothing else to do, you are good to go

[Frank Heimes (fheimes)]

Thanks for the confirmation Claudio.
With that I'm updating this ticket to Fix Released.