Re: [PATCH v1 00/11] KVM: s390: pv: implement lazy destroy

Cornelia Huck
2021-05-18T16:04:23Z

On Tue, 18 May 2021 17:36:24 +0200
Claudio Imbrenda <imbrenda@linux.ibm.com> wrote:

> On Tue, 18 May 2021 17:05:37 +0200
> Cornelia Huck <cohuck@redhat.com> wrote:
>
> > On Mon, 17 May 2021 22:07:47 +0200
> > Claudio Imbrenda <imbrenda@linux.ibm.com> wrote:

> > > This means that the same address space can have memory belonging to
> > > more than one protected guest, although only one will be running,
> > > the others will in fact not even have any CPUs.
> >
> > Are those set-aside-but-not-yet-cleaned-up pages still possibly
> > accessible in any way? I would assume that they only belong to the
>
> in case of reboot: yes, they are still in the address space of the
> guest, and can be swapped if needed
>
> > 'zombie' guests, and any new or rebooted guest is a new entity that
> > needs to get new pages?
>
> the rebooted guest (normal or secure) will re-use the same pages of the
> old guest (before or after cleanup, which is the reason of patches 3
> and 4)

Took a look at those patches, makes sense.

>
> the KVM guest is not affected in case of reboot, so the userspace
> address space is not touched.

'guest' is a bit ambiguous here -- do you mean the vm here, and the
actual guest above?