Re: [PATCH v4 0/6] Dynamic allocation of memory regions and IBM vTPM 2.0

[Daniel Kiper]

On Tue, Feb 28, 2023 at 12:50:39PM -0500, Robbie Harwood wrote:
> Stefan Berger <stefanb@linux.ibm.com> writes:
>
> > Hello,
> >
> > This is an addition to the series sent from Daniel Axtens
> > (https://lists.gnu.org/archive/html/grub-devel/2022-04/msg00064.html).
> >
> > Patch 'ieee1275: request memory with ibm,client-architecture-support'
> > implements vectors 1-4 of client-architecture-support negotiation
> > However, during some tests, we found this can be a problem if:
> >
> > - we have more than 64 CPUs
> > - Hardware Management Console (HMC) is configured to minimum of CPUs >64 
> > (for
> > example, min of 200 CPUs)
> > - Grub needs to request memory.
> >
> > If vector 5 is not implemented, Power Hypervisor will consider the default
> > value for vector 5 and 64 will bet set as the maximum  number of CPUs
> > supported by the OS, causing the machine to fail to init. Today we support
> > 256 CPUs (max) on Power, so we need to implement vector 5 and set the MAX
> > CPUs bits to this value.
> >
> > Add an IBM/ieee1275 vTPM 2.0 driver that requires the preceeding memory
> > patches due to the grub's TPM subsystem needing large chunks of memory for
> > hashing of files such as initrd and kernel.
> >
> >   Stefan
>
> For the series:
>
> Reviewed-by: Robbie Harwood <rharwood@redhat.com>

Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>

Thank you for doing this work!

Daniel