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

[Robbie Harwood <rharwood@redhat.com>]

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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>

Be well,
--Robbie

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