Re: [PATCH Part2 RFC v4 04/40] x86/sev: Add the host SEV-SNP initialization support

[Jarkko Sakkinen]

On Wed, Jul 07, 2021 at 01:35:40PM -0500, Brijesh Singh wrote:
> The memory integrity guarantees of SEV-SNP are enforced through a new
> structure called the Reverse Map Table (RMP). The RMP is a single data
> structure shared across the system that contains one entry for every 4K
> page of DRAM that may be used by SEV-SNP VMs. The goal of RMP is to
> track the owner of each page of memory. Pages of memory can be owned by
> the hypervisor, owned by a specific VM or owned by the AMD-SP. See APM2
> section 15.36.3 for more detail on RMP.
> 
> The RMP table is used to enforce access control to memory. The table itself
> is not directly writable by the software. New CPU instructions (RMPUPDATE,
> PVALIDATE, RMPADJUST) are used to manipulate the RMP entries.

What's the point of throwing out a set of opcodes, if there's
no explanation what they do?

BR, Jarkko