RE: [PATCH Part2 v6 13/49] crypto:ccp: Provide APIs to issue SEV-SNP commands

Kalra, Ashish
2022-10-03T17:11:28Z

[AMD Official Use Only - General]

>> There are actually only 8 functions

>Only 8?

>Lemme ask it differently then: what is the point of the wrappers at all?

They are basically providing the APIs for the hypervisor to manage a SNP guest.

And this is the original commit for the API to manage the SEV guest:

commit 200664d5237f3f8cd2a2f9f5c5dea08502336bd1
Author: Brijesh Singh <brijesh.singh@amd.com>
Date: Mon Dec 4 10:57:28 2017 -0600

crypto: ccp: Add Secure Encrypted Virtualization (SEV) command support

AMD's new Secure Encrypted Virtualization (SEV) feature allows the
memory contents of virtual machines to be transparently encrypted with a
key unique to the VM. The programming and management of the encryption
keys are handled by the AMD Secure Processor (AMD-SP) which exposes the
commands for these tasks. The complete spec is available at:

http://support.amd.com/TechDocs/55766_SEV-KM%20API_Specification.pdf

Extend the AMD-SP driver to provide the following support:

- an in-kernel API to communicate with the SEV firmware. The API can be
used by the hypervisor to create encryption context for a SEV guest.

- a userspace IOCTL to manage the platform certificates.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Radim Krčmář" <rkrcmar@redhat.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Gary Hook <gary.hook@amd.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: linux-crypto@vger.kernel.org
Cc: kvm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Improvements-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>

Thanks,
Ashish