On 1/31/23 14:21, Alexey Kardashevskiy wrote:
On 01/02/2023 03:23, Tom Lendacky wrote:
On 1/30/23 19:54, Alexey Kardashevskiy wrote:
On 11/1/23 13:01, Kalra, Ashish wrote:
On 1/10/2023 6:48 PM, Alexey Kardashevskiy wrote:
On 10/1/23 19:33, Kalra, Ashish wrote:
On 1/9/2023 8:28 PM, Alexey Kardashevskiy wrote:
On 10/1/23 10:41, Kalra, Ashish wrote:
On 1/8/2023 9:33 PM, Alexey Kardashevskiy wrote:
On 15/12/22 06:40, Michael Roth wrote:
From: Brijesh Singh <brijesh.singh@xxxxxxx>
Version 2 of GHCB specification added the support for two SNP Guest
Request Message NAE events. The events allows for an SEV-SNP
guest to
make request to the SEV-SNP firmware through hypervisor using the
SNP_GUEST_REQUEST API define in the SEV-SNP firmware specification.
The SNP_EXT_GUEST_REQUEST is similar to SNP_GUEST_REQUEST with the
difference of an additional certificate blob that can be passed
through
the SNP_SET_CONFIG ioctl defined in the CCP driver. The CCP driver
provides snp_guest_ext_guest_request() that is used by the KVM
to get
both the report and certificate data at once.
Signed-off-by: Brijesh Singh <brijesh.singh@xxxxxxx>
Signed-off-by: Ashish Kalra <ashish.kalra@xxxxxxx>
Signed-off-by: Michael Roth <michael.roth@xxxxxxx>
---
And GET ioctls() return what SET passed on (not something the firware
returned, for example), what is ever going to call SET? The userspace can
As stated above, the firmware already has the information needed to sign
the attestation report. The SET IOCTL is used to supply the certficates
to the guest for validation of the attestation report.
Does the firmware have to have all certificates beforehand? How does the
firmware choose which certificate to use for a specific VM, or just signs
all reports with all certificates it knows?
From the SNP API spec, the firmware uses the VCEK, which is derived from
chip-unique secrets, to sign the attestation report.
The guest can then use the returned VCEK certificate, the ASK certificate
and ARK certificate from the extended guest request to validate the
attestation report.
This reduces the traffic and complexity of the guest requesting the
certficates from the KDS.
Guest <-> HV interaction is clear, I am only wondering about HV <-> FW.
I'm not sure what you mean here. The HV doesn't put the signing key in the
firmware, it is derived.
Thanks,
Tom
