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Re: SEV guest attestation
From: |
Daniel P . Berrangé |
Subject: |
Re: SEV guest attestation |
Date: |
Thu, 25 Nov 2021 13:52:02 +0000 |
User-agent: |
Mutt/2.1.3 (2021-09-10) |
On Thu, Nov 25, 2021 at 08:14:28AM +0100, Sergio Lopez wrote:
> For SEV-SNP, this is pretty much the end of the story, because the
> attestation exchange is driven by an agent inside the guest. Well,
> there's also the need to have in the VM a well-known vNIC bridged to a
> network that's routed to the Attestation Server, that everyone seems
> to consider a given, but to me, from a CSP perspective, looks like
> quite a headache. In fact, I'd go as far as to suggest this
> communication should happen through an alternative channel, such as
> vsock, having a proxy on the Host, but I guess that depends on the CSP
> infrastructure.
Allowing network connections from inside the VM, to any kind
of host side mgmt LAN services is a big no for some cloud hosts.
They usually desire for any guest network connectivity to be
associated with a VLAN/network segment that is strictly isolated
from any host mgmt LAN.
OpenStack provides a virtual CCDROM for injecting cloud-init
metadata as an alternative to the network based metadata REST
service, since they latter often isn't deployed.
Similarly for virtual filesystems, we've designed virtiofs,
rather than relying on a 2nd NIC combined with NFS.
We cannot assume availability of a real network device for the
attestation. If one does exist fine, but there needs to be an
alternative option that can be used.
On a slightly different topic - if the attestation is driven
from an agent inside the guest, this seems to imply we let the
guest vCPUs start beforre attestation is done. Contrary to
the SEV/SEV-ES where we seem to be wanting vCPUs to remain
in the stopped state until attestation is complete & secrets
provided. If the vCPUs are started, is there some mechanism
to restrict what can be done before attestation is complete?
Regards,
Daniel
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- Re: SEV guest attestation, (continued)
- Re: SEV guest attestation, Daniel P . Berrangé, 2021/11/24
- Re: SEV guest attestation, Dr. David Alan Gilbert, 2021/11/25
- Re: SEV guest attestation, Daniel P . Berrangé, 2021/11/25
- Re: SEV guest attestation,
Daniel P . Berrangé <=
- Re: SEV guest attestation, Dov Murik, 2021/11/25
- Re: SEV guest attestation, Dr. David Alan Gilbert, 2021/11/25
- Re: SEV guest attestation, Daniel P . Berrangé, 2021/11/25
- Re: SEV guest attestation, Dov Murik, 2021/11/25
- Re: SEV guest attestation, Daniel P . Berrangé, 2021/11/25
- Re: SEV guest attestation, Dr. David Alan Gilbert, 2021/11/25