On 9/20/2023 4:34 PM, Parav Pandit wrote:
> There can be malicious SW on the host, and the host may be hacked
and compromised.
> For example:
> 1) SUSPEND the a running guest by admin vq
> 2) dumping guest memory through admin vq dirty page tracking.
No. hypervisor is trusted entity who is hosting the VM.
The PF may not owned by the hypervisor and the host can be hacked and
computerized.
The device migration is initiated by the hypervisor.
I am omitting the TDISP question for now as talked before.
TDISP spec will evolve for hypercalls when we get there.
Confidential computing is out of the spec, as we discussed and agreed.
This is to demonstrate why even using a bar cap as proxy for admin vq LM
is still problematic.
TDISP gives examples of the attacking models, and admin vq based LM
conforms to the models.
*From:* virtio-dev@lists.oasis-open.org
<virtio-dev@lists.oasis-open.org> *On Behalf Of *Zhu, Lingshan
*Sent:* Wednesday, September 20, 2023 12:01 PM
*To:* Parav Pandit <pa...@nvidia.com>; Michael S. Tsirkin <m...@redhat.com>
*Cc:* virtio-dev@lists.oasis-open.org; Jason Wang <jasow...@redhat.com>
*Subject:* Re: [virtio-dev] Re: [PATCH 0/5] virtio: introduce SUSPEND
bit and vq state
On 9/20/2023 2:08 PM, Parav Pandit wrote:
From: Zhu, Lingshan<lingshan....@intel.com>
<mailto:lingshan....@intel.com>
Sent: Wednesday, September 20, 2023 11:36 AM
On 9/19/2023 2:49 AM, Michael S. Tsirkin wrote:
On Mon, Sep 18, 2023 at 06:41:55PM +0000, Parav Pandit wrote:
Please refer to the code for setting FEATURES_OK.
It wont work when one needs to suspend the device.
There is no point of doing such work over registers as
fundamental
framework is over the AQ.
Well not really. It's over admin commands. When these were built the
intent always was that it's possible to use admin commands through
another interface, other than admin queue. Is there a problem
implementing admin commands over a memory BAR? For example, I can
see
an "admin command" capability pointing at a BAR where commands are
supplied, and using a new group type referring to device itself.
I am not sure, if a bar cap would be implemented as a proxy for the
admin vq
based live migration. then the problems of admin vq LM that we have
discussed
still exist. the bar is only a proxy, doesn't fix anything. and even
larger side
channel attacking surface: vf-->pf-->vf
AQ LM using PF has no side channel attack as hypervisor and owner device is
trusted entity as already discussed.
I believe we have discussed this for many times, and I even provide
you some examples.
Let me repeat for the last time.
There can be malicious SW on the host, and the host may be hacked and
compromised.
For example:
1) SUSPEND the a running guest by admin vq
2) dumping guest memory through admin vq dirty page tracking.
These above can happen right?
You made TDISP as an example, but have you really read the TDISP spec?
In the spec:
Device Security Architecture - Administrative interfaces (e.g., a PF)
may be
used to influence the security properties of the TDI used by the TVM.
TEE-I/O requires the device to organize its hardware/software
interfaces such that the PF cannot
be used to affect the security of a TDI when it is in use by a TVM
Clear?
