Re: [PATCH v1 00/15] Add support for Nitro Enclaves

Paolo Bonzini
2020-04-30T11:39:03Z

On 30/04/20 13:21, Alexander Graf wrote:
>> Also, would you consider a mode where ne_load_image is not invoked and
>> the enclave starts in real mode at 0xffffff0?
>
> Consider, sure. But I don't quite see any big benefit just yet. The
> current abstraction level for the booted payloads is much higher. That
> allows us to simplify the device model dramatically: There is no need to
> create a virtual flash region for example.

It doesn't have to be flash, it can be just ROM.

> In addition, by moving firmware into the trusted base, firmware can
> execute validation of the target image. If you make it all flat, how do
> you verify whether what you're booting is what you think you're booting?

So the issue would be that a firmware image provided by the parent could
be tampered with by something malicious running in the parent enclave?

Paolo

> So in a nutshell, for a PV virtual machine spawning interface, I think
> it would make sense to have memory fully owned by the parent. In the
> enclave world, I would rather not like to give the parent too much
> control over what memory actually means, outside of donating a bucket of
> it.