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Subject: Re: [PATCH v1 00/15] Add support for Nitro Enclaves
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From:   Paolo Bonzini <pbonzini@redhat.com>
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Date:   Thu, 30 Apr 2020 13:38:55 +0200
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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.