On Mon, Jul 20, 2026 at 01:14:18PM -0300, Fabiano Rosas wrote:
> Daniel P. Berrangé <[email protected]> writes:
> 
> > On Thu, Jul 16, 2026 at 11:08:49AM -0300, Fabiano Rosas wrote:
> >> Assumptions:
> >> 
> >> A) The migration stream is assumed to be secured by TLS on a per-host
> >> basis.
> >> 
> >> B) For migration streams stored to file, including snapshots, it is
> >> assumed that the storage file is authentic, i.e. the files are owned by
> >> the party performing the live migration and have not been tampered with.
> >> 
> >> C) The network ports used for migration are expected to be available
> >> only during migration. No long-standing listening destination QEMU
> >> process.
> >> 
> >> D) The network used for migration is expected to be adequately isolated.
> >> 
> >> E) The migration source QEMU process is assumed to be secure. Compromise
> >> of the source QEMU process is nonetheless possible but exploiting the
> >> migration process is expected to grant no further privileges.
> >
> >
> > In the security.rst doc, we have an "Architecture" heading where
> > we outline design principals  for security. The "Assumptions" feels
> > like it has overlap with that section.
> >
> 
> What if we tweak that section to be more broad?
> 
> - Under "Guest Isolation":
> 
> Disk image files and network traffic must be protected from other guests...
> 
> s/unless explicitly shared between/, users and processes unless explicitly 
> shared with/
> 
> ... them by the user.
> 
> - Under Isolation Mechanisms, we can add a bullet:
> 
>   - Transport Layer Security (TLS) protocol can be used to ensure
>     hypervisor authenticity and encryption of the live migration
>     connection.
> 
> I can send a separate patch with this.
> 
> >> For security consideration, the following are considered:
> >> 
> >> OUT OF SCOPE:
> >> 
> >> 1) Abort of destination QEMU process while migration is still in course.
> >> Rationale: the source virtual machine is not affected.
> >> 
> >> 2) Migration failure.
> >> Rationale: eventual failed migrations are part of normal operation.
> >> 
> >> 3) Memory over-allocation issues in the destination QEMU process.
> >> Rationale: the destination host's operating system is expected to
> >> constrain resource usage. Process termination due to OOM falls under
> >> point 1 above.
> >
> > The "Security boundary scope" section has primarily been listing
> > things that are definitely "out of scope".
> >
> 
> I think the only point not yet covered is the destination crash
> situation, could we add this to your patch?

FYI, my patch is already merged, so please just submit a followup
patch to augment the info I added.

> 
> * **migration and snapshots**. Migration failures and snapshot load
> failures are considered part of normal operation as long as the source
> virtual machine and savevm file, respectively, are still
> functional. Aborting the QEMU process at the migration/snapshot
> destination is similarly not considered a security issue.

We should likely distinguish live migration from snapshots
a little.

In live migration if loading aborts, we still have the source
VM running fine.

With snapshots if you launch a new QEMU and restore from snapshot
there was no source VM that's relevant.

With snapshots if you have a running QEMU and rollback to a
snapshot (with loadvm), and QEMU crashes, you've lost your
currently running QEMU.

With regards,
Daniel
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