Re: [PATCH 1/2] misc: Add Nitro Secure Module driver

[Alexander Graf]

Hey Greg,

On 29.09.23 07:44, Greg Kroah-Hartman wrote:
> On Thu, Sep 28, 2023 at 10:46:44PM +0000, Alexander Graf wrote:
> > When running Linux inside a Nitro Enclave, the hypervisor provides a
> > special virtio device called "NSM". This device has 2 main functions:
> >
> >    1) Provide attestation reports
> >    2) Modify PCR state
> >    3) Provide entropy
> >
> > This patch adds the core NSM driver that exposes a /dev/nsm device node
> > which user space can use to request attestation documents and influence
> > PCR states. A follow up patch will add a hwrng driver to feed its entropy
> > into the kernel.
> >
> > Originally-by: Petre Eftime <petre.eftime@xxxxxxxxx>
> Hasn't this been submitted a long time ago?  What changed from that
> submission?  Or am I mis-remembering things?


With Nitro Enclaves, there are 2 parties: Parent and Enclave.

The parent launches the Enclave. To do so, it creates a sibling VM using 
a special Enclaves PCI device. The driver for that is in 
drivers/virt/nitro_enclaves and you helped to upstream that back then.

The enclave is what is running inside the sibling VM. It sees a 
Firecracker like device model with virtio-vsock to communicate to the 
parent as well as a special virtio-mmio device called "NSM" to 
communicate to the hypervisor. This driver is for the latter.

I'm now aware of previous attempts to upstream it.


> > --- /dev/null
> > +++ b/drivers/misc/nsm.c
> > @@ -0,0 +1,470 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Amazon Nitro Secure Module driver.
> > + *
> > + * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
> > + *
> > + * This program is free software; you can redistribute it and/or modify it
> > + * under the terms and conditions of the GNU General Public License,
> > + * version 2, as published by the Free Software Foundation.
> > + *
> > + * This program is distributed in the hope that it will be useful,
> > + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> > + * GNU General Public License for more details.
> > + *
> > + * You should have received a copy of the GNU General Public License
> > + * along with this program; if not, see <http://www.gnu.org/licenses/>.
> Please drop the license "boiler-plate" text, the SPDX line is
> sufficient.


Sure, happy to! :)


Alex




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