mbox series

[00/10] Add dynamic boost control support

Message ID 20230420163140.14940-1-mario.limonciello@amd.com
Headers
Series Add dynamic boost control support |

Message

Mario Limonciello April 20, 2023, 4:31 p.m. UTC 
  Dynamic boost control is a feature of some SoCs that allows
an authenticated entity to send commands to the security processor
to control certain SOC characteristics with the intention to improve
performance.

This is implemented via a mechanism that a userspace application would
authenticate using a nonce and key exchange over an IOCTL interface.

After authentication is complete an application can exchange signed
messages with the security processor and both ends can validate the
data transmitted.

This series includes a test suite that can be run on real hardware
to ensure that the communication works as expected.  This can also be
used for an application to model the communication path.

Two sysfs files are introduced for reading the PSP bootloader version
as well as TEE version which can be useful data points for debugging
communication problems.

Mario Limonciello (10):
  crypto: ccp: Rename macro for security attributes
  crypto: ccp: Add support for displaying PSP firmware versions
  crypto: ccp: Add bootloader and TEE version offsets
  crypto: ccp: move setting PSP master to earlier in the init
  crypto: ccp: Add support for fetching a nonce for dynamic boost
    control
  crypto: ccp: Add support for setting user ID for dynamic boost control
  crypto: ccp: Add support for getting and setting DBC parameters
  crypto: ccp: Add a sample script for Dynamic Boost Control
  crypto: ccp: Add unit tests for dynamic boost control
  crypto: ccp: Add Mario to MAINTAINERS

 Documentation/ABI/testing/sysfs-driver-ccp |  18 ++
 MAINTAINERS                                |  11 +
 drivers/crypto/ccp/Makefile                |   3 +-
 drivers/crypto/ccp/dbc.c                   | 250 +++++++++++++++++++
 drivers/crypto/ccp/dbc.h                   |  56 +++++
 drivers/crypto/ccp/psp-dev.c               |  16 +-
 drivers/crypto/ccp/psp-dev.h               |   1 +
 drivers/crypto/ccp/sp-dev.h                |   7 +
 drivers/crypto/ccp/sp-pci.c                |  90 ++++++-
 include/linux/psp-platform-access.h        |   4 +
 include/uapi/linux/psp-dbc.h               | 147 ++++++++++++
 tools/crypto/ccp/.gitignore                |   1 +
 tools/crypto/ccp/dbc.py                    |  98 ++++++++
 tools/crypto/ccp/dbc_cli.py                | 123 ++++++++++
 tools/crypto/ccp/test_dbc.py               | 266 +++++++++++++++++++++
 15 files changed, 1074 insertions(+), 17 deletions(-)
 create mode 100644 drivers/crypto/ccp/dbc.c
 create mode 100644 drivers/crypto/ccp/dbc.h
 create mode 100644 include/uapi/linux/psp-dbc.h
 create mode 100644 tools/crypto/ccp/.gitignore
 create mode 100644 tools/crypto/ccp/dbc.py
 create mode 100755 tools/crypto/ccp/dbc_cli.py
 create mode 100755 tools/crypto/ccp/test_dbc.py


base-commit: 482c84e906e535072c55395acabd3a58e9443d12

Comments

Pavel Machek April 26, 2023, 1:47 p.m. UTC | #1 
Hi!

> Dynamic boost control is a feature of some SoCs that allows
> an authenticated entity to send commands to the security processor
> to control certain SOC characteristics with the intention to improve
> performance.
> 
> This is implemented via a mechanism that a userspace application would
> authenticate using a nonce and key exchange over an IOCTL interface.
> 
> After authentication is complete an application can exchange signed
> messages with the security processor and both ends can validate the
> data transmitted.

Why is this acceptable? This precludes cross-platform interfaces,
right? Why would application want to validate data from PSP? That
precludes virtualization, right?

Just put the key in kernel. Users have right to control their own
hardware.
							Pavel

--
Mario Limonciello April 26, 2023, 2:43 p.m. UTC | #2 
On 4/26/23 08:47, Pavel Machek wrote:
> Hi!
>
>> Dynamic boost control is a feature of some SoCs that allows
>> an authenticated entity to send commands to the security processor
>> to control certain SOC characteristics with the intention to improve
>> performance.
>>
>> This is implemented via a mechanism that a userspace application would
>> authenticate using a nonce and key exchange over an IOCTL interface.
>>
>> After authentication is complete an application can exchange signed
>> messages with the security processor and both ends can validate the
>> data transmitted.
> Why is this acceptable? This precludes cross-platform interfaces,
> right? Why would application want to validate data from PSP? That
> precludes virtualization, right?
>
> Just put the key in kernel. Users have right to control their own
> hardware.
> 							Pavel

This matches exactly how the interface works in Windows as well.

The reason for validating the data from the PSP is because the data
crosses multiple trust boundaries and this ensures that the application
can trust it to make informed decisions.
Pavel Machek July 15, 2023, 6:23 a.m. UTC | #3 
On Wed 2023-04-26 09:43:43, Mario Limonciello wrote:
> 
> On 4/26/23 08:47, Pavel Machek wrote:
> > Hi!
> > 
> > > Dynamic boost control is a feature of some SoCs that allows
> > > an authenticated entity to send commands to the security processor
> > > to control certain SOC characteristics with the intention to improve
> > > performance.
> > > 
> > > This is implemented via a mechanism that a userspace application would
> > > authenticate using a nonce and key exchange over an IOCTL interface.
> > > 
> > > After authentication is complete an application can exchange signed
> > > messages with the security processor and both ends can validate the
> > > data transmitted.
> > Why is this acceptable? This precludes cross-platform interfaces,
> > right? Why would application want to validate data from PSP? That
> > precludes virtualization, right?
> > 
> > Just put the key in kernel. Users have right to control their own
> > hardware.
> > 							Pavel
> 
> This matches exactly how the interface works in Windows as well.

Windows has different design constrants.

> The reason for validating the data from the PSP is because the data
> crosses multiple trust boundaries and this ensures that the application
> can trust it to make informed decisions.

If the application can not trust kernel, you are already doomed on
Linux.

									Pavel