[RFC PATCH 00/19] vhost-user-rpmb (Replay Protected Memory Block)

[Alex Bennée]

Hi,

This is an initial implementation of a vhost-user backend for the
VirtIO RPMB device. The device is currently in the draft of the next
VirtIO specification and describes block device which uses combination
of a key, nonce, hashing and a persistent write counter to prevent
replay attacks (hence Replay Protected Memory Block).

It is implemented as a vhost-user device because we want to experiment
in making portable backends that can be used with multiple
hypervisors. We also want to support backends isolated in their own
separate service VMs with limited memory cross-sections with the
principle guest. This is part of a wider initiative called project
Stratos for which you can find information here:

  https://collaborate.linaro.org/display/STR/Stratos

I mention this to explain the decision to duplicate some of the
utility functions (specifically iov and hmac handling) and write the
daemon as a fairly pure glib application that just depends on
libvhost-user. As it happens I ended up having to include libqemuutil
as libvhost-user requires qemu_memfd_alloc. Whether this is an
oversight for libvhost-user or it means we should split these daemons
into a separate repository is a discussion I would like to have with
the community. Now I have a working reference implementation I also
want to explore how easy it is to write a Rust version of the backend
which raises similar questions about where such a project should live.

The current Linux kernel doesn't support RPMB devices in the vanilla
tree so if you want to test you will need to look at my testing tree
which is based on Thomas Winkler's original patches although somewhat
cut down and pared back to just support the JDEC style frames of the
upstream spec and the simple chardev based userspace interface. You
can find my kernel testing tree here:

  
https://git.linaro.org/people/alex.bennee/linux.git/log/?h=testing/virtio-rpmb  
 

The above branch includes a simple test script with the rpmb userspace
tool which I've used to exercise the various features. I'm unsure if
there will ever be a push to upstream support for RPMB to the kernel
as access to these sorts of devices are usually the preserve of
firmware living in the secure world. There is currently work underway
to support this device in uboot and I suspect eventually there will be
support for OPTEE as well.

Any review comments gratefully received as well as discussion about if
we should consider creating some new projects for housing these sort
of vhost-user backends. 

Alex Bennée (19):
  tools/virtiofsd: add support for --socket-group
  hw/block: add boilerplate for vhost-user-rpmb device
  hw/virtio: move virtio-pci.h into shared include space
  hw/block: add vhost-user-rpmb-pci boilerplate
  virtio-pci: add notification trace points
  tools/vhost-user-rpmb: add boilerplate and initial main
  tools/vhost-user-rpmb: implement --print-capabilities
  tools/vhost-user-rpmb: connect to fd and instantiate basic run loop
  tools/vhost-user-rpmb: add a --verbose/debug flags for logging
  tools/vhost-user-rpmb: handle shutdown and SIGINT/SIGHUP cleanly
  tools/vhost-user-rpmb: add --flash-path for backing store
  tools/vhost-user-rpmb: import hmac_sha256 functions
  tools/vhost-user-rpmb: implement the PROGRAM_KEY handshake
  tools/vhost-user-rpmb: implement VIRTIO_RPMB_REQ_GET_WRITE_COUNTER
  tools/vhost-user-rpmb: implement VIRTIO_RPMB_REQ_DATA_WRITE
  tools/vhost-user-rpmb: implement VIRTIO_RPMB_REQ_DATA_READ
  tools/vhost-user-rpmb: add key persistence
  tools/vhost-user-rpmb: allow setting of the write_count
  docs: add a man page for vhost-user-rpmb

 docs/tools/index.rst                       |   1 +
 docs/tools/vhost-user-rpmb.rst             | 102 +++
 docs/tools/virtiofsd.rst                   |   4 +
 include/hw/virtio/vhost-user-rpmb.h        |  46 ++
 {hw => include/hw}/virtio/virtio-pci.h     |   0
 tools/vhost-user-rpmb/hmac_sha256.h        |  87 ++
 tools/virtiofsd/fuse_i.h                   |   1 +
 hw/block/vhost-user-rpmb-pci.c             |  82 ++
 hw/block/vhost-user-rpmb.c                 | 333 ++++++++
 hw/virtio/vhost-scsi-pci.c                 |   2 +-
 hw/virtio/vhost-user-blk-pci.c             |   2 +-
 hw/virtio/vhost-user-fs-pci.c              |   2 +-
 hw/virtio/vhost-user-input-pci.c           |   2 +-
 hw/virtio/vhost-user-scsi-pci.c            |   2 +-
 hw/virtio/vhost-user-vsock-pci.c           |   2 +-
 hw/virtio/vhost-vsock-pci.c                |   2 +-
 hw/virtio/virtio-9p-pci.c                  |   2 +-
 hw/virtio/virtio-balloon-pci.c             |   2 +-
 hw/virtio/virtio-blk-pci.c                 |   2 +-
 hw/virtio/virtio-input-host-pci.c          |   2 +-
 hw/virtio/virtio-input-pci.c               |   2 +-
 hw/virtio/virtio-iommu-pci.c               |   2 +-
 hw/virtio/virtio-net-pci.c                 |   2 +-
 hw/virtio/virtio-pci.c                     |   5 +-
 hw/virtio/virtio-rng-pci.c                 |   2 +-
 hw/virtio/virtio-scsi-pci.c                |   2 +-
 hw/virtio/virtio-serial-pci.c              |   2 +-
 tools/vhost-user-rpmb/hmac_sha256.c        | 331 ++++++++
 tools/vhost-user-rpmb/main.c               | 880 +++++++++++++++++++++
 tools/virtiofsd/fuse_lowlevel.c            |   6 +
 tools/virtiofsd/fuse_virtio.c              |  20 +-
 MAINTAINERS                                |   5 +
 hw/block/Kconfig                           |   5 +
 hw/block/meson.build                       |   3 +
 hw/virtio/trace-events                     |   7 +-
 tools/meson.build                          |   8 +
 tools/vhost-user-rpmb/50-qemu-rpmb.json.in |   5 +
 tools/vhost-user-rpmb/meson.build          |  12 +
 38 files changed, 1956 insertions(+), 21 deletions(-)
 create mode 100644 docs/tools/vhost-user-rpmb.rst
 create mode 100644 include/hw/virtio/vhost-user-rpmb.h
 rename {hw => include/hw}/virtio/virtio-pci.h (100%)
 create mode 100644 tools/vhost-user-rpmb/hmac_sha256.h
 create mode 100644 hw/block/vhost-user-rpmb-pci.c
 create mode 100644 hw/block/vhost-user-rpmb.c
 create mode 100644 tools/vhost-user-rpmb/hmac_sha256.c
 create mode 100644 tools/vhost-user-rpmb/main.c
 create mode 100644 tools/vhost-user-rpmb/50-qemu-rpmb.json.in
 create mode 100644 tools/vhost-user-rpmb/meson.build

-- 
2.20.1