[PATCH v4 00/15] s390: vfio-ap: guest dedicated crypto adapters

[Tony Krowiak]

On s390, we have cryptographic coprocessor cards, which are modeled on
Linux as devices on the AP bus. Each card can be partitioned into domains
which can be thought of as a set of hardware registers for processing 
crypto commands. Crypto commands are sent to a specific domain within a
card is via a queue which is identified as a (card,domain) tuple. We model 
this something like the following (assuming we have access to cards 3 and 
4 and domains 1 and 2):

AP -> card3 -> queue (3,1)
            -> queue (3,2)
   -> card4 -> queue (4,1)
            -> queue (4,2)

If we want to virtualize this, we can use a feature provided by the
hardware. We basically attach a satellite control block to our main
hardware virtualization control block and the hardware takes care of
most of the rest.

For this control block, we don't specify explicit tuples, but a list of
cards and a list of domains. The guest will get access to the cross
product.

Because of this, we need to take care that the lists provided to
different guests don't overlap; i.e., we need to enforce sane
configurations. Otherwise, one guest may get access to things like
secret keys for another guest.

The idea of this patch set is to introduce a new device, the matrix
device. This matrix device hangs off a different root and acts as the
parent node for mdev devices.

If you now want to give the tuples (4,1) and (4,2), you need to do the
following:

- Unbind the (4,1) and (4,2) tuples from their ap bus driver.
- Bind the (4,1) and (4,2) tuples to the vfio_ap driver.
- Create the mediated device.
- Assign card 4 and domains 1 and 2 to the mediated device

QEMU will now simply consume the mediated device and things should work.

For a complete description of the architecture and concepts underlying the 
design, see the Documentation/s390/vfio-ap.txt file included with this
patch set.

Change log v3 -> v4
===================
* Resolved issue with enabling ZCRYPT when KVM is enabled by using
  #ifdef ZCRYPT in relevant functions
* Added patch with a new function for resetting the crypto attributes
  for all vcpus to resolve the issue raised with running vcpus getting out 
  of sync.
* Removed KVM_S390_VM_CRYPTO_INTERPRET_AP: Setting interpretive exec mode
  from vfio_ap driver when mdev device is opened.


Tony Krowiak (15):
  s390: zcrypt: externalize AP instructions available function
  KVM: s390: reset crypto attributes for all vcpus
  KVM: s390: refactor crypto initialization
  KVM: s390: CPU model support for AP virtualization
  KVM: s390: enable/disable AP interpretive execution
  s390: vfio-ap: base implementation of VFIO AP device driver
  s390: vfio-ap: register matrix device with VFIO mdev framework
  KVM: s390: interfaces to (de)configure guest's AP matrix
  s390: vfio-ap: sysfs interfaces to configure adapters
  s390: vfio-ap: sysfs interfaces to configure domains
  s390: vfio-ap: sysfs interfaces to configure control domains
  s390: vfio-ap: sysfs interface to view matrix mdev matrix
  KVM: s390: configure the guest's AP devices
  s390: vfio-ap: implement VFIO_DEVICE_GET_INFO ioctl
  s390: doc: detailed specifications for AP virtualization

 Documentation/s390/vfio-ap.txt        |  567 +++++++++++++++++++++
 MAINTAINERS                           |   12 +
 arch/s390/Kconfig                     |   11 +
 arch/s390/include/asm/ap.h            |    7 +
 arch/s390/include/asm/kvm-ap.h        |  136 +++++
 arch/s390/include/asm/kvm_host.h      |    3 +
 arch/s390/include/uapi/asm/kvm.h      |    1 +
 arch/s390/kvm/Makefile                |    2 +-
 arch/s390/kvm/kvm-ap.c                |  339 +++++++++++++
 arch/s390/kvm/kvm-s390.c              |   93 ++---
 arch/s390/kvm/kvm-s390.h              |   14 +
 arch/s390/tools/gen_facilities.c      |    2 +
 drivers/s390/crypto/Makefile          |    4 +
 drivers/s390/crypto/ap_bus.c          |    6 +
 drivers/s390/crypto/vfio_ap_drv.c     |  143 ++++++
 drivers/s390/crypto/vfio_ap_ops.c     |  873 +++++++++++++++++++++++++++++++++
 drivers/s390/crypto/vfio_ap_private.h |   46 ++
 include/uapi/linux/vfio.h             |    2 +
 18 files changed, 2200 insertions(+), 61 deletions(-)
 create mode 100644 Documentation/s390/vfio-ap.txt
 create mode 100644 arch/s390/include/asm/kvm-ap.h
 create mode 100644 arch/s390/kvm/kvm-ap.c
 create mode 100644 drivers/s390/crypto/vfio_ap_drv.c
 create mode 100644 drivers/s390/crypto/vfio_ap_ops.c
 create mode 100644 drivers/s390/crypto/vfio_ap_private.h