[PATCH v6 0/9] Xen FF-A mediator

[Jens Wiklander <jens.wiklander@xxxxxxxxxx>]

Hi,

This patch sets add a FF-A [1] mediator modeled after the TEE mediator
already present in Xen. The FF-A mediator implements the subset of the FF-A
1.1 specification needed to communicate with OP-TEE using FF-A as transport
mechanism instead of SMC/HVC as with the TEE mediator. It allows a similar
design in OP-TEE as with the TEE mediator where OP-TEE presents one virtual
partition of itself to each guest in Xen.

The FF-A mediator is generic in the sense it has nothing OP-TEE specific
except that only the subset needed for OP-TEE is implemented so far. The
hooks needed to inform OP-TEE that a guest is created or destroyed is part
of the FF-A specification.

It should be possible to extend the FF-A mediator to implement a larger
portion of the FF-A 1.1 specification without breaking with the way OP-TEE
is communicated with here. So it should be possible to support any TEE or
Secure Partition using FF-A as transport with this mediator.

[1] https://developer.arm.com/documentation/den0077/latest

Thanks,
Jens

v5->v6:
* Updated "xen/arm: move regpair_to_uint64() and uint64_to_regpair() to regs.h"
  commit message and moved the patch right before the patch which needs it.
  Applied Michal Orzel's R-B tag.
* Renamed the guest configuration option "ffa_enabled" to "ffa" and
  updated the description.
* More tools update in "xen/arm: add a primitive FF-A mediator" with the "ffa"
  option, including golang and ocaml.
* Update ffa_domain_init() to return an error if communication with
  the SPMC can't be established.
* Factored out a ffa_domain_destroy() from ffa_relinquish_resources().
* Added ffa_get_call_count() to give an accurate number of FF-A function,
  updated in each patch as new FF-A functions are added.
* Added a flags field in struct xen_arch_domainconfig that replaces the
  ffa_enabled field.
* Made check_mandatory_feature() __init
* Replaced a few printk() calls with gprintk() where needed.
* Rebased on staging as of 2022-09-14

V4->v5:
* Added "xen/arm: move regpair_to_uint64() and uint64_to_regpair() to regs.h"
* Added documentation for the "ffa_enabled" guest config flag
* Changed to GPL license for xen/arch/arm/ffa.c
* Added __read_mostly and const where applicable
* Added more describing comments in the code
* Moved list of shared memory object ("ffa_mem_list") into the guest context
  as they are guest specific
* Simplified a few of the simple wrapper functions for SMC to SPMC
* Added a BUILD_BUG_ON(PAGE_SIZE != FFA_PAGE_SIZE) since the mediator
  currently depends on the page size to be same as FFA_PAGE_SIZE (4k).
* Added max number of shared memory object per guest and max number of
  size of each shared memory object
* Added helper macros to calculate offsets of different FF-A data structures
  in the communication buffer instead of relying on pointer arithmetic
* Addressed style issues and other comments
* Broke the commit "xen/arm: add FF-A mediator" into multiple parts, trying
  to add a few features at a time as requested
* Added a missing call to rxtx_unmap() in ffa_relinquish_resources()
* Assignment of "ffa_enabled" is kept as is until I have something definitive
  on the type etc.
* Tested with CONFIG_DEBUG=y

v3->v4:
* Missed v3 and sent a v4 instead by mistake.

v2->v3:
* Generates offsets into struct arm_smccc_1_2_regs with asm-offsets.c in
  order to avoid hard coded offsets in the assembly function
  arm_smccc_1_2_smc()
* Adds an entry in SUPPORT.md on the FF-A status
* Adds a configuration variable "ffa_enabled" to tell if FF-A should be
  enabled for a particular domu guest
* Moves the ffa_frag_list for fragmented memory share requests into
  struct ffa_ctx instead to keep it per guest in order to avoid mixups
  and simplify locking
* Adds a spinlock to struct ffa_ctx for per guest locking
* Addressing style issues and suggestions
* Uses FFA_FEATURES to check that all the needed features are available
  before initializing the mediator
* Rebased on staging as of 2022-06-20

v1->v2:
* Rebased on staging to resolve some merge conflicts as requested

Jens Wiklander (9):
  xen/arm: smccc: add support for SMCCCv1.2 extended input/output
    registers
  xen/arm: add a primitive FF-A mediator
  xen/arm: ffa: add direct request support
  xen/arm: ffa: map SPMC rx/tx buffers
  xen/arm: ffa: send guest events to Secure Partitions
  xen/arm: ffa: support mapping guest RX/TX buffers
  xen/arm: ffa: support guest FFA_PARTITION_INFO_GET
  xen/arm: move regpair_to_uint64() and uint64_to_regpair() to regs.h
  xen/arm: ffa: support sharing memory

 SUPPORT.md                           |    7 +
 docs/man/xl.cfg.5.pod.in             |   15 +
 tools/golang/xenlight/helpers.gen.go |    6 +
 tools/golang/xenlight/types.gen.go   |    1 +
 tools/include/libxl.h                |    6 +
 tools/libs/light/libxl_arm.c         |    6 +
 tools/libs/light/libxl_types.idl     |    1 +
 tools/ocaml/libs/xc/xenctrl.ml       |    1 +
 tools/ocaml/libs/xc/xenctrl.mli      |    1 +
 tools/xl/xl_parse.c                  |    1 +
 xen/arch/arm/Kconfig                 |   11 +
 xen/arch/arm/Makefile                |    1 +
 xen/arch/arm/arm64/asm-offsets.c     |    9 +
 xen/arch/arm/arm64/smc.S             |   42 +
 xen/arch/arm/domain.c                |   11 +
 xen/arch/arm/domain_build.c          |    1 +
 xen/arch/arm/ffa.c                   | 1827 ++++++++++++++++++++++++++
 xen/arch/arm/include/asm/domain.h    |    4 +
 xen/arch/arm/include/asm/ffa.h       |   78 ++
 xen/arch/arm/include/asm/regs.h      |   12 +
 xen/arch/arm/include/asm/smccc.h     |   40 +
 xen/arch/arm/tee/optee.c             |   11 -
 xen/arch/arm/vsmc.c                  |   19 +-
 xen/include/public/arch-arm.h        |    4 +
 24 files changed, 2100 insertions(+), 15 deletions(-)
 create mode 100644 xen/arch/arm/ffa.c
 create mode 100644 xen/arch/arm/include/asm/ffa.h

-- 
2.31.1