Re: [XEN PATCH v9 00/24] Xen FF-A mediator

[Bertrand Marquis <Bertrand.Marquis@xxxxxxx>]

Hi Jens,

> On 5 Jul 2023, at 11:34, Jens Wiklander <jens.wiklander@xxxxxxxxxx> wrote:
> 
> Hi,
> 
> This patch sets add an FF-A [1] mediator to the TEE mediator framework
> 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 are 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.
> 
> The patches are also available at https://github.com/jenswi-linaro/xen
> branch "xen_ffa_v9".
> 
> With help from Bertrand I've integrated this in a test setup with OP-TEE.
> Please check prerequisites at
> https://optee.readthedocs.io/en/latest/building/prerequisites.html
> 
> My setup is duplicated using:
> repo init -u https://github.com/jenswi-linaro/manifest.git -m qemu_v8.xml \
>        -b qemu_xen_ffa
> repo sync -j8
> cd build
> make -j8 toolchains
> make -j8 all
> make run-only
> 
> Test in dom0 with for instance:
> xtest 1004
> 
> at the prompt.
> 
> To start up a domu and connect to it do:
> cd /mnt/host/build/qemu_v8/xen
> xl create guest_ffa.cfg
> xl console domu
> 
> Then test as usual with "xtest 1004".
> 
> The setup uses the branch "ffa" from https://github.com/jenswi-linaro/xen.
> That's currently the same as the "xen_ffa_v9" branch, but the "ffa" branch
> may change later as I update for a new version of the patch set.
> 
> [1] https://developer.arm.com/documentation/den0077/latest
> 
> Thanks,
> Jens
> 
> v8->v9:
> * Patch "xen/arm: ffa: add remaining SMC function IDs"
>  - mention the documentation number used
>  - Adding Reviewed-by: Henry Wang <Henry.Wang@xxxxxxx>
> * Patch "xen/arm: ffa: add flags for FFA_PARTITION_INFO_GET"
>  - Adding a reference to the documentation
>  - Renaming FFA_PART_PROP_IS_MASK to FFA_PART_PROP_IS_TYPE_MASK
>  - Adding Reviewed-by: Henry Wang <Henry.Wang@xxxxxxx>
> * Patch "xen/arm: ffa: add defines for framework direct request/response 
> messages"
>  - add a reference to the documentation
>  - Adding Reviewed-by: Henry Wang <Henry.Wang@xxxxxxx>
> * Patch "docs: add Arm FF-A mediator"
>  - Updating the wording as requested.
>  - Adding Reviewed-by: Henry Wang <Henry.Wang@xxxxxxx>
>  - Fixing a few typos and adding a reference to the code for a list of
>    limitations
> * Patch "xen/arm: ffa: list current limitations"
>  - Fixing a couple of typos
>  - Adding Reviewed-by: Henry Wang <Henry.Wang@xxxxxxx>
>  - Removing an invalid limitation of FFA_RXTX_MAP_*
> * Patch "xen/arm: ffa: add defines for sharing memory"
>  - Fixing a few typos
>  - Adding a reference to the documentation
>  - Adding Reviewed-by: Henry Wang <Henry.Wang@xxxxxxx>
>  - Updating FFA_MAX_SHM_PAGE_COUNT to have a safe margin to
>    TEEC_CONFIG_SHAREDMEM_MAX_SIZE
> * Patch "xen/arm: ffa: add direct request support"
>  - Fixing a coding style issue
>  - Adding Reviewed-by: Henry Wang <Henry.Wang@xxxxxxx>
>  - Updating the TODO comment about features.
> * Patch "xen/arm: ffa: send guest events to Secure Partitions"
>  - Adding a TODO comment and a limit on the loop in ffa_direct_req_send_vm()
> * Patch "xen/arm: ffa: support mapping guest RX/TX buffers"
>  - Change FFA_MAX_RXTX_PAGE_COUNT to 1 with a TODO for a larger value
>  - Replace !p2m_is_ram(t) test with t != p2m_ram_rw
>  - Rename the introduced field tx_is_free to tx_is_free
> * Patch "xen/arm: ffa: support sharing memory"
>  - Fixing read_atomic() issue in get_shm_pages()
>  - Fixing style issue in free_ffa_shm_mem()
>  - Replace !p2m_is_ram(t) test with t != p2m_ram_rw in get_shm_pages()
> * Patch "tools: add Arm FF-A mediator"
>  - Adding Reviewed-by: Henry Wang <Henry.Wang@xxxxxxx>
>  - Adding Acked-by: Anthony PERARD <anthony.perard@xxxxxxxxxx>
>  - Moving the patch to just before the docs patch.
> * Adding Reviewed-by: Henry Wang <Henry.Wang@xxxxxxx to:
>  - "xen/arm: ffa: enforce dependency on 4k pages"
>  - "xen/arm: move regpair_to_uint64() and uint64_to_regpair() to regs.h"
>  - "xen/arm: ffa: add ABI structs for sharing memory"
> * Adding "xen: Introduce arch_domain_teardown()" by Andrew Cooper
> * Adding "xen/arm: add TEE teardown to arch_domain_teardown()" 
>  based on a patch from Andrew Cooper

It makes it easier for reviewers if you put the changelog per patch
instead of having all of them in the cover letter.

Cheers
Bertrand

> 
> v7->v8:
> * Adding "xen/arm: ffa: list current limitations" as requested
> * Adding tags to "xen/arm: smccc: add support for SMCCCv1.2 extended
>  input/output registers"
> * Patch "xen/arm: tee: add a primitive FF-A mediator":
>  - Changing license for ffa.h and ffa.c to GPL-2.0-only
>  - Avoiding IS_ENABLED() in the constant FFA_NR_FUNCS
>  - Accepting version 1.1 SPMC only to keep things simple
>  - Removes 32bit and only supports 64bit to keep things simple
> * Patch "tools: add Arm FF-A mediator"
>  - Adding Reviewed-by: Bertrand Marquis <bertrand.marquis@xxxxxxx>
>  - Adding LIBXL_HAVE_BUILDINFO_ARCH_ARM_TEE_FFA for the "ffa" value 
>    in arch_arm.tee
> * Patch "docs: add Arm FF-A mediator"
>  - Fixing a spell error
>  - Moving the patch last in the series
> * Patch "xen/arm: ffa: add remaining SMC function IDs"
>  - Adding Reviewed-by: Bertrand Marquis <bertrand.marquis@xxxxxxx>
>  - Renaming the define FFA_MSG_RUN to FFA_RUN to match the specification
> * Patch "xen/arm: ffa: add flags for FFA_PARTITION_INFO_GET"
>  - Updating the comment describing the flags for FFA_PARTITION_INFO_GET
> * Patch "xen/arm: ffa: add defines for framework direct request/response
>  messages"
>  - Updating the comment describing the flags for MSG_SEND_DIRECT_REQ/RESP
> * Patch "xen/arm: ffa: enforce dependency on 4k pages"
>  - Updating title of patch
>  - Adding Reviewed-by: Bertrand Marquis <bertrand.marquis@xxxxxxx>
> * Patch "xen/arm: ffa: add support for FFA_ID_GET"
>  - In ffa_domain_init(), check that domain_id isn't greater than
>    UINT16_MAX to avoid a future potential integer overflow in get_vm_id()
> * Patch "xen/arm: ffa: add direct request support"
>  - Move preemption (interrupted) parts to a separate patch "xen/arm: ffa:
>    support preemption of SP during direct request"
>  - Remove loop in handle_msg_send_direct_req() to return eventual
>    errors back to the VM instead of the SP.
> * Patch "xen/arm: ffa: map SPMC rx/tx buffers"
>  - Adding a FFA_RXTX_PAGE_COUNT define instead of using 1 directly
> * New patch "xen/arm: ffa: support preemption of SP during direct request"
> * Patch "xen/arm: ffa: send guest events to Secure Partitions"
>  - Replacing unsigned int with uint16_t for subscr_vm_created_count and
>    subscr_vm_destroyed_count plus the needed range check to see that
>    they don't overflow.
> * Patch "xen/arm: ffa: support mapping guest RX/TX buffers"
>  - Limit the number of pages in VM RX/TX buffers to 32 using a new
>    FFA_MAX_RXTX_PAGE_COUNT define.
> * Patch "xen/arm: ffa: support guest FFA_PARTITION_INFO_GET"
>  - Renaming tx_is_mine to rx_is_free as requested
>  - Simplified the FFA_PARTITION_INFO_GET_COUNT_FLAG check in
>    handle_partition_info_get()
>  - Adding a comment on ownership of the RX buffer
>  - Adding the patch "xen/arm: ffa: improve lock granularity" to address
>    parts of the locking concerns.
> * Patch "xen/arm: move regpair_to_uint64() and uint64_to_regpair() to regs.h"
>  - Adding Reviewed-by: Bertrand Marquis <bertrand.marquis@xxxxxxx>
> * Patch "xen/arm: ffa: add defines for sharing memory"
>  - Fixing reference for FFA_NORMAL_MEM_REG_ATTR and FFA_MEM_ACC_RW
>  - Updating descirption for FFA_MAX_SHM_PAGE_COUNT
> * Patch "xen/arm: ffa: add ABI structs for sharing memory"
>  - Changing name of the "global_handle" memeber in struct
>    ffa_mem_transaction_* to "handle".
> * Patch "xen/arm: ffa: support sharing memory"
>  - Use FFA_MEM_SHARE_64 only since we changed to only suporting ARM_64.
>  - Rename struct ffa_mem_transaction_x to struct ffa_mem_transaction_int
>    as requested.
>  - Adding a check that shm->page_count isn't 0 before calling share_shm()
>  - Masking return value from FFA_MEM_FRAG_RX to avoid an implic cast to
>    the int32_t returned by ffa_mem_share().
> * Patch "xen/arm: ffa: add support to reclaim shared memory"
>  - Adding Reviewed-by: Bertrand Marquis <bertrand.marquis@xxxxxxx>
> * Patch "xen/arm: ffa: support sharing large memory ranges"
>  - Adding commetns for struct ffa_ctx
>  - Cleaning up and removing the fragmentation state if handle_mem_frag_tx()
>    detects an error.
> * Adding "xen/arm: ffa: improve lock granularity" to address some of the
>  locking concerns.
> 
> v6->v7:
> * Split some of the larger patches into smaller patches for easier review.
>  For instance, the v6 patch "xen/arm: add a primitive FF-A mediator" has
>  been replaced with:
>  - "xen/arm: add a primitive FF-A mediator"
>  - "tools: add Arm FF-A mediator"
>  - "docs: add Arm FF-A mediator"
>  - "xen/arm: ffa: add remaining SMC function IDs"
> * Some small fixes in the error path for handle_mem_share()
> * Switched to SPDX for license in new files.
> * Fixed comment style issues in
>  "xen/arm: smccc: add support for SMCCCv1.2 extended input/output registers"
> * Made FFA support UNSUPPORTED in "xen/arm: add a primitive FF-A mediator"
> * Replaced ffa_get_call_count() with FFA_NR_FUNCS
> * Update the FFA_MAX_SHM_PAGE_COUNT with a formula instead of a value.
> * Replaced XEN_ARM_FLAGS_FFA with XEN_DOMCTL_CONFIG_TEE_FFA to minimize impact
>  on struct xen_arch_domainconfig. This works because the FF-A mediator and
>  the OP-TEE mediator will not be used at the same time in by a guest.
> * Replaced "ffa" boolean in the guest config with a new "ffa" value to the
>  enumeration "tee_type".
> * Integrated the FF-A mediator in the TEE mediator framework instead of
>  being its own.
> * Rebased on staging as of 2023-02-16
> 
> 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
> 
> Andrew Cooper (1):
>  xen: Introduce arch_domain_teardown()
> 
> Jens Wiklander (23):
>  xen/arm: add TEE teardown to arch_domain_teardown()
>  xen/arm: smccc: add support for SMCCCv1.2 extended input/output
>    registers
>  xen/arm: tee: add a primitive FF-A mediator
>  xen/arm: ffa: add remaining SMC function IDs
>  xen/arm: ffa: add flags for FFA_PARTITION_INFO_GET
>  xen/arm: ffa: add defines for framework direct request/response
>    messages
>  xen/arm: ffa: enforce dependency on 4k pages
>  xen/arm: ffa: add support for FFA_ID_GET
>  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: add defines for sharing memory
>  xen/arm: ffa: add ABI structs for sharing memory
>  xen/arm: ffa: support sharing memory
>  xen/arm: ffa: add support to reclaim shared memory
>  xen/arm: ffa: support sharing large memory ranges
>  xen/arm: ffa: improve lock granularity
>  xen/arm: ffa: list current limitations
>  tools: add Arm FF-A mediator
>  docs: add Arm FF-A mediator
> 
> SUPPORT.md                         |    9 +
> docs/man/xl.cfg.5.pod.in           |   15 +
> tools/include/libxl.h              |    5 +
> tools/libs/light/libxl_arm.c       |    3 +
> tools/libs/light/libxl_types.idl   |    3 +-
> xen/arch/arm/arm64/asm-offsets.c   |    9 +
> xen/arch/arm/arm64/smc.S           |   42 +
> xen/arch/arm/domain.c              |   41 +
> xen/arch/arm/include/asm/psci.h    |    4 +
> xen/arch/arm/include/asm/regs.h    |   12 +
> xen/arch/arm/include/asm/smccc.h   |   40 +
> xen/arch/arm/include/asm/tee/ffa.h |   35 +
> xen/arch/arm/include/asm/tee/tee.h |    7 +
> xen/arch/arm/tee/Kconfig           |   11 +
> xen/arch/arm/tee/Makefile          |    1 +
> xen/arch/arm/tee/ffa.c             | 1988 ++++++++++++++++++++++++++++
> xen/arch/arm/tee/optee.c           |   11 +-
> xen/arch/arm/tee/tee.c             |    8 +
> xen/arch/arm/vsmc.c                |   19 +-
> xen/arch/x86/domain.c              |    5 +
> xen/common/domain.c                |    6 +
> xen/include/public/arch-arm.h      |    1 +
> xen/include/xen/domain.h           |    1 +
> xen/include/xen/sched.h            |    1 +
> 24 files changed, 2264 insertions(+), 13 deletions(-)
> create mode 100644 xen/arch/arm/include/asm/tee/ffa.h
> create mode 100644 xen/arch/arm/tee/ffa.c
> 
> -- 
> 2.34.1
>