Re: [PATCH v20 00/28] Intel SGX1 support
From: Jarkko Sakkinen
Date: Tue Apr 23 2019 - 07:56:25 EST
On Wed, Apr 17, 2019 at 01:39:10PM +0300, Jarkko Sakkinen wrote:
> Intel(R) SGX is a set of CPU instructions that can be used by applications
> to set aside private regions of code and data. The code outside the enclave
> is disallowed to access the memory inside the enclave by the CPU access
> control. In a way you can think that SGX provides inverted sandbox. It
> protects the application from a malicious host.
>
> There is a new hardware unit in the processor called Memory Encryption
> Engine (MEE) starting from the Skylake microacrhitecture. BIOS can define
> one or many MEE regions that can hold enclave data by configuring them with
> PRMRR registers.
>
> The MEE automatically encrypts the data leaving the processor package to
> the MEE regions. The data is encrypted using a random key whose life-time
> is exactly one power cycle.
>
> The current implementation requires that the firmware sets
> IA32_SGXLEPUBKEYHASH* MSRs as writable so that ultimately the kernel can
> decide what enclaves it wants run. The implementation does not create
> any bottlenecks to support read-only MSRs later on.
>
> You can tell if your CPU supports SGX by looking into /proc/cpuinfo:
>
> cat /proc/cpuinfo | grep sgx
>
> v20:
> * Fine-tune Kconfig messages and spacing and remove MMU_NOTIFIER
> dependency as MMU notifiers are no longer used in the driver.
> * Use mm_users instead of mm_count as refcount for mm_struct as mm_count
> only protects from deleting mm_struct, not removing its contents.
> * Sanitize EPC when the reclaimer thread starts by doing EREMOVE for all
> of them. They could be in initialized state when the kernel starts
> because it might be spawned by kexec().
> * Documentation overhaul.
> * Use a device /dev/sgx/provision for delivering the provision token
> instead of securityfs.
> * Create a reference to the enclave when already when opening
> /dev/sgx/enclave. The file is then associated with this enclave only.
> mmap() can be done at free at any point and always get a reference to
> the enclave. To summarize the file now represents the enclave.
>
> v19:
> * Took 3-4 months but in some sense this was more like a rewrite of most
> of the corners of the source code. If I've forgotten to deal with some
> feedback, please don't shout me. Make a remark and I will fix it for
> the next version. Hopefully there won't be this big turnovers anymore.
> * Validate SECS attributes properly against CPUID given attributes and
> against allowed attributes. SECS attributes are the ones that are
> enforced whereas SIGSTRUCT attributes tell what is required to run
> the enclave.
> * Add KSS (Key Sharing Support) to the enclave attributes.
> * Deny MAP_PRIVATE as an enclave is always a shared memory entity.
> * Revert back to shmem backing storage so that it can be easily shared
> by multiple processes.
> * Split the recognization of an ENCLS leaf failure by using three
> functions to detect it: encsl_faulted(), encls_returned_code() and
> sgx_failed(). encls_failed() is only caused by a spurious expections that
> should never happen. Thus, it is not defined as an inline function in
> order to easily insert a kprobe to it.
> * Move low-level enclave management routines, page fault handler and page
> reclaiming routines from driver to the core. These cannot be separated
> from each other as they are heavily interdependent. The rationale is that
> the core does not call any code from the driver.
> * Allow the driver to be compiled as a module now that it no code is using
> its routines and it only uses exported symbols. Now the driver is
> essentially just a thin ioctl layer.
> * Reworked the driver to maintain a list of mm_struct's. The VMA callbacks
> add new entries to this list as the process is forked. Each entry has
> its own refcount because they have a different life-cycle as the enclave
> does. In effect @tgid and @mm have been removed from struct sgx_encl
> and we allow forking by removing VM_DONTCOPY from vm flags.
> * Generate a cpu mask in the reclaimer from the cpu mask's of all
> mm_struct's. This will kick out the hardware threads out of the enclave
> from multiple processes. It is not a local variable because it would
> eat too much of the stack space but instead a field in struct
> sgx_encl.
> * Allow forking i.e. remove VM_DONTCOPY. I did not change the API
> because the old API scaled to the workload that Andy described. The
> codebase is now mostly API independent i.e. changing the API is a
> small task. For me the proper trigger to chanage it is a as concrete
> as possible workload that cannot be fulfilled. I hope you understand
> my thinking here. I don't want to change anything w/o proper basis
> but I'm ready to change anything if there is a proper basis. I do
> not have any kind of attachment to any particular type of API.
> * Add Sean's vDSO ENCLS(EENTER) patches and update selftest to use the
> new vDSO.
>
> v18:
> * Update the ioctl-number.txt.
> * Move the driver under arch/x86.
> * Add SGX features (SGX, SGX1, SGX2) to the disabled-features.h.
> * Rename the selftest as test_sgx (previously sgx-selftest).
> * In order to enable process accounting, swap EPC pages and PCMD's to a VMA
> instead of shmem.
> * Allow only to initialize and run enclaves with a subset of
> {DEBUG, MODE64BIT} set.
> * Add SGX_IOC_ENCLAVE_SET_ATTRIBUTE to allow an enclave to have privileged
> attributes e.g. PROVISIONKEY.
>
> v17:
> * Add a simple selftest.
> * Fix a null pointer dereference to section->pages when its
> allocation fails.
> * Add Sean's description of the exception handling to the documentation.
>
> v16:
> * Fixed SOB's in the commits that were a bit corrupted in v15.
> * Implemented exceptio handling properly to detect_sgx().
> * Use GENMASK() to define SGX_CPUID_SUB_LEAF_TYPE_MASK.
> * Updated the documentation to use rst definition lists.
> * Added the missing Documentation/x86/index.rst, which has a link to
> intel_sgx.rst. Now the SGX and uapi documentation is properly generated
> with 'make htmldocs'.
> * While enumerating EPC sections, if an undefined section is found, fail
> the driver initialization instead of continuing the initialization.
> * Issue a warning if there are more than %SGX_MAX_EPC_SECTIONS.
> * Remove copyright notice from arch/x86/include/asm/sgx.h.
> * Migrated from ioremap_cache() to memremap().
>
> v15:
> * Split into more digestable size patches.
> * Lots of small fixes and clean ups.
> * Signal a "plain" SIGSEGV on an EPCM violation.
>
> v14:
> * Change the comment about X86_FEATURE_SGX_LC from âSGX launch
> configurationâ to âSGX launch controlâ.
> * Move the SGX-related CPU feature flags as part of the Linux defined
> virtual leaf 8.
> * Add SGX_ prefix to the constants defining the ENCLS leaf functions.
> * Use GENMASK*() and BIT*() in sgx_arch.h instead of raw hex numbers.
> * Refine the long description for CONFIG_INTEL_SGX_CORE.
> * Do not use pr_*_ratelimited() in the driver. The use of the rate limited
> versions is legacy cruft from the prototyping phase.
> * Detect sleep with SGX_INVALID_EINIT_TOKEN instead of counting power
> cycles.
> * Manually prefix with âsgx:â in the core SGX code instead of redefining
> pr_fmt.
> * Report if IA32_SGXLEPUBKEYHASHx MSRs are not writable in the driver
> instead of core because it is a driver requirement.
> * Change prompt to bool in the entry for CONFIG_INTEL_SGX_CORE because the
> default is ânâ.
> * Rename struct sgx_epc_bank as struct sgx_epc_section in order to match
> the SDM.
> * Allocate struct sgx_epc_page instances one at a time.
> * Use â__iomem void *â pointers for the mapped EPC memory consistently.
> * Retry once on SGX_INVALID_TOKEN in sgx_einit() instead of counting power
> cycles.
> * Call enclave swapping operations directly from the driver instead of
> calling them .indirectly through struct sgx_epc_page_ops because indirect
> calls are not required yet as the patch set does not contain the KVM
> support.
> * Added special signal SEGV_SGXERR to notify about SGX EPCM violation
> errors.
>
> v13:
> * Always use SGX_CPUID constant instead of a hardcoded value.
> * Simplified and documented the macros and functions for ENCLS leaves.
> * Enable sgx_free_page() to free active enclave pages on demand
> in order to allow sgx_invalidate() to delete enclave pages.
> It no longer performs EREMOVE if a page is in the process of
> being reclaimed.
> * Use PM notifier per enclave so that we don't have to traverse
> the global list of active EPC pages to find enclaves.
> * Removed unused SGX_LE_ROLLBACK constant from uapi/asm/sgx.h
> * Always use ioremap() to map EPC banks as we only support 64-bit kernel.
> * Invalidate IA32_SGXLEPUBKEYHASH cache used by sgx_einit() when going
> to sleep.
>
> v12:
> * Split to more narrow scoped commits in order to ease the review process and
> use co-developed-by tag for co-authors of commits instead of listing them in
> the source files.
> * Removed cruft EXPORT_SYMBOL() declarations and converted to static variables.
> * Removed in-kernel LE i.e. this version of the SGX software stack only
> supports unlocked IA32_SGXLEPUBKEYHASHx MSRs.
> * Refined documentation on launching enclaves, swapping and enclave
> construction.
> * Refined sgx_arch.h to include alignment information for every struct that
> requires it and removed structs that are not needed without an LE.
> * Got rid of SGX_CPUID.
> * SGX detection now prints log messages about firmware configuration issues.
>
> v11:
> * Polished ENCLS wrappers with refined exception handling.
> * ksgxswapd was not stopped (regression in v5) in
> sgx_page_cache_teardown(), which causes a leaked kthread after driver
> deinitialization.
> * Shutdown sgx_le_proxy when going to suspend because its EPC pages will be
> invalidated when resuming, which will cause it not function properly
> anymore.
> * Set EINITTOKEN.VALID to zero for a token that is passed when
> SGXLEPUBKEYHASH matches MRSIGNER as alloc_page() does not give a zero
> page.
> * Fixed the check in sgx_edbgrd() for a TCS page. Allowed to read offsets
> around the flags field, which causes a #GP. Only flags read is readable.
> * On read access memcpy() call inside sgx_vma_access() had src and dest
> parameters in wrong order.
> * The build issue with CONFIG_KASAN is now fixed. Added undefined symbols
> to LE even if âKASAN_SANITIZE := falseâ was set in the makefile.
> * Fixed a regression in the #PF handler. If a page has
> SGX_ENCL_PAGE_RESERVED flag the #PF handler should unconditionally fail.
> It did not, which caused weird races when trying to change other parts of
> swapping code.
> * EPC management has been refactored to a flat LRU cache and moved to
> arch/x86. The swapper thread reads a cluster of EPC pages and swaps all
> of them. It can now swap from multiple enclaves in the same round.
> * For the sake of consistency with SGX_IOC_ENCLAVE_ADD_PAGE, return -EINVAL
> when an enclave is already initialized or dead instead of zero.
>
> v10:
> * Cleaned up anon inode based IPC between the ring-0 and ring-3 parts
> of the driver.
> * Unset the reserved flag from an enclave page if EDBGRD/WR fails
> (regression in v6).
> * Close the anon inode when LE is stopped (regression in v9).
> * Update the documentation with a more detailed description of SGX.
>
> v9:
> * Replaced kernel-LE IPC based on pipes with an anonymous inode.
> The driver does not require anymore new exports.
>
> v8:
> * Check that public key MSRs match the LE public key hash in the
> driver initialization when the MSRs are read-only.
> * Fix the race in VA slot allocation by checking the fullness
> immediately after succeesful allocation.
> * Fix the race in hash mrsigner calculation between the launch
> enclave and user enclaves by having a separate lock for hash
> calculation.
>
> v7:
> * Fixed offset calculation in sgx_edbgr/wr(). Address was masked with PAGE_MASK
> when it should have been masked with ~PAGE_MASK.
> * Fixed a memory leak in sgx_ioc_enclave_create().
> * Simplified swapping code by using a pointer array for a cluster
> instead of a linked list.
> * Squeezed struct sgx_encl_page to 32 bytes.
> * Fixed deferencing of an RSA key on OpenSSL 1.1.0.
> * Modified TC's CMAC to use kernel AES-NI. Restructured the code
> a bit in order to better align with kernel conventions.
>
> v6:
> * Fixed semaphore underrun when accessing /dev/sgx from the launch enclave.
> * In sgx_encl_create() s/IS_ERR(secs)/IS_ERR(encl)/.
> * Removed virtualization chapter from the documentation.
> * Changed the default filename for the signing key as signing_key.pem.
> * Reworked EPC management in a way that instead of a linked list of
> struct sgx_epc_page instances there is an array of integers that
> encodes address and bank of an EPC page (the same data as 'pa' field
> earlier). The locking has been moved to the EPC bank level instead
> of a global lock.
> * Relaxed locking requirements for EPC management. EPC pages can be
> released back to the EPC bank concurrently.
> * Cleaned up ptrace() code.
> * Refined commit messages for new architectural constants.
> * Sorted includes in every source file.
> * Sorted local variable declarations according to the line length in
> every function.
> * Style fixes based on Darren's comments to sgx_le.c.
>
> v5:
> * Described IPC between the Launch Enclave and kernel in the commit messages.
> * Fixed all relevant checkpatch.pl issues that I have forgot fix in earlier
> versions except those that exist in the imported TinyCrypt code.
> * Fixed spelling mistakes in the documentation.
> * Forgot to check the return value of sgx_drv_subsys_init().
> * Encapsulated properly page cache init and teardown.
> * Collect epc pages to a temp list in sgx_add_epc_bank
> * Removed SGX_ENCLAVE_INIT_ARCH constant.
>
> v4:
> * Tied life-cycle of the sgx_le_proxy process to /dev/sgx.
> * Removed __exit annotation from sgx_drv_subsys_exit().
> * Fixed a leak of a backing page in sgx_process_add_page_req() in the
> case when vm_insert_pfn() fails.
> * Removed unused symbol exports for sgx_page_cache.c.
> * Updated sgx_alloc_page() to require encl parameter and documented the
> behavior (Sean Christopherson).
> * Refactored a more lean API for sgx_encl_find() and documented the behavior.
> * Moved #PF handler to sgx_fault.c.
> * Replaced subsys_system_register() with plain bus_register().
> * Retry EINIT 2nd time only if MSRs are not locked.
>
> v3:
> * Check that FEATURE_CONTROL_LOCKED and FEATURE_CONTROL_SGX_ENABLE are set.
> * Return -ERESTARTSYS in __sgx_encl_add_page() when sgx_alloc_page() fails.
> * Use unused bits in epc_page->pa to store the bank number.
> * Removed #ifdef for WQ_NONREENTRANT.
> * If mmu_notifier_register() fails with -EINTR, return -ERESTARTSYS.
> * Added --remove-section=.got.plt to objcopy flags in order to prevent a
> dummy .got.plt, which will cause an inconsistent size for the LE.
> * Documented sgx_encl_* functions.
> * Added remark about AES implementation used inside the LE.
> * Removed redundant sgx_sys_exit() from le/main.c.
> * Fixed struct sgx_secinfo alignment from 128 to 64 bytes.
> * Validate miscselect in sgx_encl_create().
> * Fixed SSA frame size calculation to take the misc region into account.
> * Implemented consistent exception handling to __encls() and __encls_ret().
> * Implemented a proper device model in order to allow sysfs attributes
> and in-kernel API.
> * Cleaned up various "find enclave" implementations to the unified
> sgx_encl_find().
> * Validate that vm_pgoff is zero.
> * Discard backing pages with shmem_truncate_range() after EADD.
> * Added missing EEXTEND operations to LE signing and launch.
> * Fixed SSA size for GPRS region from 168 to 184 bytes.
> * Fixed the checks for TCS flags. Now DBGOPTIN is allowed.
> * Check that TCS addresses are in ELRANGE and not just page aligned.
> * Require kernel to be compiled with X64_64 and CPU_SUP_INTEL.
> * Fixed an incorrect value for SGX_ATTR_DEBUG from 0x01 to 0x02.
>
> v2:
> * get_rand_uint32() changed the value of the pointer instead of value
> where it is pointing at.
> * Launch enclave incorrectly used sigstruct attributes-field instead of
> enclave attributes-field.
> * Removed unused struct sgx_add_page_req from sgx_ioctl.c
> * Removed unused sgx_has_sgx2.
> * Updated arch/x86/include/asm/sgx.h so that it provides stub
> implementations when sgx in not enabled.
> * Removed cruft rdmsr-calls from sgx_set_pubkeyhash_msrs().
> * return -ENOMEM in sgx_alloc_page() when VA pages consume too much space
> * removed unused global sgx_nr_pids
> * moved sgx_encl_release to sgx_encl.c
> * return -ERESTARTSYS instead of -EINTR in sgx_encl_init()
>
> Jarkko Sakkinen (11):
> x86/sgx: Add ENCLS architectural error codes
> x86/sgx: Add SGX1 and SGX2 architectural data structures
> x86/sgx: Add wrappers for ENCLS leaf functions
> x86/sgx: Add functions to allocate and free EPC pages
> x86/sgx: Add the Linux SGX Enclave Driver
> x86/sgx: Add provisioning
> x86/sgx: Add swapping code to the core and SGX driver
> x86/sgx: ptrace() support for the SGX driver
> selftests/x86: Add a selftest for SGX
> x86/sgx: Update MAINTAINERS
> docs: x86/sgx: Document the enclave API
>
> Kai Huang (2):
> x86/cpufeatures: Add Intel-defined SGX feature bit
> x86/cpufeatures: Add Intel-defined SGX_LC feature bit
>
> Sean Christopherson (15):
> x86/cpufeatures: Add SGX sub-features (as Linux-defined bits)
> x86/msr: Add IA32_FEATURE_CONTROL.SGX_ENABLE definition
> x86/msr: Add SGX Launch Control MSR definitions
> x86/mm: x86/sgx: Add new 'PF_SGX' page fault error code bit
> x86/mm: x86/sgx: Signal SIGSEGV for userspace #PFs w/ PF_SGX
> x86/cpu/intel: Detect SGX support and update caps appropriately
> x86/sgx: Enumerate and track EPC sections
> x86/sgx: Add sgx_einit() for initializing enclaves
> x86/vdso: Add support for exception fixup in vDSO functions
> x86/fault: Add helper function to sanitize error code
> x86/fault: Attempt to fixup unhandled #PF in vDSO before signaling
> x86/traps: Attempt to fixup exceptions in vDSO before signaling
> x86/vdso: Add __vdso_sgx_enter_enclave() to wrap SGX enclave
> transitions
> docs: x86/sgx: Add Architecture documentation
> docs: x86/sgx: Document kernel internals
>
> Documentation/index.rst | 1 +
> Documentation/ioctl/ioctl-number.txt | 1 +
> Documentation/x86/index.rst | 10 +
> Documentation/x86/sgx/1.Architecture.rst | 431 +++++++++
> Documentation/x86/sgx/2.Kernel-internals.rst | 56 ++
> Documentation/x86/sgx/3.API.rst | 27 +
> Documentation/x86/sgx/index.rst | 18 +
> MAINTAINERS | 12 +
> arch/x86/Kconfig | 27 +
> arch/x86/entry/vdso/Makefile | 6 +-
> arch/x86/entry/vdso/extable.c | 37 +
> arch/x86/entry/vdso/extable.h | 29 +
> arch/x86/entry/vdso/vdso-layout.lds.S | 9 +-
> arch/x86/entry/vdso/vdso.lds.S | 1 +
> arch/x86/entry/vdso/vdso2c.h | 58 +-
> arch/x86/entry/vdso/vsgx_enter_enclave.S | 101 +++
> arch/x86/include/asm/cpufeatures.h | 24 +-
> arch/x86/include/asm/disabled-features.h | 14 +-
> arch/x86/include/asm/msr-index.h | 8 +
> arch/x86/include/asm/traps.h | 1 +
> arch/x86/include/asm/vdso.h | 5 +
> arch/x86/include/uapi/asm/sgx.h | 86 ++
> arch/x86/include/uapi/asm/sgx_errno.h | 91 ++
> arch/x86/kernel/cpu/Makefile | 1 +
> arch/x86/kernel/cpu/intel.c | 39 +
> arch/x86/kernel/cpu/scattered.c | 2 +
> arch/x86/kernel/cpu/sgx/Makefile | 2 +
> arch/x86/kernel/cpu/sgx/arch.h | 424 +++++++++
> arch/x86/kernel/cpu/sgx/driver/Makefile | 3 +
> arch/x86/kernel/cpu/sgx/driver/driver.h | 38 +
> arch/x86/kernel/cpu/sgx/driver/ioctl.c | 850 ++++++++++++++++++
> arch/x86/kernel/cpu/sgx/driver/main.c | 368 ++++++++
> arch/x86/kernel/cpu/sgx/encl.c | 709 +++++++++++++++
> arch/x86/kernel/cpu/sgx/encl.h | 136 +++
> arch/x86/kernel/cpu/sgx/encls.c | 22 +
> arch/x86/kernel/cpu/sgx/encls.h | 244 +++++
> arch/x86/kernel/cpu/sgx/main.c | 360 ++++++++
> arch/x86/kernel/cpu/sgx/reclaim.c | 482 ++++++++++
> arch/x86/kernel/cpu/sgx/sgx.h | 90 ++
> arch/x86/kernel/traps.c | 14 +
> arch/x86/mm/fault.c | 44 +-
> tools/arch/x86/include/asm/cpufeatures.h | 21 +-
> tools/testing/selftests/x86/Makefile | 10 +
> tools/testing/selftests/x86/sgx/Makefile | 48 +
> tools/testing/selftests/x86/sgx/defines.h | 39 +
> tools/testing/selftests/x86/sgx/encl.c | 20 +
> tools/testing/selftests/x86/sgx/encl.lds | 33 +
> .../selftests/x86/sgx/encl_bootstrap.S | 94 ++
> tools/testing/selftests/x86/sgx/encl_piggy.S | 18 +
> tools/testing/selftests/x86/sgx/encl_piggy.h | 14 +
> tools/testing/selftests/x86/sgx/main.c | 279 ++++++
> tools/testing/selftests/x86/sgx/sgx_call.S | 15 +
> tools/testing/selftests/x86/sgx/sgxsign.c | 508 +++++++++++
> .../testing/selftests/x86/sgx/signing_key.pem | 39 +
> 54 files changed, 5987 insertions(+), 32 deletions(-)
> create mode 100644 Documentation/x86/index.rst
> create mode 100644 Documentation/x86/sgx/1.Architecture.rst
> create mode 100644 Documentation/x86/sgx/2.Kernel-internals.rst
> create mode 100644 Documentation/x86/sgx/3.API.rst
> create mode 100644 Documentation/x86/sgx/index.rst
> create mode 100644 arch/x86/entry/vdso/extable.c
> create mode 100644 arch/x86/entry/vdso/extable.h
> create mode 100644 arch/x86/entry/vdso/vsgx_enter_enclave.S
> create mode 100644 arch/x86/include/uapi/asm/sgx.h
> create mode 100644 arch/x86/include/uapi/asm/sgx_errno.h
> create mode 100644 arch/x86/kernel/cpu/sgx/Makefile
> create mode 100644 arch/x86/kernel/cpu/sgx/arch.h
> create mode 100644 arch/x86/kernel/cpu/sgx/driver/Makefile
> create mode 100644 arch/x86/kernel/cpu/sgx/driver/driver.h
> create mode 100644 arch/x86/kernel/cpu/sgx/driver/ioctl.c
> create mode 100644 arch/x86/kernel/cpu/sgx/driver/main.c
> create mode 100644 arch/x86/kernel/cpu/sgx/encl.c
> create mode 100644 arch/x86/kernel/cpu/sgx/encl.h
> create mode 100644 arch/x86/kernel/cpu/sgx/encls.c
> create mode 100644 arch/x86/kernel/cpu/sgx/encls.h
> create mode 100644 arch/x86/kernel/cpu/sgx/main.c
> create mode 100644 arch/x86/kernel/cpu/sgx/reclaim.c
> create mode 100644 arch/x86/kernel/cpu/sgx/sgx.h
> create mode 100644 tools/testing/selftests/x86/sgx/Makefile
> create mode 100644 tools/testing/selftests/x86/sgx/defines.h
> create mode 100644 tools/testing/selftests/x86/sgx/encl.c
> create mode 100644 tools/testing/selftests/x86/sgx/encl.lds
> create mode 100644 tools/testing/selftests/x86/sgx/encl_bootstrap.S
> create mode 100644 tools/testing/selftests/x86/sgx/encl_piggy.S
> create mode 100644 tools/testing/selftests/x86/sgx/encl_piggy.h
> create mode 100644 tools/testing/selftests/x86/sgx/main.c
> create mode 100644 tools/testing/selftests/x86/sgx/sgx_call.S
> create mode 100644 tools/testing/selftests/x86/sgx/sgxsign.c
> create mode 100644 tools/testing/selftests/x86/sgx/signing_key.pem
>
> --
> 2.19.1
>
I'm on leave for this week and next week's Monday if you wonder why I'm
so passive in the discussion. Looking at the things next week's Tue.
Just a quick comment about Andy's proposal. Probably pretty DSO like
ELF blob could work with an addition of a section called ".tcs" for
entry points. They need to be recognized so that the loader can add
them as TCS pages.
My self-test already is a PoC for enclave binary with a custom linker
script to define the binary format. Too simplistic for a "generic"
case but still a starting point.
/Jarkko