Re: [PATCH v17 00/23] Intel SGX1 support

For unknown reason this never reached any MLs (used the same command line for git send-email as usual).

/Jarkko

On Fri, Nov 16, 2018 at 03:38:08AM +0200, 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

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 “SGX launch configuration” to “SGX launch control”.
• 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 “sgx:” 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 ‘n’.
• 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 “__iomem void *” 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 “KASAN_SANITIZE := false” 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 (13): x86/sgx: Update MAINTAINERS x86/sgx: Define SGX1 and SGX2 ENCLS leafs x86/sgx: Add ENCLS architectural error codes x86/sgx: Add SGX1 and SGX2 architectural data structures x86/sgx: Add definitions for SGX's CPUID leaf and variable sub-leafs x86/sgx: Add wrappers for ENCLS leaf functions x86/sgx: Add functions to allocate and free EPC pages platform/x86: Intel SGX driver platform/x86: sgx: Add swapping functionality to the Intel SGX driver x86/sgx: Add a simple swapper for the EPC memory manager platform/x86: ptrace() support for the SGX driver x86/sgx: SGX documentation selftests/x86: Add a selftest for SGX

Kai Huang (2): x86/cpufeatures: Add Intel-defined SGX feature bit x86/cpufeatures: Add Intel-defined SGX_LC feature bit

Sean Christopherson (8): x86/cpufeatures: Add SGX sub-features (as Linux-defined bits) x86/msr: Add IA32_FEATURE_CONTROL.SGX_ENABLE definition x86/cpu/intel: Detect SGX support and update caps appropriately 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/msr: Add SGX Launch Control MSR definitions x86/sgx: Enumerate and track EPC sections x86/sgx: Add sgx_einit() for initializing enclaves

Documentation/index.rst | 1 + Documentation/x86/index.rst | 8 + Documentation/x86/intel_sgx.rst | 233 +++++ MAINTAINERS | 7 + arch/x86/Kconfig | 18 + arch/x86/include/asm/cpufeatures.h | 23 +- arch/x86/include/asm/msr-index.h | 8 + arch/x86/include/asm/sgx.h | 324 ++++++ arch/x86/include/asm/sgx_arch.h | 400 +++++++ arch/x86/include/asm/traps.h | 1 + arch/x86/include/uapi/asm/sgx.h | 59 ++ arch/x86/include/uapi/asm/sgx_errno.h | 91 ++ arch/x86/kernel/cpu/Makefile | 1 + arch/x86/kernel/cpu/intel.c | 37 + arch/x86/kernel/cpu/intel_sgx.c | 488 +++++++++ arch/x86/kernel/cpu/scattered.c | 2 + arch/x86/mm/fault.c | 13 + drivers/platform/x86/Kconfig | 2 + drivers/platform/x86/Makefile | 1 + drivers/platform/x86/intel_sgx/Kconfig | 20 + drivers/platform/x86/intel_sgx/Makefile | 14 + drivers/platform/x86/intel_sgx/sgx.h | 212 ++++ drivers/platform/x86/intel_sgx/sgx_encl.c | 977 ++++++++++++++++++ .../platform/x86/intel_sgx/sgx_encl_page.c | 178 ++++ drivers/platform/x86/intel_sgx/sgx_fault.c | 109 ++ drivers/platform/x86/intel_sgx/sgx_ioctl.c | 234 +++++ drivers/platform/x86/intel_sgx/sgx_main.c | 267 +++++ drivers/platform/x86/intel_sgx/sgx_util.c | 156 +++ drivers/platform/x86/intel_sgx/sgx_vma.c | 167 +++ tools/arch/x86/include/asm/cpufeatures.h | 21 +- tools/testing/selftests/x86/Makefile | 10 + tools/testing/selftests/x86/sgx/Makefile | 47 + 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 | 16 + tools/testing/selftests/x86/sgx/encl_piggy.h | 13 + .../testing/selftests/x86/sgx/sgx-selftest.c | 149 +++ tools/testing/selftests/x86/sgx/sgx_arch.h | 109 ++ tools/testing/selftests/x86/sgx/sgx_call.S | 20 + tools/testing/selftests/x86/sgx/sgx_uapi.h | 100 ++ tools/testing/selftests/x86/sgx/sgxsign.c | 503 +++++++++ .../testing/selftests/x86/sgx/signing_key.pem | 39 + 43 files changed, 5213 insertions(+), 12 deletions(-) create mode 100644 Documentation/x86/index.rst create mode 100644 Documentation/x86/intel_sgx.rst create mode 100644 arch/x86/include/asm/sgx.h create mode 100644 arch/x86/include/asm/sgx_arch.h 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/intel_sgx.c create mode 100644 drivers/platform/x86/intel_sgx/Kconfig create mode 100644 drivers/platform/x86/intel_sgx/Makefile create mode 100644 drivers/platform/x86/intel_sgx/sgx.h create mode 100644 drivers/platform/x86/intel_sgx/sgx_encl.c create mode 100644 drivers/platform/x86/intel_sgx/sgx_encl_page.c create mode 100644 drivers/platform/x86/intel_sgx/sgx_fault.c create mode 100644 drivers/platform/x86/intel_sgx/sgx_ioctl.c create mode 100644 drivers/platform/x86/intel_sgx/sgx_main.c create mode 100644 drivers/platform/x86/intel_sgx/sgx_util.c create mode 100644 drivers/platform/x86/intel_sgx/sgx_vma.c create mode 100644 tools/testing/selftests/x86/sgx/Makefile 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/sgx-selftest.c create mode 100644 tools/testing/selftests/x86/sgx/sgx_arch.h create mode 100644 tools/testing/selftests/x86/sgx/sgx_call.S create mode 100644 tools/testing/selftests/x86/sgx/sgx_uapi.h create mode 100644 tools/testing/selftests/x86/sgx/sgxsign.c create mode 100644 tools/testing/selftests/x86/sgx/signing_key.pem

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