V1: https://lore.kernel.org/linux-sgx/cover.1638381245.git.reinette.chatre@xxxxxxxxx/ Changes since V1 that directly impact user space: - SGX2 permission changes changed from a single ioctl() named SGX_IOC_PAGE_MODP to two new ioctl()s: SGX_IOC_ENCLAVE_RELAX_PERMISSIONS and SGX_IOC_ENCLAVE_RESTRICT_PERMISSIONS, supported by two different parameter structures (SGX_IOC_ENCLAVE_RELAX_PERMISSIONS does not support a result output parameter) (Jarkko). User space flow impact: After user space runs ENCLU[EMODPE] it needs to call SGX_IOC_ENCLAVE_RELAX_PERMISSIONS to have PTEs updated. Previously running SGX_IOC_PAGE_MODP in this scenario resulted in EPCM.PR being set but calling SGX_IOC_ENCLAVE_RELAX_PERMISSIONS will not result in EPCM.PR being set anymore and thus no need for an additional ENCLU[EACCEPT]. - SGX_IOC_ENCLAVE_RELAX_PERMISSIONS and SGX_IOC_ENCLAVE_RESTRICT_PERMISSIONS obtain new permissions from secinfo as parameter instead of the permissions directly (Jarkko). - ioctl() supporting SGX2 page type change is renamed from SGX_IOC_PAGE_MODT to SGX_IOC_ENCLAVE_MODIFY_TYPE (Jarkko). - SGX_IOC_ENCLAVE_MODIFY_TYPE obtains new page type from secinfo as parameter instead of the page type directly (Jarkko). - ioctl() supporting SGX2 page removal is renamed from SGX_IOC_PAGE_REMOVE to SGX_IOC_ENCLAVE_REMOVE_PAGES (Jarkko). - All ioctl() parameter structures have been renamed as a result of the ioctl() renaming: SGX_IOC_ENCLAVE_RELAX_PERMISSIONS => struct sgx_enclave_relax_perm SGX_IOC_ENCLAVE_RESTRICT_PERMISSIONS => struct sgx_enclave_restrict_perm SGX_IOC_ENCLAVE_MODIFY_TYPE => struct sgx_enclave_modt SGX_IOC_ENCLAVE_REMOVE_PAGES => struct sgx_enclave_remove_pages Changes since V1 that do not directly impact user space: - Number of patches in series increased from 25 to 32 primarily because of splitting the original submission: - Wrappers for the new SGX2 functions are introduced in three separate patches replacing the original "x86/sgx: Add wrappers for SGX2 functions" (Jarkko). - Moving and renaming sgx_encl_ewb_cpumask() is done with two patches replacing the original "x86/sgx: Use more generic name for enclave cpumask function" (Jarkko). - Support for SGX2 EPCM permission changes is split into two ioctls(), one for relaxing and one for restricting permissions, each introduced by a new patch replacing the original "x86/sgx: Support enclave page permission changes" (Jarkko). - Extracted code used by existing ioctls() for usage by new ioctl()s into a new utility in new patch "x86/sgx: Create utility to validate user provided offset and length" (Dave did not specifically ask for this but it addresses his review feedback). - Two new Documentation patches to support the SGX2 work ("Documentation/x86: Introduce enclave runtime management") and a dedicated section on the enclave permission management ("Documentation/x86: Document SGX permission details") (Andy). - Most patches were reworked to improve the language by: * aiming to refer to exact item instead of English rephrasing (Jarkko). * use ioctl() instead of ioctl throughout (Dave). * Use "relaxed" instead of "exceed" when referring to permissions (Dave). - Improved documentation with several additions to Documentation/x86/sgx.rst. - Many smaller changes, please refer to individual patches. Hi Everybody, The current Linux kernel support for SGX includes support for SGX1 that requires that an enclave be created with properties that accommodate all usages over its (the enclave's) lifetime. This includes properties such as permissions of enclave pages, the number of enclave pages, and the number of threads supported by the enclave. Consequences of this requirement to have the enclave be created to accommodate all usages include: * pages needing to support relocated code are required to have RWX permissions for their entire lifetime, * an enclave needs to be created with the maximum stack and heap projected to be needed during the enclave's entire lifetime which can be longer than the processes running within it, * an enclave needs to be created with support for the maximum number of threads projected to run in the enclave. Since SGX1 a few more functions were introduced, collectively called SGX2, that support modifications to an initialized enclave. Hardware supporting these functions are already available as listed on https://github.com/ayeks/SGX-hardware This series adds support for SGX2, also referred to as Enclave Dynamic Memory Management (EDMM). This includes: * Support modifying permissions of regular enclave pages belonging to an initialized enclave. New permissions are not allowed to exceed the originally vetted permissions. For example, RX isn't allowed unless the page was originally added with RX or RWX. Modifying permissions is accomplished with two new ioctl()s: SGX_IOC_ENCLAVE_RELAX_PERMISSIONS and SGX_IOC_ENCLAVE_RESTRICT_PERMISSIONS. * Support dynamic addition of regular enclave pages to an initialized enclave. Pages are added with RW permissions as their "originally vetted permissions" (see previous bullet) and thus not allowed to be made executable at this time. Enabling dynamically added pages to obtain executable permissions require integration with user space policy that is deferred until the core SGX2 enabling is complete. Pages are dynamically added to an initialized enclave from the SGX page fault handler. * Support expanding an initialized enclave to accommodate more threads. More threads can be accommodated by an enclave with the addition of Thread Control Structure (TCS) pages that is done by changing the type of regular enclave pages to TCS pages using a new ioctl() SGX_IOC_ENCLAVE_MODIFY_TYPE. * Support removing regular and TCS pages from an initialized enclave. Removing pages is accomplished in two stages as supported by two new ioctl()s SGX_IOC_ENCLAVE_MODIFY_TYPE (same ioctl() as mentioned in previous bullet) and SGX_IOC_ENCLAVE_REMOVE_PAGES. * Tests covering all the new flows, some edge cases, and one comprehensive stress scenario. No additional work is needed to support SGX2 in a virtualized environment. The tests included in this series can also be run from a guest and was tested with the recent QEMU release based on 6.2.0 that supports SGX. Patches 1 to 14 prepares the existing code for SGX2 support by introducing the SGX2 functions, making sure pages remain accessible after their enclave permissions are changed, and tracking enclave page types as well as runtime permissions as needed by SGX2. Patches 15 through 32 are a mix of x86/sgx and selftests/sgx patches that follow the format where first an SGX2 feature is enabled and then followed by tests of the new feature and/or tests of scenarios that combine SGX2 features enabled up to that point. In two cases (patches 20 and 31) code in support of SGX2 is separated out with detailed motivation to support the review. This series is based on v5.17-rc2 with the following fixes additionally applied: "selftests/sgx: Remove extra newlines in test output" https://lore.kernel.org/linux-sgx/16317683a1822bbd44ab3ca48b60a9a217ac24de.1643754040.git.reinette.chatre@xxxxxxxxx/ "selftests/sgx: Ensure enclave data available during debug print" https://lore.kernel.org/linux-sgx/eaaeeb9122916d831942fc8a3043c687137314c1.1643754040.git.reinette.chatre@xxxxxxxxx/ "selftests/sgx: Do not attempt enclave build without valid enclave" https://lore.kernel.org/linux-sgx/4e4ea6d70c286c209964bec1e8d29ac8e692748b.1643754040.git.reinette.chatre@xxxxxxxxx/ "selftests/sgx: Fix NULL-pointer-dereference upon early test failure" https://lore.kernel.org/linux-sgx/89824888783fd8e770bfc64530c7549650a41851.1643754040.git.reinette.chatre@xxxxxxxxx/ "x86/sgx: Add poison handling to reclaimer" https://lore.kernel.org/linux-sgx/dcc95eb2aaefb042527ac50d0a50738c7c160dac.1643830353.git.reinette.chatre@xxxxxxxxx/ "x86/sgx: Silence softlockup detection when releasing large enclaves" https://lore.kernel.org/linux-sgx/b5e9f218064aa76e3026f778e1ad0a1d823e3db8.1643133224.git.reinette.chatre@xxxxxxxxx/ Your feedback will be greatly appreciated. Regards, Reinette Reinette Chatre (32): x86/sgx: Add short descriptions to ENCLS wrappers x86/sgx: Add wrapper for SGX2 EMODPR function x86/sgx: Add wrapper for SGX2 EMODT function x86/sgx: Add wrapper for SGX2 EAUG function Documentation/x86: Document SGX permission details x86/sgx: Support VMA permissions more relaxed than enclave permissions x86/sgx: Add pfn_mkwrite() handler for present PTEs x86/sgx: x86/sgx: Add sgx_encl_page->vm_run_prot_bits for dynamic permission changes x86/sgx: Export sgx_encl_ewb_cpumask() x86/sgx: Rename sgx_encl_ewb_cpumask() as sgx_encl_cpumask() x86/sgx: Move PTE zap code to new sgx_zap_enclave_ptes() x86/sgx: Make sgx_ipi_cb() available internally x86/sgx: Create utility to validate user provided offset and length x86/sgx: Keep record of SGX page type x86/sgx: Support relaxing of enclave page permissions x86/sgx: Support restricting of enclave page permissions selftests/sgx: Add test for EPCM permission changes selftests/sgx: Add test for TCS page permission changes x86/sgx: Support adding of pages to an initialized enclave x86/sgx: Tighten accessible memory range after enclave initialization selftests/sgx: Test two different SGX2 EAUG flows x86/sgx: Support modifying SGX page type x86/sgx: Support complete page removal Documentation/x86: Introduce enclave runtime management section selftests/sgx: Introduce dynamic entry point selftests/sgx: Introduce TCS initialization enclave operation selftests/sgx: Test complete changing of page type flow selftests/sgx: Test faulty enclave behavior selftests/sgx: Test invalid access to removed enclave page selftests/sgx: Test reclaiming of untouched page x86/sgx: Free up EPC pages directly to support large page ranges selftests/sgx: Page removal stress test Documentation/x86/sgx.rst | 64 +- arch/x86/include/asm/sgx.h | 8 + arch/x86/include/uapi/asm/sgx.h | 81 + arch/x86/kernel/cpu/sgx/encl.c | 334 +++- arch/x86/kernel/cpu/sgx/encl.h | 12 +- arch/x86/kernel/cpu/sgx/encls.h | 33 + arch/x86/kernel/cpu/sgx/ioctl.c | 831 ++++++++- arch/x86/kernel/cpu/sgx/main.c | 70 +- arch/x86/kernel/cpu/sgx/sgx.h | 3 + tools/testing/selftests/sgx/defines.h | 23 + tools/testing/selftests/sgx/load.c | 41 + tools/testing/selftests/sgx/main.c | 1484 +++++++++++++++++ tools/testing/selftests/sgx/main.h | 1 + tools/testing/selftests/sgx/test_encl.c | 68 + .../selftests/sgx/test_encl_bootstrap.S | 6 + 15 files changed, 2963 insertions(+), 96 deletions(-) base-commit: 26291c54e111ff6ba87a164d85d4a4e134b7315c prerequisite-patch-id: 3c3908f1c3536cc04ba020fb3e81f51395b44223 prerequisite-patch-id: e860923423c3387cf6fdcceb2fa41dc5e9454ef4 prerequisite-patch-id: 986260c8bc4255eb61e2c4afa88d2b723e376423 prerequisite-patch-id: ba014a99fced2b57d5d9e2dfb9d80ddf4333c13e prerequisite-patch-id: 65cbb72889b6353a5639b984615d12019136b270 prerequisite-patch-id: e3296a2f0345a77c8a7ca91f76697ae2e1dca21f -- 2.25.1
