Caution

This is documentation for the development version of the project, aka master branch. If you installed Gramine from packages, documentation for the stable version is available at https://gramine.readthedocs.io/en/stable/.

Manifest syntax

A manifest file is an application-specific configuration text file that specifies the environment and resources for running an application inside Gramine. A manifest file contains key-value pairs (as well as more complicated table and array objects) in the TOML syntax. For the details of the TOML syntax, see the official documentation.

A typical string entry looks like this:

[Key][.Key][.Key] = "[Value]"

A typical integer entry looks similar to the above but without double quotes:

[Key][.Key][.Key] = [Value]

Comments can be inlined in a manifest by starting them with a hash sign (# comment...).

There is also a preprocessor available: gramine-manifest, which renders manifests from Jinja templates.

Common syntax

Log level

loader.log_level = "[none|error|warning|debug|trace|all]"
(Default: "error")

loader.log_file = "[PATH]"

This configures Gramine’s debug log. The log_level option specifies what messages to enable (e.g. loader.log_level = "debug" will enable all messages of type error, warning and debug). By default, the messages are printed to the standard error. If log_file is specified, the messages will be appended to that file.

Gramine outputs log messages of the following types:

  • error: A serious error preventing Gramine from operating properly (for example, error initializing one of the components).
  • warning: A non-fatal issue. Might mean that application is requesting something unsupported or poorly emulated.
  • debug: Detailed information about Gramine’s operation and internals.
  • trace: More detailed information, such as all system calls requested by the application. Might contain a lot of noise.

Warning

Only error log level is suitable for production. Other levels may leak sensitive data.

Loader entrypoint

loader.entrypoint = "[URI]"

This specifies the LibOS component that Gramine will load and run before loading the first executable of the user application. Currently, there is only one LibOS implementation: libsysdb.so.

Note that the loader (the PAL binary) loads the LibOS binary specified in loader.entrypoint and passes control to this binary. Next, the LibOS binary loads the actual executable (the user application) specified in libos.entrypoint. Also note that, in contrast to libos.entrypoint, the loader.entrypoint option specifies a PAL URI (with the file: prefix).

LibOS Entrypoint

libos.entrypoint = "[PATH]"

This specifies the first executable of the user application which is to be started when spawning a Gramine instance from this manifest file. Needs to be a path inside Gramine pointing to a mounted file. Relative paths will be interpreted as starting from the current working directory (i.e. from / by default, or fs.start_dir if specified).

The recommended usage is to provide an absolute path, and mount the executable at that path. For example:

libos.entrypoint = "/usr/bin/python3.8"

fs.mounts = [
  { path = "/usr/bin/python3.8", uri = "file:/usr/bin/python3.8" },
  # Or, if using a binary from your local directory:
  # { path = "/usr/bin/python3.8", uri = "file:python3.8" },
]

Command-line arguments

loader.insecure__use_cmdline_argv = true

or

loader.argv = ["arg0", "arg1", "arg2", ...]

or

loader.argv_src_file = "file:file_with_serialized_argv"

If you want your application to use commandline arguments, you must choose one of the three mutually exclusive options:

  • set loader.insecure__use_cmdline_argv (insecure in almost all cases),
  • put commandline arguments into loader.argv array,
  • point loader.argv_src_file to a file containing output of gramine-argv-serializer.

If none of the above arguments-handling manifest options is specified in the manifest, the application will get argv = [ <libos.entrypoint value> ].

loader.argv_src_file is intended to point to either a trusted file or an encrypted file. The former allows to securely hardcode arguments, the latter allows the arguments to be provided at runtime from an external (trusted) source.

Note

Pointing to an encrypted file is currently not supported, due to the fact that encryption key provisioning currently happens after setting up arguments.

Domain names configuration

sys.enable_extra_runtime_domain_names_conf = [true|false]
(Default: false)

This option will generate the following extra configuration:

  • Hostname (obtained by apps via nodename field in uname syscall), set to the host’s hostname at initialization.

  • Pseudo-file /etc/resolv.conf, with keywords:

    • nameserver
    • search
    • options (inet6 | rotate)

    Unsupported keywords and malformed lines from /etc/resolv.conf are ignored.

The functionality is achieved by taking the host’s configuration via various APIs and reading the host’s configuration files. In the case of Linux PAL, most information comes from the host’s /etc. The gathered information is used to create /etc files inside Gramine’s file system, or change Gramine process configuration. For security-enforcing modes (such as SGX), Gramine additionally sanitizes the information gathered from the host. Invalid host’s configuration is reported as an error (e.g. invalid hostname, or invalid IPv4 address in nameserver keyword).

Note that Gramine supports only a subset of the configuration. Refer to the list of supported keywords.

This option takes precedence over fs.mounts. This means that etc files provided via fs.mounts will be overridden with the ones added via this option.

Environment variables

loader.insecure__use_host_env = [true|false]

By default, environment variables from the host will not be passed to the app. This can be overridden by the option above, but most applications and runtime libraries trust their environment variables and are completely insecure when these are attacker-controlled. For example, an attacker can execute an additional dynamic library by specifying LD_PRELOAD variable.

To securely set up the execution environment for an app you should use one or both of the following options:

loader.env.[ENVIRON] = "[VALUE]"
or
loader.env.[ENVIRON] = { value = "[VALUE]" }
or
loader.env.[ENVIRON] = { passthrough = true }

loader.env_src_file = "file:file_with_serialized_envs"

loader.env.[ENVIRON] adds/overwrites/passes a single environment variable and can be used multiple times to specify more than one variable. To add/overwrite the environment variable, specify a TOML string ("[VALUE]") or a TOML table with the key-value pair { value = "[VALUE]" }. To pass the environment variable from the host, specify a TOML table with the key-value pair { passthrough = true }. If you specify a variable, it needs to either have a value or be a passthrough.

loader.env_src_file allows to specify a URI to a file containing serialized environment, which can be generated using gramine-argv-serializer. This option is intended to point to either a trusted file or an encrypted file. The former allows to securely hardcode environments (in a more flexible way than loader.env.[ENVIRON] option), the latter allows the environments to be provided at runtime from an external (trusted) source.

Note

Pointing to an encrypted file is currently not supported, due to the fact that encryption key provisioning currently happens after setting up environment variables.

If the same variable is set in both, then loader.env.[ENVIRON] takes precedence. It is prohibited to specify both value and passthrough keys for the same environment variable. If manifest option insecure__use_host_env is specified, then passthrough = true manifest options have no effect (they are “consumed” by insecure__use_host_env).

Note

It is tempting to try to passthrough all environment variables using insecure__use_host_env and then disallow some of them using passthrough = false. However, this deny list approach is intentionally prohibited because it’s inherently insecure (doesn’t provide any real security). Gramine loudly fails if passthrough = false manifest options are set.

User ID and Group ID

loader.uid = [NUM]
loader.gid = [NUM]
(Default: 0)

This specifies the initial, Gramine emulated user/group ID and effective user/group ID. It must be non-negative. By default Gramine emulates the user/group ID and effective user/group ID as the root user (uid = gid = 0).

Disabling ASLR

loader.insecure__disable_aslr = [true|false]
(Default: false)

This specifies whether to disable Address Space Layout Randomization (ASLR). Since disabling ASLR worsens security of the application, ASLR is enabled by default.

Check invalid pointers

libos.check_invalid_pointers = [true|false]
(Default: true)

This specifies whether to enable checks of invalid pointers on syscall invocations. In particular, when this manifest option is set to true, Gramine’s LibOS will return an EFAULT error code if a user-supplied buffer points to an invalid memory region. Setting this manifest option to false may improve performance for certain workloads but may also generate SIGSEGV/SIGBUS exceptions for some applications that specifically use invalid pointers (though this is not expected for most real-world applications).

Gramine internal metadata size

loader.pal_internal_mem_size = "[SIZE]"
(default: "0")

This syntax specifies how much additional memory Gramine reserves for its internal use (e.g., metadata for trusted files, internal handles, etc.). By default, Gramine pre-allocates 64MB of internal memory for this metadata, but for huge workloads this limit may be not enough. In this case, Gramine loudly fails with “out of PAL memory” error. To run huge workloads, increase this limit by setting this option to e.g. 64M (this would result in a total of 128MB used by Gramine for internal metadata). Note that this limit is included in sgx.enclave_size, so if your enclave size is e.g. 512MB and you specify loader.pal_internal_mem_size = "64M", then your application is left with 384MB of usable memory.

Stack size

sys.stack.size = "[SIZE]"
(default: "256K")

This specifies the stack size of each thread in each Gramine process. The default value is determined by the library OS. Units like K (KiB), M (MiB), and G (GiB) can be appended to the values for convenience. For example, sys.stack.size = "1M" indicates a 1 MiB stack size.

Program break (brk) size

sys.brk.max_size = "[SIZE]"
(default: "256K")

This specifies the maximal program break (brk) size in each Gramine process. The default value of the program break size is determined by the library OS. Units like K (KiB), M (MiB), and G (GiB) can be appended to the values for convenience. For example, sys.brk.max_size = "1M" indicates a 1 MiB brk size.

Allowing eventfd

sys.insecure__allow_eventfd = [true|false]
(Default: false)

This specifies whether to allow system calls eventfd() and eventfd2(). Since eventfd emulation currently relies on the host, these system calls are disallowed by default due to security concerns.

External SIGTERM injection

sys.enable_sigterm_injection = [true|false]
(Default: false)

This specifies whether to allow for a one-time injection of SIGTERM signal into Gramine. Could be useful to handle graceful shutdown. Be careful! In SGX environment, the untrusted host could inject that signal in an arbitrary moment. Examine what your application’s SIGTERM handler does and whether it poses any security threat.

Root FS mount point

fs.root.type = "[chroot|...]"
fs.root.uri  = "[URI]"

This syntax specifies the root file system to be mounted inside the library OS. Both parameters are optional. If not specified, then Gramine mounts the current working directory as the root.

FS mount points

fs.mounts = [
  { type = "[chroot|...]", path = "[PATH]", uri = "[URI]" },
  { type = "[chroot|...]", path = "[PATH]", uri = "[URI]" },
]

Or, as separate sections:

[[fs.mounts]]
type = "[chroot|...]"
path = "[PATH]"
uri  = "[URI]"

[[fs.mounts]]
type = "[chroot|...]"
path = "[PATH]"
uri  = "[URI]"

This syntax specifies how file systems are mounted inside the library OS. For dynamically linked binaries, usually at least one chroot mount point is required in the manifest (the mount point of linked libraries). The filesystems will be mounted in the order in which they appear in the manifest.

Note

Keep in mind that TOML does not allow trailing commas in inline tables: { path = "...", uri = "...", } is a syntax error.

The type parameter specifies the mount point type. If omitted, it defaults to "chroot". The path parameter must be an absolute path (i.e. must begin with /).

Gramine currently supports the following types of mount points:

  • chroot (default): Host-backed files. All host files and sub-directories found under [URI] are forwarded to the Gramine instance and placed under [PATH]. For example, with a host-level path specified as uri = "file:/one/path/" and forwarded to Gramine via path = "/another/path", a host-level file /one/path/file is visible to graminized application as /another/path/file. This concept is similar to FreeBSD’s chroot and to Docker’s named volumes. Files under chroot mount points support mmap and fork/clone.

  • encrypted: Host-backed encrypted files. See Encrypted files for more information.

  • tmpfs: Temporary in-memory-only files. These files are not backed by host-level files. The tmpfs files are created under [PATH] (this path is empty on Gramine instance startup) and are destroyed when a Gramine instance terminates. The [URI] parameter is always ignored, and can be omitted.

    tmpfs is especially useful in trusted environments (like Intel SGX) for securely storing temporary files. This concept is similar to Linux’s tmpfs. Files under tmpfs mount points currently do not support mmap and each process has its own, non-shared tmpfs (i.e. processes don’t see each other’s files).

Start (current working) directory

fs.start_dir = "[URI]"

This syntax specifies the start (current working) directory. If not specified, then Gramine sets the root directory as the start directory (see fs.root).

SGX syntax

If Gramine is not running with SGX, the SGX-specific syntax is ignored. All keys in the SGX-specific syntax are optional.

Debug/production enclave

sgx.debug = [true|false]
(Default: false)

This syntax specifies whether the enclave can be debugged. Set it to true for a debug enclave and to false for a production enclave.

Enclave size

sgx.enclave_size = "[SIZE]"
(default: "256M")

This syntax specifies the size of the enclave set during enclave creation time (recall that SGX v1 requires a predetermined maximum size of the enclave). The PAL and library OS code/data count towards this size value, as well as the application memory itself: application’s code, stack, heap, loaded application libraries, etc. The application cannot allocate memory that exceeds this limit.

Be careful when setting the enclave size to large values: on systems where the EDMM feature is not enabled, Gramine not only reserves sgx.enclave_size bytes of virtual address space but also commits them to the backing store (EPC, RAM and/or swap file). For example, if sgx.enclave_size = "4G", then 4GB of EPC/RAM will be immediately allocated to back the enclave memory (recall that EPC is the SGX-protected part of RAM). Thus, if your system has 4GB of backing store or less, then the host Linux kernel will fail to start the SGX enclave and will typically print the Killed message. If you encounter this situation, you can try the following:

  • If possible, decrease sgx.enclave_size to a value less than the amount of RAM. For example, if you have 4GB of RAM, set sgx.enclave_size = "2G".
  • Switch to a system that has more RAM. For example, if you must use sgx.enclave_size = "4G", move to a system with at least 5GB of RAM.
  • If the above options are ruled out, then increase the swap file size (recall that the swap file is a space on hard disk used as a virtual “extension” to real RAM). For example, if you have 4GB of RAM and you must use sgx.enclave_size = "4G", then create the swap file of size 1GB. Note that as soon as the SGX application starts using the swap file, its performance degrades significantly!

Also, be careful with multi-process SGX applications: each new child process runs in its own SGX enclave and thus requires an additional sgx.enclave_size amount of RAM. For example, if you run bash -c ls and your manifest contains sgx.enclave_size = "4G", then two SGX enclaves (bash and ls processes) will consume 8GB of RAM in total. If there is less than 8GB of RAM (+ swap file) on your system, such bash -c ls SGX workload will fail.

Non-PIE binaries

sgx.nonpie_binary = [true|false]
(Default: false)

This setting tells Gramine whether to use a specially crafted memory layout, which is required to support non-relocatable binaries (non-PIE).

Number of threads

sgx.thread_num = [NUM]
(Default: 4)

This syntax specifies the maximum number of threads that can be created inside the enclave (recall that SGX v1 requires a predetermined maximum number of thread slots). The application cannot have more threads than this limit at a time (however, it is possible to create new threads after old threads are destroyed).

Note that Gramine uses several helper threads internally:

  • The IPC thread to facilitate inter-process communication. This thread is always spawned at Gramine startup. Its activity depends on the communication patterns among Gramine processes; if there is only one Gramine process, the IPC thread always sleeps.
  • The Async thread to implement timers and other asynchronous events/notifications. This thread is spawned on demand. It terminates itself if there are no pending events/notifications.
  • The TLS-handshake thread on pipes creation. This thread is spawned on demand, each time a new pipe is created. It terminates itself immediately after the TLS handshake is performed.

Given these internal threads, sgx.thread_num should be set to at least 4 even for single-threaded applications (to accommodate for the main thread, the IPC thread, the Async thread and one TLS-handshake thread).

Number of RPC threads (Exitless feature)

sgx.insecure__rpc_thread_num = [NUM]
(Default: 0)

This syntax specifies the number of RPC threads that are created outside of the enclave. RPC threads are helper threads that run in untrusted mode alongside enclave threads. RPC threads issue system calls on behalf of enclave threads. This allows “exitless” design when application threads never leave the enclave (except for a few syscalls where there is no benefit, e.g., nanosleep()).

If user specifies 0 or omits this directive, then no RPC threads are created and all system calls perform an enclave exit (“normal” execution).

Note that the number of created RPC threads should match the maximum number of simultaneous enclave threads. If there are more RPC threads, then CPU time is wasted. If there are less RPC threads, some enclave threads may starve, especially if there are many blocking system calls by other enclave threads.

The Exitless feature may be detrimental for performance. It trades slow OCALLs/ECALLs for fast shared-memory communication at the cost of occupying more CPU cores and burning more CPU cycles. For example, a single-threaded Redis instance on Linux becomes 5-threaded on Gramine with Exitless. Thus, Exitless may negatively impact throughput but may improve latency.

This feature is currently marked as insecure, because it reads untrusted memory in potentially insecure manner - susceptible to CVE-2022-21233 (INTEL-SA-00657).

Optional CPU features (AVX, AVX512, MPX, PKRU, AMX)

sgx.require_avx    = [true|false]
sgx.require_avx512 = [true|false]
sgx.require_mpx    = [true|false]
sgx.require_pkru   = [true|false]
sgx.require_amx    = [true|false]
(Default: false)

This syntax ensures that the CPU features are available and enabled for the enclave. If the options are set in the manifest but the features are unavailable on the platform, enclave initialization will fail. If the options are unset, enclave initialization will succeed even if these features are unavailable on the platform.

ISV Product ID and SVN

sgx.isvprodid = [NUM]
sgx.isvsvn    = [NUM]
(Default: 0)

This syntax specifies the ISV Product ID and SVN to be added to the enclave signature.

Attribute masks for SGX sealing key derivation

sgx.seal_key.flags_mask = "[8-byte hex value]"  (default: "0xffffffffffffffff")
sgx.seal_key.xfrm_mask  = "[8-byte hex value]"  (default: "0xfffffffffff9ff1b")
sgx.seal_key.misc_mask  = "[4-byte hex value]"  (default: "0xffffffff")

This syntax specifies masks used to generate the SGX sealing key. These masks correspond to the following SGX KEYREQUEST struct fields:

  • flags_mask: KEYREQUEST.ATTRIBUTESMASK.FLAGS
  • xfrm_mask: KEYREQUEST.ATTRIBUTESMASK.XFRM
  • misc_mask: KEYREQUEST.MISCMASK

Most users do not need to set these masks. Only advanced users with knowledge of SGX sealing should use these masks. In particular, these masks allow to specify a subset of enclave/machine attributes to be used in sealing key derivation. Moreover, these masks themselves are used in sealing key derivation.

Allowed files

sgx.allowed_files = [
  "[URI]",
  "[URI]",
]

This syntax specifies the files that are allowed to be created or loaded into the enclave unconditionally. In other words, allowed files can be opened for reading/writing and can be created if they do not exist already. Allowed files are not cryptographically hashed and are thus not protected.

Warning

It is insecure to allow files containing code or critical information; developers must not allow files blindly! Instead, use trusted or encrypted files.

Trusted files

# entries can be strings
sgx.trusted_files = [
  "[URI]",
  "[URI]",
]

# entries can also be tables
[[sgx.trusted_files]]
uri = "[URI]"
sha256 = "[HASH]"

This syntax specifies the files to be cryptographically hashed at build time, and allowed to be accessed by the app in runtime only if their hashes match. This implies that trusted files can be only opened for reading (not for writing) and cannot be created if they do not exist already. The signer tool will automatically generate hashes of these files and add them to the SGX-specific manifest (.manifest.sgx). The manifest writer may also specify the hash for a file using the TOML-table syntax, in the field sha256; in this case, hashing of the file will be skipped by the signer tool and the value in sha256 field will be used instead.

Marking files as trusted is especially useful for shared libraries: a trusted library cannot be silently replaced by a malicious host because the hash verification will fail.

Encrypted files

fs.mounts = [
  { type = "encrypted", path = "[PATH]", uri = "[URI]", key_name = "[KEY_NAME]" },
]

fs.insecure__keys.[KEY_NAME] = "[32-character hex value]"

This syntax allows mounting files that are encrypted on disk and transparently decrypted when accessed by Gramine or by application running inside Gramine. Encrypted files guarantee data confidentiality and integrity (tamper resistance), as well as file swap protection (an encrypted file can only be accessed when in a specific host path).

Encrypted files were previously known as protected files, and some Gramine tools might still use the old name.

URI can be a file or a directory. If a directory is mounted, all existing files/directories within it are recursively treated as encrypted (and are expected to be encrypted in the PF format). New files created in an encrypted mount are also automatically treated as encrypted.

Warning

The current implementation assumes that type = "encrypted" mounts do not overlap on host, i.e. there are no host files reachable through more than one type = "encrypted" mount. Otherwise, changes made to such files might not be correctly persisted by Gramine.

Note that path size of an encrypted file is limited to 512 bytes and filename size is limited to 260 bytes.

The key_name mount parameter specifies the name of the encryption key. If omitted, it will default to "default". This feature can be used to mount different files or directories with different encryption keys.

fs.insecure__keys.[KEY_NAME] can be used to specify the encryption keys directly in manifest. This option must be used only for debugging purposes.

Warning

sgx.insecure__keys.[KEY_NAME] hard-codes the key in the manifest. This option is thus insecure and must not be used in production environments! Typically, you want to provision the encryption keys using SGX local/remote attestation, thus you should not specify any sgx.insecure__keys.[KEY_NAME] manifest options at all. Instead, use the Secret Provisioning interface (see Attestation and Secret Provisioning).

Key names beginning with underscore (_) denote special keys provided by Gramine:

  • "_sgx_mrenclave" (SGX only) is the SGX sealing key based on the MRENCLAVE identity of the enclave. This is useful to allow only the same enclave (on the same platform) to unseal files.
  • "_sgx_mrsigner" (SGX only) is the SGX sealing key based on the MRSIGNER identity of the enclave. This is useful to allow all enclaves signed with the same key (and on the same platform) to unseal files.

File check policy

sgx.file_check_policy = "[strict|allow_all_but_log]"
(Default: "strict")

This syntax specifies the file check policy, determining the behavior of authentication when opening files. By default, only files explicitly listed as trusted_files or allowed_files declared in the manifest are allowed for access.

If the file check policy is allow_all_but_log, all files other than trusted and allowed are allowed for access, and Gramine emits a warning message for every such file. Effectively, this policy operates on all unknown files as if they were listed as allowed_files. (However, this policy still does not allow writing/creating files specified as trusted.) This policy is a convenient way to determine the set of files that the ported application uses.

Attestation and quotes

sgx.remote_attestation = "[none|epid|dcap]"
(Default: "none")

sgx.ra_client_linkable = [true|false]
sgx.ra_client_spid     = "[HEX]"
(Only for EPID based attestation)

This syntax specifies the parameters for remote attestation. By default it is not enabled.

For EPID based attestation, remote_attestation must be set to epid. In addition, ra_client_linkable and ra_client_spid must be filled with your registered Intel SGX EPID Attestation Service credentials (linkable/unlinkable mode and SPID of the client respectively).

For DCAP based attestation, remote_attestation must be set to dcap. ra_client_spid and ra_client_linkable are ignored.

Pre-heating enclave

sgx.preheat_enclave = [true|false]
(Default: false)

When enabled, this option instructs Gramine to pre-fault all heap pages during initialization. This has a negative impact on the total run time, but shifts the EPC page faults cost to the initialization phase, which can be useful in a scenario where a server starts and receives connections / work packages only after some time. It also makes the later run time and latency much more predictable.

Please note that using this option makes sense only when the EPC is large enough to hold the whole heap area.

Enabling per-thread and process-wide SGX stats

sgx.enable_stats = [true|false]
(Default: false)

This syntax specifies whether to enable SGX enclave-specific statistics:

  1. TCS.FLAGS.DBGOPTIN flag. This flag is set in all enclave threads and enables certain debug and profiling features with enclaves, including breakpoints, performance counters, Intel PT, etc.
  2. Printing the stats on SGX-specific events. Currently supported stats are: number of EENTERs (corresponds to ECALLs plus returns from OCALLs), number of EEXITs (corresponds to OCALLs plus returns from ECALLs) and number of AEXs (corresponds to interrupts/exceptions/signals during enclave execution). Prints per-thread and per-process stats.
  3. Printing the SGX enclave loading time at startup. The enclave loading time includes creating the enclave, adding enclave pages, measuring them and initializing the enclave.

Warning

This option is insecure and cannot be used with production enclaves (sgx.debug = false). If a production enclave is started with this option set, Gramine will fail initialization of the enclave.

SGX profiling

sgx.profile.enable = ["none"|"main"|"all"]
(Default: "none")

This syntax specifies whether to enable SGX profiling. Gramine must be compiled with DEBUG=1 or DEBUGOPT=1 for this option to work (the latter is advised).

If this option is set to main, the main process will collect IP samples and save them as sgx-perf.data. If it is set to all, all processes will collect samples and save them to sgx-perf-<PID>.data.

The saved files can be viewed with the perf tool, e.g. perf report -i sgx-perf.data.

See SGX profiling for more information.

Warning

This option is insecure and cannot be used with production enclaves (sgx.debug = false). If a production enclave is started with this option set, Gramine will fail initialization of the enclave.

sgx.profile.mode = ["aex"|"ocall_inner"|"ocall_outer"]
(Default: "aex")

Specifies what events to record:

  • aex: Records enclave state during asynchronous enclave exit (AEX). Use this to check where the CPU time is spent in the enclave.
  • ocall_inner: Records enclave state during OCALL.
  • ocall_outer: Records the outer OCALL function, i.e. what OCALL handlers are going to be executed. Does not include stack information (cannot be used with sgx.profile.with_stack = true).

See also OCALL profiling for more detailed advice regarding the OCALL modes.

sgx.profile.with_stack = [true|false]
(Default: false)

This syntax specifies whether to include stack information with the profiling data. This will enable perf report to show call chains. However, it will make the output file much bigger, and slow down the process.

sgx.profile.frequency = [INTEGER]
(Default: 50)

This syntax specifies approximate frequency at which profiling samples are taken (in samples per second). Lower values will mean less accurate results, but also lower overhead.

Note that the accuracy is limited by how often the process is interrupted by Linux scheduler: the effective maximum is 250 samples per second.

Note

This option applies only to aex mode. In the ocall_* modes, currently all samples are taken.

SGX profiling with Intel VTune Profiler

sgx.vtune_profile = [true|false]
(Default: false)

This syntax specifies whether to enable SGX profiling with Intel VTune Profiler. Gramine must be compiled with DEBUG=1 or DEBUGOPT=1 for this option to work (the latter is advised). In addition, the application manifest must also contain sgx.debug = true.

Note

The manifest options sgx.vtune_profile and sgx.profile.* can work independently.

See Profiling SGX hotspots with Intel VTune Profiler for more information.

Deprecated options

FS mount points (deprecated syntax)

fs.mount.[identifier].type = "[chroot|...]"
fs.mount.[identifier].path = "[PATH]"
fs.mount.[identifier].uri  = "[URI]"

This syntax used a TOML table schema with keys for each mount. It has been replaced with the fs.mounts TOML array.

Experimental sysfs topology support

fs.experimental__enable_sysfs_topology = [true|false]

This feature is now enabled by default and the option was removed.

Protected files (deprecated syntax)

sgx.protected_files = [
  "[URI]",
  "[URI]",
]

sgx.protected_mrenclave_files = [
  "[URI]",
  "[URI]",
]

sgx.protected_mrsigner_files = [
  "[URI]",
  "[URI]",
]

This syntax specified the previous SGX-only protected files. It has been replaced with type = "encrypted" mounts (see Encrypted files).

Warning

Gramine will attempt to convert this syntax to mounted filesystems, but might fail to do so correctly in more complicated cases (e.g. when a single host file belongs to multiple mounts). It is recommended to rewrite all usages of this syntax to type = "encrypted" mounts.

fs.insecure__protected_files_key = "[32-character hex value]"

This syntax allowed specifying the default encryption key for protected files. It has been replaced by fs.insecure__keys.[KEY_NAME]]. Note that both old and new syntax are suitable for debugging purposes only.

Attestation and quotes (deprecated syntax)

sgx.remote_attestation = [true|false]

This syntax specified whether to enable SGX remote attestation. The boolean value has been replaced with the string value. The none value in the new syntax corresponds to the false boolean value in the deprecated syntax. The explicit epid and dcap values in the new syntax replace the ambiguous true boolean value in the deprecated syntax.