[V5,21/31] Documentation/x86: Introduce enclave runtime management section

Commit Message

Reinette Chatre May 10, 2022, 6:08 p.m. UTC

Enclave runtime management is introduced following the pattern
of the section describing enclave building. Provide a brief
summary of enclave runtime management, pointing to the functions
implementing the ioctl()s that will contain details within their
kernel-doc.

Reviewed-by: Jarkko Sakkinen <[e-mail]>
Signed-off-by: Reinette Chatre <[e-mail]>
---
Changes since V4:
- Rename sgx_ioc_enclave_modify_type -> sgx_ioc_enclave_modify_types.
  (Jarkko)
- Add Jarkko's Reviewed-by tag.

Changes since V2:
- Remove references to ioctl() to relax permissions and update to reflect
  function renaming sgx_ioc_enclave_restrict_perm() ->
  sgx_ioc_enclave_restrict_permissions().
- Rename sgx_ioc_enclave_modt -> sgx_ioc_enclave_modify_type

Changes since V1:
- New patch.

 Documentation/x86/sgx.rst | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

Patch

diff --git a/Documentation/x86/sgx.rst b/Documentation/x86/sgx.rst
index 265568a9292c..2bcbffacbed5 100644
--- a/Documentation/x86/sgx.rst
+++ b/Documentation/x86/sgx.rst
@@ -100,6 +100,21 @@  pages and establish enclave page permissions.
                sgx_ioc_enclave_init
                sgx_ioc_enclave_provision
 
+Enclave runtime management
+--------------------------
+
+Systems supporting SGX2 additionally support changes to initialized
+enclaves: modifying enclave page permissions and type, and dynamically
+adding and removing of enclave pages. When an enclave accesses an address
+within its address range that does not have a backing page then a new
+regular page will be dynamically added to the enclave. The enclave is
+still required to run EACCEPT on the new page before it can be used.
+
+.. kernel-doc:: arch/x86/kernel/cpu/sgx/ioctl.c
+   :functions: sgx_ioc_enclave_restrict_permissions
+               sgx_ioc_enclave_modify_types
+               sgx_ioc_enclave_remove_pages
+
 Enclave vDSO
 ------------