[tip: x86/sgx] Documentation/x86: Introduce enclave runtime management section

[tip: x86/sgx] Documentation/x86: Introduce enclave runtime management section

[tip-bot2 for Reinette Chatre]

The following commit has been merged into the x86/sgx branch of tip:

Commit-ID:     629b5155d01b699e50ee63a3973402c64d0ac5d6
Gitweb:        https://git.kernel.org/tip/629b5155d01b699e50ee63a3973402c64d0ac5d6
Author:        Reinette Chatre <reinette.chatre@intel.com>
AuthorDate:    Tue, 10 May 2022 11:08:57 -07:00
Committer:     Dave Hansen <dave.hansen@linux.intel.com>
CommitterDate: Thu, 07 Jul 2022 10:13:03 -07:00

Documentation/x86: Introduce enclave runtime management section

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.

Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Link: https://lkml.kernel.org/r/1da0b9a938b28e68e6870ebd5291490d680e700b.1652137848.git.reinette.chatre@intel.com
---
 Documentation/x86/sgx.rst | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/Documentation/x86/sgx.rst b/Documentation/x86/sgx.rst
index 265568a..2bcbffa 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
 ------------