[Pal/Linux-SGX] Recognize upstreamed Intel SGX driver

Intel SGX driver was upstreamed in Linux version 5.11. There, the SGX
device is exposed as `/dev/sgx_enclave` instead of `/dev/sgx/enclave`.
This commit updates link-intel-driver.py to recognize this new name.

Documentation/sgx-intro.rst

@@ -1,6 +1,8 @@
 Introduction to SGX
 ===================
 
+.. highlight:: sh
+
 Graphene project uses :term:`SGX` to securely run software. SGX is
 a |~| complicated topic, which may be hard to learn, because the documentation
 is scattered through official/reference documentation, blogposts and academic
@@ -80,7 +82,7 @@ Installation Instructions
 Linux kernel drivers
 ^^^^^^^^^^^^^^^^^^^^
 
-For historical reasons, there are three SGX drivers currently (March 2020):
+For historical reasons, there are three SGX drivers currently (January 2021):
 
 - https://github.com/intel/linux-sgx-driver -- old one, does not support DCAP,
   deprecated
@@ -90,13 +92,21 @@ For historical reasons, there are three SGX drivers currently (March 2020):
   old EPID remote-attestation technique) and the new DCAP (with new ECDSA and
   more "normal" PKI infrastructure).
 
-- Upstreaming in-kernel SGX driver (see LKML patches) -- will be upstreamed one
-  day, supports both non-DCAP and DCAP. The DCAP driver closely matches this
-  upstreaming version.
-
-  The in-tree driver will not be a |~| module
-  (https://lore.kernel.org/linux-sgx/[email protected]/),
-  so "installation instructions" will likely be minimal.
+- SGX support was upstreamed to the Linux mainline starting from 5.11.
+  It currently supports only DCAP attestation. The driver is accessible through
+  /dev/sgx_enclave and /dev/sgx_provision.
+
+  The following udev rules are recommended for users to access the SGX node::
+
+    groupadd -r sgx
+    gpasswd -a USERNAME sgx
+    groupadd -r sgx_prv
+    gpasswd -a USERNAME sgx_prv
+    cat > /etc/udev/rules.d/65-graphene-sgx.rules << EOF
+      SUBSYSTEM=="misc",KERNEL=="sgx_enclave",MODE="0660",GROUP="sgx"
+      SUBSYSTEM=="misc",KERNEL=="sgx_provision",MODE="0660",GROUP="sgx_prv"
+      EOF
+    udevadm trigger
 
   Also it will not require :term:`IAS` and kernel maintainers consider
   non-writable :term:`FLC` MSRs as non-functional SGX:

Pal/src/host/Linux-SGX/link-intel-driver.py

@@ -6,8 +6,15 @@
 import sys
 
 DRIVER_VERSIONS = {
+        # For Non-DCAP, older versions of legacy OOT SGX driver
         'sgx_user.h':                 '/dev/isgx',
+        # For DCAP driver 1.6+, but below 1.10
         'include/uapi/asm/sgx_oot.h': '/dev/sgx/enclave',
+        # For DCAP driver 1.10+
+        'include/sgx_user.h':         '/dev/sgx/enclave',
+        # For upstreamed in-kernel SGX driver, kernel version 5.11+
+        'include/uapi/asm/sgx.h':     '/dev/sgx_enclave',
+        # By default, using sgx_in_kernel.h in current dir of this script
         'sgx_in_kernel.h':            '/dev/sgx/enclave',
 }
 
@@ -16,8 +23,12 @@ def find_intel_sgx_driver(isgx_driver_path):
     Graphene only needs one header from the Intel SGX Driver:
       - sgx_user.h for non-DCAP, older version of the driver
         (https://github.com/intel/linux-sgx-driver)
-      - include/uapi/asm/sgx_oot.h for DCAP 1.6+ version of the driver
+      - include/uapi/asm/sgx_oot.h for DCAP 1.6+ version but below 1.10 of the driver
         (https://github.com/intel/SGXDataCenterAttestationPrimitives)
+      - include/sgx_user.h for DCAP 1.10+ version of the driver
+        (https://github.com/intel/SGXDataCenterAttestationPrimitives)
+      - include/uapi/asm/sgx.h for upstreamed SGX in-kernel driver from mainline kernel version 5.11
+        (https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git)
       - default sgx_in_kernel.h for in-kernel 32+ version of the driver
         (https://lore.kernel.org/linux-sgx/[email protected])
 
@@ -61,7 +72,10 @@ def main(args=None):
     except KeyError:
         print(
             'ISGX_DRIVER_PATH environment variable is undefined. You can define\n'
-            'ISGX_DRIVER_PATH="" to use the default in-kernel driver\'s C header.',
+            'ISGX_DRIVER_PATH="" to use the in-kernel driver\'s C header from version\n'
+            '32 (bundled with Graphene but NOT upstreamed). For upstreamed\n'
+            'in-kernel driver (if you are using Linux kernel 5.11+), define\n'
+            'ISGX_DRIVER_PATH="/usr/src/linux-headers-$(uname -r)/arch/x86"\n',
             file=sys.stderr)
         sys.exit(1)
 
@@ -76,7 +90,7 @@ def main(args=None):
     final = template.safe_substitute(
         DRIVER_SGX_H=header_path,
         ISGX_FILE=dev_path,
-        DEFINE_DCAP=('#define SGX_DCAP 1' if dev_path == '/dev/sgx/enclave' else '')
+        DEFINE_DCAP=('#define SGX_DCAP 1' if dev_path != '/dev/isgx' else '')
     )
 
     with open(args.output, 'w') as f: