[RFC PATCH v6 08/25] x86/sgx: Expose SGX architectural definitions to the kernel

[Kai Huang <kai.huang@intel.com>]

From: Sean Christopherson <sean.j.christopherson@intel.com>

Expose SGX architectural structures, as KVM will use many of the
architectural constants and structs to virtualize SGX.

Name the new header file as asm/sgx.h, rather than asm/sgx_arch.h, to
have single header to provide SGX facilities to share with other kernel
componments.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Co-developed-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Kai Huang <kai.huang@intel.com>
---
v5->v6:

 - Renamed asm/sgx_arch.h to asm/sgx.h, which will contain both archiitectural
   definitions and Linux defined sofware structures and functions, suggested by
   Boris.
 - Removed the comment saying "Data structures defined by Linux software stack
   should not be placed here", since it is not valid anymore. Added comments to
   explain asm/sgx.h is for both architectural and non-architectural
   definitions. Added a comment to split the two parts, suggested by Boris.
 - Added one more sentence in commit msg to explain asm/sgx.h is intended for
   single header file for sharing with other kernel componments.

v4->v5:

 - No code change.

v3->v4:

 - No code change.
 - Added Jarkko's Acked-by. Restored Dave's Acked-by.

v2->v3:

 - Added "Expose SGX architectural structures, as..." to commit message,
   per Jarkko.

---
 .../cpu/sgx/arch.h => include/asm/sgx.h}      | 20 ++++++++++++++-----
 arch/x86/kernel/cpu/sgx/encl.c                |  2 +-
 arch/x86/kernel/cpu/sgx/sgx.h                 |  2 +-
 tools/testing/selftests/sgx/defines.h         |  2 +-
 4 files changed, 18 insertions(+), 8 deletions(-)
 rename arch/x86/{kernel/cpu/sgx/arch.h => include/asm/sgx.h} (95%)

diff --git a/arch/x86/kernel/cpu/sgx/arch.h b/arch/x86/include/asm/sgx.h
similarity index 95%
rename from arch/x86/kernel/cpu/sgx/arch.h
rename to arch/x86/include/asm/sgx.h
index abf99bb71fdc..d4ad35f6319a 100644
--- a/arch/x86/kernel/cpu/sgx/arch.h
+++ b/arch/x86/include/asm/sgx.h
@@ -2,15 +2,20 @@
 /**
  * Copyright(c) 2016-20 Intel Corporation.
  *
- * Contains data structures defined by the SGX architecture.  Data structures
- * defined by the Linux software stack should not be placed here.
+ * Intel Software Guard Extensions (SGX) support.
  */
-#ifndef _ASM_X86_SGX_ARCH_H
-#define _ASM_X86_SGX_ARCH_H
+#ifndef _ASM_X86_SGX_H
+#define _ASM_X86_SGX_H
 
 #include <linux/bits.h>
 #include <linux/types.h>
 
+/*
+ * This file contains both data structures defined by SGX architecture and Linux
+ * defined software data structures and functions.  The two should not be mixed
+ * together for better readibility.  The architectural definitions come first.
+ */
+
 /* The SGX specific CPUID function. */
 #define SGX_CPUID		0x12
 /* EPC enumeration. */
@@ -337,4 +342,9 @@ struct sgx_sigstruct {
 
 #define SGX_LAUNCH_TOKEN_SIZE 304
 
-#endif /* _ASM_X86_SGX_ARCH_H */
+/*
+ * Do not put any hardware-defined SGX structure representations below this
+ * line!
+ */
+
+#endif /* _ASM_X86_SGX_H */
diff --git a/arch/x86/kernel/cpu/sgx/encl.c b/arch/x86/kernel/cpu/sgx/encl.c
index 7a09a98fe68d..e023c7a2d062 100644
--- a/arch/x86/kernel/cpu/sgx/encl.c
+++ b/arch/x86/kernel/cpu/sgx/encl.c
@@ -7,7 +7,7 @@
 #include <linux/shmem_fs.h>
 #include <linux/suspend.h>
 #include <linux/sched/mm.h>
-#include "arch.h"
+#include <asm/sgx.h>
 #include "encl.h"
 #include "encls.h"
 #include "sgx.h"
diff --git a/arch/x86/kernel/cpu/sgx/sgx.h b/arch/x86/kernel/cpu/sgx/sgx.h
index 1bff93be7bf4..5d71c9c8644d 100644
--- a/arch/x86/kernel/cpu/sgx/sgx.h
+++ b/arch/x86/kernel/cpu/sgx/sgx.h
@@ -8,7 +8,7 @@
 #include <linux/rwsem.h>
 #include <linux/types.h>
 #include <asm/asm.h>
-#include "arch.h"
+#include <asm/sgx.h>
 
 #undef pr_fmt
 #define pr_fmt(fmt) "sgx: " fmt
diff --git a/tools/testing/selftests/sgx/defines.h b/tools/testing/selftests/sgx/defines.h
index 592c1ccf4576..0bd73428d2f3 100644
--- a/tools/testing/selftests/sgx/defines.h
+++ b/tools/testing/selftests/sgx/defines.h
@@ -14,7 +14,7 @@
 #define __aligned(x) __attribute__((__aligned__(x)))
 #define __packed __attribute__((packed))
 
-#include "../../../../arch/x86/kernel/cpu/sgx/arch.h"
+#include "../../../../arch/x86/include/asm/sgx.h"
 #include "../../../../arch/x86/include/asm/enclu.h"
 #include "../../../../arch/x86/include/uapi/asm/sgx.h"
 
-- 
2.29.2