[PATCH v9 01/18] x86/tdx: Define TDX supported page sizes as macros

Kai Huang
2023-02-13T12:00:47Z

TDX supports 4K, 2M and 1G page sizes. The corresponding values are
defined by the TDX module spec and used as TDX module ABI. Currently,
they are used in try_accept_one() when the TDX guest tries to accept a
page. However currently try_accept_one() uses hard-coded magic values.

Define TDX supported page sizes as macros and get rid of the hard-coded
values in try_accept_one(). TDX host support will need to use them too.

Signed-off-by: Kai Huang <kai.huang@intel.com>
Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
---

v8 -> v9:
- Added Dave's Reviewed-by

v7 -> v8:
- Improved the comment of TDX supported page sizes macros (Dave)

v6 -> v7:
- Removed the helper to convert kernel page level to TDX page level.
- Changed to use macro to define TDX supported page sizes.

---
arch/x86/coco/tdx/tdx.c | 6 +++---
arch/x86/include/asm/tdx.h | 5 +++++
2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/arch/x86/coco/tdx/tdx.c b/arch/x86/coco/tdx/tdx.c
index b593009b30ab..e27c3cd97fcb 100644
--- a/arch/x86/coco/tdx/tdx.c
+++ b/arch/x86/coco/tdx/tdx.c
@@ -777,13 +777,13 @@ static bool try_accept_one(phys_addr_t *start, unsigned long len,
*/
switch (pg_level) {
case PG_LEVEL_4K:
- page_size = 0;
+ page_size = TDX_PS_4K;
break;
case PG_LEVEL_2M:
- page_size = 1;
+ page_size = TDX_PS_2M;
break;
case PG_LEVEL_1G:
- page_size = 2;
+ page_size = TDX_PS_1G;
break;
default:
return false;
diff --git a/arch/x86/include/asm/tdx.h b/arch/x86/include/asm/tdx.h
index 28d889c9aa16..25fd6070dc0b 100644
--- a/arch/x86/include/asm/tdx.h
+++ b/arch/x86/include/asm/tdx.h
@@ -20,6 +20,11 @@

#ifndef __ASSEMBLY__

+/* TDX supported page sizes from the TDX module ABI. */
+#define TDX_PS_4K 0
+#define TDX_PS_2M 1
+#define TDX_PS_1G 2
+
/*
* Used to gather the output registers values of the TDCALL and SEAMCALL
* instructions when requesting services from the TDX module.
--
2.39.1