[PATCH v7 01/20] x86/tdx: Define TDX supported page sizes as macros

From: Kai Huang
Date: Sun Nov 20 2022 - 19:27:39 EST


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.

Reviewed-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Signed-off-by: Kai Huang <kai.huang@xxxxxxxxx>
---

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 | 9 +++++++++
2 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/arch/x86/coco/tdx/tdx.c b/arch/x86/coco/tdx/tdx.c
index cfd4c95b9f04..7fa7fb54f438 100644
--- a/arch/x86/coco/tdx/tdx.c
+++ b/arch/x86/coco/tdx/tdx.c
@@ -722,13 +722,13 @@ 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..e9a3f4a6fba1 100644
--- a/arch/x86/include/asm/tdx.h
+++ b/arch/x86/include/asm/tdx.h
@@ -20,6 +20,15 @@

#ifndef __ASSEMBLY__

+/*
+ * TDX supported page sizes (4K/2M/1G).
+ *
+ * Those values are part of the TDX module ABI. Do not change them.
+ */
+#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.
--
2.38.1