[PATCHv7 13/14] x86/tdx: Refactor try_accept_one()

Kirill A. Shutemov
2022-06-14T12:03:10Z

Rework try_accept_one() to return accepted size instead of modifying
'start' inside the helper. It makes 'start' in-only argumaent and
streamlines code on the caller side.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Suggested-by: Borislav Petkov <bp@alien8.de>
---
arch/x86/coco/tdx/tdx.c | 38 +++++++++++++++++++-------------------
1 file changed, 19 insertions(+), 19 deletions(-)

diff --git a/arch/x86/coco/tdx/tdx.c b/arch/x86/coco/tdx/tdx.c
index b75fe670032b..b10c95307f6e 100644
--- a/arch/x86/coco/tdx/tdx.c
+++ b/arch/x86/coco/tdx/tdx.c
@@ -624,18 +624,18 @@ static bool tdx_cache_flush_required(void)
return true;
}

-static bool try_accept_one(phys_addr_t *start, unsigned long len,
- enum pg_level pg_level)
+static unsigned long try_accept_one(phys_addr_t start, unsigned long len,
+ enum pg_level pg_level)
{
unsigned long accept_size = page_level_size(pg_level);
u64 tdcall_rcx;
u8 page_size;

- if (!IS_ALIGNED(*start, accept_size))
- return false;
+ if (!IS_ALIGNED(start, accept_size))
+ return 0;

if (len < accept_size)
- return false;
+ return 0;

/*
* Pass the page physical address to the TDX module to accept the
@@ -654,15 +654,14 @@ static bool try_accept_one(phys_addr_t *start, unsigned long len,
page_size = 2;
break;
default:
- return false;
+ return 0;
}

- tdcall_rcx = *start | page_size;
+ tdcall_rcx = start | page_size;
if (__tdx_module_call(TDX_ACCEPT_PAGE, tdcall_rcx, 0, 0, 0, NULL))
- return false;
+ return 0;

- *start += accept_size;
- return true;
+ return accept_size;
}

/*
@@ -699,21 +698,22 @@ static bool tdx_enc_status_changed(unsigned long vaddr, int numpages, bool enc)
*/
while (start < end) {
unsigned long len = end - start;
+ unsigned long accept_size;

/*
* Try larger accepts first. It gives chance to VMM to keep
- * 1G/2M SEPT entries where possible and speeds up process by
- * cutting number of hypercalls (if successful).
+ * 1G/2M Secure EPT entries where possible and speeds up
+ * process by cutting number of hypercalls (if successful).
*/

- if (try_accept_one(&start, len, PG_LEVEL_1G))
- continue;
-
- if (try_accept_one(&start, len, PG_LEVEL_2M))
- continue;
-
- if (!try_accept_one(&start, len, PG_LEVEL_4K))
+ accept_size = try_accept_one(start, len, PG_LEVEL_1G);
+ if (!accept_size)
+ accept_size = try_accept_one(start, len, PG_LEVEL_2M);
+ if (!accept_size)
+ accept_size = try_accept_one(start, len, PG_LEVEL_4K);
+ if (!accept_size)
return false;
+ start += accept_size;
}

return true;
--
2.35.1