[PATCH 16/20] x86/tdx: Convert VP_INFO tdcall to use new TDCALL_5() macro

Kirill A. Shutemov
2024-05-17T14:20:06Z

Use newly introduced TDCALL_5() instead of tdcall() to issue VP_INFO
tdcall.

It cuts code bloat slightly:

Function old new delta
tdx_early_init 780 744 -36

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
---
arch/x86/coco/tdx/tdx.c | 27 +++++++++++++--------------
1 file changed, 13 insertions(+), 14 deletions(-)

diff --git a/arch/x86/coco/tdx/tdx.c b/arch/x86/coco/tdx/tdx.c
index e7ffe1cd6d32..e1849878f3bc 100644
--- a/arch/x86/coco/tdx/tdx.c
+++ b/arch/x86/coco/tdx/tdx.c
@@ -247,20 +247,22 @@ static void enable_cpu_topology_enumeration(void)
tdg_vm_wr(TDCS_TD_CTLS, TD_CTLS_ENUM_TOPOLOGY, TD_CTLS_ENUM_TOPOLOGY);
}

+static void tdg_vp_info(u64 *gpa_width, u64 *attributes)
+{
+ u64 dummy, ret;
+
+ ret = TDCALL_5(TDG_VP_INFO, 0, 0, 0, 0, *gpa_width, *attributes, dummy,
+ dummy, dummy);
+ BUG_ON(ret);
+
+ *gpa_width &= GENMASK(5, 0);
+}
+
static void tdx_setup(u64 *cc_mask)
{
- struct tdx_module_args args = {};
- unsigned int gpa_width;
- u64 td_attr;
+ u64 gpa_width, td_attr;

- /*
- * TDINFO TDX module call is used to get the TD execution environment
- * information like GPA width, number of available vcpus, debug mode
- * information, etc. More details about the ABI can be found in TDX
- * Guest-Host-Communication Interface (GHCI), section 2.4.2 TDCALL
- * [TDG.VP.INFO].
- */
- tdcall(TDG_VP_INFO, &args);
+ tdg_vp_info(&gpa_width, &td_attr);

/*
* The highest bit of a guest physical address is the "sharing" bit.
@@ -269,11 +271,8 @@ static void tdx_setup(u64 *cc_mask)
* The GPA width that comes out of this call is critical. TDX guests
* can not meaningfully run without it.
*/
- gpa_width = args.rcx & GENMASK(5, 0);
*cc_mask = BIT_ULL(gpa_width - 1);

- td_attr = args.rdx;
-
/* Kernel does not use NOTIFY_ENABLES and does not need random #VEs */
tdg_vm_wr(TDCS_NOTIFY_ENABLES, 0, -1ULL);

--
2.43.0