[PATCH v2 2/5] x86/virt/tdx: Move TDMR metadata fields map table to local variable

From: Kai Huang
Date: Tue Mar 26 2024 - 06:24:19 EST


The kernel reads all TDMR related global metadata fields based on a
table which maps the metadata fields to the corresponding members of
'struct tdx_tdmr_sysinfo'.

Currently this table is a static variable. But this table is only used
by the function which reads these metadata fields and becomes useless
after reading is done.

Change the table to function local variable. This also saves the
storage of the table from the kernel image.

Signed-off-by: Kai Huang <kai.huang@xxxxxxxxx>
Reviewed-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Reviewed-by: Binbin Wu <binbin.wu@xxxxxxxxxxxxxxx>
---
arch/x86/virt/vmx/tdx/tdx.c | 17 ++++++++---------
1 file changed, 8 insertions(+), 9 deletions(-)

diff --git a/arch/x86/virt/vmx/tdx/tdx.c b/arch/x86/virt/vmx/tdx/tdx.c
index 2aee64d2f27f..cdcb3332bc5d 100644
--- a/arch/x86/virt/vmx/tdx/tdx.c
+++ b/arch/x86/virt/vmx/tdx/tdx.c
@@ -301,17 +301,16 @@ struct field_mapping {
{ .field_id = MD_FIELD_ID_##_field_id, \
.offset = offsetof(struct tdx_tdmr_sysinfo, _member) }

-/* Map TD_SYSINFO fields into 'struct tdx_tdmr_sysinfo': */
-static const struct field_mapping fields[] = {
- TD_SYSINFO_MAP(MAX_TDMRS, max_tdmrs),
- TD_SYSINFO_MAP(MAX_RESERVED_PER_TDMR, max_reserved_per_tdmr),
- TD_SYSINFO_MAP(PAMT_4K_ENTRY_SIZE, pamt_entry_size[TDX_PS_4K]),
- TD_SYSINFO_MAP(PAMT_2M_ENTRY_SIZE, pamt_entry_size[TDX_PS_2M]),
- TD_SYSINFO_MAP(PAMT_1G_ENTRY_SIZE, pamt_entry_size[TDX_PS_1G]),
-};
-
static int get_tdx_tdmr_sysinfo(struct tdx_tdmr_sysinfo *tdmr_sysinfo)
{
+ /* Map TD_SYSINFO fields into 'struct tdx_tdmr_sysinfo': */
+ const struct field_mapping fields[] = {
+ TD_SYSINFO_MAP(MAX_TDMRS, max_tdmrs),
+ TD_SYSINFO_MAP(MAX_RESERVED_PER_TDMR, max_reserved_per_tdmr),
+ TD_SYSINFO_MAP(PAMT_4K_ENTRY_SIZE, pamt_entry_size[TDX_PS_4K]),
+ TD_SYSINFO_MAP(PAMT_2M_ENTRY_SIZE, pamt_entry_size[TDX_PS_2M]),
+ TD_SYSINFO_MAP(PAMT_1G_ENTRY_SIZE, pamt_entry_size[TDX_PS_1G]),
+ };
int ret;
int i;

--
2.43.2