[RFC PATCH 15/21] x86/virt/tdx: Reserve TDX module global KeyID

[Kai Huang <kai.huang@intel.com>]

TDX module initialization requires to use one TDX private KeyID as the
global KeyID to crypto protect TDX metadata.  The global KeyID is
configured to the TDX module along with TDMRs.

Just reserve the first TDX private KeyID as the global KeyID.

Signed-off-by: Kai Huang <kai.huang@intel.com>
---
 arch/x86/virt/vmx/tdx.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/arch/x86/virt/vmx/tdx.c b/arch/x86/virt/vmx/tdx.c
index 8dac98b91c77..e6c54b2a1f6e 100644
--- a/arch/x86/virt/vmx/tdx.c
+++ b/arch/x86/virt/vmx/tdx.c
@@ -111,6 +111,9 @@ static struct cmr_info tdx_cmr_array[MAX_CMRS] __aligned(CMR_INFO_ARRAY_ALIGNMEN
 static int tdx_cmr_num;
 static struct tdsysinfo_struct tdx_sysinfo;
 
+/* TDX global KeyID to protect TDX metadata */
+static u32 tdx_global_keyid;
+
 static bool __seamrr_enabled(void)
 {
 	return (seamrr_mask & SEAMRR_ENABLED_BITS) == SEAMRR_ENABLED_BITS;
@@ -1239,6 +1242,12 @@ static int init_tdx_module(void)
 	if (ret)
 		goto out_free_tdmrs;
 
+	/*
+	 * Reserve the first TDX KeyID as global KeyID to protect
+	 * TDX module metadata.
+	 */
+	tdx_global_keyid = tdx_keyid_start;
+
 	/*
 	 * Return -EFAULT until all steps of TDX module
 	 * initialization are done.
-- 
2.33.1