[PATCH v5 17/22] x86/virt/tdx: Reserve TDX module global KeyID

[Kai Huang]

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

Just reserve the first TDX private KeyID as the global KeyID.  Keep the
global KeyID as a static variable as KVM will need to use it too.

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

diff --git a/arch/x86/virt/vmx/tdx/tdx.c b/arch/x86/virt/vmx/tdx/tdx.c
index 86d98c47bd37..df87a9f9ee24 100644
--- a/arch/x86/virt/vmx/tdx/tdx.c
+++ b/arch/x86/virt/vmx/tdx/tdx.c
@@ -55,6 +55,9 @@ static struct tdsysinfo_struct tdx_sysinfo;
 static struct cmr_info tdx_cmr_array[MAX_CMRS] __aligned(CMR_INFO_ARRAY_ALIGNMENT);
 static int tdx_cmr_num;
 
+/* TDX module global KeyID.  Used in TDH.SYS.CONFIG ABI. */
+static u32 tdx_global_keyid;
+
 /* Detect whether CPU supports SEAM */
 static int detect_seam(void)
 {
@@ -990,6 +993,12 @@ 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 -EINVAL until all steps of TDX module initialization
 	 * process are done.
-- 
2.36.1