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From:   Kai Huang <kai.huang@intel.com>
To:     linux-kernel@vger.kernel.org, kvm@vger.kernel.org
Cc:     seanjc@google.com, pbonzini@redhat.com, dave.hansen@intel.com,
        len.brown@intel.com, tony.luck@intel.com,
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        kirill.shutemov@linux.intel.com,
        sathyanarayanan.kuppuswamy@linux.intel.com,
        isaku.yamahata@intel.com, kai.huang@intel.com
Subject: [PATCH v3 15/21] x86/virt/tdx: Reserve TDX module global KeyID
Date:   Wed,  6 Apr 2022 16:49:27 +1200
Message-Id: <3e4929500a7b5bbaaf8ed23cde088172862acae0.1649219184.git.kai.huang@intel.com>
In-Reply-To: <cover.1649219184.git.kai.huang@intel.com>
References: <cover.1649219184.git.kai.huang@intel.com>
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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/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 bf0d13644898..ecd65f7014e2 100644
--- a/arch/x86/virt/vmx/tdx/tdx.c
+++ b/arch/x86/virt/vmx/tdx/tdx.c
@@ -112,6 +112,9 @@ 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;
@@ -1320,6 +1323,12 @@ 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.
-- 
2.35.1