Implement TDX specific ConfidentialGuestSupportClass::kvm_init()
callback, tdx_kvm_init().

Mark guest state is proctected for TDX VM.  More TDX specific
initialization will be added later.

Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
---
Changes in v6:
 - remove Acked-by from Gerd since the patch changed due to use
   ConfidentialGuestSupportClass::kvm_init();
---
 target/i386/kvm/kvm.c | 11 +----------
 target/i386/kvm/tdx.c | 10 ++++++++++
 2 files changed, 11 insertions(+), 10 deletions(-)

diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c
index ed2e89946c44..2bbac603da70 100644
--- a/target/i386/kvm/kvm.c
+++ b/target/i386/kvm/kvm.c
@@ -3204,16 +3204,7 @@ int kvm_arch_init(MachineState *ms, KVMState *s)
     Error *local_err = NULL;
 
     /*
-     * Initialize SEV context, if required
-     *
-     * If no memory encryption is requested (ms->cgs == NULL) this is
-     * a no-op.
-     *
-     * It's also a no-op if a non-SEV confidential guest support
-     * mechanism is selected.  SEV is the only mechanism available to
-     * select on x86 at present, so this doesn't arise, but if new
-     * mechanisms are supported in future (e.g. TDX), they'll need
-     * their own initialization either here or elsewhere.
+     * Initialize confidential guest (SEV/TDX) context, if required
      */
     if (ms->cgs) {
         ret = confidential_guest_kvm_init(ms->cgs, &local_err);
diff --git a/target/i386/kvm/tdx.c b/target/i386/kvm/tdx.c
index bf8947549a96..85f006c1d6b4 100644
--- a/target/i386/kvm/tdx.c
+++ b/target/i386/kvm/tdx.c
@@ -14,9 +14,17 @@
 #include "qemu/osdep.h"
 #include "qom/object_interfaces.h"
 
+#include "hw/i386/x86.h"
 #include "kvm_i386.h"
 #include "tdx.h"
 
+static int tdx_kvm_init(ConfidentialGuestSupport *cgs, Error **errp)
+{
+    kvm_mark_guest_state_protected();
+
+    return 0;
+}
+
 static int tdx_kvm_type(X86ConfidentialGuest *cg)
 {
     /* Do the object check */
@@ -51,7 +59,9 @@ static void tdx_guest_finalize(Object *obj)
 
 static void tdx_guest_class_init(ObjectClass *oc, void *data)
 {
+    ConfidentialGuestSupportClass *klass = CONFIDENTIAL_GUEST_SUPPORT_CLASS(oc);
     X86ConfidentialGuestClass *x86_klass = X86_CONFIDENTIAL_GUEST_CLASS(oc);
 
+    klass->kvm_init = tdx_kvm_init;
     x86_klass->kvm_type = tdx_kvm_type;
 }
-- 
2.34.1