TDX VM requires VM type KVM_X86_TDX_VM to be passed to
kvm_ioctl(KVM_CREATE_VM).

If tdx-guest object is specified to confidential-guest-support, like,

  qemu -machine ...,confidential-guest-support=tdx0 \
       -object tdx-guest,id=tdx0,...

it parses VM type as KVM_X86_TDX_VM.

Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
---
 target/i386/kvm/kvm.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c
index 2e47fda25f95..c4050cbf998e 100644
--- a/target/i386/kvm/kvm.c
+++ b/target/i386/kvm/kvm.c
@@ -32,6 +32,7 @@
 #include "sysemu/runstate.h"
 #include "kvm_i386.h"
 #include "sev.h"
+#include "tdx.h"
 #include "xen-emu.h"
 #include "hyperv.h"
 #include "hyperv-proto.h"
@@ -164,12 +165,17 @@ static int kvm_get_one_msr(X86CPU *cpu, int index, uint64_t *value);
 static const char* vm_type_name[] = {
     [KVM_X86_DEFAULT_VM] = "default",
     [KVM_X86_SW_PROTECTED_VM] = "sw-protected-vm",
+    [KVM_X86_TDX_VM] = "tdx",
 };
 
 int kvm_get_vm_type(MachineState *ms, const char *vm_type)
 {
     int kvm_type = KVM_X86_DEFAULT_VM;
 
+    if (ms->cgs && object_dynamic_cast(OBJECT(ms->cgs), TYPE_TDX_GUEST)) {
+        kvm_type = KVM_X86_TDX_VM;
+    }
+
     /*
      * old KVM doesn't support KVM_CAP_VM_TYPES and KVM_X86_DEFAULT_VM
      * is always supported
-- 
2.34.1