[PATCH v5 55/65] i386/tdx: Disable SMM for TDX VMs

[Xiaoyao Li]

TDX doesn't support SMM and VMM cannot emulate SMM for TDX VMs because
VMM cannot manipulate TDX VM's memory.

Disable SMM for TDX VMs and error out if user requests to enable SMM.

Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
---
 target/i386/kvm/tdx.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/target/i386/kvm/tdx.c b/target/i386/kvm/tdx.c
index 811a3b81af99..c3fadbc5c58e 100644
--- a/target/i386/kvm/tdx.c
+++ b/target/i386/kvm/tdx.c
@@ -707,11 +707,19 @@ static Notifier tdx_machine_done_notify = {
 static int tdx_kvm_init(ConfidentialGuestSupport *cgs, Error **errp)
 {
     MachineState *ms = MACHINE(qdev_get_machine());
+    X86MachineState *x86ms = X86_MACHINE(ms);
     TdxGuest *tdx = TDX_GUEST(cgs);
     int r = 0;
 
     ms->require_guest_memfd = true;
 
+    if (x86ms->smm == ON_OFF_AUTO_AUTO) {
+        x86ms->smm = ON_OFF_AUTO_OFF;
+    } else if (x86ms->smm == ON_OFF_AUTO_ON) {
+        error_setg(errp, "TDX VM doesn't support SMM");
+        return -EINVAL;
+    }
+
     if (!tdx_caps) {
         r = get_tdx_capabilities(errp);
         if (r) {
-- 
2.34.1