diff mbox series

[RFC,v4,27/36] i386/tdx: Disable SMM for TDX VMs

Message ID 20220512031803.3315890-28-xiaoyao.li@intel.com (mailing list archive)
State New, archived
Headers show
Series TDX QEMU support | expand

Commit Message

Xiaoyao Li May 12, 2022, 3:17 a.m. UTC 
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>
---
 target/i386/kvm/tdx.c | 8 ++++++++
 1 file changed, 8 insertions(+)

Comments

Gerd Hoffmann May 24, 2022, 8 a.m. UTC | #1 
On Thu, May 12, 2022 at 11:17:54AM +0800, Xiaoyao Li wrote:
> 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.

Acked-by: Gerd Hoffmann <kraxel@redhat.com>
diff mbox series

Patch

diff --git a/target/i386/kvm/tdx.c b/target/i386/kvm/tdx.c
index 4a7c149f895c..7ff4c6a9a7ca 100644
--- a/target/i386/kvm/tdx.c
+++ b/target/i386/kvm/tdx.c
@@ -322,9 +322,17 @@  static Notifier tdx_machine_done_notify = {
 
 int tdx_kvm_init(MachineState *ms, Error **errp)
 {
+    X86MachineState *x86ms = X86_MACHINE(ms);
     TdxGuest *tdx = (TdxGuest *)object_dynamic_cast(OBJECT(ms->cgs),
                                                     TYPE_TDX_GUEST);
 
+    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) {
         get_tdx_capabilities();
     }