diff mbox series

[RFC,v3,27/36] i386/tdx: Disable SMM for TDX VMs

Message ID 20220317135913.2166202-28-xiaoyao.li@intel.com
State New
Headers show
Series TDX QEMU support | expand

Commit Message

Xiaoyao Li March 17, 2022, 1:59 p.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 | 13 +++++++++++++
 1 file changed, 13 insertions(+)

Comments

Xiaoyao Li March 21, 2022, 6:51 a.m. UTC | #1 
On 3/17/2022 9:59 PM, 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.
> 
> Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
> ---
>   target/i386/kvm/tdx.c | 13 +++++++++++++
>   1 file changed, 13 insertions(+)
> 
> diff --git a/target/i386/kvm/tdx.c b/target/i386/kvm/tdx.c
> index deb9634b27dc..ec6f5d7a2e48 100644
> --- a/target/i386/kvm/tdx.c
> +++ b/target/i386/kvm/tdx.c
> @@ -302,12 +302,25 @@ 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 (!tdx) {
>           return -EINVAL;
>       }
>   
> +    if (!kvm_enable_x2apic()) {
> +        error_setg(errp, "Failed to enable x2apic in KVM");
> +        return -EINVAL;
> +    }

above change is not relevant to this patch, will remove it in next version.

> +
> +    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();
>       }
diff mbox series

Patch

diff --git a/target/i386/kvm/tdx.c b/target/i386/kvm/tdx.c
index deb9634b27dc..ec6f5d7a2e48 100644
--- a/target/i386/kvm/tdx.c
+++ b/target/i386/kvm/tdx.c
@@ -302,12 +302,25 @@  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 (!tdx) {
         return -EINVAL;
     }
 
+    if (!kvm_enable_x2apic()) {
+        error_setg(errp, "Failed to enable x2apic in KVM");
+        return -EINVAL;
+    }
+
+    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();
     }