[RFC PATCH v3 35/36] i386/tdx: Don't get/put guest state for TDX VMs

[Xiaoyao Li]

From: Sean Christopherson <sean.j.christopherson@intel.com>

Don't get/put state of TDX VMs since accessing/mutating guest state of
production TDs is not supported.

Note, it will be allowed for a debug TD. Corresponding support will be
introduced when debug TD support is implemented in the future.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
---
 target/i386/kvm/kvm.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c
index 9c7eb3dea0a8..dafb63d4d2d7 100644
--- a/target/i386/kvm/kvm.c
+++ b/target/i386/kvm/kvm.c
@@ -4395,6 +4395,11 @@ int kvm_arch_put_registers(CPUState *cpu, int level)
 
     assert(cpu_is_stopped(cpu) || qemu_cpu_is_self(cpu));
 
+    /* TODO: Allow accessing guest state for debug TDs. */
+    if (is_tdx_vm()) {
+        return 0;
+    }
+
     /* must be before kvm_put_nested_state so that EFER.SVME is set */
     ret = has_sregs2 ? kvm_put_sregs2(x86_cpu) : kvm_put_sregs(x86_cpu);
     if (ret < 0) {
@@ -4489,6 +4494,12 @@ int kvm_arch_get_registers(CPUState *cs)
     if (ret < 0) {
         goto out;
     }
+
+    /* TODO: Allow accessing guest state for debug TDs. */
+    if (is_tdx_vm()) {
+        return 0;
+    }
+
     ret = kvm_getput_regs(cpu, 0);
     if (ret < 0) {
         goto out;
-- 
2.27.0