i386/tdx: Set value of <GetTdVmCallInfo> based on capabilities of both KVM and QEMU

KVM reports the supported TDVMCALL sub leafs in TDX capabilities.

one for kernel-supported
    TDVMCALLs (userspace can set those blindly) and one for user-supported
    TDVMCALLs (userspace can set those if it knows how to handle them)

Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
Link: https://lore.kernel.org/r/20250703024021.3559286-4-xiaoyao.li@intel.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/target/i386/kvm/tdx.c b/target/i386/kvm/tdx.c
index 8c661c3ecfdbb6a5ecb0be352b430d6ce7a62072..10dfb80d22e2f47e58b36410a123ce83fe76227a 100644 (file)
--- a/target/i386/kvm/tdx.c
+++ b/target/i386/kvm/tdx.c
@@ -1256,14 +1256,21 @@ out_free:
     g_free(task);
 }
 
+#define SUPPORTED_TDVMCALLINFO_1_R11    (0)
+#define SUPPORTED_TDVMCALLINFO_1_R12    (0)
+
 void tdx_handle_get_tdvmcall_info(X86CPU *cpu, struct kvm_run *run)
 {
     if (run->tdx.get_tdvmcall_info.leaf != 1) {
         return;
     }
 
-    run->tdx.get_tdvmcall_info.r11 = 0;
-    run->tdx.get_tdvmcall_info.r12 = 0;
+    run->tdx.get_tdvmcall_info.r11 = (tdx_caps->user_tdvmcallinfo_1_r11 &
+                                      SUPPORTED_TDVMCALLINFO_1_R11) |
+                                      tdx_caps->kernel_tdvmcallinfo_1_r11;
+    run->tdx.get_tdvmcall_info.r12 = (tdx_caps->user_tdvmcallinfo_1_r12 &
+                                      SUPPORTED_TDVMCALLINFO_1_R12) |
+                                      tdx_caps->kernel_tdvmcallinfo_1_r12;
     run->tdx.get_tdvmcall_info.r13 = 0;
     run->tdx.get_tdvmcall_info.r14 = 0;