i386/tdx: Enable user exit on KVM_HC_MAP_GPA_RANGE

KVM translates TDG.VP.VMCALL<MapGPA> to KVM_HC_MAP_GPA_RANGE, and QEMU
needs to enable user exit on KVM_HC_MAP_GPA_RANGE in order to handle the
memory conversion requested by TD guest.

Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Link: https://lore.kernel.org/r/20250508150002.689633-28-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 287bf7147e11462676c60a44c0bc22936b4129ee..971f4becfa410c5ffb7831e61aaa04568a804ab9 100644 (file)
--- a/target/i386/kvm/tdx.c
+++ b/target/i386/kvm/tdx.c
@@ -19,6 +19,8 @@
 #include "system/system.h"
 #include "system/ramblock.h"
 
+#include <linux/kvm_para.h>
+
 #include "hw/i386/e820_memory_layout.h"
 #include "hw/i386/tdvf.h"
 #include "hw/i386/x86.h"
@@ -376,6 +378,11 @@ static int tdx_kvm_init(ConfidentialGuestSupport *cgs, Error **errp)
         }
     }
 
+    /* TDX relies on KVM_HC_MAP_GPA_RANGE to handle TDG.VP.VMCALL<MapGPA> */
+    if (!kvm_enable_hypercall(BIT_ULL(KVM_HC_MAP_GPA_RANGE))) {
+        return -EOPNOTSUPP;
+    }
+
     qemu_add_machine_init_done_notifier(&tdx_machine_done_notify);
 
     tdx_guest = tdx;