1 files changed, 19 insertions, 0 deletions

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 6eaedac7cf6a..71450aca3b86 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -1892,6 +1892,17 @@ setup_syscalls_segments(struct x86_emulate_ctxt *ctxt,
         ss->p = 1;
 }
 
+static bool vendor_intel(struct x86_emulate_ctxt *ctxt)
+{
+        u32 eax, ebx, ecx, edx;
+
+        eax = ecx = 0;
+        return ctxt->ops->get_cpuid(ctxt, &eax, &ebx, &ecx, &edx)
+                && ebx == X86EMUL_CPUID_VENDOR_GenuineIntel_ebx
+                && ecx == X86EMUL_CPUID_VENDOR_GenuineIntel_ecx
+                && edx == X86EMUL_CPUID_VENDOR_GenuineIntel_edx;
+}
+
 static bool em_syscall_is_enabled(struct x86_emulate_ctxt *ctxt)
 {
         struct x86_emulate_ops *ops = ctxt->ops;
@@ -2008,6 +2019,14 @@ static int em_sysenter(struct x86_emulate_ctxt *ctxt)
         if (ctxt->mode == X86EMUL_MODE_REAL)
                 return emulate_gp(ctxt, 0);
 
+        /*
+         * Not recognized on AMD in compat mode (but is recognized in legacy
+         * mode).
+         */
+        if ((ctxt->mode == X86EMUL_MODE_PROT32) && (efer & EFER_LMA)
+            && !vendor_intel(ctxt))
+                return emulate_ud(ctxt);
+
         /* XXX sysenter/sysexit have not been tested in 64bit mode.
         * Therefore, we inject an #UD.
         */