From 529ccf68e87aa7b85d4a9db4c5af6e54e0ac3b85 Mon Sep 17 00:00:00 2001
From: Jan Beulich <jbeulich@suse.com>
Date: Tue, 18 Dec 2018 18:03:49 +0100
Subject: [PATCH] x86emul: permit SAE for V{,U}COMIS{S,D}

The avx512_vlen_check() invocation needs to be conditional.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
---
 xen/arch/x86/x86_emulate/x86_emulate.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/xen/arch/x86/x86_emulate/x86_emulate.c b/xen/arch/x86/x86_emulate/x86_emulate.c
index 20510151c8..9aebb1b662 100644
--- a/xen/arch/x86/x86_emulate/x86_emulate.c
+++ b/xen/arch/x86/x86_emulate/x86_emulate.c
@@ -6187,7 +6187,8 @@ x86_emulate(
                                evex.w != evex.pfx),
                               EXC_UD);
         host_and_vcpu_must_have(avx512f);
-        avx512_vlen_check(true);
+        if ( !evex.br )
+            avx512_vlen_check(true);
         get_fpu(X86EMUL_FPU_zmm);
 
         opc = init_evex(stub);
-- 
2.39.5