The check needs to happen whenever EVEX.b is clear, not just in the memory operand case.
Signed-off-by: Jan Beulich <jbeul...@suse.com> --- a/xen/arch/x86/x86_emulate/x86_emulate.c +++ b/xen/arch/x86/x86_emulate/x86_emulate.c @@ -8526,11 +8526,9 @@ x86_emulate( case X86EMUL_OPC_EVEX_66(0x0f38, 0xbd): /* vfnmadd231s{s,d} xmm/mem,xmm,xmm{k} */ case X86EMUL_OPC_EVEX_66(0x0f38, 0xbf): /* vfnmsub231s{s,d} xmm/mem,xmm,xmm{k} */ host_and_vcpu_must_have(avx512f); - if ( ea.type == OP_MEM ) - { - generate_exception_if(evex.br, EXC_UD); + generate_exception_if(ea.type != OP_REG && evex.br, EXC_UD); + if ( !evex.br ) avx512_vlen_check(true); - } goto simd_zmm; case X86EMUL_OPC(0x0f38, 0xc8): /* sha1nexte xmm/m128,xmm */ _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel