From: Jan Beulich <jbeulich@suse.com>
Date: Tue, 14 Mar 2017 17:20:27 +0000 (+0100)
Subject: x86emul: correct {,v}{ld,st}mxcsr handling
X-Git-Tag: archive/raspbian/4.11.1-1+rpi1~1^2~66^2~2485
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=ff0bced09f91d0698c8a9b2b3c3c0b885cdff7e0;p=xen.git

x86emul: correct {,v}{ld,st}mxcsr handling

Calls to get_fpu() were missing. Calls to put_fpu() are deliberately
not being added: Neither instruction can raise #XM, so the catch-all
_put_fpu() is just fine here.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
---

diff --git a/xen/arch/x86/x86_emulate/x86_emulate.c b/xen/arch/x86/x86_emulate/x86_emulate.c
index 0cbeb31db4..4872f19c5d 100644
--- a/xen/arch/x86/x86_emulate/x86_emulate.c
+++ b/xen/arch/x86/x86_emulate/x86_emulate.c
@@ -6509,6 +6509,7 @@ x86_emulate(
             vcpu_must_have(sse);
         ldmxcsr:
             generate_exception_if(src.type != OP_MEM, EXC_UD);
+            get_fpu(vex.opcx ? X86EMUL_FPU_ymm : X86EMUL_FPU_xmm, &fic);
             generate_exception_if(src.val & ~mxcsr_mask, EXC_GP, 0);
             asm volatile ( "ldmxcsr %0" :: "m" (src.val) );
             break;
@@ -6518,6 +6519,7 @@ x86_emulate(
             vcpu_must_have(sse);
         stmxcsr:
             generate_exception_if(dst.type != OP_MEM, EXC_UD);
+            get_fpu(vex.opcx ? X86EMUL_FPU_ymm : X86EMUL_FPU_xmm, &fic);
             asm volatile ( "stmxcsr %0" : "=m" (dst.val) );
             break;