diff mbox

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

Message ID 58C808560200007800142E6D@prv-mh.provo.novell.com (mailing list archive)
State New, archived
Headers show

Commit Message

Jan Beulich March 14, 2017, 2:12 p.m. UTC 
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>
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>

--- 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;

Comments

Andrew Cooper March 14, 2017, 2:22 p.m. UTC | #1 
On 14/03/17 14:12, Jan Beulich wrote:
> 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 mbox

Patch

--- 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;