x86: Add EFER descriptions for FFXSR

AMD k10 includes support for the FFXSR feature, which leaves out
XMM registers on FXSAVE/FXSAVE when the EFER_FFXSR bit is set in
EFER.

The CPUID feature bit exists already, but the EFER bit is missing
currently, so this patch adds it to the list of known EFER bits.
Signed-off-by: Alexander Graf <agraf@suse.de>
CC: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

arch/x86/include/asm/msr-index.h

@@ -19,12 +19,14 @@
 #define _EFER_LMA		10 /* Long mode active (read-only) */
 #define _EFER_NX		11 /* No execute enable */
 #define _EFER_SVME		12 /* Enable virtualization */
+#define _EFER_FFXSR		14 /* Enable Fast FXSAVE/FXRSTOR */
 
 #define EFER_SCE		(1<<_EFER_SCE)
 #define EFER_LME		(1<<_EFER_LME)
 #define EFER_LMA		(1<<_EFER_LMA)
 #define EFER_NX			(1<<_EFER_NX)
 #define EFER_SVME		(1<<_EFER_SVME)
+#define EFER_FFXSR		(1<<_EFER_FFXSR)
 
 /* Intel MSRs. Some also available on other CPUs */
 #define MSR_IA32_PERFCTR0		0x000000c1