From 4b46e7be783df641b2889e514e85643febd378c2 Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Fri, 11 Oct 2013 09:30:31 +0200 Subject: x86: use {rd,wr}{fs,gs}base when available ... as being intended to be faster than MSR reads/writes. In the case of emulate_privileged_op() also use these in favor of the cached (but possibly stale) addresses from arch.pv_vcpu. This allows entirely removing the code that was the subject of XSA-67. Signed-off-by: Jan Beulich Reviewed-by: Andrew Cooper Acked-by: Keir Fraser --- xen/arch/x86/Rules.mk | 1 + 1 file changed, 1 insertion(+) (limited to 'xen/arch/x86/Rules.mk') diff --git a/xen/arch/x86/Rules.mk b/xen/arch/x86/Rules.mk index c93d2affd3..576985e710 100644 --- a/xen/arch/x86/Rules.mk +++ b/xen/arch/x86/Rules.mk @@ -31,6 +31,7 @@ $(call cc-options-add,CFLAGS,CC,$(EMBEDDED_EXTRA_CFLAGS)) $(call cc-option-add,CFLAGS,CC,-Wnested-externs) $(call as-insn-check,CFLAGS,CC,"vmcall",-DHAVE_GAS_VMX) $(call as-insn-check,CFLAGS,CC,"invept (%rax)$$(comma)%rax",-DHAVE_GAS_EPT) +$(call as-insn-check,CFLAGS,CC,"rdfsbase %rax",-DHAVE_GAS_FSGSBASE) ifeq ($(supervisor_mode_kernel),y) CFLAGS += -DCONFIG_X86_SUPERVISOR_MODE_KERNEL=1 -- cgit v1.2.3