From 566f83823996cf9c95f9a0562488f6b1215a1052 Mon Sep 17 00:00:00 2001 From: Keir Fraser Date: Mon, 22 Nov 2010 19:13:00 +0000 Subject: [PATCH] x86: Check for MWAIT in CPUID before using it in ACPI idle code. Signed-off-by: Keir Fraser --- xen/arch/x86/acpi/cpu_idle.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/xen/arch/x86/acpi/cpu_idle.c b/xen/arch/x86/acpi/cpu_idle.c index a4ebbb52e7..46febb0e0d 100644 --- a/xen/arch/x86/acpi/cpu_idle.c +++ b/xen/arch/x86/acpi/cpu_idle.c @@ -841,7 +841,8 @@ static void set_cx( { case ACPI_ADR_SPACE_FIXED_HARDWARE: if ( xen_cx->reg.bit_width == VENDOR_INTEL && - xen_cx->reg.bit_offset == NATIVE_CSTATE_BEYOND_HALT ) + xen_cx->reg.bit_offset == NATIVE_CSTATE_BEYOND_HALT && + boot_cpu_has(X86_FEATURE_MWAIT) ) cx->entry_method = ACPI_CSTATE_EM_FFH; else cx->entry_method = ACPI_CSTATE_EM_HALT; -- 2.30.2